Hydrogeology, Hydrologic Budget, and Water Chemistry of the Medina Lake Area, Texas

Home , Hydrogeology

In cooperation with the Bexar-Medina-Atascosa Counties Water Control and Improvement District No. 1, Bexar Metropolitan Water District, Texas Water Development Board, and Edwards Aquifer Authority

Water-Resources Investigations Report 00–4148

U.S. Department of the Interior U.S. Geological Survey Cover: Medina Dam and Medina Lake, August 1994. (Photograph by Ted A. Small, U.S. Geological Survey.) U.S. Department of the Interior U.S. Geological Survey

Hydrogeology, Hydrologic Budget, and Water Chemistry of the Medina Lake Area, Texas

By Rebecca B. Lambert, Kenneth C. Grimm, and Roger W. Lee

U.S. GEOLOGICAL SURVEY Water-Resources Investigations Report 00–4148

In cooperation with the Bexar-Medina-Atascosa Counties Water Control and Improvement District No. 1, Bexar Metropolitan Water District, Texas Water Development Board, and Edwards Aquifer Authority

Austin, Texas 2000 U.S. DEPARTMENT OF THE INTERIOR Bruce Babbitt, Secretary

U.S. GEOLOGICAL SURVEY Charles G. Groat, Director

Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government.

For additional information write to

District Chief U.S. Geological Survey 8027 Exchange Dr. Austin, TX 78754–4733 E-mail: [email protected]

Copies of this report can be purchased from

U.S. Geological Survey Branch of Information Services Box 25286 Denver, CO 80225–0286 E-mail: [email protected]

ii CONTENTS

Abstract ...... 1 Introduction ...... 2 Purpose and Scope ...... 2 Previous Studies ...... 4 Methods of Analysis ...... 5 Acknowledgments ...... 6 Hydrogeology ...... 6 Geologic Framework ...... 7 Flow Systems ...... 8 Hydrologic Budget ...... 9 Precipitation ...... 12 Evaporation ...... 12 Mass-Transfer Theory ...... 12 Evaporation Rates ...... 13 Surface Water ...... 15 Storage ...... 16 Ground Water ...... 16 Ground-Water Inflow ...... 16 Ground-Water Outflow ...... 17 Estimated Ground-Water Recharge Methods ...... 23 Water Chemistry ...... 26 Surface Water ...... 26 Ground Water ...... 27 Environmental Isotopes ...... 28 Geochemistry ...... 33 Summary and Conclusions ...... 34 References Cited ...... 36 Appendices A. Hydrologic Data ...... A–1 B. Hydrologic Budgets ...... B–1 C. Water-Quality Data ...... C–1

PLATES

[Plates in pocket}

1. Map showing hydrogeologic sections A–A' and B–B' and showing subdivisions of the Edwards and Trinity aquifers, Medina Lake area, Texas 2. Map showing locations of water-level and water-quality sites of the Edwards and Trinity aquifers, Medina Lake area, Texas

CONTENTS iii FIGURES

1–3. Maps showing: 1. Location of the Medina Lake area ...... 3 2. Regional ground-water-flow units of the Edwards aquifer, Texas ...... 10 3. Location of hydrologic budget data-collection sites and Quihi monitoring well (TD–69–40–102), Medina Lake area, Texas ...... 11 4–9. Graphs showing: 4. Daily evaporation rates for Medina and Diversion Lakes, Medina Lake area, Texas ...... 14

5. Relation of ground-water outflow (GWout) to Medina Lake stage for selected hydrologic budget periods, Medina Lake area, Texas ...... 18 6. Relation of monthly average Quihi well water-level altitude to monthly average Medina Lake stage, Medina Lake area, Texas, October 1993–February 1997 ...... 19

7. Relation of ground-water outflow (GWout) to Diversion Lake stage for selected hydrologic budget periods, Medina Lake area, Texas ...... 21 8. Relation of Medina/Diversion Lakes combined ground-water outflow (GWout) to Medina Lake stage for selected budget periods, Medina Lake area, Texas ...... 22 9. Relation of estimated monthly average recharge from Medina/Diversion Lakes using three methods to monthly average Quihi well water-level altitude, Medina Lake area, Texas, December 1995–July 1996...... 25 10–11. Trilinear diagrams of: 10. Waters for surface-water and lake-water samples, Medina Lake area, Texas ...... 26 11. Waters for ground-water samples in the Edwards and Trinity aquifers, Medina Lake area, Texas ...... 27 12–13. Graphs showing: 12. Relation between deuterium (δD) and del oxygen (δ18O) in water samples from Medina Lake, Medina River, and from selected wells and springs, Medina Lake area, Texas ...... 30 13. Relation of 1/strontium to 87Sr/86Sr in aquifer and lake water, Medina Lake area, Texas ...... 32

TABLES

1. Summary of lithologic and hydrologic properties of the hydrogeologic subdivisions of the Edwards and Trinity aquifers, Medina Lake area, Texas ...... 39 2. Hydrologic budget data-collection sites in the Medina Lake area, Texas ...... 40 3. Summary of hydrologic budgets for Medina, Diversion, and Medina/Diversion Lakes (combined), Medina Lake area, Texas ...... 41 4. Water-level and water-quality data-collection sites and isotopic data, Medina Lake area, Texas ...... 43 5. Comparison of estimated average losses (recharge to the Edwards aquifer), Medina Lake area, Texas, December 1995–August 1996 ...... 51 6. Comparison of mixing fractions of endmember Medina Lake water and endmember Edwards aquifer water calculated from deuterium and del oxygen data and from NETPATH mixing models in selected wells and springs, Medina Lake area, Texas ...... 52 7. Results of NETPATH simulations of mixing water from Medina Lake with water from the Edwards aquifer, Medina Lake area, Texas ...... 53 iv VERTICAL DATUM AND ABBREVIATIONS

Sea level: In this report, “sea level” refers to the National Geodetic Vertical Datum of 1929—a geodetic datum derived from a general adjustment of the first-order level nets of the United States and Canada, formerly called Sea Level Datum of 1929. Per mil: A unit expressing the ratio of stable-isotope abundances of an element in a sample to those of a standard material. Per mil units are equivalent to parts per thousand. Stable-isotope ratios are calculated as follows: Rsample() δX = ------– 1 × 1, 000 , Rs()tan dard where X is the heavier isotope, and R is the ratio of the heavier stable isotope to the lighter stable isotope in a sample or standard.

The δ values for stable-isotope ratios discussed in this report are referenced to the following standard materials:

Element R Standard identity and reference

hydrogen hydrogen-2 (deuterium)/hydrogen-1 (δD) Vienna Standard Mean Ocean Water (Fritz and Fontes, 1980)

oxygen oxygen-18/oxygen-16 (δ18O) Vienna Standard Mean Ocean Water (Fritz and Fontes, 1980)

The other isotope ratio used in this report is referenced as follows:

Element R Standard identity and reference

strontium strontium-87/strontium-86 (87Sr/86Sr) National Institute of Standards and Technology—Standard Reference Material- 987 (Fritz and Fontes, 1980)

CONTENTS v Hydrogeology, Hydrologic Budget, and Water Chemistry of the Medina Lake area, Texas

By Rebecca B. Lambert, Kenneth C. Grimm, and Roger W. Lee

Abstract (1) losses from Medina and Diversion Lakes can be quantified; (2) a portion of those losses are entering A three-phase study of the Medina Lake area the Edwards aquifer; and (3) losses to the Trinity in Texas was done to assess the hydrogeology and aquifer in the Medina Lake area are minimal and hydrology of Medina and Diversion Lakes com- within the error of the hydrologic budgets. bined (the lake system) and to determine what frac- Hydrologic budgets based on streamflow, tion of seepage losses from the lake system might precipitation, evaporation, and change in lake stor- enter the regional ground-water-flow system of the age were used to quantify losses (recharge) to the Edwards and (or) Trinity aquifers. Phase 1 con- ground-water system from Medina Lake, Diversion sisted of revising the geologic framework for the Lake, and Medina/Diversion Lakes combined dur- Medina Lake area. Results of field mapping show ing October 1995–September 1996. Water losses that the upper member of the Glen Rose Limestone from Medina Lake to the Edwards/Trinity aquifers underlies Medina Lake and the intervening stream ranged from -14.0 to 135 acre-feet per day; Diver- channel from the outflow of Medina Lake to the sion Lake ranged from -1.2 to 93.1 acre-feet per midpoint of Diversion Lake, where the Diversion day; and Medina/Diversion Lakes combined Lake fault intersects Diversion Lake. A thin ranged from 36.1 to 119 acre-feet per day. sequence of strata consisting primarily of the basal Monthly average recharge during December nodular and dolomitic members of the Kainer For- 1995–July 1996 was estimated using an alternative mation of the Edwards Group, is present in the method developed during this study (current southern part of the study area. On the southern study method) and compared to monthly average side of Medina Lake, the contact between the upper recharge during December 1995–July 1996 esti- member of the Glen Rose Limestone and the basal mated using the existing USGS method and the nodular member is approximately 1,000 feet above Trans-Texas method. Recharge to the Edwards mean sea level, and the contact between the basal aquifer estimated using the current study method nodular member and the dolomitic member is was about 69 and 73 percent of the recharge esti- approximately 1,050 feet above mean sea level. mated using the USGS and Trans-Texas methods, The most porous and permeable part of the basal respectively. The USGS and Trans-Texas methods nodular member is about 1,045 feet above mean overestimated recharge from Medina Lake com- sea level. At these altitudes, Medina Lake is in pared to the recharge estimated with the current hydrologic connection with rocks in the Edwards study method when Medina Lake stage was aquifer recharge zone, and Medina Lake appears to between about 1,027 and 1,032 feet above mean lose more water to the ground-water system along sea level and underestimated recharge from this bedding plane contact. Medina Lake when lake stage was between about Hydrologic budgets calculated during phase 1,036 and 1,045 feet above mean sea level. The 2 for Medina Lake, Diversion Lake, and USGS and Trans-Texas methods underestimated Medina/Diversion Lakes combined indicate that: recharge from Diversion Lake compared to the

Abstract 1 recharge estimated with the current study method Diversion Lake covers about 169 acres, with a storage when Diversion Lake stage was greater than capacity of about 2,555 acre-ft. 913 feet above mean sea level and overestimated Although Medina Dam (fig. 1) was completed in recharge from Diversion Lake when lake stage was 1912, water was not impounded until May 1913 (Texas less than 913 feet above mean sea level. Water Development Board, 1996a). Seepage losses The water quality of Medina Lake and from Medina Lake have been documented since May Medina River and in selected wells and springs in 1913, when it was suggested that the losses were con- the Edwards and Trinity aquifers was characterized tributing substantial recharge to the Edwards aquifer. The estimated average recharge to the Edwards aquifer during phase 3 of the study. Environmental isotope from Medina and Diversion Lakes combined (hereafter analyses and geochemical modeling also were used referred to as the lake system) ranges from about 38,900 to determine where water losses from the lake to about 61,000 acre-feet per year (acre-ft/yr) (Lowry, system might be entering the ground-water-flow 1955; Espey, Huston and Associates, Inc., 1989; system. Isotopic ratios of deuterium, oxygen, and Choffel and Vaugh, 1993; U.S. Geological Survey, strontium were analyzed in selected surface-water, 1997). These estimated losses account for about 6 to 9 lake-water, and ground-water samples to trace the percent of the 668,700 acre-ft/yr estimated average isotopic “signature” of the lake water as it mixes annual (1934–96) recharge to the Edwards aquifer, thus with the ground water and to determine the fraction representing a substantial source of water to the aquifer of lake water and ground water in selected Edwards (U.S. Geological Survey, 1997). However, the methods aquifer wells. Isotopic data and geochemical mod- used to estimate recharge to the Edwards aquifer from eling were used to show that lake water is moving the lake system are adequate to assess long-term into the Edwards aquifer in two fault blocks in the recharge only. eastern Medina storage unit. One fault block is Monthly estimates of recharge have a large uncertainty during periods of high runoff and are not suffi- bounded on the north by the Vandenburg School ciently accurate for current water-supply management fault and on the south by the Haby Crossing fault, purposes. To help reduce the uncertainty, a three-phase and the second fault block is bounded on the north study was done for the Medina Lake area by the U.S. by the Diversion Lake fault and on the south by the Geological Survey (USGS), in cooperation with the Haby Crossing fault. In selected Edwards aquifer Bexar-Medina-Atascosa Counties Water Control and wells located southwest of Medina Lake and west Improvement District No. 1 (BMA), Bexar Metropoli- of Diversion Lake, the proportion of lake water tan Water District (BexarMet), Texas Water Develop- ranged from about 10 to 45 percent. Geochemical ment Board (TWDB), and Edwards Aquifer Authority modeling using NETPATH confirms the degree of (EAA). mixing between lake water and aquifer water shown by the isotopes. Purpose and Scope INTRODUCTION The purpose of this report is to summarize the hydrogeology, hydrologic budget, and water chemistry Medina Lake and Diversion Lake (fig. 1) are of the Medina Lake area in an attempt to better define located on the Medina River in northeastern Medina short-term recharge from the lake system to the County and in southeastern Bandera County in south- Edwards and Trinity aquifers compared to previous esti- central Texas. Medina Dam and Lake were constructed mates. The study area includes Medina and Diversion to supplement existing irrigation supplies. The Medina Lakes (fig. 1) and several miles downgradient along River is impounded by Medina Dam, and water released ground-water flowpaths in the Edwards and Trinity from Medina Lake is discharged through a canyon to a aquifers to the south and west of the lakes. small impoundment (Diversion Lake), where part of the The objectives of the study were to: (1) describe water is then diverted into the Medina irrigation canal the hydrogeology in the Medina Lake area; (2) prepare (pl. 1). Medina Lake, which encompasses about 6,070 hydrologic budgets of Medina Lake, Diversion Lake, acres, has a storage capacity of about 254,850 acre-feet and Medina/Diversion Lakes combined and attempt (acre-ft) (Texas Water Development Board, 1996a); to quantify the losses from the lake system into the

2 Hydrogeology, Hydrologic Budget, and Water Chemistry of the Medina Lake area, Texas o 99 30' 99o15'

99o

MEDINA

29o45' EXPLANATION Edwards aquifer BANDERA COUNTY catchment area MEDINA Edwards aquifer MEDINA COUNTY LAKE recharge zone

Medina Dam 29o30' DIVERSION LAKE Diversion Dam

Study area RIVER

29o15'

TEXAS Base modified from University of Texas, Bureau of Economic Geology, 1983 0 4 8 12 MILES

HAYS COUNTY COUNTRY BANDERA HILL COUNTY COMAL COUNTY

KINNEY ZONE COUNTY Study area

BALCONES FAULT BEXAR SAN COUNTY UVALDE MEDINA ANTONIO COUNTY COUNTY

Figure 1. Location of the Medina lake area.

INTRODUCTION 3 underlying aquifers; and (3) determine if those losses ous and dissected than had been mapped by previous are entering the regional ground-water-flow systems of investigations. the Edwards or Trinity aquifers, or both. Geologic, Maclay and Small (1976, 1986) discussed the hydrologic, and hydrochemical data were collected as regional hydrogeology of the Edwards Group in the San part of the three-phase study. Phase 1 consisted of refin- Antonio region and subdivided the rocks of the Kainer ing the geologic and hydrogeologic framework in the and Person Formations of the Edwards Group into study area by subdividing the rocks composing the smaller, mappable hydrogeologic subdivisions. Their Edwards and Trinity aquifers into smaller hydrogeo- hydrogeologic sections constructed perpendicular to the logic subdivisions. Wells were inventoried, and water Balcones fault zone show the heterogeneous nature of levels were measured. Phase 2 quantified the losses the Edwards aquifer and indicate an influence of fault- from the lake system during October 1995–September ing on ground-water flowpaths. Maclay (1995) and 1996. Phase 3 characterized the quality of water in Groschen (1996) described the geologic history of the Medina Lake, Medina River, Koenig Creek, and in Edwards aquifer and the hydrogeologic factors, includ- selected wells and springs in the Edwards and Trinity ing those in the Medina Lake area, that influence the aquifers. Additionally, environmental isotope analyses regional ground-water-flow system. Ashworth (1983) discussed the hydrogeology and and geochemical modeling were used during phase 3 to availability of water in the lower, middle, and upper help determine where losses from the lake system might Trinity aquifers in the Lower Cretaceous formations in be entering the ground-water-flow system. the south-central Texas Hill Country (fig. 1). Ashworth (1983) reported that, in the Medina Lake area, the Previous Studies regional flow direction of the Trinity aquifer (including the Glen Rose Limestone) generally is to the south, Previous studies of the Medina Lake area subdi- southeast, and east. Bluntzer (1992) did additional work vided the rocks into groups or formations only, separat- on the Trinity aquifer by evaluating the ground-water ing the Edwards Group (rocks forming the Edwards resources and projecting water demands for the Hill aquifer) from the Glen Rose Limestone (rocks forming Country. the upper Trinity aquifer) (table 1, at end of report). Although transmissivity of the Trinity aquifer in Sayre (1936) mapped the Edwards Limestone and the Hill Country ranges from about 100 to about 58,000 Georgetown Limestone as a single unit in the Medina feet squared per day (ft2/d) (Kuniansky and Holligan, Lake area and mapped the Glen Rose Limestone in 1994), the transmissivity of the Edwards aquifer in the areas northwest and east of Medina Lake. Holt (1956, Balcones fault zone ranges from about 10,000 to more 1959) concluded that Medina Lake overlies the Glen than 5,000,000 ft2/d (Barker and Ardis, 1996). Differ- Rose Limestone and that the distribution of the Edwards ences between the transmissivity of the Edwards aquifer Limestone was not as widespread as had been previ- and the transmissivity of the Trinity aquifer can be ously mapped. More recent studies (Barnes and others, attributed to the effects of rock fractures that close with 1992; Collins, 1995) report that Medina Lake, the inter- depth, cementation, and recrystallization in the Trinity vening canyon between Medina and Diversion Dams, aquifer as opposed to the dominant effects of carbonate and the upper end of Diversion Lake rests on the upper dissolution in the Edwards aquifer (Barker and Ardis, member of the Glen Rose Limestone, while the lower 1996, p. 41). end of Diversion Lake rests on the lower part of the LBG-Guyton Associates (1995) attempted to Kainer Formation of the Edwards Group (pl. 1). estimate the amount of water moving from the Glen Rose Limestone (upper part of the Trinity aquifer) Interpretation of cores bored at Medina Dam into the Edwards aquifer in the San Antonio region indicate that much of the Medina Lake spillway and (including the Medina Lake area). Their study con- the channel of the Medina River downstream from cluded that—under 1994 water-level conditions—the the dam are in the Glen Rose Limestone (U.S. Army Glen Rose Limestone contributed an estimated 314 Corps of Engineers, 1965) (pl. 1). Rose (1972) reported acre-ft/yr to the Edwards aquifer along 14 miles (mi) of that the Glen Rose Limestone comprises a greater part the Haby Crossing fault located in northeastern Medina of the outcrop in the Medina Lake area and that the and northwestern Bexar Counties. They concluded that Edwards Group outcrop appears to be more discontinu- the transmissivity of the Glen Rose Limestone is the

4 Hydrogeology, Hydrologic Budget, and Water Chemistry of the Medina Lake area, Texas limiting factor in the transmission of water between the mated that during 1940–86 the average ground-water Trinity and Edwards aquifers. recharge from the lake system was 39,801 acre-ft/yr. Previous studies of the lake system have explored, Water chemistry and geochemical analyses have both qualitatively and quantitatively, the importance of been used to help define the hydrogeology of the water loss from the lakes. Kuehne (1966, p. 76) Edwards and Trinity aquifers. Pearson and others observed that there was considerable leakage from (1975) analyzed tritium concentrations in water samples Medina Lake and reported that the greatest loss of collected from 50 wells and springs in the Edwards water to the subsurface was in the 4-mi reach between aquifer in the San Antonio area. Analysis of the tritium Medina Dam and Diversion Dam (fig. 1). Quantitative estimates of recharge have indicated that substantial data confirmed previous interpretations of ground-water losses of water from the lake system have recharged pri- movement near Medina Lake: recharge to the Edwards marily the Edwards aquifer. The Bureau of Reclamation aquifer was occurring along the lower limit of the estimated that seepage from Medina and Diversion Edwards aquifer outcrop (recharge zone) (Pearson and Lakes and the connecting reach, combined, totaled others, 1975, p. 15). Pearson and Rettman (1976) used almost 72,000 acre-ft/yr (Burleigh, 1949, p. 9–15). the results of water-quality analyses for selected ions Streamflow measurements along 24 mi of the Medina and environmental isotopes to group Edwards aquifer irrigation canal (pl. 1) that predominantly traverse geo- water into five distinct water types on the basis of their logic formations of the upper confining unit (table 1) chemical composition. For the USGS Edwards-Trinity indicated that losses were 4 cubic feet per second (ft3/s) Regional Aquifer-System Analysis (RASA) program, or almost 2,900 acre-ft/yr, and that most of the decrease Bush and others (1994) described the spatial distribu- in flow could be attributed to evaporation and transpira- tion of dissolved solids concentrations and hydrochem- tion (Land, 1970). ical facies in the Edwards-Trinity aquifer system. Water Lowry (1953, p. 41) analyzed the hydrology of samples were collected from selected permeable zones the Medina River and estimated that the average loss of the Trinity aquifer and analyzed for general water from Medina Lake owing to leakage, alone, was 41,000 quality and selected isotopes. Results from these analy- acre-ft/yr during 1912–53. Lowry also determined that ses were used to determine rock-water interactions in seepage was related to changes in reservoir stage. In a the aquifer and to estimate travel time and ground-water later report, Lowry (1955, p. 24) estimated that recharge velocities for selected flowpaths (Jones and others, from the lake system to the ground-water system aver- 1997). aged 46,900 acre-ft/yr during 1934–53. William F. Guyton and Associates (1955, 1958) Methods of Analysis described the stratigraphy, structure, and hydrology of the Edwards aquifer in the San Antonio region and dis- The hydrogeologic subdivisions (table 1) of the cussed the quantity and distribution of leakage from Edwards aquifer modified from Maclay and Small Medina Lake. William F. Guyton and Associates (1958) (1976) and the stratigraphic nomenclature of Rose concluded that any leakage from Medina Lake returned to the Medina River below Medina Dam when the lake (1972) for the Edwards Group were used to map the level was higher than about 960 feet (ft). Estimated Edwards aquifer outcrop in the Medina Lake area. The recharge to the Edwards aquifer in 1962 and 1963 was lower and upper members of the Glen Rose Limestone 45,400 and 28,200 acre-ft, respectively (William F. were mapped using the stratigraphic nomenclature of Guyton and Associates, 1965). Stricklin and others (1971). Previous mapping in the Espey, Huston and Associates, Inc. (EH&A) Medina Lake area placed the rock units into groups and (1989) did hydrologic and hydraulic analyses to deter- formations only and separated the Edwards Group mine the availability of surface water from the lake (Edwards aquifer) from the Glen Rose Limestone (Trin- system under various operating scenarios. EH&A ity aquifer). Additionally, Small and Lambert (1998) developed a computer model that simulated recharge to mapped the thickness of Edwards strata in the study area the underlying ground-water system for each of the and determined which hydrogeologic subdivisions operating scenarios. As part of their analysis, EH&A might be hydraulically connected to the lake system. developed a set of rising and falling loss curves and esti- Wells and springs were inventoried and water-level

INTRODUCTION 5 measurements were made where possible (Texas Water duplicate quality-control samples were collected and Development Board, 1996b). submitted to the USGS National Water Quality Labora- Individual hydrologic budgets were developed for tory, Arvada, Colo. Medina Lake, Diversion Lake, and Medina/Diversion Environmental isotope data were collected from Lakes combined using data collected during August Medina Lake, Medina River, Koenig Creek, and 1995–September 1996. Remote Operating selected wells and springs to determine the proportion Systems, Inc. (ROS) constructed an extensive monitor- of lake water that might have mixed with ground water ing network for BMA and EAA to measure stream in selected wells completed in the Edwards aquifer. The discharge, lake stage, precipitation, and climatological isotope samples were analyzed for ratios of deuterium/ properties useful for calculating evaporation losses. protium (2H/1H), oxygen (18O/16O), and strontium Discharge, lake stage, and precipitation were collected (87Sr/86Sr) by USGS research personnel in Reston, Va., at continuous recording or peak stage sites by BMA and and Menlo Park, Calif. Geochemical modeling to deter- EAA, the data were reviewed by USGS, and feedback mine the amount of mixing between lake and ground was provided to BMA and EAA for data quality control. water was done with NETPATH (Plummer and others, Climatological data to estimate evaporation losses from 1994). Medina and Diversion Lakes were obtained from two weather stations. The Medina Dam weather station, Acknowledgments located adjacent to the spillway on the dam was Special thanks are extended to James McNair, installed by ROS and operated by BMA. The Medina BMA; Kenneth Sandifer, Medina Ranch; Herb Young, Lake weather station was installed on the lake and oper- Flying L Ranch; Emmit Schmidt, Ranch Manager of the ated by USGS. Continuous readings of air and water Flying A Ranch; William Walker, Sr.; Louis Haby; temperature, relative humidity, and wind speed were Alton Seekatz; and Leon Mangold for their time and collected by BMA and USGS and were reviewed by assistance. Thanks also are extended to Luana Buckner, USGS. Medina County Underground Water Conservation Dis- Hydrologic data for the project were processed trict, and to Springhills Water Management District for and reviewed following USGS protocol. Daily mean assistance in locating wells and providing ground-water values were calculated for each hydrologic budget com- information. The authors wish to thank all property ponent. Evaporation from each reservoir was calculated owners and ranch managers who granted permission to using a mass-transfer method that is based on reservoir enter their property, supplied information, and aided in area. Hydrographic surveys of Medina and Diversion the collection of field data. Lakes were done in July 1995 by the TWDB to revise existing area-capacity curves for each lake at the conser- HYDROGEOLOGY vation pool and to establish baseline information for future surveys (Texas Water Development Board, Medina Lake mostly overlies rocks of the 1996a). Edwards and Trinity aquifers. The Edwards aquifer in Water-quality characteristics of the lake system the Balcones fault zone is one of the most permeable were studied to determine, if possible, regions where and productive carbonate aquifers in the Nation, con- lake water might enter the underlying Edwards and (or) sisting of extensively faulted, fractured, and cavernous Trinity aquifers. Water-quality samples were collected limestone and dolomite (Maclay, 1995). The Edwards from Medina Lake, Medina River, Koenig Creek, and aquifer comprises the Kainer and Person Formations of selected wells and springs during 1995–96 to character- the Edwards Group, plus the overlying Georgetown ize the water chemistry of the surface- and ground- Formation (table 1). The Kainer and Person Formations water resources in the study area. The water samples were divided into seven informal members by Rose were collected according to the methods described in (1972). These members were modified by Maclay Wells and others (1990). Specific conductance, pH, and Small (1976) into eight informal hydrogeologic temperature, and dissolved oxygen were measured on- subdivisions that include the overlying Georgetown site at lake and surface-water data-collection sites by Formation. USGS personnel. Water-quality samples were analyzed The Edwards aquifer has relatively large porosity for major cations and anions, nutrients, and trace ele- and high permeability resulting, in part, from the ments by TWDB contract laboratories. Additional development or redistribution of secondary porosity

6 Hydrogeology, Hydrologic Budget, and Water Chemistry of the Medina Lake area, Texas (Small and Lambert, 1998). Lithology, stratigraphy, porous, permeable units of the Trinity aquifer. Maclay diagenesis, and selective dissolution (karstification) and Small (1986) define flow-barrier faults as faults that account for the effective porosity and permeability in have a vertical displacement of greater than 50 percent the Edwards aquifer outcrop. The porosity of the rocks of the total thickness of the Edwards aquifer. in the Edwards aquifer is related directly to depositional and diagenetic elements that exist along specific Geologic Framework lithostratigraphic horizons (fabric selective) and to dissolution and structural elements that can exist in any In the Medina Lake area, the Trinity aquifer out- lithostratigraphic horizon (not fabric selective). Perme- crop consists of the lower and upper members of the ability depends on the physical properties of the rock, Glen Rose Limestone and the Edwards aquifer outcrop particularly the size, shape, and distribution of the primarily consists of the basal nodular and dolomitic pores. The most porous and permeable hydrogeologic members of the Kainer Formation (pl. 1). The Glen subdivisions of the Edwards aquifer outcrop appear to Rose Limestone and the Edwards Group are mostly be subdivision VI, the Kirschberg evaporite member of consistent in thickness throughout the region and dip the Kainer Formation, and subdivision III, the leached slightly southeastward. The Glen Rose Limestone crops and collapsed members, undivided, of the Person For- out in the northern part of the study area, while the mation (table 1). Edwards Group forms bluffs and hilltop caps in the Rocks of the middle and upper Trinity aquifers southern part of the study area. The lower member of are stratigraphically lower than rocks composing the the Glen Rose Limestone crops out along the Medina Edwards aquifer (table 1). These aquifer units consist of River channel from the upper end of Medina Lake, fractured and cavernous limestone and dolomite inter- northward to Bandera (pl. 1). Permeability in the lower bedded with shale and evaporitic minerals (Ashworth, member of the Glen Rose Limestone generally is low 1983). The middle Trinity aquifer consists of the Cow unless the zone is cavernous or is fractured (Ashworth, Creek Limestone, the Hensel Sand, and the lower mem- 1983). ber of the Glen Rose Limestone, while the upper Trinity The upper member of the Glen Rose Limestone aquifer consists of the upper member of the Glen Rose underlies Medina Lake and also crops out in the channel Limestone. Caverns formed in limestone and evaporite from the outflow of Medina Lake to the midpoint of strata are common in the Glen Rose Limestone. The Diversion Lake where the Diversion Lake fault inter- middle Trinity aquifer is a source of potable water in the sects Diversion Lake (pl. 1). The upper member is rela- region, but yields much smaller quantities of a more tively impermeable, although lateral cave development highly mineralized water than the Edwards aquifer is common at the contact between the upper member (Ashworth, 1983). In the Medina Lake area, the upper and the overlying basal nodular member of the Kainer Trinity aquifer yields only a limited quantity (0 to 20 Formation. The cave development probably results from gallons per minute [gal/min]) of highly mineralized dissolution associated with the perching of infiltrated water and functions locally as a confining unit between meteoric water above the relatively impermeable upper the middle Trinity aquifer and Edwards aquifer because member of the Glen Rose Limestone (Kastning, 1986). of the large differences in transmissivity (table 1). On the southern side of Medina Lake, the Movement of water in the Edwards aquifer, Edwards Group crops out as limestone bluffs comprised and to a lesser extent in the Trinity aquifer, is controlled primarily of the basal nodular and dolomitic members by an extensive fault system known as the Balcones of the Kainer Formation. A thicker sequence of the fault zone (fig. 1). The Balcones fault zone consists Edwards aquifer (hydrogeologic subdivisions VIII of a dense series of near parallel, primarily northeast- through III) is exposed in an area adjacent to Diversion trending faults that commonly are normal, high-angle Lake downstream of the Diversion Lake fault (pl. 1). structures with the downthrown side to the southeast Hydrogeologic subdivision II (cyclic and marine mem- (Maclay, 1995). These faults can form barriers or con- bers, undivided) and subdivision I (the overlying duits to flow. The degree of hydraulic connection Georgetown Formation) have been eroded and are not between two adjacent fault blocks depends on the exposed in the study area. A thin layer of the basal nod- amount of vertical displacement (or throw) on the fault ular member forms the floor of Diversion Lake from the and the proportion of total thickness of porous, perme- midpoint of the reservoir downstream, past the dam, to able units of the Edwards aquifer juxtaposed against Haby Crossing fault. Field observations and geophysi-

HYDROGEOLOGY 7 cal information from well TD–68–25–904 (pl. 1) con- of the lake is about 1,050 ft above MSL. The fault block firm that the remnant of Edwards aquifer underlying the bounded by the Medina Lake fault and the Diversion lower one-half of Diversion Lake is approximately 50 ft Lake fault (B–B') contains additional faults and frac- thick. Southwest of Medina Lake, the Edwards Group tures with no substantial vertical displacement of the changes lithology and grades into the stratigraphically hydrogeologic subdivisions; thus the permeable rock equivalent Devils River Formation (pl. 1). units provide a potential pathway for movement of Rocks in the southern part of the Medina Lake water from Medina Lake into the adjacent Edwards area are extensively faulted and fractured. Three major aquifer when the lake stage is greater than 1,000 ft faults are present—Medina Lake, Diversion Lake, and above MSL. During the study, the lake stage was always Haby Crossing (pl. 1). The Medina Lake fault intersects greater than 1,000 ft above MSL, and field observations Medina Lake upstream of Medina Dam. The vertical confirmed water seeping from the bluffs into the spill- displacement of the Medina Lake fault is about 70 to way channel adjacent to Medina Lake and from the hill- 100 ft; the displacement of the Diversion Lake fault is sides downstream of both Medina and Diversion Dams. about 50 to 60 ft. The Haby Crossing fault intersects the Farther south on section B–B' (pl. 1), the Kainer Medina River downstream of Diversion Dam, juxtapos- Formation grades into the Devils River Formation, ing rocks of the Edwards Group/Devils River Formation which is the stratigraphic equivalent of the Edwards against the much younger rocks of the upper confining Group in central and western Medina County. Data in unit (pl. 1). The Haby Crossing fault, with a vertical dis- USGS files for well TD–68–33–102 indicate that the placement of about 600 to 900 ft, is the only known top of the basal nodular member of the Kainer Forma- flow-barrier fault in the Medina Lake area (Small and tion (hydrogeologic subdivision VIII) is about 535 ft Lambert, 1998). above MSL and that the top of the Glen Rose Limestone Generalized hydrogeologic section A–A' (pl. 1) is about 475 ft above MSL. This fault block is bounded shows the relative positions of rocks of the Edwards on the south by the Haby Crossing fault, where rocks aquifer approximately parallel to Diversion Lake and of the Edwards aquifer on the upthrown side are com- southeastward across the Haby Crossing fault. The pletely offset from those on the downthrown side (pl. 1). Edwards aquifer rocks in this area primarily consist of The displacement of permeable rocks across the the basal nodular, dolomitic, Kirschberg evaporite, and Haby Crossing fault is large enough that the fault forms grainstone members of the Kainer Formation, with caps a barrier to ground-water flow. The Haby Crossing of the regional dense member and the leached and col- fault diverts ground water into a southwesterly path lapsed members, undivided, of the Person Formation. parallel to the trend of the fault rather than following The large vertical displacement on the Haby Crossing the regional dip of the rock units to the southeast, the fault completely offsets the Kainer Formation on the direction of regional flowpaths in the Trinity aquifer upthrown side of the fault from the cyclic and marine (Maclay, 1995; Groschen, 1996). members, undivided, of the Person Formation and the Georgetown Formation on the downthrown side. The Flow Systems Medina irrigation canal and the Medina River cut into the dolomitic member and parts of the upper basal nod- The Edwards aquifer and Trinity aquifer systems ular member of the Kainer Formation near the south- primarily depend on the amount of precipitation eastern end of the hydrogeologic section (pl. 1). received in their respective recharge areas. Recharge to Hydrogeologic section B–B' (pl. 1) shows the rel- the Edwards aquifer in the San Antonio area results ative positions of the hydrogeologic subdivisions in from the infiltration of precipitation on the aquifer out- each major fault block. The contact between the upper crop and seepage from lakes and rivers in the recharge member of the Glen Rose Limestone and the basal nod- zone (fig. 1). Rivers and streams in the catchment area ular member of the Kainer Formation on the southern upstream of the recharge zone flow across exposed out- side of Medina Lake is at an altitude of about 1,000 ft crops of the Edwards aquifer, losing much or all of their above mean sea level (MSL). The Glen Rose Lime- base flow to the unconfined part of the aquifer. The stone/Edwards Group contact gradually decreases in Edwards aquifer is anisotropic, with preferential flow- altitude southeastward because of the regional structural paths controlled by the distribution and displacement of dip of the rocks. The contact between the basal nodular joints and faults in the Balcones fault zone. Transmis- member and the dolomitic member on the southern side sivity in the Edwards aquifer varies from about 200,000

8 Hydrogeology, Hydrologic Budget, and Water Chemistry of the Medina Lake area, Texas to more than 2 million ft2/d (Maclay and Small, 1986), and Swancar, 1997). The general hydrologic budget with the maximum transmissivity aligned with regional equation for a lake is: faults (Kuniansky and Holligan, 1994). Similar to the way most recharge reaches the ∆Se± = Pe± –eE ± + SW ± e Edwards aquifer, most recharge to the Trinity aquifer S P E in SWi results from the infiltration of precipitation on the out- – SWout ±e SWo + GWin ± eGW crop and through seepage losses from lakes and rivers – GWout ±e GWo, (1) (Ashworth, 1983). The Hensel Sand and the lower and upper members of the Glen Rose Limestone (table 1) where have the largest outcrop exposure and receive the largest ∆S is change in lake storage; amount of direct recharge. The Cow Creek Limestone primarily is recharged by vertical leakage from overly- P is precipitation on the lake; ing strata. After entering the Trinity aquifer, the water E is evaporation from the lake surface; moves downdip toward the southeast. Transmissivity in SWin is surface-water inflow to the lake; the Trinity aquifer in the Hill Country typically is at SW is surface-water outflow from the lake; least one order of magnitude less than that in the out GW is subsurface inflow into the watershed from Edwards aquifer, ranging from about 100 to about in 58,000 ft2/d (Kuniansky and Holligan, 1994). the Edwards or Trinity aquifers, or both; Maclay and Land (1988) identified four generally GWout is subsurface outflow from the lake (losses independent regional ground-water-flow units in the from lakes/recharge to the ground-water Edwards aquifer that are delineated by downgradient system); and major faults and aquifer discharge (fig. 2). Each flow ei is uncertainty or error in each term i . unit is an area of the aquifer that includes a storage unit All units are in acre-feet. and a zone in which water is transmitted from a partic- The hydrologic budget equation then can be rewritten ular storage unit to a major point of discharge. Two of to solve for the residual term, GWout : these flow units, the south-central and north-central, derive part of their flow from the Medina Lake area. GWout ± eGWo = Pe± P –eE ± E Water infiltrates these storage units and moves downdip +WS in""± e""SWi into the flow units and confined part of the Edwards – SW ± e aquifer, where most eventually discharges to area out SWo .(2) springs (primarily Comal and San Marcos Springs) or is +eGWin ± GWi – ∆Se± S withdrawn through wells in the San Antonio area. Measured terms (for example, SWin ) have an HYDROLOGIC BUDGET associated error that depends on the method of mea- surement, precision of the instrumentation, and region- Individual hydrologic budgets for October 1995– alization (interpretation) of the data that results from September 1996 were calculated for Medina Lake, estimating quantities in a time/space continuum from Diversion Lake, and Medina/Diversion Lakes combined point data (Winter, 1981). Hydrologic budget terms that to estimate water losses from these lakes to the local are calculated from more than one measured variable ground-water systems. Locations of the data- might reflect an accumulation of errors in the measured collection sites used for the hydrologic budget are terms (Lee and Swancar, 1997). If a term is derived as shown in figure 3 and listed in table 2 (at end of report). the sum or difference of other measured terms, then Hydrologic data, budget estimates, and estimated errors the potential error is the sum of the variances in the associated with the individual budget components for measured terms (Winter, 1981). For the hydrologic Medina Lake, Diversion Lake, and Medina/Diversion budget, each measured term used to calculate GWout Lakes combined are included in appendices A and B (at was assigned a percentage error to define the confidence end of report). Error estimates indicate how well indi- limits around the measured values. The percentage vidual hydrologic fluxes are measured and understood error for each measured term was based on the accuracy and also provide a measure of the reliability and accu- rating assigned to an individual station record or on the racy of the hydrologic budget as a predictive tool (Lee error associated with using a specific method to esti-

HYDROLOGIC BUDGET 9

COUNTY CALDWELL

San Marco Springs 1-35 Buda Kyle

CR.

Comal Springs o

98 ONION New Braunfels

San Marcos

290

12 FM

R. COUNTY

WILSON WILSON

BLANCO Dripping Springs COUNTY US HAYS COUNTY

GUADALUPE CREEK CALAVERAS LAKE

SAN ANTONIO RIVER US 90 US Hueco Springs inflow Springs Hueco

BRAUNIG LAKE

BLANCO COUNTY BLANCO Eastern storage unit storage Eastern

PE 1604

U CANYON

COMAL COUNTY L LAKE A

G 46

30 281 US 30'

o Eastern flow unit flow Eastern STATE 98

CIBOLO 1604 LOOP SAN

ANTONIO

COUNTY LOOP KENDALL

I-10

ATASCOSA COUNTY

RIVER

MEDINA

BEXAR COUNTY I-35

Lytle Rio Medina inflow Medina Rio

Eastern Medina storage unit storage Medina Eastern North-central flow unit flow North-central MEDINA LAKE Devine o 99 US 90

STATE 173

D U

CR.

Hondo

storage unit storage Western Medina Western 20 MILES

MEDINA COUNTY SECO unit flow South-central BANDERA COUNTY

15 Western-southern flow unit flow Western-southern 30' o SABINAL R.

D 10 U 5 RIVER EXPLANATION 0

U, upthrown; D, downthrown. Dashed where inferred FRIO US 83 US Uvalde Tom Nunn Hill outflow Ground-water divide Boundary separating storage and flow units Recharge zone Line separating unconfined zone to the north from the confined zone to south, July 1974 Approximate downdip limit of freshwater zone of the Edwards aquifer Faults—

RIVER REAL COUNTY ZAVALA COUNTY

o NUECES 100 D U

US 90 Western storage unit UVALDE COUNTY R.

NUECES WEST Brackettville Brackettville outflow FM 674

MAVERICK COUNTY STATE 131 STATE 30' o 100

US 90 Kinney County inflow Regional ground-water-flow units of the Edwards aquifer, Texas (modified from Maclay, 1995, pl. 10). pl. 1995, Maclay, from (modified Texas aquifer, Edwards the of units ground-water-flow Regional KINNEY COUNTY EDWARDS COUNTY

US 277 GRANDE RIO 30' o 29 Figure 2. Figure

10 Hydrogeology, Hydrologic Budget, and Water Chemistry of the Medina Lake area, Texas 99o07'30" 99o 98o52'30"

29o45' MEDINA 123 State State 16 46

State 16 RIVER Pipe State Creek

Bandera MEDINA Creek

Bluff

Red RIVER

Bruins FM 1283 1

State

Creek 2

16 11

Rocky

Creek

37 State 173 State BANDERA COUNTY Cypress Park 29o37'30" MEDINA COUNTY

Creek 12 State Elm

Creek 3

fault Creek 10 Verde 4 14 MEDINA LAKE fault Creek fault Creek Lake Parker 13 MEDINA FM 6 DAM 1283 Medina fault DIVERSION Verde Quihi Cr. 5 U LAKE Main D Elm fault Creek School 15 8 7 U o 29 30' D U Lake 9 Vandenburg D U U D MEDINA D fault FM 471 canal Diversion o Creek Crossing im n fault Ger o Haby TD–69–40–102 RIVER

FM 2676 irrigation San 173 Lincoln Riomedina Elm 1957 FM State

Medina

Cr.

0 1 2 3 MILES EXPLANATION 1 U — Surface-water site—Number is referenced D PRIMARY FAULT U, upthrown; in table 2 D, downthrown. Dashed where 14 inferred Lake site—Number is referenced TD–69–40–102 in table 2 Quihi monitoring well—Number is state well number

Figure 3. Location of hydrologic budget data-collection sites and Quihi monitoring well (TD–69–40–102), Medina Lake area, Texas.

HYDROLOGIC BUDGET 11 mate a hydrologic variable (Novak, 1985, p. 65). Error stage between about 1,018 and 1,046 ft above MSL estimates for each component of the budget are dis- (1,026 and 1,054 ft above BMA datum). cussed in subsequent sections. The equation used to calculate the error Precipitation (±e ) associated with the residual term (GW ) GWout out During 1995–96, the Medina Lake area received is: below normal precipitation, and most of the smaller tributaries (inflow sites) remained dry or ceased to flow. 2 2 eGWout = ()%eP ⋅ P + ()%eE ⋅ E During October 1995–September 1996, only 16.59 inches (in.) of precipitation were recorded at the 2 + ()%eSWin ⋅ SWin National Weather Service station at Seaworld, which represents 53 percent of the average (1988–97) precipi- 2 tation of 31.13 in. (Hydrosphere Data Products, 1998). + ()%eSWout ⋅ SWout Precipitation was a minor component in the hydrologic 2 2 budgets (table 3). ++()%eGWin ⋅ GWin ()%e∆S ⋅ ∆S ,(3) Precipitation for Medina Lake was determined by averaging the daily precipitation measured by gages on where Red Bluff Creek (site 2), Elm Creek (site 3), Cypress %eP is percentage error of precipitation data; Creek (site 10), Bruins Creek (site 11), and Medina Dam (site 13) (fig. 3, table 2), and then multiplying the %eE is percentage error of evaporation data; resulting value by the surface area of Medina Lake %e is percentage error of SW data; SWin in (appendix A. Evaporation). Precipitation for Diversion %eSWout is percentage error of SWout data; Lake was determined by multiplying the daily precipi-

%eGWin is percentage error of subsurface inflow tation at Diversion Lake by the surface area (appendix (GWin ) into the watershed; and A). Precipitation records were assigned a fair accuracy rating because of instrumentation problems, including %e is percentage error of change in storage. ∆S transmission errors and equipment failure; the error Daily values for each of the hydrologic budget associated with the fair rating was estimated to be about components were measured during August 1995– 15 percent (Novak, 1985, p. 65). September 1996, or calculated (appendix A). Once daily values were determined, hydrologic budgets for Evaporation Medina Lake, Diversion Lake, and Medina/Diversion Lakes combined were calculated for selected budget Evaporation can be a substantial component of periods of 5 or more days during November 1995– the hydrologic budget in Texas (Larkin and Bomar, September 1996 (appendix B). A total of 21 budget 1983). Data collected from the Medina Lake weather periods were calculated for Medina Lake using data for station (site 14), and Medina Lake near San Antonio 162 days, or about 44 percent of the dataset; 22 budget (site 13) (fig. 3, table 2) were used to compute evapora- periods were calculated for Diversion Lake using data tion rates for the Medina Lake area. Daily mean evapo- for 147 days, or about 40 percent; and 24 budget periods ration from the lakes was computed by multiplying the were calculated for Medina/Diversion Lakes combined evaporation rates calculated using the mass-transfer using data for 194 days, or about 53 percent of the method by the surface area of the lakes (appendix A). dataset (table 3, at end of report). These selected budget The accuracy of the evaporation rates using the mass- periods represent intervals when little or no data were transfer method was estimated to be 25 percent (Winter, missing for all budget components and when lake levels 1981). were assumed to be at steady state. Mass-Transfer Theory During the study, Medina Lake stage remained much lower than the normal pool altitude of 1,064.2 ft Mass-transfer theory treats evaporation as a above MSL (1,072 ft above BMA datum) because of dry function of vapor pressure gradient and wind speed climatic conditions. Thus the hydrologic budget above the surface of a lake (Rosenberg and others, calculations are valid only for a range in Medina Lake 1983). Harbeck (1962) modified the equation during

12 Hydrogeology, Hydrologic Budget, and Water Chemistry of the Medina Lake area, Texas previous studies (Marciano and Harbeck, 1954; of the air above the lake surface was greater than the sat- Harbeck and others, 1958) by relating the mass-transfer uration vapor pressure of the lake-surface air tempera- coefficient (N ) to lake-surface area. The resulting equa- ture, producing a negative vapor pressure difference tion is: (e0 – ea ). This occurred primarily on days in winter and early spring when the relative humidity was high and EMT = Nu2()e0 – ea ,(4)might result from the instrumentation’s inability to pre- cisely measure small differences in the vapor pressures. where

EMT is evaporation by mass-transfer method, in Evaporation Rates centimeters per day; Evaporation was one of the smaller components N is mass-transfer coefficient, which can be related of the Medina Lake hydrologic budget, contributing to lake-surface area; between 1.4 and 11.8 percent to the total Medina Lake u2 is daily average wind speed at 2 meters (m) above hydrologic budget for the selected budget periods. The the lake, in miles per hour; evaporation component of the Diversion Lake hydro- e0 is saturation vapor pressure at the water-surface logic budget was even smaller, contributing between temperature, in millibars; and 0.09 and 1.7 percent to the Diversion Lake hydrologic

ea is vapor pressure of the air at 2 m above the lake budget for selected budget periods. Daily evaporation surface, in millibars. rates for Medina and Diversion Lakes are shown in Estimates of N for Medina and Diversion Lakes figure 4 and listed in appendix A. Average evaporation ranged from 0.00564 to 0.00583 and from 0.00670 to from Medina Lake, Diversion Lake, and Medina/ 0.00681, respectively (appendix A), using the empirical Diversion Lakes combined for the selected hydrologic relation N= 0.00859⁄ A0.05 developed by Harbeck budget periods are listed in table 3 and appendix B. (1962), where A is the lake-surface area, in acres. The largest average rate of evaporation from The saturation vapor pressure at the water-surface Medina Lake for the selected hydrologic budget periods was 0.269 in/d during July 19–23, 1996, for a total of temperature (e0 ) and saturation vapor pressure of the air 1.34 in. (appendix A); the smallest was 0.029 in/d dur- 2 m above the lake surface (es ) were calculated using: ing February 21–27, 1996, for a total of 0.205 in. The average volume of water evaporated from Medina Lake e = 0.61078exp ------17.269⋅ T ,(5) 0s, T+ 237.30 ranged from 10.2 to 62.2 acre-feet per day (acre-ft/d) for the selected hydrologic budget periods (table 3). where Although the daily rate of evaporation from Diversion Lake was slightly more than that from Teis water-surface temperature for 0 and Medina Lake (fig. 4), the volume of evaporation was air temperature for es , in degrees Celsius (Rosenberg and others, 1983). less because the surface area of Diversion Lake is substantially smaller than the surface area of Medina Lake. To calculate ea , Rosenberg and others (1983) used the following equation: The equation used to calculate N is based on the recip- rocal of the area to a power (1/A0.05). The largest aver- RH× e age rate of evaporation from Diversion Lake for the e = ------s- ,(6) a 100 selected budget periods was 0.316 in/d during July 18– 23, 1996, for a total of 1.90 in.; the smallest was 0.042 where in/d for 6 days during February 21–26, 1996, for a total RH is relative humidity (ratio of actual to saturation of 0.25 in. One of the smallest components of the Diver- vapor pressure at the same temperature), in sion Lake budget, the average volume of evaporation percent. ranged from 0.4 to 3.4 acre-ft/d for the selected hydro- Daily saturation vapor pressures for the lake sur- logic budget periods (table 3). face and for the air above the lake were calculated using Evaporation losses from Medina/Diversion Lakes data from site 14 (fig. 3, table 2); where lake data were combined were calculated by summing the evaporation not available, data from site 13 were used to supplement from both lakes. The average volume of evaporation the record. In some cases, the saturation vapor pressure from the lakes combined for the selected budget periods

HYDROLOGIC BUDGET 13 0.700

Medina Lake 0.600

0.500

0.400

0.300

0.200

0.100 EVAPORATION, IN INCHES PER DAY

-0.100 SEPT OCT NOV DEC JAN FEB MAR APR MAY JUNE JULY AUG SEPT 1995 1996

0.700

Diversion Lake 0.600

0.500

0.400

0.300

0.200

0.100 EVAPORATION, IN INCHES PER DAY

-0.100 SEPT OCT NOV DEC JAN FEB MAR APR MAY JUNE JULY AUG SEPT 1995 1996

Figure 4. Daily evaporation rates for Medina and Diversion Lakes, Medina Lake area, Texas.

14 Hydrogeology, Hydrologic Budget, and Water Chemistry of the Medina Lake area, Texas ranged from 10.5 to 63.6 acre-ft/d (table 3). Evaporation SWout from Diversion Lake was calculated by from the lakes combined also was one of the smaller summing the discharges from sites 7 and 8. SWout from components of the hydrologic budget during most of the Diversion Lake primarily is flow released down the study, except during summer 1996, when SWin Medina irrigation canal system and measured at site 7. decreased. Site 8 adds a small amount to the SWout component and is a measure of the seepage from Diversion Lake that is Surface Water reentering the surface-water system immediately downstream of Diversion Dam. The SW component for Surface-water inflow (SWin ) to and surface-water out Diversion Lake was calculated using data from sites 7 outflow (SWout ) from Medina Lake are major components of the Medina Lake and Diversion Lake hydro- and 8 and from sites 7 and 9. The SWout component was calculated both ways because flow in the Medina logic budgets. The average values of SWin to Medina Lake were calculated by summing the discharges from River increases between sites 8 and 9, where an addi- sites 1, 2, 3, and 10 (fig. 3, table 2). Sites 4, 11, and 12 tional 23 to 51 acre-ft/d reenters the surface-water sys- were dry for most of the study and did not contribute to tem as seepage from the adjacent hillsides, most likely the SWin component of the Medina Lake hydrologic from Medina and Diversion Lakes. Site 8 was selected budget. The station records for the SW sites were rated in as the SWout site for the Diversion Lake hydrologic good to fair and were assigned an error rating ranging budget because the estimated ground-water outflow from 10 to 15 percent (Novak, 1985, p. 65). (GWout ) from Diversion Lake was negative when site 9 During 1996, the primary contribution of SW to in was used in the hydrologic budget calculations. GWout Medina Lake was from site 1, with minor contributions was negative in part because Medina Lake water that is from sites 3 and 10. SWin to Medina Lake ranged from included in hillside seepage returns as unaccountable 6.6 to 145.2 acre-ft/d for selected hydrologic ground-water inflow (GW ) to Diversion Lake. These budget periods, with the largest flows measured at the in results indicate that part of the GW losses accounted beginning of the data-collection period and generally out for in the Medina Lake hydrologic budget are returning decreasing throughout the remainder of the study to the surface-water system near Diversion Lake and are (table 3). SW from Medina Lake was obtained out not recharging the Edwards aquifer. Station records from site 6 for stages of less than about 2.5 ft. A stage- discharge relation cannot be determined for stages were rated as good and assigned an error of 10 percent greater than about 2.5 ft at site 6 because the river chan- (Novak, 1985, p. 65). Average SWout for Diversion nel is not well defined and is filled with gravel and Lake ranged from 10.7 to 288.5 acre-ft/d for selected hydrologic budget periods (table 3). debris. The station record for SWout was rated good and assigned an error of 10 percent (Novak, 1985, p. 65). SWin to Medina/Diversion Lakes combined was Average SWout from Medina Lake ranged from 57.5 to calculated using the same sites as for Medina Lake (sites 372.9 acre-ft/d for the selected hydrologic budget peri- 1, 2, 3, and 10); SWout was calculated using sites 7 and ods (table 3). 9. Site 9 was selected as the downstream site because Similar to Medina Lake, SWin and SWout are the gage provides a better estimate of the total losses major components of the Diversion Lake hydrologic from Medina and Diversion Lakes that are reentering budget. SW to Diversion Lake was obtained by sum- in the stream channel, and also because additional seepage ming the discharges from sites 5 and 6 (fig. 3, table 2). that reentered the stream channel downstream of the Site 6 measured outflow and leakage from Medina Lake outflow site used in the Diversion Lake budget could be that was the primary source of inflow to Diversion Lake. Site 5 is a minor tributary that generally contributed less accounted for as SWout . Average SWin to than 2 acre-ft/d to Diversion Lake during the study and Medina/Diversion Lakes combined ranged from 5.1 to ceased to flow in June 1996 (appendix A). Station 142.3 acre-ft/d, and average SWout ranged from 73.4 to 430.1 acre-ft/d for the selected hydrologic budget peri- records for the SWin sites were rated good to fair, and assigned an error rating ranging from 10 to 15 percent ods (table 3). The largest SWout occurred during the summer months when large quantities of water were (Novak, 1985, p. 65). Average SWin to Diversion Lake for the selected hydrologic budget periods ranged from released down the Medina irrigation canal to meet irri- 30.7 to 366.6 acre-ft/d (table 3). gation demands.

HYDROLOGIC BUDGET 15 Storage pared to other hydrologic budget components, ranging from -547.8 to -63.3 acre-ft/d (table 3). Overall storage The changes in storage (∆S ) in Medina and Diver- in the lakes combined decreased as a result of providing sion Lakes were calculated using stage-volume-area water to local irrigators during the summer months. (area-capacity) tables from the 1995 volumetric survey (Texas Water Development Board, 1996a) and stage Ground Water data from sites 13 and 15. Volumetric surveys of Medina and Diversion Lakes were done in July 1995 because Medina and Diversion Lakes lie atop outcrops of the existing capacity curves for Medina Lake were the Edwards aquifer and atop outcrops of the middle and based on a volumetric survey completed in 1912 and upper Trinity aquifers, thus providing the potential for because the data available for Diversion Lake were water to migrate between the lake system and the insufficient. The volumetric survey was done when the ground-water-flow system (pl. 1). In a hydrologic bud- stage at Medina Lake ranged from 1,048.57 to 1,048.60 get, GWin represents the potential contribution of water ft above MSL (1,056.37 to 1,056.40 ft above BMA from the Edwards and Trinity aquifers, while GWout datum). Additional data were obtained from aerial sur- represents seepage loss from the lake system that enters veys made during 1984–85 to complete the upper end of the ground-water-flow system. In the case of Medina the stage-volume-area tables (above 1,048 ft above Lake, however, an unaccountable part of the GWout MSL) for Medina Lake. The Medina Lake volumetric returns to Diversion Lake and to the surface-water survey results indicate that the stage-volume-area tables system downstream of Diversion Dam. have not changed appreciably since 1912. The station Ground-Water Inflow records were rated good for Medina Lake and fair for Diversion Lake and were assigned an error of 10 and 15 Water-level altitudes from wells open to the mid- percent, respectively (Novak, 1985, p. 65). dle and upper Trinity aquifers and from springs (pl. 2; Similar to SWin and SWout , ∆S in Medina Lake table 4, at end of report) were used to determine if there also was a major component of the hydrologic budget. is a GWin component from the Trinity aquifer. Water- Total storage in Medina Lake ranged from about 69,000 level altitudes in wells near Medina Lake that are open to 155,000 acre-ft (appendix A) during the study, and to the Trinity aquifer are influenced by Medina Lake, stage ranged from about 1,019 to 1,045 ft above MSL similar to the way wells open to the Edwards aquifer are (1,027 to 1,053 ft above BMA datum). The average ∆S influenced by the lake. for the selected hydrologic budget periods ranged from Most springs in the area originate from caps of -443.6 to -48.5 acre-ft/d (table 3). A negative ∆S indi- the upper member of the Glen Rose Limestone (upper cates a decrease in the amount of water stored in the lake Trinity aquifer; table 1) that form hydrologically dis- from the previous day. A positive ∆S indicates an crete, local flow systems that discharge along bedding increase in water stored in the lake from the previous planes or that occur at the contact between the lower and day. A zero ∆S indicates that there was neither an upper members of the Glen Rose Limestone (middle increase nor a decrease in the storage from the previous and upper Trinity aquifers). Rocks of the upper Trinity day. Throughout most of the study, precipitation was aquifer are relatively impermeable and probably did not below average and total storage in Medina Lake contribute flow to the lake system that was not decreased. accounted for as part of SWin . Diversion Lake has substantially less storage Wells open to the middle Trinity aquifer are sepa- capacity than Medina Lake. Total storage in Diversion rated from the lake system by the upper member of the Lake ranged from 1,210 to 2,070 acre-ft (appendix A), Glen Rose Limestone (upper Trinity aquifer), which and average ∆S ranged from -25.8 to 20.6 acre-ft/d forms a confining unit in the Medina lake area (pl. 1, (table 3). The ∆S in Diversion Lake is a relatively minor table 1). LBG-Guyton Associates (1995) determined component of the Diversion Lake hydrologic budget that transmissivity of the Glen Rose Limestone is the because the lake generally is kept at a constant stage. limiting factor in the exchange of water between the The average ∆S in Medina/Diversion Lakes com- Edwards and Trinity aquifers and estimated that—under bined was calculated by summing the ∆S for each lake. 1994 water-level conditions—the Glen Rose Limestone Similar to the Medina Lake budget, the average ∆S can contribute only 314 acre-ft/yr along 14 mi of the component for the lakes combined is substantial com- Haby Crossing fault in Medina and Bexar Counties near

16 Hydrogeology, Hydrologic Budget, and Water Chemistry of the Medina Lake area, Texas the Medina Lake area, or about 22.4 acre-ft/yr per mile segment of the curve. Along the lower left segment— of stream reach. Thus, the GWin component of the between 1,025 and about 1,035 ft—few hydrologic hydrologic budget was determined to be inconsequen- budget periods are represented because SWout could tial and was removed from the overall equation. The not be estimated at site 6 above a stage of about 2.5 ft resulting hydrologic budget equation is simplified as owing to channel geometry, gravel, and debris. Between follows: stages of 1,035 and 1,043 ft, the observed rates of GWout are highly irregular, ranging up to 135 acre-ft/d GWout ± eGWo = Pe± P + SWin ± eSWi at a stage of 1,042 ft. Above 1,043 ft, the observed rates are less variable and average less than 115 acre-ft/d. – SW ± e out SWo Nevertheless, the greatest losses from the lake to the ground-water system appear to result from lake stages – Ee± E – ∆Se± S. (7) that range from about 1,040 to 1,045 ft above MSL, Ground-Water Outflow which coincides with the altitude of one of the most porous and permeable parts of the basal nodular mem- GWout was calculated as the residual term in ber of the Kainer Formation on the southern side of the hydrologic budget equation and represents the water Medina Lake (pl. 1). in the hydrologic system that was not accounted for by Localized recharge to the Edwards aquifer from the other hydrologic components including the errors. Medina Lake also is indicated in water-level data col- The GWout components for Medina Lake and Diver- lected from the Quihi monitoring well (TD–69–40– sion Lake represent losses from the lakes that are 102), which taps the north-central flow unit (fig. 2) of assumed the Edwards aquifer southwest of Medina Lake (fig. 3). to contribute recharge to the local ground-water-flow Figure 6 shows monthly average water levels in the systems of the Edwards aquifer and the upper Trinity Quihi well plotted against monthly average lake stages aquifer. Nonlinear polynomial functions were used to during October 1993–February 1997. Characteristics of calculate a least-squares fit to data points from the the resulting curve indicate that water levels in down- selected hydrologic budget periods to develop com- gradient parts of the Edwards aquifer are related to puter-generated curves relating GWout to lake stage for Medina Lake stage in ways similar to the relation Medina and Diversion Lakes. No curve was developed between GWout and lake stage (fig. 5). The slope of the for Medina/Diversion Lakes combined because of the relation is very steep between stages of about 1,015 ft influence of reservoir operations on the estimated and about 1,020 ft, where there is a comparatively large GWout from Diversion Lake and the inability to relate increase in water-level altitude for a given increment of the total GWout to a particular stage in either reservoir. lake stage. Each curve shows moderate increases in Estimated average GW from Medina Lake ranged out GWout (fig. 5) and in water level (fig. 6) with lake stages from about -14.0 to 135 acre-ft/d for the selected hydro- between about 1,025 ft and 1,045 ft above MSL (1,033 logic budget periods (table 3). The cumulative error to 1,053 ft above BMA datum). Above 1,045 ft, the associated with the estimated average GWout ranged curve in figure 6 steepens sharply, indicating compara- from 19.9 to 60.1 acre-ft/d. The error was similar to the tively large increases in water-level altitude for given estimated GWout for some budget periods during the increments of lake stage. This abrupt change in slope summer of 1996. The negative GWout of -14.0 acre-ft/d occurs at about the same altitude, about 1,045 ft above (hydrologic budget period July 12–18, 1996, table 3) is MSL, as that of one of the most porous and permeable probably the result of large error associated with some parts of the basal nodular member of the Kainer Forma- of the hydrologic budget components, such as storage, tion on the southern side of Medina Lake (pl. 1). and is not an indication of inflow to Medina Lake. The basal nodular member and the overlying The relation between Medina Lake stage and dolomitic member of the Kainer Formation form bluffs Medina Lake loss to the ground-water system (fig. 5) on the southern sides of Medina and Diversion Lakes shows that GWout increases between elevations of (pl. 1). Caves have developed along bedding planes about 1,025 and 1,045 ft above MSL (1,033 to 1,053 ft between these hydrogeologic subdivisions (table 1). above BMA datum). The slope of the relation flattens Hydrogeologic section B–B' shows that the basal toward 1,045 ft, resulting in smaller increases in nodular member and the dolomitic member are in GWout for given increments of stage along the upper right hydrologic connection with Medina and Diversion

HYDROLOGIC BUDGET 17 1,050 1,045 1,040 1,035 ) to Medina Lake stage for selected hydrologic budget periods, Medina Lake area, Texas. area, Lake Medina periods, budget hydrologic selected for stage Lake to Medina ) out AVERAGE MEDINA LAKE STAGE, IN FEET ABOVE MEAN SEA LEVEL trend line trend line inferred data point with out out out GW GW error bar GW 1,030 + 534.92x - 280145 2 = 0.789 2 R y = -0.2552x Relation of ground-water outflow (GW outflow ground-water of Relation 1,025 0 80 60 40 20

120 180 140 –40 –60 160 100 –20

out , IN ACRE-FEET PER DAY PER ACRE-FEET IN , GW AVERAGE Figure 5. Figure

18 Hydrogeology, Hydrologic Budget, and Water Chemistry of the Medina Lake area, Texas tober tober 1,055 1,060 1,050 1,045 1,040 1,030 1,035 1,025 MONTHLY AVERAGE MEDINA LAKE STAGE, IN FEET ABOVE MEAN SEA LEVEL 1,020 1,015 Relation of monthly average Quihi well water-level altitude to monthly average Medina Lake stage, Medina Lake area, Texas, Oc 1,010

830 860 890 880 870 850 840 820 810 800

IN FEET ABOVE MEAN SEA LEVEL SEA MEAN ABOVE FEET IN MONTHLY AVERAGE WATER-LEVEL ALTITUDE, QUIHI WELL, QUIHI ALTITUDE, WATER-LEVEL AVERAGE MONTHLY Figure 6. Figure 1993–February 1997. 1993–February

HYDROLOGIC BUDGET 19 Lakes, thus providing a potential for water to move from hydrologic budget was similar to the GWout error for the lakes into the surrounding Edwards aquifer. The the Medina Lake hydrologic budget for most of the contact between the upper member of the Glen Rose study. GWout for Medina/Diversion Lakes combined Limestone and the basal nodular member of the Kainer hydrologic budget periods are less than the sum of Formation (Edwards aquifer) occurs at about 1,000 ft GWout for similar Medina and Diversion Lakes hydro- above MSL on the southern side of Medina Lake near logic budget periods. As described previously, this Medina Dam. Geophysical logs indicate a change in decrease in the total GWout results in part from the lithology about 20 to 25 ft above the base of the basal difference in calculating the SWout using site 8 for nodular member. Field observations indicate the likeli- the Diversion Lake hydrologic budget or site 9 for the hood of larger porosity and higher permeability in the Medina/Diversion Lakes combined hydrologic budget, middle and upper parts of the basal nodular member, and in part from unaccountable inflow to Diversion compared to the lower part. These field observations, Lake from Medina Lake when Medina Lake stage is the geophysical logs, and the characteristics of the greater than about 1,025 ft above MSL. By using site 9, curves in figures 5 and 6 indicate that the local geology the additional seepage from Medina and Diversion largely determines the rate of water loss from Medina Lakes that reenters the Medina River channel down- Lake to the ground-water system. Such losses are appar- stream of Diversion Dam (below site 8) is accounted for ently greater when Medina Lake stages are higher than in the Medina/Diversion Lakes combined SWout com- the base of the basal nodular member, or higher than ponent and is not attributed to the overall GWout com- about 1,020 to 1,025 ft above MSL. ponent. The increase in streamflow between sites 8 and The average GWout from Diversion Lake for the 9 during the study ranged from 22.4 to 51.0 acre-ft/d selected hydrologic budget periods ranged from -1.2 to (8,180 to 18,610 acre-ft/yr) (appendix A). 93.1 acre-ft/d (table 3), which is generally much less Seeps and springs visible in the hillside adjacent than the volumes associated with SWin and SWout . The to and downstream of Diversion Lake provide evidence error associated with GWout from Diversion Lake to support the concept of discharge of water from ranged from 4.4 to 45.7 acre-ft/d. In most cases, the Medina and Diversion Lakes into the Medina River. A GWout error was comparable to, or greatly exceeded, comparison of GWout from Medina/Diversion Lakes the value for GWout . The high error results, in part, combined with Medina Lake stage (fig. 8) shows that from the 10- to 15-percent error associated with large GWout for all but one hydrologic budget period ranges values of SWin and the 10-percent error associated with from 60 to 120 acre-ft/d when Medina Lake stage SWout . Although the negative GWout values from ranges from 1,021 to 1,045 ft above MSL. The distribu- Diversion Lake can be accounted for by the large errors tion of data points is different than that shown for associated with small GWout values, they might also Medina Lake (fig. 5) because of the contribution of indicate inflow to Diversion Lake from Medina Lake. GWout from Diversion Lake to the Medina/Diversion The hydrologic budget results indicate that, under Lakes combined budget. The contribution of GWout steady-state conditions, GWout from Diversion Lake is from Diversion Lake is dependent on the managed related to Diversion Lake stage (fig. 7). GWout from stage and the water needed for downstream users, which Diversion Lake gradually increases as the stage in often are not the same conditions as those for Medina Diversion Lake increases, ranging from zero at 911.0 ft Lake. above MSL to about 70 acre-ft/d at 913.5 ft above MSL The hydrologic budgets for Medina Lake and (918.8 to 921.3 ft above BMA datum). Similar to condi- Medina/Diversion Lakes combined show an increase in tions at Medina Lake, the higher rates of GWout from GWout for each corresponding increase in Medina Lake Diversion Lake occur at about the same altitude as the stage during the study; likewise the hydrologic budget middle part of the basal nodular member of the Kainer for Diversion Lake shows an increase in GWout for each Formation. corresponding increase in Diversion Lake stage. How- Average GWout from Medina/Diversion Lakes ever, the GWout in each hydrologic budget represents combined ranged from 36.1 to 119 acre-ft/d (table 3) for only a short term (less than 1 year). The increase in the selected hydrologic budget periods. The GWout GWout from Medina Lake and from Medina/Diversion error for the Medina/Diversion Lakes combined hydro- Lakes combined is limited to a range in Medina Lake logic budget ranged from 23.1 to 71.3 acre-ft/d. The stage from about 1,025 to 1,045 ft above MSL (fig. 5) magnitude of the GWout error for the lakes combined and from about 1,021 to 1,045 ft above MSL (fig. 8),

20 Hydrogeology, Hydrologic Budget, and Water Chemistry of the Medina Lake area, Texas 914.0 912.5 913.0 913.5 912.0 6 ) to Diversion Lake stage for selected hydrologic budget periods, Medina Lake area, Texas. area, Lake Medina periods, budget hydrologic selected for stage Lake to Diversion ) out = 0.7308 2 R trend line data point with AVERAGE DIVERSION LAKE STAGE, IN FEET ABOVE MEAN SEA LEVEL IN FEET ABOVE DIVERSION LAKE STAGE, AVERAGE - 10477x + 5 x 10 2 out out GW error bar GW y = –5.7586x 911.0 911.5 Relation of ground-water outflow (GW outflow ground-water of Relation 910.5 0

80 60 40 20

120 140 100 –20 out , IN ACRE-FEET PER DAY PER ACRE-FEET IN , GW AVERAGE Figure 7. Figure

HYDROLOGIC BUDGET 21 1,050 data point with out GW error bar 1,045 ) to Medina Lake stage for selected budget periods, Medina Medina periods, budget selected for stage Lake Medina to ) out 1,035 1,040 AVERAGE MEDINA LAKE STAGE, IN FEET ABOVE MEAN SEA LEVEL IN FEET ABOVE MEDINA LAKE STAGE, AVERAGE 1,025 1,030 Relation of Medina/Diversion Lakes combined ground-water outflow (GW outflow ground-water combined Lakes Medina/Diversion of Relation 1,020 0

60 80 40 20

160 out 180 140 120 100 , IN ACRE-FEET PER DAY PER ACRE-FEET IN , GW AVERAGE Lake area, Texas. Figure 8. Figure

22 Hydrogeology, Hydrologic Budget, and Water Chemistry of the Medina Lake area, Texas respectively. Likewise, the increase in GWout from developed using historical (1912–53) streamflow, pan Diversion Lake is limited to a range in Diversion Lake evaporation, and reservoir stage data that reflect the stage from 911.0 to 913.5 ft above MSL (fig. 7). The water balance of the lake system (Puente, 1978). The accuracy of the estimated GWout for these hydrologic correlation curves relate monthly average lake contents, budgets is influenced by the estimated errors associated in thousands of acre-feet, to seepage losses to the with individual budget components. Edwards aquifer. The curves differ substantially; Lowry assumed that the difference was a reflection of bank- ESTIMATED GROUND-WATER RECHARGE storage effects. METHODS The USGS method also accounts for losses from Diversion Lake. Lowry (1953) estimated that, when Historically, losses from Medina and Diversion Diversion Lake is full or nearly full, a constant seepage Lakes have been assumed to recharge the Edwards of 1,500 acre-ft/month recharges the Edwards aquifer. aquifer either directly, or indirectly through the Trinity The TWDB volumetric survey (Texas Water Develop- aquifer. The hydrologic budgets were used to compare ment Board, 1996a) determined that Diversion Lake is the results of the current study with earlier methods at capacity at 918.7 ft above MSL (926.5 ft above BMA used to estimate recharge to the Edwards aquifer. datum). Continuous leakage around and below Medina Recharge to the Edwards aquifer from Medina and Dam has maintained the level of Diversion Lake to near Diversion Lakes ranges from about 6 to 9 percent of the capacity, except during periods of extended droughts estimated annual recharge to the entire Edwards aquifer (Puente, 1978). During the current study, GWout (Lowry, 1955; Choffel and Vaugh, 1993; Raba-Kistner from Diversion Lake (at 913.5 ft above MSL) was deter- Consultants, Inc., 1993; U.S. Geological Survey, 1997; mined to be about 70 acre-ft/d (fig. 7, table 3) or 2,100 HDR Engineering, Inc., 1998). acre-ft/month, which is greater than Diversion Lake Two methods are used to estimate recharge to losses estimated with the USGS method. the Edwards aquifer in the Medina Lake area. The first The USGS has used Lowry’s curves to calculate method (USGS method), developed by Lowry (1953, monthly recharge to the ground-water system since 1955), has been used by USGS and EAA to estimate 1934, assuming that all water lost from the lake system annual recharge to the Edwards aquifer. The second enters the Edwards aquifer. However, because of errors method (Trans-Texas method), developed by Espey, associated with components of the monthly estimates, Huston and Associates, Inc. (1989), is a modification the monthly values are summed and reported as annual of the U.S. Soil Conservation Service runoff curve totals. The relatively short-term, monthly errors are number (CN) procedure to estimate potential runoff for assumed to cancel over the course of an entire year the area over the recharge zone and includes stage- (Puente, 1978). recharge curves for Medina and Diversion Lakes. The Although the USGS method relies primarily on Trans-Texas method is currently (1999) being used by reservoir stage versus seepage loss correlation curves to HDR Engineering, Inc. (HDR) to estimate recharge to estimate losses from Medina and Diversion Lakes the Edwards aquifer for the Trans-Texas Program (Choffel and Vaugh, 1993), the Trans-Texas method (Texas Water Development Board, 1992), and has been also uses correlation curves, in addition to attempting to proposed as an alternative to the USGS method for account for differences in soil cover, precipitation, and estimating recharge in the Medina Lake Basin (Choffel historical diversions and return flows. Similar to the and Vaugh, 1993; HDR Engineering, Inc., 1998). way monthly losses from Medina Lake (recharge to the The USGS method used for the Medina Lake area Edwards aquifer) are calculated by the USGS method, differs from the USGS approach for other drainage the Trans-Texas method estimates these losses on a basins in the region because the Medina River is regu- monthly basis, but reports them as annual rates of lated by reservoirs (Puente, 1978). The USGS method recharge. for estimating ground-water recharge in the area is The USGS estimated average annual (1934–96) based on correlations between reservoir stage and seep- recharge to the Edwards aquifer in the Medina River age losses into the aquifer. Lowry (1953) developed two Basin is 61,000 acre-ft, or about 9 percent of the esti- correlation curves: one representing seepage losses dur- mated average recharge of 668,700 acre-ft/yr to the ing rising stages, and the other representing losses dur- entire Edwards aquifer during 1934–96 (U.S. Geologi- ing falling stages. Lowry’s correlation curves were cal Survey, 1997). The USGS estimated recharge

ESTIMATED GROUND-WATER RECHARGE METHODS 23 ranged from 6,300 acre-ft during 1956 to 104,000 acre- ranged from 3,510 acre-ft during July 1996 to 3,900 ft during 1960, with the annual differences resulting acre-ft during December 1995. The difference between mainly from different climatic conditions. The USGS estimated monthly average recharge from Medina Lake estimated average recharge was 61,700 acre-ft during using the USGS method compared to that using the 1995 and 42,300 acre-ft during 1996 (U.S. Geological Trans-Texas method ranged from -0.5 to 10.7 percent; Survey, 1997). the greater differences coincide with higher stages in Using the Trans-Texas method, HDR estimated Medina Lake. The difference between estimated that the average annual (1934–96) recharge to the monthly average recharge from Diversion Lake using Edwards aquifer in the Medina Lake area was 42,393 the USGS method and using the Trans-Texas method acre-ft (HDR Engineering, Inc., 1998). This estimate was similar, ranging from -3.4 to 11.5 percent. represents about 6.5 percent of the HDR estimated The estimated average recharge to the Edwards average recharge of 652,706 acre-ft/yr during 1934–96. aquifer using the current study method was much less The HDR estimated recharge in the Medina Lake area than that using either the USGS method or the Trans- ranged from 10,256 acre-ft during 1951 to 53,275 acre- Texas method (table 5). The estimated recharge using ft during 1936. HDR’s estimated average recharge in the the current study method was 22,004 acre-ft, or about 69 Medina Lake area was 47,498 acre-ft during 1995 and and 73 percent of the recharge estimated using the 42,397 acre-ft during 1996. USGS and Trans-Texas methods, respectively. The An alternative method to estimate monthly aver- monthly average recharge using the current study age loss (recharge to the ground-water system) was method ranged from 919 acre-ft during July 1996 to developed during this study. Monthly average recharge 3,285 acre-ft during April 1996. The greatest differ- during December 1995–August 1996 estimated using ences between the current study method and the USGS this method was compared with monthly average loss and Trans-Texas methods are shown by the estimated (recharge) estimated using the USGS and Trans-Texas monthly average recharge from Medina Lake and from methods (table 5, at end of report). The alternative Diversion Lake. While the USGS and Trans-Texas method (hereafter referred to as the current study methods estimate similar recharge from Medina Lake method) (table 5) used monthly average stage data from and from Diversion Lake, the current study method esti- the hydrologic budgets (appendix A) to develop plots of mates recharge from each lake that can vary greatly stage versus GWout . The average rate of GWout was depending on the lake stage. From December 1995 to determined from stage versus GWout curves for Medina April 1996, the current study method greatly overesti- Lake (fig. 5) and for Diversion Lake (fig. 7). The rate of mated recharge from Medina Lake compared to that GWout (loss) was then multiplied by 30 to obtain a estimated using the USGS and Trans-Texas methods, monthly estimate (assuming 30 days in a month). The and from June to July 1996, the USGS and Trans-Texas estimated monthly loss from Medina Lake and from methods overestimated recharge from Medina Lake Diversion Lake then were summed, and the monthly compared to that estimated using the current study average ground-water loss that returns as increased sur- method. Over the study period, the USGS and Trans- face-water flow to the Medina River between sites 8 and Texas methods overestimated recharge from Medina 9 was subtracted to obtain a total loss from Medina/ Lake when the lake stage was between about 1,027 and Diversion Lakes combined (table 5). Results of the 1,032 ft above MSL and underestimated recharge when recharge analysis indicate that losses from Medina Lake the lake stage was between about 1,036 and 1,045 ft and losses from Diversion Lake contribute recharge pri- above MSL. Estimated recharge from Diversion Lake marily to the Edwards aquifer and only minimally to the was similar to that from Medina Lake; the USGS and upper Trinity aquifer (mainly the upper member of the Trans-Texas methods underestimated recharge at Diver- Glen Rose Limestone) in the Medina Lake area. sion Lake stages greater than 913 ft above MSL and The estimated recharge to the Edwards aquifer overestimated recharge at stages less than 913 ft above from the lake system calculated by the USGS method MSL compared to recharge estimated using the current was 31,860 acre-ft during December 1995–July 1996; study method. monthly average recharge ranged from 3,600 acre-ft Over the study period, the USGS and Trans-Texas during July 1996 to 4,300 acre-ft during January 1996 methods greatly overestimated recharge to the Edwards (table 5). The estimated recharge using the Trans-Texas aquifer from the lake system compared to that estimated method was 30,056 acre-ft; monthly average recharge using the current study method (table 5). The USGS

24 Hydrogeology, Hydrologic Budget, and Water Chemistry of the Medina Lake area, Texas 4,500

4,000

3,500

04/96 03/96 3,000 02/96 05/96 12/95 01/96 2,500 06/96

2,000 USGS method Trans-Texas method 1,500 Current study method

1,000 MONTHLY AVERAGE RECHARGE, IN ACRE-FEET 07/96

500 824 826 828 830 832 834 836 838 840 MONTHLY AVERAGE WATER-LEVEL ALTITUDE, QUIHI WELL, IN FEET ABOVE SEA LEVEL

Figure 9. Relation of estimated monthly average recharge from Medina/Diversion Lakes using three methods to monthly average Quihi well water-level altitude, Medina Lake area, Texas, December 1995–July 1996. estimates are higher, in part, because the USGS method of the Edwards aquifer. The losses primarily infiltrate does not account for the loss from Medina and Diver- the basal nodular member of the Kainer Formation sion Lakes that returns to the surface-water system (Edwards aquifer). The estimated losses (GWout ) from downstream of Diversion Dam. The Trans-Texas Medina and Diversion Lakes (figs. 5, 7) decrease (near method also might overestimate the recharge to the zero for Diversion Lake) when lake stage is below the ground-water system by underestimating the water upper part of the basal nodular member of the Kainer losses from Medina Lake that return as unaccountable Formation (Edwards aquifer) adjacent to the lakes, indi- ground-water inflow to Diversion Lake and as surface- cating that losses to the Trinity aquifer are within the water outflow to the Medina River downstream of error of the hydrologic budget and, therefore, are Diversion Dam. The hydrogeology of the lake system assumed to be minimal. also could account for the difference between recharge Losses from the lake system can be related to the estimates determined using the current study method Quihi monitoring well (fig. 6). Results of all methods and those determined using the USGS and Trans-Texas used to estimate monthly average recharge to the methods. Similar to estimates of recharge from Medina Edwards aquifer were compared to the water-level alti- Lake, estimates of recharge from Diversion Lake are tudes recorded in this well during December 1995–July related to lake stage and are likely nonlinear because of 1996 (fig. 9). The comparison shows that the USGS and the effect of the hydrogeology on the flow system. Trans-Texas estimates are similar, but are much differ- The hydrologic budgets and water-quality data ent from the current study method estimates when the from the current study indicate that losses from Medina average stage in Medina Lake is less than about 1,045 ft and Diversion Lakes can be quantified and that those above MSL. The large difference in the USGS and losses are entering the local ground-water-flow system Trans-Texas methods compared to the current study

ESTIMATED GROUND-WATER RECHARGE METHODS 25 100 CALCIUM PLUS MAGNESIUM 100 CALCIUM PLUS MAGNESIUM

100 100

80 80 Surface water 80 80 60 Medina Lake 60 60 60

40 40 40 40

20 20 20 20 SULFATE PLUS CHLORIDE SULFATE PLUS CHLORIDE

0 0 0 0 0 0 0 0

SODIUM PLUS POTASSIUM SODIUM PLUS POTASSIUM 20 20 20 20 0 0 0 0 100 40 100 100 40 100

40 20 40 20 80 20 80 20 60 80 60 80 SULFATE SULFATE 60 40 60 40 60 40 60 40 80 60 80 60 80 60 80 60 60 60 40 100 40 40 100 40 MAGNESIUM MAGNESIUM 80 80 100 100 20 80 20 20 80 20 100 100 CARBONATE PLUS BICARBONATE CARBONATE PLUS BICARBONATE 0 100 0 0 100 0 100 80 60 40 20 0 100 80 60 40 20 0 0 0 20 40 60 80 20 40 60 80 100 100 CALCIUM CHLORIDE, FLUORIDE, NITRITE + NITRATE CALCIUM CHLORIDE, FLUORIDE, NITRITE + NITRATE PERCENT MILLIEQUIVALENTS PERCENT MILLIEQUIVALENTS

Figure 10. Trilinear diagrams of waters for surface-water and lake-water samples, Medina Lake, area, Texas. method suggests that the former methods might over- Surface Water estimate recharge to the Edwards aquifer from the lake system when the stage in Medina Lake is less than about Surface-water samples were collected from three 1,045 ft above MSL (1,053 ft above BMA datum). sites on the Medina River (08178990, 08179520, and However, the dataset used to develop the current study 08180500) and from one site on Koenig Creek method curves was limited because the data were sparse (08179530) (sites 1–4; pl. 2, table 4). Analyses of the at some stages in the lakes, were collected during a rel- water samples from these sites showed some variability, atively dry year, and were short term. The current study with a general increase in the dissolved solids concen- shows that using a hydrologic budget approach to esti- tration over time for each site. All the surface-water mating recharge is feasible; however additional data are samples can be classified as a calcium-bicarbonate needed over a range in stage and climatic conditions to water type (fig. 10), with dissolved solids concentra- verify the results and better explain uncertainties and tions ranging from 163 to 356 milligrams per liter differences between all methods. (mg/L) (appendix C). The concentrations of major ions and trace elements in the surface-water samples gener- WATER CHEMISTRY ally are smaller than the concentrations in water samples from the Edwards and Trinity aquifers. Water-quality samples were collected from Lake-water samples were collected from six sites selected surface-water, lake, and ground-water sites and and selective depths on Medina Lake (sites 5–10; pl. 2, were analyzed for ions, nutrients, trace elements, and table 4). Results from the lake analyses indicate that, selected environmental isotopes (table 4; appendix C, at similar to the surface water, the lake water is a calcium- end of report). Water types were determined by the rel- bicarbonate water type (fig. 10), with dissolved solids ative contributions of cations and anions in a solution. concentrations ranging from 146 to 269 mg/L (appendix For example, in a water where calcium accounts for 50 C). Water-quality properties and constituents in samples percent or more of the cations and where bicarbonate collected from the surface-water and lake sites meet the accounts for 50 percent or more of the anions, the water U.S. Environmental Protection Agency (EPA) drinking -2 was classified as a calcium-bicarbonate (Ca-HCO3 ) water standards for a public water system (U.S. Envi- water type. ronmental Protection Agency, 1996).

26 Hydrogeology, Hydrologic Budget, and Water Chemistry of the Medina Lake area, Texas 100 CALCIUM PLUS MAGNESIUM 100 CALCIUM PLUS MAGNESIUM Edwards aquifer 100 Trinity aquifer, 100 80 80 80 undifferentiated 80

60 60 60 60

40 40 40 40

20 20 20 20 SULFATE PLUS CHLORIDE SULFATE PLUS CHLORIDE

0 0 0 0 0 0 0 0

SODIUM PLUS POTASSIUM SODIUM PLUS POTASSIUM 20 20 20 20 0 0 100 0 0 40 100 100 40 100

40 20 40 20 80 20 80 20 60 80 60 80 SULFATE SULFATE 60 40 60 40 60 40 60 40 80 60 80 60 80 60 80 60 60 60 40 100 40 40 100 40 MAGNESIUM MAGNESIUM 80 80 100 100 20 80 20 20 80 20 100 100 CARBONATE PLUS BICARBONATE CARBONATE PLUS BICARBONATE 0 100 100 0 0 0 0 100 80 60 40 20 100 80 60 40 20 0 0 0 20 40 60 80 20 40 60 80 100 100 CALCIUM CHLORIDE, FLUORIDE, NITRITE + NITRATE CALCIUM CHLORIDE, FLUORIDE, NITRITE + NITRATE PERCENT MILLIEQUIVALENTS PERCENT MILLIEQUIVALENTS

100 CALCIUM PLUS MAGNESIUM 100 CALCIUM PLUS MAGNESIUM

100 100

80 80 Upper Trinity 80 Middle Trinity 80 60 60 aquifer 60 aquifer 60

40 40 40 40

20 20 20 20 SULFATE PLUS CHLORIDE SULFATE PLUS CHLORIDE

0 0 0 0 0 0 0 0

SODIUM PLUS POTASSIUM SODIUM PLUS POTASSIUM 20 20 20 20 0 0 100 0 0 40 100 100 40 100

40 20 40 20 80 20 80 20 60 80 60 80 SULFATE SULFATE 60 40 60 40 60 40 60 40 80 60 80 60 80 60 80 60 60 60 40 100 40 40 100 40 MAGNESIUM MAGNESIUM 80 80 100 100 20 80 20 20 80 20 100 100 CARBONATE PLUS BICARBONATE CARBONATE PLUS BICARBONATE 0 100 100 0 0 0 0 100 80 60 40 20 100 80 60 40 20 0 0 0 20 40 60 80 20 40 60 80 100 100 CALCIUM CHLORIDE, FLUORIDE, NITRITE + NITRATE CALCIUM CHLORIDE, FLUORIDE, NITRITE + NITRATE PERCENT MILLIEQUIVALENTS PERCENT MILLIEQUIVALENTS

Figure 11. Trilinear diagrams of waters for ground-water samples in the Edwards and Trinity aquifers, Medina Lake area, Texas.

Ground Water dissolved solids concentrations ranging from 226 to 421 mg/L (appendix C). Bush and others (1994, p. 9) Ground-water samples were collected from wells reported in a regional study that the median dissolved and springs in the Edwards aquifer and in the middle solids concentration in 600 water samples collected and upper Trinity aquifers (sites 11–150; pl. 2, table 4). Similar to the surface- and lake-water samples, the from wells completed in the Edwards aquifer is 297 water samples from the Edwards aquifer are predomi- mg/L. The dissolved solids concentration and water nantly a calcium-bicarbonate type (fig. 11), with type of the Edwards aquifer are consistent with the

WATER CHEMISTRY 27 mineral composition of the rock (carbonate) and also Water samples collected from two wells in the are indicative of the source of the water, which is upper Trinity aquifer (sites 104 and 112) are a calcium- streamflow that originates as spring or base flow from sulfate (Ca-SO4) water type and are classified as carbonate rocks along the southern margin of the slightly saline according to Winslow and Kister (1956), Edwards Plateau and in the interstream areas of the Hill with dissolved solids concentrations ranging from Country. Water-quality properties and constituents in 1,160 to 2,020 mg/L (appendix C). Sulfate concentra- samples collected from the Edwards aquifer meet the tions in the two wells ranged from 698 to 1,330 mg/L, EPA drinking water standards for a public water system exceeding the MCL of 500 mg/L (U.S. Environmental (U.S. Environmental Protection Agency, 1996). Protection Agency, 1996). The large dissolved solids In the Medina Lake area, water samples col- and sulfate concentrations might result from sulfate lected from wells and springs in the middle and upper minerals associated with evaporite beds that are com- Trinity aquifers varied more in composition than those mon in the upper member of the Glen Rose Limestone. collected from the Edwards aquifer (pl. 2, table 4, Such evaporite beds are common where the Trinity appendix C). For purposes of this report, water chemis- aquifer rocks have not been subjected to vigorously try is discussed for the middle and upper Trinity aqui- flowing freshwater through geologic time (Bush and fers, and the Trinity aquifer, undifferentiated. Water others, 1994). samples from the middle Trinity aquifer are from wells Water samples collected from wells in the in the lower member of the Glen Rose Limestone and in Trinity aquifer, undifferentiated, varied from calcium- the Cow Creek Limestone; samples from the upper bicarbonate to magnesium-sulfate water types (fig. 11, Trinity aquifer are from wells in the upper member of appendix C). The water samples were fresh to moder- the Glen Rose Limestone; samples from the Trinity ately saline, with dissolved solids concentrations aquifer, undifferentiated, are from wells in the Glen ranging from 237 to 3,320 mg/L. Dissolved solids con- Rose Limestone. centrations in water samples from wells near Medina Water samples collected from wells in the middle Trinity aquifer varied from calcium-bicarbonate to mag- and Diversion Lakes (sites 74, 79, 82, and 107) (pl. 2) were generally less than the MCL of 500 mg/L. Dis- nesium-sulfate (Mg-SO4) water types (fig. 11), with dissolved solids concentrations ranging from 315 to 2,800 solved solids concentrations in the remaining wells in mg/L (appendix C). In most cases, the dissolved solids the Trinity aquifer, undifferentiated, mostly exceeded concentrations of water from the middle Trinity aquifer the MCL. Similar to concentrations in the middle Trin- in the Medina Lake area exceeded the secondary maxi- ity aquifer, the greater dissolved solids concentrations mum contaminant level (SMCL) of 500 mg/L for drink- probably originated from evaporite dissolution of the ing water designated by the U.S. Environmental aquifer rocks where ground-water flow is concentrated. Protection Agency (1996). The larger dissolved solids Water samples from three wells in the Trinity aquifer, concentrations probably originated from evaporite dis- undifferentiated (sites 91, 143, and 147), exceeded the solution typical of some limestone aquifers (Bush and SMCL for fluoride of 2.0 mg/L (3.2 to 7.2 mg/L) others, 1994). The smaller dissolved solids concentra- (appendix C). tions are in water from wells near Medina Lake, and the chemical composition of water from those wells is sim- Environmental Isotopes ilar to, and might be affected by, water flowing from the lake. Isotopic ratios of deuterium (δD), oxygen (δ18O), Most wells in the middle Trinity aquifer had dis- and strontium (87Sr/86Sr) were analyzed in selected solved sulfate and fluoride concentrations exceeding surface-water, lake-water, and ground-water samples to: the EPA maximum contaminant levels (MCLs) and (1) determine where water from the lake system might SMCLs. Sulfate concentrations exceeding the MCL of be entering the local ground-water-flow system by com- 500 mg/L ranged from 1,320 to 1,850 mg/L, and fluo- paring the isotopic “signature” of lake water exposed to ride concentrations exceeding the MCL of 4.0 mg/L evaporative processes with the isotopic ranged from 4.3 to 4.8 mg/L (appendix C). In addition, “signature” of subsurface waters; and (2) determine all water samples from sites 136, 137, and 138 had iron the mixing proportion of lake water relative to ground concentrations exceeding the SMCL of 300 µg/L (1,320 water. δD and δ18O isotopes were selected because they to 12,640 µg/L). can be used to indicate where Medina and Diversion

28 Hydrogeology, Hydrologic Budget, and Water Chemistry of the Medina Lake area, Texas Lakes are contributing water to the ground-water flow respectively. Two samples from site 104 (TD–68–25– system in the Medina Lake area. 87Sr/86Sr isotopic 807) are close to the mixing line indicating a contribu- ratios also were analyzed in water to confirm the mixing tion of lake or surface water (fig. 12). Most δD and δ 18 results from the comparison of δD and δ O isotopic 18O values for the Trinity aquifer, undifferentiated, were ratios. similar to those for the middle and upper Trinity aqui- The isotopic composition of surface water is dis- fers, ranging from -27.8 to -5.30 ‰ and from -4.79 to - tinctly different from that of most ground water in the Edwards and Trinity aquifers. For sites 1–4 (surface 0.88 ‰, respectively. Most samples from the Trinity water), δD ranged from -18.7 to -6.00 per mil (‰), and aquifer, undifferentiated, are clustered close to the glo- δ18O ranged from -3.52 to -0.80 ‰ (table 4). The isoto- bal meteoric water line, although a few samples are pic composition for samples collected from Medina close to the mixing line in the same region as Edwards Lake (sites 5–10) were similar to samples collected aquifer and surface-water samples (fig. 12). from surface-water sites 2, 3, and 4, with δD and δ18O δD and δ18O can be used to determine mixing of values ranging from -8.20 to -3.60 ‰ and from -1.45 to endmember waters where the differences between the -0.82 ‰, respectively. Lake and surface-water samples mostly plot below the global meteoric water line (Craig, isotopic signatures are substantial. For the endmember 18 1961) (fig. 12), indicating that water from these samples Medina Lake water, the δD and δ O for the period of has undergone isotopic fractionation and is enriched sampling averaged -6.57 and -1.01 ‰, respectively. with the heavier isotopic fraction (18O), relative to the These values indicate that Medina Lake water has lighter isotopic fraction (16O) that has evaporated. The undergone some evaporation compared to globally- greater the distance below the meteoric water line that a averaged precipitation samples (Fritz and Fontes, 18 sample plots, the greater the concentration of O rela- 1980), with the average values to the right of the global 16 tive to O in that water sample compared to globally meteoric water line (fig. 12). For deep ground water, averaged precipitation samples. Water samples from such as water from the middle Trinity aquifer, δD and lakes tend to have a greater concentration of 18O relative δ18O averaged -26.6 and -4.69 ‰, respectively. These to 16O because evaporation leaves the remaining lake water enriched in the heavier isotope. Because of the values are close to the meteoric water line and indicate differences between isotopic composition of the that ground water is unaffected by evaporation prior to surface water and the ground water, the data can be recharge. used to estimate the contribution of lake water to the For water samples collected from the Edwards ground-water-flow system. aquifer south of Medina Lake, isotopic data indicate Isotopic composition of water samples from the that the samples could contain mixes of water from Edwards aquifer varies; some samples are indicative of the lake system and water from the Edwards aquifer. water similar to the global meteoric water line, while others are representative of a line (mixing line) inter- Average isotopic values of typical lake water and of typ- secting the lake and surface-water samples (fig. 12). ical Edwards aquifer water were calculated to determine Water samples represented by this line have been mixed the endmember values used to determine the isotopic with evaporated water. The δD and δ18O composition ratios. The Medina Lake endmember isotope value was in water samples from the Edwards aquifer ranged from determined by calculating the average ratios of two -26.1 to -3.40 ‰ and from -4.31 to -0.41 ‰, respec- bottom samples taken at Medina Lake sites AL and DC tively (table 4). The widespread, variable distribution (table 4). The Edwards aquifer endmember isotopic of Edwards aquifer values indicates that some of the ratio was determined by averaging the samples taken Edwards aquifer wells contain part of a water similar in from site 103 (TD–68–25–806). Site 103, the farthest composition to the lake and surface-water samples. well from the surface-water samples, was used as the Water samples from the middle Trinity aquifer 18 plot close to the global meteoric water line, with δD δD/δ O endmember in calculations of relative contri- ranging from -29.9 to -21.4 ‰ and δ18O ranging bution of lake water and was assumed to yield primarily from -4.99 to -3.81 ‰ (table 4). The isotopic composi- Edwards aquifer water with little or no contribution tion of δD and δ 18O in the upper Trinity aquifer ranged from the lakes. Using these endmember ratios, the rela- from -27.0 to -15.2 ‰ and from -4.46 to -2.35 ‰, tive proportions of mixing of the two endmembers was

WATER CHEMISTRY 29 0 -0.5 -1.0 Medina River, and from selected wells selected from and River, Medina

-1.5

0-1.75 0-1.75

D=5.25 D=5.25

δ -2.0

=0.98

2 r Mixing line line Mixing -2.5 O, IN PER MIL

) in water samples from Medina Lake, samples from ) in water 18 O+10

18 δ 18

D= 8 D= -3.0 δ

-3.5

(Craig, 1961) (Craig, Meteoric water line line water Meteoric ) andoxygen del ( D δ -4.0 Medina Lake Edwards aquifer Middle Trinity aquifer Trinity aquifer, undifferentiated Upper Trinity aquifer Surface water (Medina River) -4.5 Relation between deuterium ( 0 -5.0

-5

-10 -15 -20 -25 -30

D , IN PER MIL PER IN , δ Figure 12. Figure Texas. area, Lake Medina springs, and

30 Hydrogeology, Hydrologic Budget, and Water Chemistry of the Medina Lake area, Texas calculated from the isotopic data using the following verify the mixing relations derived from the δD and formulas: δ18O values. The relation of the inverse of the strontium concentration to 87Sr/86Sr provides further evidence of % Medina Lake water = the contribution of lake water to Edwards aquifer water δDsample()δ– D() ground water ------(fig. 13). As the relative contribution of lake water to δD()δ lake water – D() ground water well water increases, the values for 1/strontium and × 100, (8) 87Sr/86Sr in the Edwards aquifer water decrease, more closely approximating the values of the surface water. where For example, the value of 1/strontium compared to 87 86 δDsample()is deuterium ratio of Edwards Sr/ Sr at site 103 (TD–68–25–806), used as the 18 aquifer sample, per mil; δD/δ O endmember in calculations of relative contri- δD() ground water is deuterium ratio of average bution of lake water, plots farthest from the surface- endmember Edwards aquifer water samples and was assumed to have little or no lake sample, per mil; and water. Site 148 (TD–69–40–202) had an average lake- water contribution of 10.1 percent, on the basis of δD δD() lake water is deuterium ratio of average and δ18O calculations from the sample collected on endmember Medina Lake water August 20, 1996 (table 6). The average lake-water sample, per mil; contribution calculated from the δD/δ18O isotopes and varies from 14.4 percent at site 149 (TD–69–40–301) to 30.9 percent at site 119 (TD–68–33–103) to 27.7 per- % Medina Lake water = cent at site 120 (TD–68–33–204), and finally to 33.5 18 18 δ Osample()δ– O() ground water ------percent at site 150 (TD–69–40–604) (fig. 13). 18 18 δ O()δ lake water – O() ground water Results of the isotopic analyses can be used × 100, (9) with information on the hydrogeology and results from the hydrologic budget analysis to delineate flow- where paths and determine where water from Medina and 18 Diversion Lakes is moving into the ground-water δ Osample()is oxygen-18 ratio of Edwards system. The contribution of lake water from Medina aquifer sample, per mil; 18 Lake and from Diversion Lake is reflected in the isoto- δ O() ground water is oxygen-18 ratio of average pic ratios of water samples collected from Edwards endmember Edwards aquifer aquifer wells south and southwest of Medina and sample, per mil; and Diversion Lakes. During the study, losses from 18 δ O() lake water is oxygen-18 ratio of average Medina Lake decreased from 3,420 acre-ft during endmember Medina Lake December 1995 to 60 acre-ft during July 1996 (table 5). water sample, per mil. Losses from Diversion Lake generally increased from The mixing fractions were calculated for water December 1995 to July 1996, ranging from 120 acre-ft samples from 12 wells and springs in the Edwards aqui- during January 1996 to 2,190 acre-ft during June 1996 fer (table 6, at end of report). Computations from both (table 5). isotopes were within 20 percent for each site. Also, dif- Wells 93, 148, and 149 are located southwest of ferences in the amount of mixing calculated at a single Medina Lake and west of Diversion Lake in a section of site for different time periods generally were within 15 the Edwards aquifer that is bounded by the Diversion percent, indicating that temporal changes were usually Lake fault to the south and the Vandenburg School fault small during the study. However, samples from site 148 to the north (pl. 2). This portion of the Edwards aquifer varied from 35.5 percent lake water on March 13, 1996, is part of the eastern Medina storage unit (fig. 2) that to 10.1 percent lake water on August 20, 1996. This provides flow to the north-central flow unit. The lake change indicates a substantial lowering of the relative water fraction from wells in this fault block ranged from fraction of lake water in the Edwards aquifer at this 10.1 to 35.5 percent (table 6). The lake water fraction in location between these two samples. well 93 decreased from 16.9 percent in November 1995 87Sr/86Sr isotopic ratios from selected surface- to 13.4 percent in July 1996, and the lake water fraction and ground-water samples (table 4) were used to in well 148 decreased from 35.5 percent in March 1996

WATER CHEMISTRY 31 0.014

Surface water 0.012 Edwards aquifer TD–68–25–806 (103) Middle Trinity aquifer Upper Trinity aquifer Trinity, undifferentiated 0.010 TD–68–25–701 Well and site number (table 4) (93)

Increasing contribution of lake water 0.008

TD–69–40–202 0.006 (148)

TD–69–40–301 TD–68–33–103 0.004 (149) 1/STRONTIUM, IN MILLIGRAMS PER LITER (119)

TD–68–33–101 (117) TD–68–33–204 TD–69–40–604 (120) 0.002 (150) TD–68–33–603 (123) TD–68–25–701 (93) 0 0.7074 0.7076 0.7078 0.7080 0.7082 0.7084 0.7086 0.7088 87SR/86SR

Figure 13. Relation of 1/strontium to 87Sr/86Sr in aquifer and lake water, Medina Lake area, Texas. to 10.1 percent in August 1996 (table 6). The lake water Crossing fault (pl. 2). Like wells 93, 148, and 149, these fraction in well 149 was fairly consistent, ranging from wells are in the eastern Medina storage unit (fig. 2). The 14.0 in January 1996 to 14.4 percent in August 1996 lake water fraction for these two wells is similar, rang- (table 6). The hydrogeology and faulting in the area ing from 33.5 to 44.2 percent (table 6). The wells are in where these wells are located suggest that the wells pos- the same fault block as the lower one-half of Diversion sibly are receiving a portion of lake water from both Lake and in an area where the saturated thickness of the Medina and Diversion Lakes. The decreasing percent- Edwards aquifer is greatest. The source of lake water for age of the lake water fraction from the winter/spring these wells could be either Diversion Lake or Medina samples to the summer samples in wells 93 and 148 is Lake. probably the result of the decreasing recharge from Wells 119 and 120 are located southwest of Medina Lake during the study. The remaining lake Diversion Lake in the part of the eastern Medina storage water fraction (less than 10-percent lake water) might unit (fig. 2) that is bounded on the north by Diversion be a combination of lake water from both Medina and Lake fault and on the south by Haby Crossing fault Diversion Lakes that is moving into the ground-water (pl. 2). Well 123 is located on the downthrown side of flow system along this fault. Haby Crossing fault in an area where flow in the north- Wells 117 and 150 are located in a complexly central flow unit (fig. 2) wraps around Haby Crossing faulted portion of the fault block bounded on the north fault and moves toward northwestern Bexar County. by the Diversion Lake fault and on the south by Haby Analysis of the isotopic data indicates that wells 119,

32 Hydrogeology, Hydrologic Budget, and Water Chemistry of the Medina Lake area, Texas 120, and 123 had similar lake water fractions that temperature, and alkalinity; concentrations of dissolved increased slightly from the winter/spring samples to the chemical constituents; thermodynamic data from summer samples. The average lake water fraction for WATEQF; and a standard suite of geochemical phases these wells ranged from 24.0 to 30.9 percent (table 6). typical of a carbonate aquifer (for example, CO2 disso- The thickest part of the Edwards aquifer in the study lution/outgassing, calcite dissolution/precipitation, and area is located along this flowpath and is directly south- reverse cation exchange) were used as input for the mix- west of Diversion Lake. The lake water fraction in these ing models (Jones and others, 1997). Mixing was simu- wells was fairly consistent, about 25 percent of the total lated using the computer code in NETPATH (Plummer water sample. The increase in the lake water fraction and others, 1994). The program computes SI (in milli- through time in these samples is consistent with the moles per liter) for several solid phases using WATEQF increase in losses from Diversion Lake calculated from code and mixing proportions of endmember waters in the hydrologic budget (table 5). This suggests that selected samples. Diversion Lake probably is the primary source of lake NETPATH simulations of mixing lake water with water in this fault block, contributing about 25 percent water from the Edwards aquifer were done for eight of the water that was in these wells during the study. wells in the Edwards aquifer (table 7, at end of report). In addition to mixing, reactions modeled were: (1) cal- Geochemistry cite dissolution or precipitation; (2) dolomite, gypsum, and halite (sodium chloride) dissolution only; (3) CO2 Geochemical modeling was used to simulate the dissolution or outgassing; and (4) reverse cation (cal- mixing of lake water and Edwards aquifer water, and to cium for sodium) exchange (Jones and others, 1997). determine the fraction of lake water in selected Edwards For all sites, NETPATH modeling produced more than aquifer wells. As a first step in the modeling of rock- one plausible model that usually had similar fractions of water interactions, a modified version of the aqueous lake water. Results of the NETPATH modeling were speciation code WATEQF (Plummer and others, 1976) compared to results from the isotopic analysis listed in that is part of the NETPATH code (Plummer and others, table 6. In most cases, the mixing fractions of 1994) was used with the water-chemistry analytical data lake/ground water determined from NETPATH were to determine the saturation indices (SI) of minerals dis- comparable to the mixing fractions determined from the solved in area surface and ground water. isotopic ratios. The second step in the modeling process was to The fraction of lake water in water samples simulate mixing between possible recharge water from collected from site 117 were computed to be 56.4, the lake system and background water in the Edwards 52.3, and 57.7 percent (table 7). However, NETPATH aquifer for selected Edwards aquifer sites that were produced three plausible models with lake-water sampled and found to contain mixed lake and ground proportions of 19.7, 35.4, and 11.0 percent for site 119, water. Edwards aquifer sites most likely to contain indicating that mixing might have occurred, but the pro- mixed lake and ground water were selected from areas portions of the endmembers are uncertain. For site 148 where the outcrop of the Edwards aquifer was deter- sampled on March 13, 1996, NETPATH produced four mined to be in hydrologic connection with either plausible models, with lake-water proportions ranging Medina Lake or Diversion Lake, and were located in the from 25.4 to 36.3 percent. For a later sample collected eastern Medina storage unit (fig. 2) south and southwest on August 20, 1996, NETPATH produced two plausible of Medina and Diversion Lakes where recharge enters models of 10.9 and 5.4 percent lake water, indicating the north-central flow unit. that the water chemistry from this well was variable and For the geochemical simulations, the average of dependent on the relative amount of recharge from near-bottom reservoir samples from Medina Lake was Medina Lake, Diversion Lake, or other aquifer recharge selected as the endmember value for lake water, and an that could occur over short time intervals. endmember water from the Edwards aquifer was The water chemistry of lake-, surface-, and selected as most representative of resident ground water ground-water sites in the Medina Lake area indicates before infiltration of Medina Lake water. The samples that the chemical composition of the waters from these selected were Medina Lake sites 5 and 9 (AL/bottom sites are distinctive. Additional environmental isotope and DC/bottom) and site 103 for Edwards aquifer data and geochemical modeling indicate that selected ground water (pl. 2, table 4). Field measurements of pH, Edwards aquifer wells and springs south of Medina

WATER CHEMISTRY 33 Lake receive a contribution of water from the lake tify the losses to the ground-water system from Medina system (table 6). For example, the average lake-water and Diversion Lakes. The average GWout from Medina contribution for two samples from site 110, located on Lake ranged from about -14.0 to 135 acre-ft/d for the the eastern side of Medina and Diversion Lakes, is 84 selected hydrologic budget periods. The largest compo- and 97 percent using the isotopic calculations (tables 4, nents of the Medina Lake hydrologic budget were 6). For this spring site, the NETPATH simulations indi- SWout and ∆S , and the smallest components generally cate a lake-water contribution of 78.8 and 75 percent were precipitation and evaporation. (table 7). On the southern and western sides of the lake Ground-water losses were much smaller for system, mixing calculations indicate that lake water is in Diversion Lake than for Medina Lake because of the some of the water withdrawn from Edwards aquifer difference in size and depths of the lakes. Average wells. Water from wells at sites 117, 119, 120, 148, and GWout from Diversion Lake ranged from -1.2 to 93.1 150 contains about 10 to 45 percent lake water (tables 4, acre-ft/d for the selected hydrologic budget periods. 6). These results indicate that water from the lake sys- SWin and SWout were the largest components of the tem is entering the local ground-water-flow system on Diversion Lake hydrologic budget, while precipitation, the southern side of Medina Lake and on the western evaporation, and ∆S generally were the smallest compo- side of Diversion Lake, and might be contributing nents. The negative values for some of the budget recharge to the regional Edwards aquifer ground-water- periods can be accounted for within the error of mea- flow system. surements, and also might result through seepage from Medina Lake that is returning to Diversion Lake and the SUMMARY AND CONCLUSIONS surface-water system and not entering the Edwards aquifer. Average GWout from Medina/Diversion Lakes Medina and Diversion Lakes are located on the combined ranged from 36.1 to 119 acre-ft/d for the Medina River in northeastern Medina and southeastern selected hydrologic budget periods. Bandera Counties. The Medina Lake study was done to Losses to the ground-water system from assess the hydrogeology and hydrology of the lake sys- Medina and Diversion Lakes are related to the stage in tem and to determine the influence that Medina and each reservoir and are partially controlled by the hydro- Diversion Lakes have on the regional ground-water- geology. GWout from Medina Lake was as much as 135 flow system of the Edwards aquifer or Trinity aquifers acre-ft/d between stages of 1,035 and 1,043 ft above or both. Rocks of the upper member of the Glen Rose MSL and averaged less than 115 acre-ft/d above 1,043 Limestone underlie most of Medina Lake and the chan- ft. The greatest losses from the lake to the ground-water nel between the spillway of Medina Dam and the mid- system appear to result from lake stages that range from point of Diversion Lake, where Diversion Lake fault about 1,040 to 1,045 ft above MSL, which coincides intersects Diversion Lake. Rocks of the Edwards Group, with the altitude of one of the most porous and perme- which form the Edwards aquifer, also are present in the able parts of the basal nodular member of the Kainer southern part of the Medina Lake area. Formation on the southern side of Medina Lake. On the southern side of Medina Lake, the GWout from Diversion Lake gradually increases contact between the upper member of the Glen Rose as the stage in Diversion Lake increases, ranging from Limestone and the basal nodular member is about zero at 911 ft above MSL to about 70 acre-ft/d at an alti- 1,000 ft above MSL, and the contact between the basal tude of about 913.5 ft. Similar to conditions at Medina nodular member and the dolomitic member is about Lake, the greatest losses from Diversion Lake occur at 1,050 ft above MSL. Between these altitudes, Medina about the same altitude as the most porous and perme- Lake is in hydrologic connection with rocks in the able parts of the basal nodular member. Edwards aquifer recharge zone; losses from Medina Monthly average recharge to the ground-water Lake to the ground-water-flow system appear to occur system during December 1995–July 1996 estimated by mostly along the exposed bedding plane contacts. the current study method were compared to monthly Hydrologic budgets for October 1995–September average recharge estimated using the existing USGS 1996 were calculated for Medina Lake, Diversion Lake, and Trans-Texas methods. The current study method and Medina/Diversion Lakes combined to estimate summed estimated monthly GWout obtained from losses from the lake system. Streamflow, precipitation, curves relating GWout to the stages of Medina and evaporation, and change in storage were used to quan- Diversion Lakes, and from this sum subtracted the

34 Hydrogeology, Hydrologic Budget, and Water Chemistry of the Medina Lake area, Texas monthly average ground-water loss that returns as quality data support the results of the hydrologic bud- surface-water flow to the Medina River between sites 8 gets that losses from the lake system are entering the and 9. Estimated recharge to the Edwards aquifer using ground-water-flow system of the Edwards aquifer. In the current study method was about 69 and 73 percent selected Edwards aquifer wells located on the southern of the recharge estimated using the USGS and Trans- side of Medina Lake, the proportion of lake water com- Texas methods, respectively. The USGS and Trans- pared to aquifer water ranged from about 10 to 45 per- Texas methods overestimated recharge from Medina cent. Geochemical modeling using NETPATH confirms Lake compared to the recharge estimated with the cur- the degree of mixing between lake water and aquifer rent study method when Medina Lake stage was water shown by isotopes. between about 1,027 and 1,032 feet above mean sea Synthesizing information from the hydrogeology, level and underestimated recharge from Medina Lake the hydrologic budget analysis, and water chemistry when lake stage was between about 1,036 and 1,045 feet portions of the Medina Lake study provide a more above mean sea level. The USGS and Trans-Texas concise picture of the relation between the lake system methods underestimated recharge from Diversion Lake and the Edwards and Trinity aquifers in northeastern compared to the recharge estimated with the current Medina County. Regional mapping in the Medina Lake study method when Diversion Lake stage was greater area showed that the distribution of contiguous Edwards than 913 feet above mean sea level and overestimated aquifer rocks is not as widespread as earlier noted, recharge from Diversion Lake when lake stage was less thus reducing the effective recharge zone. Additionally, than 913 feet above mean sea level. hydrogeologic mapping indicates that the Edwards Water samples collected from Medina Lake, aquifer in the Medina Lake area comprises two or three Medina River, and Koenig Creek were classified as a of the lowermost hydrogeologic subdivisions of the calcium-bicarbonate water type, with dissolved solids Edwards Group, and that the saturated thickness of concentrations ranging from 163 to 356 mg/L in the Edwards aquifer near the lakes might limit how much of Medina River and Koenig Creek and ranging from 146 the water lost from either lake can move into the aquifer. to 269 in Medina Lake. The concentrations of major The hydrologic budget analysis of Medina Lake ions and trace elements in the surface-water samples and Diversion Lake showed that losses from the lake generally are smaller than the concentrations in water can be quantified, although in some cases the error asso- samples from the Edwards and Trinity aquifers and ciated with the individual hydrologic budget variables meet the EPA drinking water standards for a public exceeded the residual GWout component. The hydro- water system. logic budget analysis also determined that a substantial Water samples collected from Edwards aquifer amount of water that is lost from the lake system returns wells were predominantly a calcium-bicarbonate type, to the surface-water system downstream of Diversion with dissolved solids concentrations ranging from 226 Dam. The data also show that GWout approaches zero to 421 mg/L, meeting EPA drinking water standards for when the stages in Medina Lake and Diversion Lake a public water system. Water samples from the middle decreases to about the altitude of the contact between and upper Trinity aquifers were a calcium-bicarbonate, the Glen Rose Limestone and the basal nodular subdivi- magnesium-sulfate, or calcium-sulfate water type. Trin- sion of the Edwards aquifer. This decrease indicates that ity aquifer, undifferentiated, water samples were fresh losses from the lake system to the Trinity aquifer are to moderately saline, with dissolved solids concentra- minimal compared to the losses entering the Edwards tions ranging from 237 to 3,320 mg/L. Most of the water aquifer and within the error of the hydrologic budgets. samples from wells in the middle Trinity aquifer had Isotopic data and geochemical modeling were concentrations of sulfate and fluoride that exceeded the used to show that lake water is moving into the Edwards EPA MCL and SMCL for those constituents. ground-water-flow system in two fault blocks. The first Environmental isotopes and geochemical model- fault block, bounded on the north by the Vandenburg ing also were used to determine where losses from the School fault and on the south by the Diversion Lake lake system might be entering the ground-water-flow fault is probably recharged by both Medina Lake and system. Water chemistry and environmental isotopes Diversion Lake. The second fault block, bounded on the indicate that Medina and Diversion Lakes contribute north by the Diversion Lake fault and on the south by some water to some wells in the Edwards aquifer and the Haby Crossing fault, is probably recharged prima- in the upper Trinity aquifer in the study area. Water- rily from Diversion Lake.

SUMMARY AND CONCLUSIONS 35 REFERENCES CITED fer, San Antonio Region, Texas: U.S. Geological Survey Water-Resources Investigations Report 96–4046, 73 p. Ashworth, J.B., 1983, Ground-water availability of the Lower Harbeck, G.E., Jr., 1962, A practical field technique for Cretaceous formations in the Hill Country of south-cen- measuring reservoir evaporation utilizing mass-transfer tral Texas: Texas Department of Water Resources Report theory: U.S. Geological Survey Professional Paper 273, 173 p. 272–E, p. 101–105. Barker, R.A., and Ardis, A.F., 1996, Hydrogeologic framework of the Edwards-Trinity Aquifer System, west- Harbeck, G.E., Jr., and others, 1958, Water-loss investiga- central Texas: U.S. Geological Survey Professional tions—Lake Mead studies: U.S. Geological Survey Pro- Paper 1421–B, 61 p. fessional Paper 298, 100 p. Barnes, V.E., and others, 1992, Geologic map of Texas: Aus- HDR Engineering, Inc., 1998, Trans-Texas water program, tin, Tex., University of Texas, Bureau of Economic west central study area—Edwards aquifer recharge Geology, scale 1:250,000. update: Private consultant report prepared for Trans- Bluntzer, R.L., 1992, Evaluation of the ground-water Texas Water Program [variously paged]. resources of the Paleozoic and Cretaceous aquifers in the Holt, C.L.R., Jr., 1956, Geology and ground-water resources Hill Country of central Texas: Texas Water Development of Medina County, Texas: Texas Board of Water Engi- Board Report 339, 130 p. neers Bulletin 5601, 278 p. Bush, P.W., Ulery, R.L., and Rittmaster, R.L., 1994, Dis- _____1959, Geology and ground-water resources of Medina solved-solids concentrations and hydrochemical facies County, Texas: U.S. Geological Survey Water-Supply in water of the Edwards-Trinity aquifer system, west- Paper 1422, 213 p. central Texas: U.S. Geological Survey Water-Resources Investigations Report 93–4126, 29 p. Hydrosphere Data Products, 1998, Climate data, volume 9.3, Burleigh, H.L., 1949, Extract from report of geologic recon- National Climatic Data Center summary of the day— naissance, Medina Project: Bureau of Reclamation West 2: National Climatic Data Center, CD-ROM. report, p. 9–15. Inden, R.F., 1974, Lithofacies and depositional model for a Choffel, K.L., and Vaugh, S.K., 1993, Historical recharge of Trinity Cretaceous sequence, Central Texas, in Aspects the Edwards aquifer in the Nueces, San Antonio, and of Trinity Division Geology, a Symposium on the Guadalupe River Basins—Notes from presentation at Stratigraphy, Sedimentary Environments, and Fauna of Texas Water Issues, Ground Water and Surface Water, the Comanche Cretaceous Trinity Division (Aptian and American Water Resources Association, Texas Section Albian) of Texas and Northern Mexico: Baton Rouge, Spring Meeting, Austin, Tex., April 16, 1993: American La., School of Geoscience, Louisiana State University, Institute of Hydrology, 5 p. Geoscience and Man, v. 8, p. 37–52. Choquette, P.W., and Pray, L.C., 1970, Geologic nomencla- Jones, S.A., Lee, R.W., and Busby, J.F., 1997, Chemical evo- ture and classification of porosity in sedimentary car- lution and estimated flow velocity of water in the Trinity bonates: American Association of Petroleum Geologists aquifer, south-central Texas: U.S. Geological Survey Bulletin, v. 54, no. 2, p. 207–250. Water-Resources Investigations Report 97–4078, 22 p. Collins, E.W., 1995, Geologic map of the Medina Lake quad- Kastning, E.H., 1986, Cavern development in the New Braun- rangle: Austin, Tex., University of Texas, Bureau of fels area, central Texas, in Abbott, P.L., and Economic Geology, scale 1:24,000. Woodruff, C.M., Jr., eds., The Balcones escarpment— Craig, Harmon, 1961, Isotopic variations in meteoric waters: Geology, hydrology, ecology, and social development Science, v. 133, p. 1,702–1,703. in central Texas: Geological Society of America, Dunham, R.J., 1962, Classification of carbonate rocks p. 91–100. according to depositional texture, in Classification of Kuehne, C.M., 1966, Ripples from Medina Lake: San Anto- Carbonate Rocks Symposium: American Association of nio, Tex., Naylor Co., 83 p. Petroleum Geologists Memoir 1, p. 108–121. Espey, Huston and Associates, Inc., 1989, Medina Lake Kuniansky, E.L., and Holligan, K.Q., 1994, Simulations of hydrology study: Private consultant report prepared for flow in the Edwards-Trinity aquifer system and contigu- Edwards Underground Water District, 26 p. ous hydraulically connected units, west-central Texas: Fritz, Peter, and Fontes, J.C., 1980, Introduction, in Fritz, U.S. Geological Survey Water-Resources Investigations Peter, and Fontes, J.C., eds., Handbook of environmental Report 93–4039, 40 p. isotope geochemistry, v. 1, The terrestrial environment, Land, L.F., 1970, Seepage investigation of Medina Canal, A: Amsterdam, Elsevier, 545 p. Bexar-Medina-Atascosa Counties, Texas, Water Groschen, G.E., 1996, Hydrogeologic factors that affect the Improvement District No. 1 canal system, August 15, flowpath of water in selected zones of the Edwards aqui- 1969: U.S. Geological Survey report, 5 p.

36 Hydrogeology, Hydrologic Budget, and Water Chemistry of the Medina Lake area, Texas Larkin, T.J., and Bomar, G.W., 1983, Climatic atlas of Texas: U.S. Geological Survey Water-Resources Investigations Texas Department of Water Resources. Report 94–4169, 130 p. LBG-Guyton Associates, 1995, Edwards/Glen Rose hydro- Puente, Celso, 1978, Method of estimating natural recharge logic communication, San Antonio region, Texas: to the Edwards aquifer in the San Antonio area, Texas: Private consultant report prepared for Edwards Under- U.S. Geological Survey Water-Resources Investigations ground Water District, 38 p. Report 78–10, 34 p. Lee, T.M., and Swancar, Amy, 1997, Influence of evapora- Raba-Kistner Consultants, Inc., 1993, Optimum streamflow tion, ground water, and uncertainty in the hydrologic and rainfall gauging site location study as part of real budget of Lake Lucerne, a seepage lake in Polk County, time data collection network assessment: Private con- Florida: U.S. Geological Survey Water-Supply Paper sultant report prepared for Edwards Underground Water 2439, 61 p. District, 28 p. Lowry, R.L., Jr., 1953, Hydrologic report—Medina River above the Applewhite Dam site: Unpublished report Rose, P.R., 1972, Edwards Group, surface and subsurface, prepared for San Antonio City Water Board, 43 p. central Texas: Austin, University of Texas, Bureau of ______1955, Recharge to Edwards ground-water reservoir: Economic Geology Report of Investigations 74, 198 p. San Antonio, Tex., City Water Board report, 66 p. Rosenberg, N.J., Blad, B.L., and Verma, S.B., 1983, Micro- Maclay, R.W., 1995, Geology and hydrology of the Edwards climate—The biological environment, 2d ed.: New aquifer in the San Antonio Area, Texas: U.S. Geological York, Wiley, 495 p. Survey Water-Resources Investigations Report Sayre, A.N., 1936, Geology and ground-water resources of 95–4186, 64 p. Uvalde and Medina Counties, Texas: U.S. Geological Maclay, R.W., and Land, L.F., 1988, Simulation of flow in Survey Water-Supply Paper 678, 146 p. the Edwards aquifer, San Antonio region, Texas, and Small, T.A., and Clark, A.K., 2000, Geologic framework and refinement of storage and flow concepts: U.S. Geologi- hydrogeologic characteristics of the Edwards aquifer cal Survey Water-Supply Paper 2336–A, 48 p. outcrop, Medina County, Texas: U.S. Geological Survey Maclay, R.W., and Small, T.A., 1976, Progress report on Water-Resources Investigations Report 00–4195. geology of the Edwards aquifer, San Antonio area, Texas, and preliminary interpretation of borehole Small, T.A., and Lambert, R.B., 1998, Geologic framework geophysical and laboratory data on carbonate rocks: and hydrogeologic characteristics of the outcrops of the U.S. Geological Survey Open-File Report 76–627, 65 p. Edwards and Trinity aquifers, Medina Lake area, Texas: ______1986, Carbonate geology and hydrology of the U.S. Geological Survey Water-Resources Investigations Edwards aquifer in the San Antonio area, Texas: Texas Report 97–4290, 17 p. Water Development Board Report 296, 90 p. Stricklin, F.L., Smith, C.I., and Lozo, F.E., 1971, Stratigraphy Marciano, J.J., and Harbeck, G.E., Jr., 1954, Mass-transfer of Lower Cretaceous Trinity deposits of central Texas: studies, in Water-loss investigations, Lake Hefner Austin, Tex., University of Texas, Bureau of Economic studies, technical report: U.S. Geological Survey Geology Report of Investigations 71, 63 p. Professional Paper 269, p. 46–70. Texas Water Development Board, 1992, Water for Texas— Novak, C.E., 1985, WRD data reports preparation guide: Today and tomorrow; Draft recommendations for the U.S. Geological Survey, 199 p. 1992 Update of the Texas Water Plan: Texas Water Pearson, F.J., Jr., and Rettman, P.L., 1976, Geochemical and Development Board, p. 90–91. isotopic analyses of waters associated with the Edwards _____1996a, Volumetric survey of Medina Lake and Diver- Limestone aquifer, central Texas: Edwards Underground sion Lake: Texas Water Development Board publication Water District Report, 35 p. prepared for Bexar-Medina-Atascosa Counties Water Pearson, F.J., Jr., Rettman, P.L., and Wyerman, T.A., 1975, Control and Improvement District No. 1, 14 p. Environmental tritium in the Edwards aquifer, Central _____1996b, Final interim report, FY1996, Medina Lake Texas, 1963–71: U.S. Geological Survey Open-File recharge study: Texas Water Development Board, Report 74–362, 32 p. Contract No. 95–483–071, 165 p. Plummer, L.N., Jones, B.F., and Truesdell, A.H., 1976, WATEQF—A FORTRAN IV version of WATEQ, a University of Texas, Bureau of Economic Geology, 1983, computer program for calculating chemical equilibria of Geologic atlas of Texas, San Antonio sheet: Austin, natural waters: U.S. Geological Survey, Water- Tex., scale 1:250,000. Resources Investigations Report 76–13, 61 p. U.S. Army Corps of Engineers, 1965, Survey report on Plummer, L.N., Prestmon, E.C., and Parkhurst, D.C., 1994, Edwards underground reservoir, Guadalupe, San Anto- An interactive code (NETPATH) for modeling NET nio, and Nueces Rivers and tributaries, Texas: U.S. geochemical reactions along a flow PATH—Version 2.0: Army Corps of Engineers, Forth Worth District; San

REFERENCES CITED 37 Antonio, Tex., Edwards Underground Water District, William F. Guyton and Associates, 1955, The Edwards Lime- v. 2 [variously paged]. stone reservoir: Austin, Tex., Private consultant report prepared for San Antonio City Water Board, 30 p. U.S. Environmental Protection Agency, 1996, Drinking water regulations and health advisories: U.S. Environmental _____1958, Leakage from Medina Lake, Medina County, Protection Agency EPA 822–B–96–002, 11 p. Texas: Austin, Tex., Private consultant report prepared for San Antonio City Water Board, 18 p. U.S. Geological Survey, 1997, Recharge to and discharge _____1965, Report on recharge to the Edwards ground-water from the Edwards aquifer in the San Antonio Area, reservoir, 1962–63: Austin, Tex., Private consultant Texas, 1996: U.S. Geological Survey, 2 p. accessed report prepared for San Antonio City Water Board, 22 p. April 12, 2000, at URL Winslow, A.G., and Kister, L.R., 1956, Saline-water http://tx.usgs.gov/reports/dist/dist-1997-01 resources of Texas: U.S. Geological Survey Water- Wells, F.C., Gibbons, W.J., and Dorsey, M.E., 1990, Guide- Supply Paper 1365, 105 p. lines for collection and field analysis of water-quality Winter, T.C., 1981, Uncertainties in estimating the water samples from streams in Texas: U.S. Geological Survey balance of lakes: Water Resources Bulletin, v.17, no. 1, Open-File Report 90–127, 79 p. p. 82–115.

38 Hydrogeology, Hydrologic Budget, and Water Chemistry of the Medina Lake area, Texas REFERENCES CITED 39 Table 1. Summary of lithologic and hydrologic properties of the hydrogeologic subdivisions of the Edwards and Trinity aquifers, Medina Lake area, Texas

[HydrogeologicTable 1subdivisions modified from Maclay and Small (1976); groups, formations, members, and thicknesses modified from Holt (1956), Stricklin and others (1971), Rose (1972), Inden (1974), and Ashworth (1983); lithology modified from Dunham (1962); and porosity type modified from Choquette and Pray (1970). CU, confining unit; AQ, aquifer; *, not exposed in the study area; gal/min, gallons per minute]

Hydrogeologic Group, formation, Hydrologic Thickness Field Cavern Porosity/permeability Lithology subdivision or member function (feet) identification development and well yields Surficial deposits and upper CU, except 665–1,200 Argillaceous, light-gray to Chert and limestone Rare to none Low to high porosity/low confining unit (Escondido for surficial buff, fossiliferous cobbles; clay, silt, to high permeability Formation, Anacacho deposits limestone; chalky, marly, sand, shale, and soft, Limestone, and Austin and hard limestone; clay, marly limestone Group), undivided silt, and sandstone Upper Eagle Ford Group CU 30–50 Brown, flaggy shale and Dark-brown shale; None Low porosity/low confining argillaceous limestone petroliferous odor permeability unit Buda Limestone CU 40–50 Buff, light-gray, dense White, dense limestone None Low porosity/low

Upper Cretaceous mudstone permeability Del Rio Clay CU 40–50 Blue-green to yellow- Blue-green to medium- None Low porosity/low brown clay brown shale; permeability Ilymatogyra arietina I Georgetown Formation Karst AQ; 2–20 Reddish-brown, gray to Red-brown to gray None Low porosity/low not karst light-tan, marly limestone marly limestone; permeability CU Kingena wacoensis II Cyclic and AQ 0–10 Mudstone to packstone; * Many subsurface; Laterally extensive; both marine miliolid grainstone; chert might be associ- fabric and not members, ated with earlier fabric/water-yielding undivided karst development III Leached and AQ 70–90 Crystalline limestone; Bioturbated iron-stained Extensive lateral Majority not fabric/one of collapsed mudstone to grainstone; beds separated by development; large the most porous and members, chert; collapsed breccia massive limestone rooms permeable undivided beds; stromatolitic

Person Formation Person limestone IV Regional dense CU 16–20 Dense, argillaceous Wispy iron-oxide stains Very few; only Not fabric/low member mudstone vertical fracture permeability; vertical enlargement barrier V Grainstone AQ 50–60 Miliolid grainstone; White crossbedded Few caves Not member mudstone to wackestone; grainstone fabric/recrystallization Edwards aquifer chert reduces permeability VI Kirschberg AQ 50–60 Highly altered crystalline Boxwork voids, with Probably extensive Majority fabric/one of the Edwards Group

Devils River Formation River Devils evaporite limestone; chalky neospar and travertine cave development most porous and member mudstone; chert frame permeable VII Dolomitic AQ 110–140 Mudstone to grainstone; Massively bedded, Caves related to Mostly not fabric; some member crystalline limestone; light gray; Toucasia structure or bedding-plane chert abundant bedding planes fabric/water-yielding

VIIIKainer Formation Basal nodular Karst 50–60 Shaly, fossiliferous, nodular Massive, nodular, and Large lateral caves Fabric; stratigraphically member AQ; limestone; mudstone; mottled; abundant at surface; a few controlled/large conduit not karst miliolid grainstone gastropods and caves near Koenig flow at surface; no Lower Cretaceous Lower CU Exogyra texana Creek (see pl. 1) permeability in subsurface Upper CU; 350–500 Yellowish-tan, thinly Stair-step topography; Some surface cave Some water production at member evaporite bedded limestone and alternating limestone development evaporite beds/relatively beds AQ marl and marl; Orbitolina impermeable (0–20

aquifer minuta gal/min) Upper Trinity Lower member AQ 300–320 Massive fossiliferous Massive, reefal Some cave Mostly fabric; small to limestone; rudistid reefs limestone; Orbitolina development moderate quantities and caves; few thin beds texana and Corbula related to fractures (5–100 gal/min) of

Glen Rose Limestone of marl and dolomitic martinae and faults water from caves and limestone reefs/low permeability Hensel Sand AQ 25–80 Red to gray clay, silt, sand, * None Not fabric; small to conglomerate; thin moderate quantities Trinity Group Trinity limestone beds (5–100 gal/min) of water Cow Creek AQ 50–60 Massive, fossiliferous, * Honeycombed in the Mostly fabric; small to Limestone white to gray, argillaceous outcrop moderate quantities Middle aquifer Trinity to dolomitic limestone (5–100 gal/min) of with local thinly bedded water

Travis Peak Peak Formation Travis layers of limestone and sand

Table 1 40 Table 2. Hydrologic budget data-collection sites in the Medina Lake area, Texas

Type of site:Table SW, surface 2 water; LK, lake Type of data: SC, stage/continuous; P, precipitation; Pe, peak; SI, stage/intermittent; E, evaporation

Site Type Type Station no. Station name Latitude Longitude of of no. (fig. 3) site data

1 08178990 Medina River at English Crossing 29°40'53" 98°58'32" SW SC 2 08179110 Red Bluff Creek at Farm Road 1283 29°40'23" 98°57'36" SW SC, P 3 08179300 Elm Creek near Pipe Creek 29°36'15" 98°55'45" SW SC, P 4 08179320 Unnamed tributary at Farm Road 1283 29°34'44" 98°53'57" SW Pe 5 08179530 Koenig Creek near Riomedina 29°31'57" 98°56'14" SW SI 6 08179520 Medina River below Medina Lake 29°32'02" 98°56'06" SW SC 7 08179990 Medina irrigation canal at Diversion Dam 29°30'30" 98°54'05" SW SC 8 08180015 Medina River below Diversion Lake 29°30'33" 98°54'01" SW SC 9 08180500 Medina River near Riomedina 29°29'52" 98°54'18" SW SC 10 08179280 Cypress Creek near Riomedina 29°35'14" 99°00'30" SW SC, P 11 08179240 Bruins Creek near Pipe Creek 29°39'23" 98°59'17" SW Pe, P 12 08179260 Rocky Creek near Pipe Creek 29°37'15" 98°59'57" SW Pe 13 08179505 Medina Lake near San Antonio 29°32'24" 98°56'01" LK SC, P, E 14 293352098552600 Medina Lake weather station 29°33'52" 98°55'26" LK E 15 08180010 Diversion Lake near Riomedina 29°30'36" 98°54'04" LK SC, P

41 Hydrogeology, Hydrologic Budget, and Water Chemistry of the Medina Lake area, Texas S, average (acre-ft/d) average (acre-ft/d) Evaporation, , surface water outflow; outflow; water , surface change in S, out, out SW average (acre-ft/d) in, Sw average (acre-ft/d) , surface-water inflow; SW inflow; , surface-water in average (acre-ft/d) Precipitation, Medina Lake Medina Diversion Lake Diversion 911.51 0 58.43 69.16 1.69 -12.45 MSL) Stage, average 1,044.791,044.871,044.661,044.51 01,044.36 1.531,043.77 10.261,043.00 5.081,042.61 01,042.12 140.05 145.16 142.30 01,041.75 01,041.49 130.70 01,041.21 59.32 59.50 01,040.72 57.52 109.08 41.141,039.89 100.35 57.52 01,039.37 97.58 01,038.94 84.56 45.06 34.10 44.66 57.52 01,038.29 96.18 119.89 85.59 8.761,037.36 52.68 33.02 190.131,035.69 95.60 225.12 01,026.95 -48.45 -62.00 -70.75 79.02 174.88 49.891,026.07 236.03 23.19 3.70 -88.33 24.38 75.27 71.95 116.81 21.28 142.81 0 23.00 -112.67 141.22 0 -159.00 36.96 95.48 10.18 0 59.83 257.45 243.07 189.09 -225.43 51.80 -271.83 48.88 -209.50 25.91 -270.29 40.79 256.20 321.57 28.49 341.65 40.45 31.82 9.71 -214.60 6.60 -194.00 223.34 48.71 -304.40 -285.82 -202.83 28.48 294.69 40.58 372.89 -316.33 60.77 -348.25 -391.50 60.29 62.18 -313.40 -331.29 -443.60 (ft above 11 910.97038383 043 912.19 912.16 911.96 912.45 58.37 .90 0 0 0 67.74 185.49 140.97 174.35 1.57 267.84 166.38 124.42 161.26 197.83 -9.73 1.11 1.74 .94 1.73 -.36 -2.54 -1.00 13.63 out, Gw average “+\-error” (acre-ft/d) out, Gw average (acre-ft/d) t/d, acre-feet per day; ft, feet; MSL, mean sea level; SW t/d,per acre-feetMSL, meanft, feet; day; sea level; period in budget No. of days Table 3 Summary of hydrologic budgets for Medina, Diversion, and Medina/Diversion Lakes combined, Medina Lake area, Texas—Continued area, Lake Medina combined, Lakes Medina/Diversion and Diversion, Medina, for budgets Summary hydrologic of Summary of hydrologic budgets for Medina, Diversion, and Medina/Diversion Lakes (combined), Medina Lake area, Texas area, Lake Medina (combined), Lakes Medina/Diversion and Diversion, Medina, for budgets Summary hydrologic of period Budget , ground-water outflow; acre-f , outflow; ground-water out 11/12/95 to 11/16/95 to 11/12/95 12/16/95 to 11/25/95 12/28/95 to 12/17/95 01/03/96 to 12/29/95 5 22 01/09/96 to 01/04/96 12 01/28/96 to 01/20/96 02/13/96 to 02/07/96 6 02/19/96 to 02/14/96 113.56 6 85.64 02/27/96 to 02/21/96 9 121.13 03/04/96 to 02/28/96 7 113.92 03/09/96 to 03/05/96 6 19.89 03/14/96 to 03/10/96 114.34 7 21.87 116.27 22.30 03/25/96 to 03/15/96 6 111.60 04/04/96 to 03/26/96 5 23.54 108.28 04/10/96 to 04/05/96 5 22.59 04/16/96 to 04/11/96 11 109.66 23.93 10 134.98 04/24/96 to 04/17/96 32.97 118.50 05/03/96 to 04/26/96 6 37.02 105.88 05/20/96 to 05/16/96 6 37.38 07/18/96 to 07/12/96 74.25 8 33.47 102.48 07/23/96 to 07/19/96 8 33.04 131.75 5 26.68 12/23/95 to 12/18/95 106.91 7 12/28/95 to 12/24/95 40.60 5 41.80 01/03/96 to 12/29/95 61.73 01/09/96 to 01/04/96 85.45 34.82 6 70.08 44.40 01/28/96 to 01/20/96 5 -13.98 02/13/96 to 02/07/96 6 15.12 48.68 02/19/96 to 02/14/96 6 55.71 02/26/96 to 02/21/96 41.99 9 2.34 47.37 03/04/96 to 02/27/96 7 7.70 03/11/96 to 03/05/96 60.13 6 03/18/96 to 03/12/96 .03 6 -1.20 03/26/96 to 03/19/96 7 8.83 8.43 7 17.26 8.12 7 24.34 9.30 8 28.82 9. 910.87 16.19 19.25 911.74 25.46 17.34 30.16 13.15 31.05 54.66 911.31 25. 912.00 .67 0 18. 912.13 23. 912.15 33. 0 58.52 0 0 58.48 0 55.70 120.60 190.72 29.20 225.67 234.88 107.15 167.77 2.02 199.64 202.58 .96 .75 -.87 .73 .79 20.62 .43 4.27 4.96 .90 3.05 Table 3. Table storage] Table 3. Table [GW

Table 3 42 S, average (acre-ft/d) average (acre-ft/d) Evaporation, out, SW average (acre-ft/d) in, Sw average (acre-ft/d) average (acre-ft/d) Precipitation, —Continued 913.24912.51 0.24913.05 1.37 258.77912.94 189.30 .71911.96 218.64044.66 199.01 341.76044.43 3.01 2.06 0.95 10.60 288.45 116.63 1.26 2.54 30.74041.72 142.30 5.77 -24.48 1.73 89.30 119.89039.89 10.68 36.16039.37 73.39 -1.41 93.06 1.15038.34 8.97037.36 96.22 1.23 34.39 46.06 -25.82 52.91 3.29034.19 181.91 25.09 75.27 -18.67 116.81 -63.33 -111.59 40.45 61.99 246.15 31.57 230.08029.06 51.80027.12 -200.03 290.03 34.13 29.63 318.59 33.08 15.70 36.38 -297.41 -227.32 33.92 383.94 42.31 14.82 10.04 -349.77 -392.91 29.68 429.99 304.07 -406.77 40.90 59.39 -533.08 -353.14 MSL) Stage, average 1,043.771,043.001,042.611,042.12 0 01,041.41 01,040.82 0 100.35 01,038.99 97.58 0 84.56 131.79 85.591,035.69 194.95 01,035.06 89.05 226.78 73.84 230.08 23.951,033.04 01,031.83 22.00 148.76 01,030.78 98.74 23.79 -154.73 205.29 10.54 0 -220.47 01,025.91 60.20 40.79 -270.93 242.38 01,021.12 28.80 -267.40 35.44 -229.00 23.08 242.78 0 47.16 17.11 -257.71 339.50 0 13.25 396.25 -286.06 63.41 405.95 57.07 430.08 6.46 5.13 -333.00 63.61 -433.10 46.32 329.54 50.29 327.27 -512.37 -501.52 -547.85 61.03 50.59 -461.93 -449.47 (ft above Diversion Lake Diversion Medina/Diversion Lakes,Medina/Diversion combined 786315 912.2847 912.6969 912.63 0 913.55 0 913.27 0 0 256.38 0 321.71 265.26 219.47 287.93 263.50 366.61 226.60 1.93 234.64 1.18 272.50 2.61 4.85 3.21 9.59 3.42 -7.43 -20.45 -2.42 out, Gw average “+\-error” (acre-ft/d) out, Gw average (acre-ft/d) period in budget No. of days Summary of hydrologic budgets for Medina, Diversion, and Medina/Diversion Lakes combined, Medina Lake area, Texas—Continued area, Lake Medina combined, Lakes Medina/Diversion and Diversion, Medina, for budgets Summary of hydrologic period Budget 04/17/96 to 04/24/9604/26/96 to 05/03/9607/12/96 to 07/17/96 807/18/96 to 07/23/96 808/23/96 to 08/27/96 6 6 47.44 5 53.71 70.53 41. 93.12 44.74 55.01 37. 45. 15.96 04/05/96 to 04/10/9604/11/96 to 04/16/96 605/16/96 to 05/22/96 6 7 14.8808/28/96 to 09/02/96 30.1212/29/95 to 01/09/96 27.84 6 43.4901/20/96 to 01/28/96 33. 02/07/96 to 02/13/96 1202/14/96 to 02/19/9602/21/96 to 02/27/96 35. 9 39.5602/28/96 to 03/05/96 703/06/96 to 03/11/96 6 88.0503/12/96 to 03/25/96 703/26/96 to 04/04/96 7 99.34 4.40 101.1004/05/96 to 04/10/96 604/11/96 to 04/15/96 14 104.93 32.81 10 112.3704/16/96 to 04/24/96 24.59 118.9304/26/96 to 05/03/96 6 33.32 109.0905/16/96 to 05/20/96 5 1, 37.13 05/21/96 to 05/26/96 90.82 9 37.02 105.8805/27/96 to 06/02/96 8 32.56 115.3506/04/96 to 06/12/96 5 33.91 06/13/96 to 06/18/96 6 95.26 36.34 06/19/96 to 06/24/96 1, 41.20 7 91.09 108.9006/25/96 to 07/08/96 9 37.4307/09/96 to 07/18/96 6 67.60 41.58 1, 07/19/96 to 07/25/96 6 65.3208/14/96 to 08/19/96 14 47.83 1, 67.73 54.31 10 75.58 43.24 7 66.36 58.80 1, 6 80.72 1, 58.50 92.71 66.84 36.11 65.62 77.81 71.27 1, 76.73 69.84 51.71 58.59 1, 56.61 1, 03/27/96 to 04/04/96 9 33.6512/17/95 to 12/28/95 33.94 12 96.77 23.14 1, Table 3.

43 Hydrogeology, Hydrologic Budget, and Water Chemistry of the Medina Lake area, Texas pled Date sam- 05/18/95 04/02/96 04/02/96 08/29/95 05/22/95 08/29/95 08/29/95 05/23/95 05/23/95 08/29/95 04/02/96 04/02/96 04/02/96 04/02/96 05/18/95 11/30/95 04/03/96 05/31/96 08/06/96 05/18/95 12/01/95 04/04/96 06/03/96 08/06/96 12/01/95 04/03/96 05/31/96 08/06/96 Sr 86 ------.70766 .70768 Sr/ 0.70765 87 O ) 18 δ ‰ / ( D δ upper members of the Glen –8.70/–1.62 –7.80/–1.22 –8.40/–1.04 –6.50/–1.05 –6.00/–.93 –6.00/–.80 –8.10/–1.30 –7.70/–1.00 –6.70/–1.00 –6.00/–.87 –3.60/–.84 –6.60/–1.00 –6.20/–.97 –8.20/–1.07 –7.60/–.91 –5.90/–.82 –7.30/–1.16 –7.00/–1.20 –5.90/–.85 –6.90/–.89 –6.30/–.85 –7.60/–1.45 –6.30/–1.07 –18.7/–3.52 –17.7/–3.02 –15.4/–2.59 –13.2/–1.89 –10.2/–1.58 applicable or not measured] not applicable or ------Date measured

------level MSL) Water- altitude (ft above ------Aquifer O, del oxygen; ‰, per mil; --, not mil; ‰, per del oxygen; O, 18 δ of site Type 58'32" SW 56'06" SW 56'06" LK 54'43" LK 55'55" LK 58'42" LK 59'03" LK 54'16" SW 56'00" LK 56'14" SW ° ° ° ° ° ° ° ° ° ° D, deuterium; δ 40'53" 98 32'02" 98 32'25" 98 34'26" 98 34'56" 98 33'24" 98 37'31" 98 29'53" 98 32'23" 98 31'57" 98 ° ° ° ° ° ° ° ° ° ° Latitude Longitude 29 , feet; MSL, mean sea level; feet;, MSL, mean sea level; nglish Crossing/site 1 29 Station name/local identifier or state well no. site 6 data listed in Appendix C; ft data listed in Appendix SW, surface water; LK, lake; GW, ground water; SPR, spring ground water; GW, lake; LK, water; surface SW, Table 4 Water-level and water-quality data-collection sites and isotopic data, Medina Lake area, Texas area, Lake Medina data, isotopic sites and data-collection and water-quality Water-level Station or site M. Trinity, middle Trinity; L. Trinity, lower Trinity; U. Trinity, upper Trinity; Trinity undiff., undifferentiated (lower and (lower undifferentiated undiff., Trinity upper Trinity; U. Trinity, Trinity; lower L. Trinity, middle Trinity; M. Trinity, Water-level and water-quality data-collection sites and isotopic data, Medina Lake area, Texas—Continued area, Lake Medina data, isotopic sites and data-collection and water-quality Water-level identification no. 1 08178990at E River Medina 3 08179520 Medina Lake/ below Medina River 6 293225098560600site AC Lake Medina 7 2934260985443008site BC Lake Medina 2934560985555009site CC Lake Medina 293324098584200site DC Lake Medina 29 29 29 29 4 081805009 near Riomedina/site River Medina 5 29 293223098560000site AL Lake Medina 29 2 08179530 5 Creek near Riomedina/site Koenig 29 10 293731098590300site EC Lake Medina 29 no. Site (pl. 2) Table 4. 4. Table site: of Type Aquifer: Rose Limestone) 4. Table water-quality [Additional

Table 4 44 -- pled Date sam- Sr 86 Sr/ 87 O ) 18 δ ------‰ / ( D δ Date measured level MSL) Water- altitude (ft above (ft Aquifer of site Type 59'16" GW58'51" M. Trinity GW58'34" L. Trinity GW58'47" 1,051.45 M. Trinity GW 09/08/94 58'47" M. Trinity 1,137.25 GW 09/08/94 1,099.6558'15" M. Trinity 09/12/94 GW 1,093.8056'55" M. Trinity 09/12/94 GW 1,096.3056'30" M. Trinity 09/12/94 GW56'16" 1,097.30 M. Trinity GW 09/13/94 56'17" 1,175 M. Trinity GW 1,100.6055'02" M. Trinity 09/13/94 09/13/94 GW 1,141.1055'06" M. Trinity 09/14/94 GW 1,143.2058'19" M. Trinity 09/14/94 GW58'22" 1,173.45 M. Trinity GW 09/14/94 57'51" 1,162.60 M. Trinity GW 09/14/94 1,099.6558'20" M. Trinity 09/15/94 GW 1,090.9058'07" M. Trinity 09/15/94 GW 1,10157'52" M. Trinity GW57'47" 1,090.90 09/15/94 L. Trinity GW 09/15/94 58'16" 1,105.30 L. Trinity GW 09/15/94 57'37" M. Trinity 1,105.95 09/16/94 GW57'45" 1,104.75 M. Trinity 09/16/94 GW57'04" 1098 L. Trinity GW56'37" L. Trinity 1038 09/16/94 GW56'27" M. Trinity 1,035.30 GW 10/03/94 10/03/94 55'19" M. Trinity 1,102.70 10/04/94 GW 1,077.3055'19" M. Trinity 10/05/94 GW 1,106.2555'23" M. Trinity 10/05/94 GW55'53" 1,102.90 M. Trinity GW 10/05/94 52'55" 1,063.60 M. Trinity GW 10/05/94 1,136.40 M. Trinity 10/07/94 1,089.70 10/10/94 1,165.35 10/06/94 -- -- ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° 43'44" 98 42'50" 98 42'57" 98 43'20" 98 43'20" 98 43'03" 98 44'02" 98 42'59" 98 42'59" 98 42'49" 98 43'41" 98 43'29" 98 41'40" 98 41'57" 98 42'14" 98 41'39" 98 41'44" 98 40'44" 98 40'44" 98 41'07" 98 40'14" 98 40'15" 98 40'56" 98 40'25" 98 41'31" 98 41'03" 98 41'10" 98 41'09" 98 40'58" 98 41'47" 98 ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° Latitude Longitude Station name/local identifier or state well no. Station or site Water-level and water-quality data-collection sites and isotopic data, Medina Lake area, Texas—Continued area, Lake Medina data, and isotopic sites data-collection water-quality and Water-level identification no. 1112 294344098591601 AS–68–17–10313 294250098585101 AS–68–17–10514 294257098583401 29 AS–68–17–107 15 294320098584701 AS–68–17–109 29432009858470216 AS–68–17–11017 294303098581501 AS–68–17–11118 294402098565501 AS–68–17–20219 294259098563001 AS–68–17–203 29 20 294259098561601 AS–68–17–210 29 29424909856170121 AS–68–17–21122 294341098550201 29 AS–68–17–21223 294329098550601 29 AS–68–17–21324 294140098581901 AS–68–17–404 29 25 294157098582201 AS–68–17–405 29 29421409857510126 AS–68–17–406 29 27 294139098582001 29 AS–68–17–40728 294144098580701 29 AS–68–17–40829 294044098575201 AS–68–17–409 29 30 294044098574701 AS–68–17–410 29 29410709858160131 AS–68–17–412 29 32 294014098573701 29 AS–68–17–41333 294015098574501 29 AS–68–17–41434 294056098570401 AS–68–17–506 29 35 294025098563701 AS–68–17–508 29 29413109856270136 AS–68–17–510 29 37 294103098551901 29 AS–68–17–51138 294110098551901 29 AS–68–17–51239 294109098552301 AS–68–17–514 29 40 294058098555301 AS–68–17–516 29 294147098525501 AS–68–17–602 29 29 29 29 29 29 29 29 no. Site (pl. 2) Table 4.

45 Hydrogeology, Hydrologic Budget, and Water Chemistry of the Medina Lake area, Texas ------pled Date sam- 07/10/96 07/24/96 08/02/95 01/22/96 Sr 86 ------Sr/ 87 O ) 18 δ ‰ / ( D δ –23.8/–4.22 –25.2/–4.11 –23.5/–4.17 -- -- Date measured 03/07/95 -- -- level MSL) Water- altitude 1,060 07/10/96 –15.2/–2.49 -- (ft above -- Aquifer of site Type 53'53" GW54'34" M. Trinity GW52'40" M. Trinity SPR58'56" 1,247.60 Trinity U. GW 10/06/9458'27" 1,232.60 L. Trinity GW 10/07/9458'17" 1,330 M. Trinity GW57'58" 1,012 -- 07/11/96 M. Trinity GW 1,013.8558'05" -- L. Trinity 10/11/94 10/10/94 GW58'41" 1,016 M. Trinity GW59'51" -- L. Trinity 1,015.30 SPR 10/11/94 -- 10/12/94 1,037.95 --58'14" Trinity M. -- 10/12/94 -- GW57'22" 1,034.50 L. Trinity GW 10/13/94 1,06558'11" -- -- M. Trinity -- GW56'32" 10/13/94 -- M. Trinity -- 1,028.55 -- SPR56'34" 10/13/94 1,000.90 Trinity U. -- GW 09/08/94 1,235.6056'49" L. Trinity -- 10/14/94 GW -- --56'36" 1,182 M./L. Trinity -- -- GW53'10" 1,010.10 -- 10/31/94 M. Trinity GW 10/31/94 -- 52'43" 998.95 -- M. Trinity 11/01/94 GW53'46" 1,016.35 -- M. Trinity GW 11/02/94 -- -- 1,04953'12" M. Trinity -- -- SPR 1,294.70 --52'34" undiff. 10/31/94 Trinity 11/01/94 -- 1,069.90 GW 1,300 -- 11/01/9457'30" M. Trinity -- GW 03/25/95 -- -- undiff. Trinity -- -- 1,284.57 1,018.05 03/25/95 ------57'47" -- GW -- 58'22" undiff. Trinity GW 1,026.41 03/15/95 undiff. Trinity -- 1,050.57 03/15/95 ------57'46" GW undiff. Trinity 1,023.58 03/15/95 -- -- 59'55" SPR ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° 41'54" 98 41'08" 98 42'16" 98 39'07" 98 39'45" 98 38'12" 98 38'39" 98 37'55" 98 38'49" 98 38'56" 98 38'28" 98 39'30" 98 38'48" 98 39'00" 98 38'57" 98 38'46" 98 38'44" 98 37'39" 98 39'09" 98 37'50" 98 37'40" 98 38'39" 98 35'52" 98 35'36' 98 35'02" 98 35'29" 98 35'16" 98 ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° Latitude Longitude Station name/local identifier or state well no. Station or site Water-level and water-quality data-collection sites and isotopic data, Medina Lake area, Texas—Continued area, Lake Medina data, isotopic sites and data-collection and water-quality Water-level identification no. 4142 294154098535301 AS–68–17–60343 294108098543401 AS–68–17–60544 294216098524001 Bridge Spring/AS–68–17–60645 293907098585601 AS–68–17–703 29394509858270146 AS–68–17–70447 293812098581701 29 AS–68–17–70648 293839098575801 AS–68–17–70749 293755098580501 AS–68–17–709 29 50 293849098584101 AS–68–17–711 29 29385609859510151 AS–68–17–71252 293828098581401 29 AS–68–17–71353 293930098572201 29 AS–68–17–80354 293848098581101 AS–68–17–805 29 55 293900098563201 AS–68–17–807 29 29385709856340156 AS–68–17–810 29 57 293846098564901 29 AS–68–17–81158 293844098563601 29 AS–68–17–81459 293739098531001 AS–68–17–903 29 60 293909098524301 AS–68–17–904 29 29375009853460161 AS–68–17–905 29 293740098531201 29 62 AS–68–17–908 29 29383909852340163 AS–68–17–910 29 293552098573001 AS–68–25–102 29 29 29 29 66 29 29353609857470167 AS–68–25–105 29 293502098582201 AS–68–25–108 29 29 29 65 293529098574601 AS–68–25–104 29 64 293516098595501 Springs/TD–68–25–103 Campground 29 no. Site (pl. 2) Table 4. Table

Table 4 46 ------pled Date sam- 07/24/96 08/08/96 07/24/96 08/08/96 07/30/96 08/02/95 01/19/96 11/29/95 08/02/95 01/22/96 01/30/96 12/15/95 Sr 86 ------.70768 .70763 .70787 Sr/ 87 O ) 18 δ ------‰ / ( D δ –9.10/–1.48 –5.30/–1.06 –7.0/–.88 –25.1/–4.40 –26.8/–4.35 –24.1/–4.40 –23.5/–4.37 –24.2/–4.37 –23.7/–4.35 –14.7/–2.44 ------Date measured 09/29/94 03/21/95 08/02/95 ------level MSL) Water- altitude (ft above (ft Aquifer of site Type 55'32" SPR57'14" undiff. Trinity GW 1,09957'23" undiff. Trinity GW 03/25/95 1,027.9056'44" 03/18/95 undiff. Trinity GW 1,045.2157'24" 04/01/95 undiff. Trinity GW 1,033.01 --57'22" 03/18/95 -- undiff. Trinity GW 1,045.9957'51" 03/25/95 -- undiff. Trinity GW 1,035.10 03/18/95 -- undiff. Trinity -- -- 950.64 -- 12/05/94 -- 58'01" -- –9.9/–1.08 GW -- 55'24" U. Trinity GW -- 55'24" undiff. Trinity 1,052.44 GW 1,040.55 03/15/95 -- 55'26" 10/13/95 undiff. Trinity GW 1,027.44 10/13/95 undiff. Trinity 1,022.27 -- 10/13/95 -- –16.1/–2.58 ------56'55" GW undiff. Trinity 1,043.27 56'38" GW56'07" Edwards GW undiff. Trinity 1,032.71 867.70 12/05/94 -- -- 56'06" GW undiff. Trinity 1,043.23 56'04" GW undiff. Trinity -- 57'27" GW U. Trinity 1,044.67 02/23/95 -- -- 57'36" GW U. Trinity 1,046.74 12/06/94 --57'23" GW undiff. Trinity -- -- ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° 36'27" 98 36'16" 98 36'33" 98 35'46" 98 36'33" 98 36'21" 98 32'49" 98 34'49" 98 34'20" 98 34'20" 98 34'20" 98 34'57" 98 33'00" 98 33'01" 98 34'29" 98 32'55" 98 34'13" 98 33'18" 98 33'53" 98 ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° Latitude Longitude Station name/local identifier or state well no. Station or site Water-level and water-quality data-collection sites and isotopic data, Medina Lake area, Texas—Continued area, Lake Medina data, and isotopic sites data-collection water-quality and Water-level identification no. 68 29362709855320169 AS–68–25–204 29361609857140170 AS–68–25–205 29363309857230271 AS–68–25–209 29354609856440172 AS–68–25–208 29363309857240173 AS–68–25–206 29362109857220174 AS–68–25–207 29 293249098575101 TD–68–25–402 29 29 76 293449098580101 29 77 AS–68–25–404 293420098552402 29 78 AS–68–25–503 293420098552401 29 79 AS–68–25–504 293420098552601 29 AS–68–25–505 29 29 29 29 83 293457098565501 AS–68–25–51185 29330009856380186 TD–68–25–515 293301098560701 TD–68–25–516 29 29 29 81 293429098560601 AS–68–25–50982 293255098560401 TD–68–25–51084 293413098572701 AS–68–25–512 29 29 29 75 293318098573601 TD–68–25–40380 293353098572301 29 AS–68–25–507 29 no. Site (pl. 2) Table 4.

47 Hydrogeology, Hydrologic Budget, and Water Chemistry of the Medina Lake area, Texas ------pled Date sam- 06/06/96 06/06/96 06/06/96 06/06/96 07/26/96 07/26/96 07/09/96 07/30/96 07/29/96 07/29/96 08/19/96 07/26/96 02/08/96 11/28.95 11/30/95 12/05/95 12/05/95 Sr 86 ------01/25/96 -- -- .70757 .70757 .70767 .70857 Sr/ 87 O ) 18 δ ‰ / ( D δ –4.70/–0.75–5.50/–0.68 -- –5.20/–0.66 -- –5.80/–0.65 -- –3.40/–0.41 -- –4.60/–0.41 -- -- –26.1/–4.10 –25.9/–4.77 –22.3/–4.44 –22.4/–4.25 –21.8/–3.99 –23.2/–3.97 –26.1/–4.31 –25.3/–4.24 –15.2/–2.35 –16.0/–2.98 –22.9/–3.89 –23.3/–3.90 ------Date measured 02/08/96 12/05/95 12/13/94 12/02/94 03/25/95 10/04/94 ------level MSL) Water- altitude (ft above Aquifer of site Type 56'46" GW56'48" U. Trinity GW56'59" U. Trinity 1,056.63 GW 03/07/9556'56" M. Trinity 1,063.08 GW 02/28/9554'19" undiff. Trinity 1,025.63 GW 1,067.70 02/28/95 -- 09/29/95 undiff. Trinity 1,099.70 ------57'51" GW57'50" Edwards GW56'19" Edwards SPR Edwards 937.94 12/08/94 983.68 10/03/94 ------55'34" GW undiff. Trinity -- 56'16" SPR56'17" Edwards SPR56'13" Edwards SPR57'16" Edwards -- GW Edwards -- -- 910.17 56'26" GW undiff. Trinity 928 07/19/95 -- -- 56'24" SPR56'17" Edwards SPR Edwards -- -- 56'04" GW U. Trinity 918.61 53'54" GW undiff. Trinity 57'37" 935.30 GW Edwards57'38" GW Edwards 947 948.28 10/30/94 -- -- ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° 34'30" 98 34'41" 98 34'07" 98 34'58" 98 33'09" 98 31'16" 98 31'58" 98 32'31" 98 32'29" 98 32'20" 98 32'28" 98 32'17" 98 30'33" 98 31'18" 98 32'35" 98 32'26" 98 31'58" 98 33'34" 98 31'27" 98 31'30" 98 ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° Latitude Longitude Station name/local identifier or state well no. Station or site Water-level and water-quality data-collection sites and isotopic data, Medina Lake area, Texas—Continued area, Lake Medina data, isotopic sites and data-collection and water-quality Water-level identification no. 87 29343009856460188 AS–68–25–517 29344109856480189 AS–68–25–518 29340709856590190 AS–68–25–519 29345809856560191 AS–68–25–520 293309098541901 TD–68–25–602 29 29 29 29 95 29 29311609857510196 TD–68–25–704 29315809857500197 TD–68–25–705 293231098561900 2/TD–68–25–8S2 channel Spillway 29 29 29 98 29323509856240099 3/TD–68–25–8S3 channel Spillway 293226098561700 5/TD–68–25–8S5 channel Spillway 29 29 92 293334098535401 TD–68–25–60393 293127098573701 TD–68–25–70194 293130098573801 TD–68–25–703 29 29 29 no. Site 106 293229098553402 TD–68–25–809 29 100 293220098561600101 7/TD–68–25–8S7 channel Spillway 293228098561700102 8/TD–68–25–8S8 channel Spillway 29 293217098561300103 9/TD–68–25–8S9 channel Spillway 29 293033098571601 TD–68–25–806 29 105 293118098562601 TD–68–25–808 29 29 104 293158098560401 TD–68–25–807 29 (pl. 2) Table 4. Table

Table 4 48 ------pled Date sam- 07/19/96 08/19/96 07/09/96 10/30/95 07/29/96 07/26/96 07/16/96 08/21/96 08/21/96 08/20/96 08/06/96 03/06/96 10/30/95 03/20/96 03/20/96 07/29/96 03/06/96 11/29/95 08/21/96 12/13/95 03/07/96 02/21/96 Sr 86 ------.70841 .70763 .70763 .70768 .70772 .70774 .70784 .70785 Sr/ 87 O ) 18 δ ‰ / ( D δ –8.10/–1.05 –26.3/–4.53 –25.0/–4.54 –11.5/–1.31 –27.0/–4.46 –26.1/–4.46 –24.2/–4.41 –25.2/–4.46 –21.9/–4.14 –22.0/–4.21 –17.2/–2.99 –17.0/–3.02 –18.4/–2.97 –21.2/–3.51 –21.2/–3.36 –20.4/–3.62 –20.1/–3.49 –19.5/–3.46 ------Date measured 03/06/96 10/30/95 04/05/95 03/29/95 08/07/95 03/06/96 04/06/95 ------level MSL) Water- altitude (ft above (ft Aquifer of site Type 56'03" GW undiff. Trinity -- 55'34" GW54'47" U. Trinity SPR Edwards 898.29 06/21/95 1,000 -- -- 49'02" SPR59'02" Edwards GW Edwards 1,260 07/19/96 842.75 57'45" –18.6/–3.16 GW Edwards -- --53'19" 04/05/95 GW –20.9/–3.67 53'46" Edwards GW Edwards 817.72 03/28/95 708.63 -- -- 55'55" GW Edwards 925.80 06/06/9554'46" SPR53'12" Edwards GW -- U. Trinity 98554'09" 10/30/95 -- GW -- –10.9/–1.72 undiff. Trinity 50'41" SPR -- 48'47" Edwards -- GW Edwards 1,160 07/16/96 1,041.67 10/30/95 –21.9/–3.8957'49" GW -- -- Edwards 898.84 -- 04/05/9557'24" GW Leona -- 919.43 -- 04/03/95 -- -- 56'46" GW Edwards -- ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° 31'17" 98 31'42" 98 32'20" 98 34'55" 98 28'31" 98 28'25" 98 29'54" 98 25'25" 98 31'39" 98 32'17" 98 32'22" 98 30'34" 98 33'23" 98 33'02" 98 28'20" 98 27'54" 98 28'43" 98 ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° Latitude Longitude Station name/local identifier or state well no. Station or site Water-level and water-quality data-collection sites and isotopic data, Medina Lake area, Texas—Continued area, Lake Medina data, and isotopic sites data-collection water-quality and Water-level identification no. no. Site 107 293117098560301 TD–68–25–810109 293142098553401110 TD–68–25–815 293220098544701 TD–68–25–901 29 29 29 116 293455098490201117 Cedar Springs/TD–68–26–503 292831098590201 TD–68–33–101 29 119 292825098574501 TD–68–33–103 29 122 292954098531901123 TD–68–33–304 292525098534601 29 TD–68–33–603 29 29 108 293139098555501 TD–68–25–811111 293217098544601112 TD–68–25–902 293222098531201 TD–68–25–903 29 113 293034098540901 TD–68–25–904114 293323098504101 29 115 Bear Spring/TD–68–26–401 293302098484701 29 TD–68–26–502 29 29 118 292820098574901 TD–68–33–102 29 121 292754098572401 TD–68–33–205 29 29 120 292843098564601 TD–68–33–204 29 (pl. 2) Table 4.

49 Hydrogeology, Hydrologic Budget, and Water Chemistry of the Medina Lake area, Texas ------pled Date sam- 07/06/96 07/18/96 08/28/96 07/06/96 07/18/96 08/06/96 08/20/96 08/20/96 07/30/96 08/07/96 08/15/96 07/05/96 07/16/96 01/31/96 12/11/95 08/06/96 11/30/95 02/05/96 01/31/96 01/25/96 03/20/96 03/20/96 Sr 86 ------.70749 .70846 .70769 .70786 .70750 .70746 .70748 Sr/ 87 O ) 18 δ ‰ / ( D δ –23.5/–4.31 –29.9/–4.96 –29.0/–4.99 –28.6/–4.92 –21.4/–3.81 –22.7/–3.85 –23.7/–4.21 –23.3/–4.18 –26.0/–4.45 –25.8/–4.57 –24.5/–4.80 –26.3/–4.82 –25.3/–4.55 –26.1/–4.51 –24.9/–4.33 ------Date measured 03/13/95 07/11/95 07/10/95 07/10/95 03/23/95 11/30/95 ------level MSL) Water- altitude (ft above Aquifer of site Type 53'58" SPR Leona52'57" SPR Leona 890 03/29/95 –11.4/–1.84 81054'03" GW 04/01/9552'53" Edwards -- –20.7/–3.73 GW02'47" Edwards GW M. Trinity -- 746 704.28 04/03/95 1,089 04/01/95 ------03'22" GW undiff. Trinity -- 07/10/95 –27.0/–4.51 53'45" SPR Leona53'41" SPR Leona 911 03/31/95 825 04/03/95 -- –9.80/–1.53 -- -- 52'58" SPR53'49" Leona SPR Leona 825 788 03/31/95 –21.4/–3.77 03/29/95 ------04'31" SPR undiff. Trinity 1,210 07/05/9601'32" GW –13.3/–2.11 M. Trinity03'48" GW -- M. Trinity -- 04'01" GW M. Trinity -- 03'11" GW M. Trinity -- 03'19" 1,199.16 SPR undiff. Trinity 1,420 03/24/95 –22.8/–4.57 -- 00'07" GW M. Trinity -- 04'02" GW undiff. Trinity 1,139.91 03/24/95 -- -- ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° 26'39" 98 26'57" 98 26'42" 98 26'50" 98 42'45" 99 37'10" 99 27'07" 98 26'54" 98 26'56" 98 25'30" 98 42'49" 99 40'05" 99 37'36" 99 38'56" 99 38'12" 99 38'19" 99 40'15" 99 37'59" 99 ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° Latitude Longitude Station name/local identifier or state well no. Station or site Water-level and water-quality data-collection sites and isotopic data, Medina Lake area, Texas—Continued area, Lake Medina data, isotopic sites and data-collection and water-quality Water-level identification no. no. Site 124 292639098535801 Spring/TD–68–33–608 Zinsmeyer 126 29 292657098525701 Boehme Spring/TD–68–33–610 29 130 292642098540301131 TD–68–33–614 292650098525301132 TD–68–33–615 294245099024701 AS–69–24–208 29 29 29 141 293710099032201 TD–69–32–201 29 125 292707098534501 TD–68–33–609127 292654098534101Spring/TD–68–33–611 1 Haby 29 29 128 292656098525801129 Spring/TD–68–33–612 Wurzbach 292530098534901 TD–68–33–613 29 29 133 294249099043101 Springs/AS–69–24–217 Dripping 135 29 294005099013201 AS–69–24–603136 293736099034801 AS–69–24–802137 293856099040101 AS–69–24–803138 293812099031101 AS–69–24–804 29 139 293819099031901 29 Springs/AS–69–24–805 Lake Langford 29 29 29 134 294015099000701 AS–69–24–602 29 140 293759099040201 AS–69–24–901 29 (pl. 2) Table 4. Table

Table 4 50 pled Date sam- 07/16/96 08/15/95 07/10/96 07/10/96 07/10/96 08/15/96 08/20/96 08/21/96 12/11/95 12/11/95 03/13/96 03/13/96 01/24/96 12/05/95 08/21/96 Sr 86 ------.70771 .70823 .70794 .70766 Sr/ 87 O ) 18 δ ‰ / ( D δ –27.1/–4.63 –24.7/–4.63 –27.8/–4.69 –24.7/–4.79 –19.4/–3.23 –18.6/–3.24 –24.2/–4.01 –23.7/–3.93 –23.3/–3.88 –17.9/–3.11 –20.2/–3.15 ------Date measured 03/23/95 03/23/95 03/13/96 07/07/95 04/06/95 ------level MSL) Water- altitude (ft above (ft Aquifer of site Type 04'02" SPR02'00" U. Trinity GW undiff. Trinity 1,300 1,079.58 03/23/95 –23.5/–4.31 -- 00'42" SPR01'12" undiff. Trinity SPR 1,09001'03" undiff. Trinity SPR 1,140 07/10/9604'12" undiff. Trinity –25.0/–4.34 GW 1,120 07/10/96 undiff. Trinity –23.1/–4.36 07/10/9604'26" -- GW –13.6/–2.51 -- Edwards -- 01'20" -- GW Edwards -- 00'32" GW Edwards 895.89 -- ° ° ° ° ° ° ° ° ° 35'05" 99 36'40" 99 35'19" 99 35'48" 99 35'53" 99 34'38" 99 28'03" 99 28'41" 99 27'27" 99 ° ° ° ° ° ° ° ° ° Latitude Longitude Station name/local identifier or state well no. Station or site Water-level and water-quality data-collection sites and isotopic data, Medina Lake area, Texas—Continued area, Lake Medina data, and isotopic sites data-collection water-quality and Water-level identification no. no. Site 142 293505099040201143 Flying A Ranch Spring/TD–69–32–202 29 293640099020001 TD–69–32–303 29 144 293519099004201145 Spring/TD–69–32–304 Pecan Grove 293548099011201146 Sheep Spring/TD–69–32–305 29 293553099010301147 Spring/TD–69–32–306 Cypress Creek 293438099041201 29 AS–69–32–501 29 148 292803099042601 TD–69–40–202149 292841099012001 TD–69–40–301150 292727099003201 29 TD–69–40–604 29 29 29 (pl. 2) Table 4.

51 Hydrogeology, Hydrologic Budget, and Water Chemistry of the Medina Lake area, Texas loss total Lakes Medina/ average Diversion Diversion = to 9) (site 8 (site Average SW gain – loss Lake average Diversion + loss Lake Medina average loss Medina/ average Diversion Lakes total ea level; SW, surface water] water] surface SW, ea level; loss Lake average average Diversion loss Lake Medina average ise indicated; MSL, mean s indicated; MSL, mean ise loss total Lakes Medina/ average Diversion Diversion loss Lake average Diversion Diversion USGS method method Trans-Texas Current method study in acre-feet unless otherw in acre-feet unless loss Lake 20,050 11,810 31,860 19,089 10,967 30,056 20,010 9,690 7,696 22,004 Medina average (feet Lake MSL) stage above average Diversion (feet Lake MSL) stage above Medina average Table 5 Comparison of estimated average losses (recharge to the Edwards aquifer), Medina Lake area, Texas, December 1995–July 1996 1995–July December Texas, area, Lake Medina aquifer), Edwards the to losses (recharge average Comparison of estimated Date 12/9501/96 1,044.7402/96 1,044.0403/96 912.03 1,042.67 911.24 1,040.9204/96 912.03 2,85005/96 912.34 1,038.68 2,80006/96 1,310 1,035.74 2,70007/96 912.74 1,500 1,031.78 4,160 2,600 913.11 1,500 1,026.75 4,300 913.49 1,500 2,500 4,200 913.46 2,300 4,100 1,500 2,546 2,200 1,500 2,530 4,000 1,354 2,100 1,500 2,499 3,800 1,328 1,500 2,452 3,900 3,700 1,354 3,858 3,600 1,364 2,394 3,853 2,324 1,377 3,420 3,816 2,234 1,389 3,390 2,110 3,771 1,401 3,300 660 3,713 1,400 3,120 120 3,635 660 2,850 3,510 945 900 2,370 750 1,320 1,500 757 3,135 1,710 829 2,760 60 2,190 3,203 885 1,041 3,191 2,130 1,218 3,285 3,039 1,271 2,472 919 Total Table 5. Table 30 days; units month = to each [Normalized

Table 5 52 Table 6. Comparison of mixing fractions of endmember Medina Lake water and endmember Edwards aquifer water calculated from deuterium and del oxygen data and from NETPATH mixing models in selected wells and springs, MedinaTable Lake 6 area, Texas [δD, deuterium; ‰, per mil; δ18O, del oxygen; --, not determined; /, separates percent mixing fraction for NETPATH models]

δD δ18O Lake NETPATH Site no. Well or spring Date of δD δ18O (percent (percent water mixing models (pl. 2) state well no. sample (‰) (‰) lake lake (average (percent lake water) water) water) percent) 93 TD–68–25–701 11/30/95 –21.8 –3.99 17.9 16.0 16.9 -- 93 TD–68–25–701 07/29/96 –23.2 –3.97 10.2 16.6 13.4 --

110 TD–68–25–901 10/30/95 –11.5 –1.31 74.3 93.9 84.1 78.8/75.0 110 TD–68–25–901 07/09/96 –8.1 –1.05 92.9 101.5 97.2 --

111 TD–68–25–902 10/30/95 –10.9 –1.72 77.5 82.0 79.8 --

114 TD–68–26–401/ 07/16/96 –21.9 –3.89 17.3 18.9 18.1 -- Bear Spring

116 TD–68–26–503/ 07/19/96 –18.6 –3.16 35.4 40.1 37.7 -- Cedar Springs

117 TD–68–33–101 11/29/95 –17.2 –2.99 43.0 45.1 44.1 56.4/52.3 117 TD–68–33–101 08/21/96 –17.0 –3.02 44.1 44.2 44.2 57.7

119 TD–68–33–103 02/21/96 –20.9 –3.67 22.8 25.3 24.0 19.7 119 TD–68–33–103 08/06/96 –19.5 –3.46 30.4 31.4 30.9 35.4/11.0

120 TD–68–33–204 12/13/95 –21.2 –3.51 21.1 29.9 25.5 26.2/32.2 120 TD–68–33–204 08/21/96 –21.2 –3.36 21.1 34.3 27.7 29.4/34.6/27.8

123 TD–68–33–603 03/07/96 –20.4 –3.62 25.5 26.7 26.1 28.8/15.4 123 TD–68–33–603 08/20/96 –20.1 –3.49 27.2 30.5 28.8 44.6

148 TD–69–40–202 03/13/96 –19.0 –3.24 33.2 37.8 35.5 36.3/26.8/36.3/25.4 148 TD–69–40–202 08/20/96 –24.2 –4.01 4.7 15.4 10.1 10.9/5.4

149 TD–69–40–301 01/24/96 –23.7 –3.93 7.4 20.6 14.0 15.9 149 TD–69–40–301 08/21/96 –23.3 –3.88 9.6 19.2 14.4 21.5

150 TD–69–40–604 12/05/95 –17.9 –3.11 39.2 41.6 40.4 32.2/58.2 150 TD–69–40–604 08/21/96 –20.2 –3.15 26.6 40.4 33.5 58.2

53 Hydrogeology, Hydrologic Budget, and Water Chemistry of the Medina Lake area, Texas Ion exchange gas dioxide Carbon ride chlo- Sodium ium exchanged from aqueous to solid phase. For from to solid phase. aqueous For ium exchanged mass transfers are in millimoles per liter; model 1, 1, model per liter; are in millimoles transfers mass unt of mineral dissolving. For exchange, negative negative exchange, For dissolving. unt of mineral dissolution or outgassing; model 4, reverse cation cation reverse model 4, or outgassing; dissolution Mass transfer carbon dioxide milliequivalents sod milliequivalents number indicates amo number .154 .264 .030.056 .132 .067 .398 .033 -- .091 –.306 -- Calcite Dolomite Gypsum oxide gas being dissolved. Mineral Mineral being oxide gas dissolved. tion only; model 3, tion ive number indicates ive ecipitating, positive positive ecipitating, water Ground r indicates carbon di (percent) Mixing fraction Lake water s amount of mineral pr , gypsum, and sodium chloride dissolu no. Model changed from solid to aqueous phase, posit changed solid to aqueous from tes degassing, positive numbe positive tes degassing, Date sampled sults, negative number indicate sults, negative ion; model 2, dolomite nge; --, not simulated] simulated] not --, nge; spring no. State well or Table 7 Results of NETPATH simulations of mixing water from Medina Lake with water from the Edwards aquifer, Medina Lake area, Texas area, Lake Medina aquifer, Edwards the from water with Lake Medina from mixing water of simulations of NETPATH Results no. Site 110110 TD–68–25–901117 TD–68–25–901117 10/30/95 TD–68–33–101 10/30/95 TD–68–33–101 1 11/29/95 2 11/29/95 1 2 78.8 75.0 56.4 52.3 21.2 25.0 43.6 47.7 0.068 -- 0.032 –.110 – .055 .182 -- .022 0.031 -- –0.371 .037 .027 –.392 0.039 –.295 .040 .031 117119 TD–68–33–101119119 TD–68–33–103 08/21/96 TD–68–33–103120 TD–68–33–103 02/21/96120 3 08/06/96120 TD–68–33–204 08/06/96120 1 TD–68–33–204 2 TD–68–33–204 12/13/95123 3 TD–68–33–204 12/13/95 57.7123 08/21/96123 1 TD–68–33–603 19.7 08/21/96 2 TD–68–33–603 35.4148 3 TD–68–33–603 03/07/96 11.0148 42.3 4 03/07/96148 TD–69–40–202 26.2 08/20/96148 80.3 1 TD–69–40–202 32.2148 64.6 2 TD–69–40–202 03/13/96 29.4148 89.0 3 TD–69–40–202 03/13/96 34.6 –.060 TD–69–40–202 03/13/96149 73.8 1 28.8 TD–69–40–202 03/13/96149 67.8 .345 2 15.4 .232 08/20/96 70.6 .425 3 TD–69–40–301 44.6150 08/20/96 65.4 4 TD–69–40–301 --150 36.3 1 – -- 01/24/96150 71.2 TD–69–40–604 26.8 2 -- 08/21/96 -- 84.6 .049 TD–69–40–604 36.3 .141 55.4 .016 1 TD–69–40–604 12/05/95 25.4 .119 .038 2 12/05/95 10.9 .098 63.7 .058 .015 08/21/96 .114 73.2 .234 5.4 1 .150 .106 63.7 .075 2 15.9 .149 –.192 74.6 .427 3 21.5 .088 .609 -- 89.1 .126 .686 .167 –.189 -- 32.2 .337 94.6 –.001 –.489 -- -- 58.2 84.1 .191 –.621 58.2 .082 .076 –.011 -- 78.5 -- .086 -- .095 .007 .131 .109 -- .077 67.8 –.274 .014 41.8 -- –.289 2.209 –.601 .140 -- .182 41.8 –.596 2.230 –.333 –.002 1.487 –1.768 .053 –.001 –1.841 -- .436 .213 –.900 –.504 .004 .016 .371 .061 –.445 .881 -- .031 –.304 .145 .885 .019 –.490 –.062 .030 .293 .036 -- –.542 .344 .194 -- –.517 .026 –.576 .203 -- .029 –.293 .023 -- .043 .082 –.323 -- .046 –.390 .051 .030 –.630 .010 .032 .043 .044 .443 .008 .141 –.037 –.084 –.091 .003 (pl. 2) carbon dioxide gas, negative number indica negative dioxide gas, carbon calcite dissolution or precipitat (calcium for sodium) excha Table 7. Table calculated mass-transfer re [For number indicates milliequivalents calcium ex calcium milliequivalents indicates number

Table 7 54 Appendix A— AppendixHydrologic A Data

Hydrogeology, Hydrologic Budget, and Water Chemistry of the Medina Lake area, Texas Hydrogeology, Hydrologic Budget, and Water Chemistry of the Medina Lake area, Texas

Appendix A A–1 (acre-ft) (+\- error) Precipitation Diversion Lake Diversion (acre-ft) 0.08 0.05 0.02 (in.) (+\- error) 08180010 0.53 0.33 0.11 Diversion Lake (in.) precipitation (site 15) (acre-ft) (+/- error) (acre-ft) Medina Lake Medina (in.) 0.02 0.11 0.11 0.12 0.07 Average precipitation Average (+\- error) 0.11 0.70 0.75 0.77 0.44 (in.) (in.) 0.84 (site 13) (site 08179505 at main dam Medina Lake Medina precipitation (in.) 0.19 1.04 0.76 0.31 0.11 Creek Bruins (site 11) 08179240 precipitation

(in.) 0.11 0.38 0.3 0.18 0.18 Creek (site 10) Cypress 08179280 precipitation

(in.) 0.03 0.19 0.23 1.79 0.96 1.03 (site 3) (site 08179300 Elm Creek Elm precipitation (in.) 1.15 1.15 0.16 1.57 Creek (site 2) Precipitation—Continued 08179110 Red Bluff Precipitation precipitation Date 8/1/1995 8/2/1995 8/3/1995 8/4/1995 8/5/1995 8/6/1995 8/7/1995 8/8/1995 8/9/1995 9/1/1995 9/2/1995 9/3/1995 9/4/1995 9/5/1995 9/6/1995 9/7/1995 9/8/1995 9/9/1995 8/10/1995 8/11/1995 8/12/1995 8/13/1995 8/14/1995 8/15/1995 8/16/1995 8/17/1995 8/18/1995 8/19/1995 8/20/1995 8/21/1995 8/22/1995 8/23/1995 8/24/1995 8/25/1995 8/26/1995 8/27/1995 8/28/1995 8/29/1995 8/30/1995 8/31/1995 9/10/1995 9/11/1995 9/12/1995 9/13/1995 9/14/1995 Appendix A. Appendix A.Appendix acre-feet] acre-ft, inches; 2. in., table 3 and figure to correspond [Site numbers

A–2 Hydrogeology, Hydrologic Budget, and Water Chemistry of the Medina Lake area, Texas (acre-ft) (+\- error) Precipitation Diversion Lake Diversion (acre-ft) (in.) (+\- error) 08180010 Diversion Lake (in.) precipitation (site 15) (acre-ft) (+/- error) (acre-ft) Medina Lake Medina (in.) Average precipitation Average (+\- error) (in.) (in.) (site 13) (site 08179505 at main dam Medina Lake Medina precipitation (in.) Creek Bruins (site 11) 08179240 precipitation (in.) Creek (site 10) Cypress 08179280 precipitation (in.) (site 3) (site 08179300 Elm Creek Elm precipitation (in.) Creek (site 2) Precipitation—Continued 08179110 Red Bluff precipitation Date 9/15/1995 9/16/1995 9/17/1995 9/18/1995 9/19/1995 9/20/19959/21/19959/22/1995 3.819/23/1995 1.29/24/1995 0.129/25/1995 9/26/1995 4.319/27/1995 0.719/28/1995 9/29/1995 9/30/1995 4.0410/1/1995 1.3310/2/1995 10/3/1995 0.0710/4/1995 4.7310/5/1995 0.9610/6/1995 10/7/1995 0.0710/8/1995 3.1610/9/1995 1.08 0.04 4.01 1.06 0.60 0.08 0.16 1,462.65 0.01 219.40 387.11 58.07 27.77 4.73 4.17 0.96 0.71 0.14 0.07 0.01 11/1/1995 1.03 1.91 1.71 0.79 1.74 1.44 0.22 533.00 79.95 0.88 0.13 9.31 1.40 10/10/1995 10/11/1995 10/12/1995 10/13/1995 10/14/1995 10/15/1995 10/16/1995 10/17/1995 10/18/1995 10/19/1995 10/20/1995 10/21/199510/22/1995 10/23/1995 10/24/1995 10/25/1995 10/26/1995 10/27/1995 10/28/1995 10/29/1995 0.15 10/30/199510/31/1995 0.2 1.07 0.15 1.93 0.18 1.41 0.11 0.19 0.72 0.07 0.24 1.54 0.08 0.19 1.33 0.03 0.09 0.20 70.54 0.01 490.13 10.58 73.52 31.84 0.12 4.78 1.74 0.02 0.26 1.22 17.55 0.18 2.63 Appendix A.

Appendix A A–3 (acre-ft) (+\- error) Precipitation Diversion Lake Diversion (acre-ft) (in.) (+\- error) 08180010 0.12 0.02 1.27 0.19 Diversion Lake (in.) precipitation (site 15) (acre-ft) (+/- error) (acre-ft) Medina Lake Medina (in.) Average precipitation Average (+\- error) (in.) (in.) (site 13) (site 08179505 at main dam Medina Lake Medina precipitation (in.) Creek Bruins (site 11) 08179240 precipitation (in.) Creek (site 10) Cypress 08179280 precipitation (in.) (site 3) (site 08179300 Elm Creek Elm precipitation (in.) Creek (site 2) Precipitation—Continued 08179110 Red Bluff precipitation Date 11/2/1995 11/3/1995 11/4/1995 11/5/1995 11/6/1995 11/7/1995 11/8/1995 11/9/1995 12/1/1995 12/2/1995 12/3/1995 12/4/1995 12/5/1995 12/6/1995 12/7/1995 12/8/199512/9/1995 0.12 0.03 0.11 0.11 0.08 0.09 0.01 33.57 5.04 0.08 0.01 0.85 0.13 11/10/1995 11/11/1995 11/12/1995 11/13/1995 11/14/1995 11/15/1995 11/16/1995 0.03 11/17/199511/18/1995 11/19/1995 1.8611/20/1995 11/21/1995 11/22/1995 11/23/1995 1.7511/24/1995 11/25/1995 11/26/1995 11/27/1995 1.5311/28/1995 11/29/1995 11/30/1995 1.51 1.9412/10/1995 1.7212/11/1995 12/12/1995 0.2612/13/1995 12/14/1995 12/15/1995 639.2412/16/1995 12/17/1995 95.8912/18/199512/19/1995 0.65 0.08 1.07 0.07 0.16 0.07 0.18 11.24 1.69 0.15 0.07 0.08 0.2 0.23 0.03 0.11 0.02 84.09 12.61 39.07 5.86 0.12 0.02 1.16 0.17 Appendix A.

A–4 Hydrogeology, Hydrologic Budget, and Water Chemistry of the Medina Lake area, Texas (acre-ft) (+\- error) Precipitation Diversion Lake Diversion (acre-ft) (in.) (+\- error) 08180010 0.3 0.05 2.88 0.43 Diversion Lake (in.) precipitation (site 15) (acre-ft) (+/- error) (acre-ft) Medina Lake Medina (in.) Average precipitation Average (+\- error) (in.) (in.) (site 13) (site 08179505 at main dam Medina Lake Medina precipitation (in.) Creek Bruins (site 11) 08179240 precipitation (in.) Creek (site 10) Cypress 08179280 precipitation (in.) (site 3) (site 08179300 Elm Creek Elm precipitation (in.) Creek (site 2) Precipitation—Continued 08179110 Red Bluff precipitation Date 1/1/1996 1/2/1996 1/3/1996 1/4/1996 1/5/1996 1/6/1996 1/7/1996 1/8/1996 1/9/1996 2/1/1996 2/2/1996 2/3/1996 2/4/19962/5/1996 0.08 0.03 0.07 0.11 0.07 0.01 26.00 3.90 1/10/1996 1/11/1996 1/12/1996 1/13/1996 1/14/1996 1/15/1996 1/16/1996 1/17/1996 1/18/1996 1/19/1996 1/20/1996 1/21/1996 1/22/1996 1/23/1996 1/24/1996 1/25/1996 1/26/1996 1/27/1996 1/28/1996 1/29/1996 1/30/1996 1/31/1996 12/21/199512/22/1995 12/23/1995 0.0812/24/1995 12/25/1995 12/26/1995 12/27/1995 12/28/1995 12/29/199512/30/1995 12/31/1995 0.12 0.03 0.07 0.07 0.11 0.08 0.01 30.47 4.57 12/20/1995 Appendix A.

Appendix A A–5 (acre-ft) (+\- error) Precipitation Diversion Lake Diversion (acre-ft) (in.) (+\- error) 08180010 Diversion Lake (in.) precipitation (site 15) (acre-ft) (+/- error) (acre-ft) Medina Lake Medina (in.) Average precipitation Average (+\- error) (in.) (in.) (site 13) (site 08179505 at main dam Medina Lake Medina precipitation (in.) Creek Bruins (site 11) 08179240 precipitation (in.) Creek (site 10) Cypress 08179280 precipitation (in.) (site 3) (site 08179300 Elm Creek Elm precipitation (in.) Creek (site 2) Precipitation—Continued 08179110 Red Bluff precipitation Date 2/6/19962/7/1996 2/8/1996 2/9/1996 3/1/1996 3/2/1996 3/3/1996 3/4/1996 3/5/19963/6/1996 3/7/1996 3/8/1996 3/9/1996 0.03 2/10/1996 2/11/1996 2/12/1996 2/13/1996 2/14/1996 2/15/1996 2/16/1996 2/17/1996 2/18/1996 2/19/1996 2/20/1996 2/21/1996 2/22/1996 2/23/1996 2/24/1996 2/25/1996 2/26/1996 2/27/1996 2/28/19962/29/1996 0.69 0.63 0.033/10/1996 0.7 0.073/11/1996 3/12/1996 3/13/1996 3/14/1996 0.59 0.073/15/1996 3/16/1996 3/17/1996 3/18/1996 0.683/19/1996 3/20/1996 3/21/1996 3/22/1996 3/23/1996 0.663/24/1996 0.06 0.10 0.01 227.23 19.62 34.08 2.94 0.61 0.09 6.30 0.95 Appendix A.

A–6 Hydrogeology, Hydrologic Budget, and Water Chemistry of the Medina Lake area, Texas (acre-ft) (+\- error) Precipitation Diversion Lake Diversion (acre-ft) (in.) (+\- error) 08180010 Diversion Lake (in.) precipitation (site 15) (acre-ft) (+/- error) (acre-ft) Medina Lake Medina (in.) Average precipitation Average (+\- error) (in.) (in.) (site 13) (site 08179505 at main dam Medina Lake Medina precipitation (in.) Creek Bruins (site 11) 08179240 precipitation (in.) Creek (site 10) Cypress 08179280 precipitation (in.) (site 3) (site 08179300 Elm Creek Elm precipitation (in.) Creek (site 2) Precipitation—Continued 08179110 Red Bluff precipitation Date 4/1/1996 4/2/1996 4/3/1996 4/4/1996 4/5/19964/6/1996 4/7/1996 0.534/8/1996 4/9/1996 0.59 0.62 0.51 0.89 0.63 0.095/1/1996 5/2/19965/3/1996 198.135/4/1996 5/5/1996 29.725/6/1996 5/7/1996 5/8/19965/9/1996 0.77 0.12 0.15 8.21 1.23 0.56 0.36 0.05 102.60 15.39 0.44 0.07 4.69 0.70 3/25/19963/26/19963/27/19963/28/1996 0.123/29/1996 0.243/30/1996 3/31/1996 0.03 0.16 0.07 0.23 0.074/10/1996 0.24/11/1996 4/12/1996 4/13/1996 0.084/14/1996 0.164/15/1996 4/16/1996 4/17/1996 4/18/1996 0.074/19/1996 0.204/20/1996 0.014/21/1996 0.034/22/19964/23/1996 23.884/24/1996 0.12 63.674/25/1996 4/26/1996 3.58 4/27/1996 9.554/28/1996 0.074/29/1996 4/30/1996 0.99 0.2 0.11 0.59 0.03 0.11 0.3 2.135/10/1996 0.085/11/1996 0.32 1 0.10 0.01 0.4 29.62 0.66 4.44 0.10 195.05 29.26 0.53 0.08 5.70 0.85 Appendix A.

Appendix A A–7 (acre-ft) (+\- error) Precipitation Diversion Lake Diversion (acre-ft) (in.) (+\- error) 08180010 Diversion Lake (in.) precipitation (site 15) (acre-ft) (+/- error) (acre-ft) Medina Lake Medina (in.) Average precipitation Average (+\- error) (in.) (in.) (site 13) (site 08179505 at main dam Medina Lake Medina precipitation (in.) Creek Bruins (site 11) 08179240 precipitation (in.) Creek (site 10) Cypress 08179280 precipitation (in.) (site 3) (site 08179300 Elm Creek Elm precipitation (in.) Creek (site 2) Precipitation—Continued 08179110 Red Bluff precipitation Date 6/1/19966/2/1996 6/3/1996 6/4/1996 6/5/1996 6/6/1996 6/7/19966/8/1996 6/9/1996 0.11 0.11 0.24 0.15 0.02 41.62 6.24 0.28 0.04 3.03 0.46 5/12/1996 5/13/1996 5/14/1996 5/15/1996 5/16/1996 5/17/1996 5/18/1996 5/19/1996 5/20/1996 5/21/1996 5/22/1996 5/23/19965/24/1996 5/25/1996 5/26/1996 5/27/19965/28/1996 5/29/1996 0.875/30/1996 5/31/1996 0.59 0.12 0.466/10/1996 1.056/11/1996 0.156/12/1996 6/13/19966/14/1996 0.486/15/1996 0.196/16/1996 6/17/1996 6/18/1996 6/19/1996 0.696/20/1996 6/21/1996 0.106/22/1996 6/23/1996 6/24/1996 190.106/25/19966/26/1996 0.15 28.516/27/1996 0.776/28/1996 0.02 0.61 1.12 41.82 0.09 6.27 0.07 6.61 1.01 0.46 0.99 0.32 0.11 0.08 0.66 0.10 0.22 164.55 0.03 24.68 53.97 8.10 0.12 0.02 1.31 0.20 Appendix A.

A–8 Hydrogeology, Hydrologic Budget, and Water Chemistry of the Medina Lake area, Texas (acre-ft) (+\- error) Precipitation Diversion Lake Diversion (acre-ft) (in.) (+\- error) 08180010 0.4 0.06 4.37 0.66 Diversion Lake (in.) precipitation (site 15) (acre-ft) (+/- error) (acre-ft) Medina Lake Medina (in.) Average precipitation Average (+\- error) (in.) (in.) (site 13) (site 08179505 at main dam Medina Lake Medina precipitation (in.) Creek Bruins (site 11) 08179240 precipitation (in.) Creek (site 10) Cypress 08179280 precipitation (in.) (site 3) (site 08179300 Elm Creek Elm precipitation (in.) Creek (site 2) Precipitation—Continued 08179110 Red Bluff precipitation Date 7/1/1996 7/2/1996 7/3/1996 7/4/1996 7/5/1996 7/6/1996 7/7/1996 7/8/1996 7/9/1996 0.18 0.168/1/1996 8/2/1996 8/3/1996 8/4/1996 8/5/1996 0.178/6/1996 8/7/1996 0.038/8/1996 8/9/1996 40.45 6.07 0.12 0.02 1.31 0.20 6/29/1996 6/30/1996 7/10/19967/11/19967/12/1996 1.077/13/19967/14/1996 7/15/1996 7/16/1996 1.237/17/1996 7/18/1996 7/19/1996 7/20/1996 1.187/21/1996 7/22/1996 7/23/1996 7/24/1996 1.047/25/1996 7/26/1996 7/27/1996 7/28/1996 1.717/29/1996 7/30/19967/31/1996 1.25 0.12 0.19 0.02 296.44 1.35 44.478/10/1996 8/11/1996 0.20 8/12/1996 2.19 0.33 24.27 3.64 8/13/19968/14/19968/15/1996 0.36 0.2 0.19 0.08 Appendix A.

Appendix A A–9 (acre-ft) (+\- error) Precipitation Diversion Lake Diversion (acre-ft) (in.) (+\- error) 08180010 0.28 0.04 2.94 0.44 Diversion Lake (in.) precipitation (site 15) (acre-ft) (+/- error) (acre-ft) Medina Lake Medina (in.) Average precipitation Average (+\- error) (in.) (in.) (site 13) (site 08179505 at main dam Medina Lake Medina precipitation (in.) Creek Bruins (site 11) 08179240 precipitation (in.) Creek (site 10) Cypress 08179280 precipitation (in.) (site 3) (site 08179300 Elm Creek Elm precipitation (in.) Creek (site 2) Precipitation—Continued 08179110 Red Bluff precipitation Date 9/1/19969/2/1996 9/3/1996 0.129/4/19969/5/19969/6/1996 0.349/7/1996 1.379/8/19969/9/1996 0.07 0.07 0.83 0.11 0.26 0.03 0.51 0.07 0.79 0.58 0.4 0.27 0.16 0.24 0.47 0.15 0.55 0.07 0.02 0.08 92.69 29.81 108.52 13.90 4.47 16.28 0.69 1.24 0.10 0.19 6.96 11.99 1.04 1.80 8/16/1996 8/17/1996 8/18/1996 8/19/19968/20/19968/21/1996 8/22/19968/23/19968/24/1996 0.498/25/1996 0.28/26/1996 0.128/27/1996 0.23 0.61 0.15 0.07 0.77 0.39 0.12 0.07 0.58 0.3 0.87 0.12 0.07 0.5 0.59 0.22 0.39 0.12 0.11 0.11 0.43 0.59 0.16 0.64 0.08 0.22 0.28 0.44 0.03 0.29 0.04 0.07 0.27 0.04 44.65 0.61 0.04 56.68 89.50 58.92 6.70 0.09 8.50 54.78 13.43 8.84 122.09 8.22 0.32 18.31 0.77 0.05 0.36 0.12 0.05 3.49 8.28 0.52 3.84 1.24 0.58 8/28/1996 8/29/19968/30/19968/31/1996 0.28 2.75 0.43 1.27 0.19 0.42 1.129/10/1996 9/11/1996 0.11 9/12/1996 2.349/13/1996 1.849/14/1996 9/15/1996 0.129/16/1996 9/17/1996 1.21 1.079/18/1996 9/19/1996 0.079/20/19969/21/1996 0.559/22/1996 1.64 0.879/23/1996 0.119/24/1996 0.25 0.139/25/1996 0.99/26/1996 0.169/27/1996 326.51 0.11 172.429/28/1996 9/29/1996 48.98 0.599/30/1996 25.86 0.71 0.18 0.53 0.72 0.07 0.08 0.19 0.10 0.77 0.02 5.39 0.11 0.08 0.81 20.30 151.73 0.87 3.05 22.76 0.15 0.02 1 0.31 29.71 0.05 0.15 4.46 61.70 0.87 8.75 0.13 0.12 9.26 1.31 0.02 170.30 25.55 1.06 0.16 Appendix A.

A–10 Hydrogeology, Hydrologic Budget, and Water Chemistry of the Medina Lake area, Texas 2 (Smt) C-mi/hr) Stability ° parameter ( )) a -e 0 (e 2 product (u (mbar-mi/hr) Mass transfer ) 2 (u Wind speed a -e 0 e (mbar) ) a (mbar) of air at 2.0 m (e Vapor pressure Vapor (RH) 66.3 3.13 78.6 14.00 Relative humidity (percent) C, degrees Celsius; mbar, millibars; m, meters; mi/hr, milescm, hour; per millibars;meters; m,mi/hr, Celsius; degrees C, mbar, ° ) s (mbar) pressure of pressure air at 2.0 m (e m 2.0 at air Saturation vapor C) ° Air ( temperature Appendix A ) 0 (mbar) Saturation vapor Hydrogeology, Hydrologic Budget, Hydrogeology, Chemistry the of Water and Texas area, Lake Medina pressure at water- surface temperature (e C) ° ( 27.0 35.65 26.0 33.61 73.3 24.64 11.01 3.58 39.41 -0.078 Water temperature Evaporation Evaporation—Continued Date 9/6/19959/7/19959/8/19959/9/1995 29.1 28.6 26.0 26.9 40.28 39.13 33.61 35.44 62.5 67.2 77.1 68.2 25.18 26.30 25.91 24.17 6.26 4.92 4.92 3.13 10/2/199510/3/199510/4/1995 10/5/1995 10/6/1995 10/7/1995 10/8/1995 10/9/1995 25.2 21.9 32.05 26.28 73.9 64.8 23.69 17.03 3.13 11.18 9/10/19959/11/19959/12/19959/13/19959/14/19959/15/19959/16/19959/17/19959/18/19959/19/19959/20/19959/21/19959/22/1995 9/23/19959/24/19959/25/19959/26/19959/27/19959/28/19959/29/19959/30/1995 26.810/1/1995 26.5 27.6 28.2 25.2 26.6 35.23 28.1 34.62 29.0 36.92 28.3 38.24 29.1 32.05 24.4 34.82 66.2 23.2 38.01 70.9 40.05 68.3 16.2 38.46 68.8 20.3 40.28 23.32 89.3 22.9 30.56 24.54 78.9 23.7 28.43 25.22 71.8 25.5 26.31 68.7 26.8 18.41 28.62 68 25.7 23.82 27.47 67.5 25.5 27.92 27.29 82.2 29.30 27.52 83.1 32.63 26.15 35.23 2.91 27.19 59.8 33.02 3.80 25.12 62.3 32.63 7.61 23.63 60.1 5.59 61.9 2.46 11.01 70.5 4.70 14.84 72.1 9.17 16.78 70.3 4.70 18.14 70 23.00 4.92 7.16 25.40 7.83 23.21 5.37 22.84 3.58 4.70 3.36 4.25 5.14 7.16 8.95 7.16 10/10/1995 10/11/1995 10/12/1995 10/13/199510/14/199510/15/199510/16/199510/17/199510/18/199510/19/199510/20/1995 10/21/1995 10/22/1995 23.2 21.7 17.5 17.7 20.2 22.0 28.43 23.1 25.96 20.00 20.25 23.67 26.44 68.5 28.26 47.6 45.7 53.1 19.48 61.6 12.36 70.3 62.7 9.14 10.75 14.58 18.58 17.72 4.03 10.29 3.13 4.70 5.59 4.03 5.14 centimeters; in., inches; acre-ft, acre-feet] acre-ft, inches; in., centimeters; Appendix A.Appendix data. station lake supplement to used data station dam weather indicates [Shading Appendix A. Appendix

Appendix A A–11 (acre-ft) (+/-error) Evaporation (cm) (in.) (acre-ft) Diversion Lake Mass transfer Mass coefficient (N) coefficient (Harbeck, 1962) 117117116 0.00677 0.00677 0.00677 (acres) Surface area Surface (acre-ft) (+/-error) Evaporation (cm) (in.) (acre-ft) Medina Lake Medina Mass transfer coefficient (N) (Harbeck, 1962) (acres) Evaporation—Continued Evaporation—Continued Surface area Date 9/6/19959/7/1995 9/8/1995 9/9/1995 9/11/1995 9/12/1995 9/13/1995 9/14/1995 9/15/1995 9/16/1995 9/17/1995 9/18/1995 9/19/1995 9/20/19959/21/19959/22/19959/23/1995 4,3779/24/1995 4,3999/25/1995 4,4439/26/1995 4,4769/27/1995 4,497 0.00565 9/28/1995 4,508 0.00565 9/29/1995 4,508 0.00564 9/30/1995 4,508 0.00564 10/1/1995 4,520 0.00564 10/2/1995 4,520 0.0056410/3/1995 4,528 0.0056410/4/1995 4,528 0.0056410/5/1995 4,528 0.00564 10/6/1995 4,528 0.00564 10/7/1995 4,528 0.00564 10/8/1995 4,528 0.0056410/9/1995 4,528 0.00564 4,520 0.00564 4,520 0.00564 4,520 0.00564 0.222 0.00564 0.00564 0.00564 0.088 0.00564 33.02 8.25 140 142 141 0.00671 0.00670 0.00671 9/10/1995 10/10/199510/11/199510/12/199510/13/1995 4,52010/14/1995 4,52010/15/1995 4,52010/16/1995 4,50810/17/1995 4,508 0.0056410/18/1995 4,497 0.0056410/19/1995 4,497 0.0056410/20/1995 4,486 0.0056410/21/1995 4,476 0.0056410/22/1995 4,476 0.00564 4,465 0.00564 4,454 0.00564 4,454 0.00564 0.00564 0.00564 0.00564 0.00564 119 118 118 119 120 0.00676 120 0.00677 121 0.00677 122 0.00676 124 0.00676 125 0.00676 125 0.00676 126 0.00676 126 0.00675 0.00675 0.00675 0.00674 0.00674 Appendix A.Appendix Appendix A. Appendix

A–12 Hydrogeology, Hydrologic Budget, and Water Chemistry of the Medina Lake area, Texas 2 (Smt) C-mi/hr) Stability ° parameter ( )) a -e 0 (e 2 product (u (mbar-mi/hr) Mass transfer ) 2 2.02.63.52.85.2 24.904.8 9.486.7 1.719.1 5.286.9 44.17 -2.736 29.00 -0.279 62.45 78.95 0.109 35.20 0.149 -0.095 -0.072 -0.071 -0.048 -0.077 (u Wind speed a -e 0 e (mbar) ) a (mbar) of air at 2.0 m (e Vapor pressure Vapor (RH) 62.570.2 10.77 12.99 10.97 4.00 7.65 5.59 43.8959.579.89289.7 42.7684.4 -0.229 6.4369.7 7.9078.7 16.14 19.3766.9 -0.055 18.6174.1 14.13 12.3693 12.45 14.67 11.0 11.25 3.65 0.49 11.67 1.89 8.49 14.03 6.04 155.48 9.32 8.68 5.10 -0.081 Relative humidity (percent) ) s (mbar) pressure of pressure air at 2.0 m (e m 2.0 at air Saturation vapor C) 8.16.8 10.81 9.90 ° Air ( 15.418.719.115.616.414.8 17.55 13.8 21.59 13.1 22.05 17.73 18.64 16.81 15.76 15.09 temperature ) 0 (mbar) Saturation vapor pressure at water- surface temperature (e C) ° ( 21.120.420.019.919.819.3 25.0419.3 24.0319.0 23.3818.8 23.3018.8 23.06 22.36 22.36 9.4 21.97 8.8 11.9 21.74 17.7 21.74 16.9 21.9 11.79 14.3 11.33 13.93 9.9 20.25 15.2 19.25 15.2 49.217.9 26.28 82.217.8 16.30 99.317.3 71.2 12.2017.4 17.27 46.817.9 5.80 17.24 18.2 9.31 13.83 79.418.1 14.42 53.1 20.57 17.9 20.35 9.01 60.817.8 19.23 60.6 19.79 14.72 20.86 9.55 19.86 8.88 20.49 8.65 6.04 14.05 20.86 7.42 4.47 10.47 20.71 5.59 1.49 20.57 6.26 116.17 13.70 20.35 5.37 65.86 14.56 11.28 53.38 8.28 55.62 8.50 75.43 -0.321 5.37 2.01 -0.582 12.35 -0.259 116.46 -0.057 -0.100 78.15 22.70 0.038 -0.069 -0.316 -0.896 Water temperature Evaporation—Continued Date 11/1/1995 11/2/1995 11/3/199511/4/1995 10.6 12.78 56.5 7.22 13.20 11/5/1995 11/6/1995 11/7/1995 11/8/1995 11/9/1995 16.4 18.65 71 13.24 8.28 12/1/1995 12/2/1995 12/3/1995 12/4/1995 12/5/1995 12/6/1995 12/7/1995 12/8/199512/9/1995 16.8 16.4 19.13 18.65 5.6 9.09 47.7 4.34 14.31 11.86 169.69 -0.077 10/23/1995 10/24/1995 10/25/1995 10/26/1995 10/27/1995 10/28/1995 10/29/1995 10/30/1995 10/31/1995 11/15/199511/16/199511/17/199511/18/1995 18.511/19/1995 18.211/20/1995 18.011/21/1995 17.911/22/1995 18.511/23/1995 18.511/24/1995 18.6 21.3011/25/1995 18.2 20.9011/26/1995 18.2 20.6411/27/1995 18.1 20.5111/28/1995 17.9 21.3011/29/1995 17.9 21.3011/30/1995 18.1 21.43 17.4 14.9 20.90 17.1 20.90 16.3 20.77 16.4 20.51 16.9 20.51 16.9 20.77 16.94 16.9 19.87 19.50 17.2 18.51 17.4 18.65 13.6 19.25 13.2 19.25 79.3 16.8 19.25 66.9 17.3 19.62 10.8 19.87 80.4 15.57 13.44 80.7 15.17 13.04 90.1 19.13 81.6 19.75 15.00 80.1 12.95 15.54 67.4 7.86 17.35 50.5 7.85 15.71 70 15.72 77.9 5.51 3.58 13.39 71.8 5.76 4.25 45.3 3.95 7.87 5.72 4.47 10.62 14.90 28.13 5.18 2.46 14.18 33.38 7.51 2.01 12.90 3.58 5.87 24.66 6.71 9.89 14.17 5.61 5.37 -0.281 6.59 5.82 -0.061 7.95 20.47 14.00 4.47 34.77 5.14 -0.075 40.29 5.59 -0.264 15.66 75.04 -0.395 -0.133 44.23 28.84 -0.022 36.85 219.29 -0.028 -0.133 -0.235 -0.042 -0.026 -0.027 11/10/1995 11/11/1995 11/12/1995 11/13/1995 11/14/1995 12/10/199512/11/1995 16.0 15.9 18.18 18.07 4.3 11.3 8.31 13.39 37.2 61.9 3.09 8.29 15.09 9.78 6.49 6.49 97.90 63.42 -0.278 -0.109 Appendix A. Appendix

Appendix A A–13 (acre-ft) (+/-error) Evaporation (cm) (in.) (acre-ft) Diversion Lake Mass transfer Mass coefficient (N) coefficient (Harbeck, 1962) (acres) Surface area Surface (acre-ft) (+/-error) Evaporation (cm) (in.) (acre-ft) Medina Lake Medina Mass transfer coefficient (N) (Harbeck, 1962) (acres) Evaporation—Continued Surface area Date 11/1/199511/2/199511/3/199511/4/1995 4,45411/5/1995 4,46511/6/1995 4,46511/7/1995 4,46511/8/1995 4,465 0.0056411/9/1995 4,465 0.00564 4,465 0.00564 4,465 0.00564 4,465 0.00564 0.00564 0.00564 0.00564 0.656 0.00564 0.372 0.301 0.258 0.314 0.146 0.426 0.119 96.03 0.124 54.44 0.168 44.13 24.01 45.98 13.61 62.35 11.03 11.49 15.59 134 135 13612/1/1995 13712/2/1995 136 0.0067212/3/1995 127 0.0067212/4/1995 4,476 130 0.0067212/5/1995 4,476 132 0.0067212/6/1995 4,476 0.00672 0.78112/7/1995 4,476 0.00674 0.44312/8/1995 4,476 0.00564 0.00673 0.35912/9/1995 4,476 0.00564 0.308 0.00673 0.374 4,476 0.00564 0.174 0.507 4,476 0.00564 136 0.141 4,476 0.00564 0.053 0.147 3.43 0.00564 0.010 0.200 1.96 0.00564 0.030 1.60 0.00564 0.021 0.249 0.86 0.00672 1.68 0.00564 0.004 0.164 0.49 2.26 0.012 0.352 0.40 7.85 0.098 0.445 0.42 1.42 0.064 0.199 0.57 4.37 0.139 0.957 36.60 1.96 0.175 24.03 0.35 0.078 51.74 1.09 0.377 9.15 65.42 6.01 29.17 12.93 140.60 16.35 136 135 7.29 35.15 134 132 131 130 0.00672 128 0.00672 0.00672 127 126 0.00673 0.00673 0.064 0.00673 0.011 0.00674 0.036 0.00674 0.297 0.00674 0.025 0.195 0.005 0.421 0.014 0.532 0.117 0.28 0.077 0.237 1.145 0.05 0.166 0.16 0.209 1.29 0.07 0.093 0.84 0.451 0.01 1.79 0.04 2.23 0.32 0.21 0.99 4.73 0.45 0.56 0.25 1.18 10/23/199510/24/199510/25/199510/26/1995 4,44310/27/1995 4,43210/28/1995 4,42010/29/1995 4,42010/30/1995 4,420 0.0056410/31/1995 4,409 0.00564 4,409 0.00565 4,409 0.00565 4,409 0.00565 0.00565 0.00565 0.00565 0.0056511/10/199511/11/199511/12/199511/13/1995 4,47611/14/1995 4,47611/15/1995 4,46511/16/1995 4,46511/17/1995 4,465 0.0056411/18/1995 4,465 0.0056411/19/1995 4,465 0.0056411/20/1995 4,465 0.0056411/21/1995 4,476 0.00564 0.07011/22/1995 4,486 0.00564 0.65711/23/1995 4,486 0.00564 0.44111/24/1995 4,486 0.00564 126 0.027 0.12811/25/1995 4,486 0.00564 126 0.259 0.24811/26/1995 4,486 0.00564 126 0.174 0.159 10.2311/27/1995 4,486 0.00564 126 0.050 0.188 96.4911/28/1995 4,486 0.00564 124 0.098 0.241 0.00674 64.6011/29/1995 4,486 0.00564 122 0.062 2.56 0.139 0.00674 18.7711/30/1995 4,486 24.12 0.00564 122 0.074 0.080 0.00674 36.28 4,486 16.15 0.00564 121 0.095 0.045 0.00674 23.25 4,476 0.00564 121 0.055 4.69 0.115 0.00675 27.59 4,476 0.00564 0.031 9.07 0.196 0.00676 35.35 0.00564 0.018 5.81 0.227 0.00676 135 20.44 0.00564 134 0.045 6.90 0.423 0.00676 11.77 0.00564 133 0.077 8.84 0.250 0.00676 0.00564 6.60 0.089 5.11 0.163 131 17.00 0.167 2.94 0.208 130 28.87 0.00672 0.098 1.237 129 33.45 0.0067212/10/1995 1.65 0.064 4.25 0.877 127 62.31 0.0067312/11/1995 0.082 7.22 0.140 126 36.73 0.00673 0.487 8.36 128 23.95 4,465 15.58 0.00673 0.083 0.345 130 30.60 0.783 4,465 0.00674 182.08 0.055 9.18 0.526 131 0.00674 128.83 5.99 133 0.033 0.00674 0.153 7.65 45.52 0.308 134 20.63 0.00564 0.00674 0.296 32.21 0.207 135 0.00564 0.00673 136 0.190 0.060 0.37 0.225 5.16 0.00673 137 3.44 0.116 0.00673 0.288 138 2.29 0.075 0.00672 0.166 0.552 139 140 0.09 0.089 0.00672 0.66 0.095 0.358 0.86 0.00672 139 0.114 1.26 0.57 0.054 0.065 0.00672 0.80 0.138 0.217 137 0.16 0.038 0.00671 0.94 0.234 0.141 0.32 0.00671 1.19 0.271 0.00671 0.021 80.93 0.504 0.20 0.054 0.70 0.00671 52.43 0.23 0.092 0.41 0.297 0.30 20.23 0.107 0.00672 0.194 0.23 0.199 0.17 13.11 0.60 0.247 1.471 0.10 0.117 1.03 1.044 0.076 1.20 0.06 2.25 0.15 0.097 0.579 0.167 0.26 1.34 0.411 124 0.30 0.88 122 0.56 0.066 1.13 6.76 0.33 4.76 0.22 0.00675 0.28 1.69 0.75 0.00676 1.19 0.19 0.661 0.428 0.260 0.169 2.69 1.72 0.67 0.43 Appendix A. Appendix

A–14 Hydrogeology, Hydrologic Budget, and Water Chemistry of the Medina Lake area, Texas 2 (Smt) C-mi/hr) Stability ° parameter ( )) a -e 0 (e 2 product (u (mbar-mi/hr) Mass transfer ) 2 (u Wind speed a -e 0 e (mbar) ) a (mbar) of air at 2.0 m (e Vapor pressure Vapor (RH) Relative humidity (percent) ) s (mbar) pressure of pressure air at 2.0 m (e m 2.0 at air Saturation vapor C) 9.6 11.96 ° Air ( 11.311.710.911.912.7 13.37 13.72 13.03 13.92 14.6516.5 18.77 temperature ) 0 (mbar) Saturation vapor pressure at water- surface temperature (e C) ° ( 11.812.312.611.8 13.82 14.28 14.60 13.87 13.1 15.03 Water temperature Evaporation—Continued Date 1/1/19961/2/19961/3/19961/4/1996 13.81/5/1996 13.21/6/1996 13.01/7/1996 13.01/8/1996 12.81/9/1996 12.4 12.1 15.78 11.9 15.17 12.0 14.98 14.98 14.78 14.40 14.12 10.4 13.93 14.02 5.7 5.6 9.0 8.7 3.6 12.61 1.8 3.0 9.16 8.2 9.09 11.48 11.25 75.7 7.91 6.96 56.6 7.58 48.5 10.87 59.6 9.55 69.9 63.9 5.18 50.1 4.41 6.84 58.6 57.4 6.23 7.86 5.05 9.99 10.57 3.48 13.87 8.13 4.44 6.24 6.92 16.55 6.93 9.35 86.42 10.63 3.58 8.28 165.37 9.49 7.78 15.66 73.27 6.04 29.11 -0.018 4.70 57.26 3.13 146.36 -0.027 64.22 -0.154 -0.312 44.59 24.37 -0.060 -0.036 -0.282 -0.403 -0.387 1/10/1996 12.2 14.21 1/12/1996 1/13/1996 1/14/1996 1/15/19961/16/19961/17/19961/18/1996 13.91/19/1996 12.61/20/1996 12.51/21/1996 11.81/22/1996 11.31/23/1996 11.71/24/1996 11.5 15.88 1/25/1996 11.5 14.591/26/1996 12.1 14.491/27/1996 12.1 13.841/28/1996 11.7 13.391/29/1996 11.9 13.751/30/1996 11.8 13.57 11.6 13.57 12.4 14.0 14.12 17.9 14.12 10.4 13.75 13.93 3.5 13.84 8.9 12.2 13.66 15.98 16.2 14.40 20.51 17.7 12.61 10.4 11.7 7.85 14.6 11.40 14.21 74 7.1 18.41 76.8 9.4 20.25 13.8 12.61 13.75 68.3 11.83 16.62 15.75 55 85.8 10.09 66.1 11.79 15.78 30.3 7.79 2.76 69.1 -1.26 15.80 56.8 7.82 13.39 26.6 11.86 4.47 3.82 66.2 5.96 9.50 -2.23 15.21 9.44 5.75 -14.90 0.73 12.35 2.68 6.93 2.01 10.30 10.74 7.81 5.82 4.25 10.07 4.49 5.14 11.16 0.038 12.00 -23.95 0.070 -0.006 9.17 33.46 5.85 8.72 7.36 -0.162 5.82 52.97 5.82 -0.691 38.97 0.041 3.80 39.20 0.021 64.89 0.055 -0.064 34.03 0.000 0.035 -0.139 -0.065 0.097 1/11/1996 12/12/199512/13/199512/14/199512/15/1995 16.012/16/1995 16.412/17/1995 16.612/18/1995 17.312/19/1995 16.812/20/1995 17.112/21/1995 16.2 18.1812/22/1995 15.9 18.6512/23/1995 15.6 18.8912/24/1995 15.2 19.7512/25/1995 14.9 19.1312/26/1995 14.7 19.5012/27/1995 14.5 18.4112/28/1995 14.4 15.5 18.0712/29/1995 14.3 17.0 17.7212/30/1995 14.1 19.3 17.2712/31/1995 14.0 20.3 16.94 13.7 16.1 16.73 13.7 18.9 16.51 14.0 17.61 12.5 16.40 19.38 16.30 8.9 22.39 16.09 5.7 23.82 15.98 5.2 18.30 15.68 5.9 21.83 78.6 15.68 5.4 14.49 82.9 15.98 5.7 79 11.40 9.7 72.5 7.6 9.16 13.84 67 8.9 8.85 16.06 90.7 10.0 9.29 73.5 17.69 7.3 8.97 17.27 12.4 57.4 9.16 14.3 12.03 4.34 12.26 73.1 19.80 10.44 2.59 75.7 10.65 11.40 12.28 75.4 1.20 2.48 4.25 6.55 60.7 10.23 4.70 14.40 61.6 6.87 -0.31 6.69 53.8 16.30 6.93 6.70 7.76 4.92 63.8 18.45 7.00 65 11.52 52.1 5.59 3.58 12.16 5.44 13.42 11.03 5.64 85.5 6.47 96.9 12.20 8.35 10.58 12.53 6.66 69.5 -0.028 9.94 38.43 -1.09 104.18 11.28 5.37 6.40 7.41 0.027 10.87 2.46 144.31 8.74 13.95 9.93 8.72 0.124 0.056 11.33 9.64 4.47 59.20 -0.022 3.58 -0.021 0.141 9.59 8.68 26.03 3.13 -0.045 6.93 2.91 1.72 86.72 50.47 4.66 4.92 4.03 38.90 -0.343 31.10 5.59 3.36 -1.652 28.03 3.36 -0.118 -0.465 47.18 34.94 -0.687 38.77 -0.479 5.78 15.63 -0.792 -0.165 -0.321 -0.205 -0.115 0.027 Appendix A. Appendix

Appendix A A–15 (acre-ft) (+/-error) Evaporation (cm) (in.) (acre-ft) Diversion Lake Mass transfer Mass coefficient (N) coefficient (Harbeck, 1962) (acres) Surface area Surface (acre-ft) (+/-error) Evaporation (cm) (in.) (acre-ft) Medina Lake Medina Mass transfer coefficient (N) (Harbeck, 1962) (acres) Evaporation—Continued Surface area Date 1/1/19961/2/19961/3/19961/4/1996 4,4321/5/1996 4,4321/6/1996 4,4201/7/1996 4,4201/8/1996 4,420 0.005641/9/1996 4,420 0.00564 4,409 0.00565 4,409 0.00565 4,409 0.00565 0.488 0.00565 0.933 0.00565 0.414 0.00565 0.192 0.164 0.00565 0.368 0.323 0.163 0.826 70.94 135.74 0.065 0.363 0.127 0.252 59.98 17.73 0.325 0.138 33.93 23.84 0.143 46.88 15.00 119.82 0.099 0.054 5.96 52.45 11.72 29.96 36.42 119 19.91 118 13.11 118 9.10 4.98 117 117 0.00676 116 0.00677 116 0.00677 115 0.00677 115 0.00677 0.585 0.00677 1.119 0.00677 0.496 0.230 0.00678 0.441 0.197 0.388 0.00678 0.991 0.195 2.28 0.435 0.078 4.33 0.153 0.390 0.302 1.92 0.165 0.57 0.171 1.08 0.76 1.49 0.119 3.77 0.48 0.065 1.66 0.19 0.37 0.94 1.14 0.62 0.41 0.28 0.16 1/10/19961/11/19961/12/19961/13/1996 4,4091/14/1996 4,3991/15/1996 4,3991/16/1996 4,3991/17/1996 4,388 0.005651/18/1996 4,388 0.005651/19/1996 4,388 0.005651/20/1996 4,377 0.005651/21/1996 4,377 0.005651/22/1996 4,366 0.005651/23/1996 4,366 0.005651/24/1996 4,366 0.005651/25/1996 4,355 0.005651/26/1996 4,355 0.005651/27/1996 4,355 0.00565 0.0701/28/1996 4,345 0.00565 -0.0841/29/1996 4,345 0.00565 1/30/1996 4,345 0.00565 0.027 -0.033 4,334 117 0.00565 0.068 4,334 117 0.00565 0.189 10.04 -12.09 4,334 0.00565 -0.135 0.00565 0.027 0.042 0.00565 -3.02 0.074 2.51 0.299 0.00677 -0.053 0.00565 0.220 0.00677 0.00565 9.71 0.016 0.222 27.08 -19.34 0.118 0.367 0.087 0.192 2.43 5.94 -4.83 0.087 6.77 118 118 42.76 0.144 31.39 115 0.076 31.58 1.48 10.69 117 52.27 117 7.85 27.35 0.00677 117 118 0.00677 7.89 118 118 13.07 118 0.00678 118 6.84 0.00677 118 118 0.00677 -0.101 0.084 0.00677 0.00677 118 0.00677 0.00677 0.00677 118 118 -0.040 0.00677 0.033 0.00677 119 0.00677 0.081 -0.162 -0.39 0.00677 0.226 0.00677 0.32 0.00677 -0.064 0.032 -0.10 0.050 0.358 0.089 0.00676 0.08 0.264 -0.63 0.265 0.020 0.31 0.141 0.439 0.88 0.104 119 0.230 -0.16 0.104 119 0.08 0.19 0.173 1.39 0.22 0.091 1.02 1.03 0.05 0.35 0.00676 1.70 0.00676 0.26 0.90 0.26 0.43 0.22 12/12/199512/13/199512/14/199512/15/1995 4,46512/16/1995 4,46512/17/1995 4,46512/18/1995 4,46512/19/1995 4,465 0.0056412/20/1995 4,465 0.0056412/21/1995 4,465 0.0056412/22/1995 4,454 0.0056412/23/1995 4,454 0.00564 0.10412/24/1995 4,454 0.00564 0.06912/25/1995 4,454 0.00564 0.04712/26/1995 4,454 0.00564 0.041 0.06912/27/1995 4,443 0.00564 0.027 0.21712/28/1995 4,443 0.00564 -0.006 0.019 15.2512/29/1995 4,443 0.00564 0.027 0.588 10.0512/30/1995 4,443 0.00564 0.085 0.814 -0.00212/31/1995 4,443 0.00564 6.91 3.81 0.334 10.08 4,432 0.00564 0.231 2.51 0.147 31.77 4,432 0.00564 -0.90 0.321 0.489 1.73 4,432 0.00564 0.132 2.52 0.285 86.12 0.00564 119.01 0.058 7.94 0.220 -0.23 0.00564 0.193 0.176 121 48.82 21.53 0.00564 0.112 0.158 29.75 119 21.46 0.00564 0.086 0.197 71.52 12.21 118 0.069 0.266 118 41.62 0.062 5.37 0.219 117 32.01 117 17.88 0.00676 0.078 0.033 25.59 10.41 0.00676 116 0.105 0.088 23.06 116 0.086 8.00 0.00677 28.75 0.00677 115 0.013 6.40 38.82 0.00677 0.125 0.035 0.00677 5.77 115 31.82 115 0.082 7.19 0.00677 4.75 117 0.00677 9.70 0.057 12.83 0.049 0.083 7.96 118 0.00678 0.032 -0.007 0.260 119 1.19 0.00678 3.21 0.022 121 0.00678 0.706 0.032 0.49 0.977 122 0.00677 -0.003 0.102 0.32 121 0.401 0.00677 0.22 0.278 121 0.12 0.00676 0.32 0.385 0.176 -0.03 0.588 0.08 119 0.00676 1.00 0.158 119 0.342 0.00676 0.05 2.69 0.08 -0.01 0.069 0.00676 0.263 3.72 0.231 0.25 0.00676 0.210 0.135 1.51 0.189 0.67 0.00676 0.104 0.93 0.00676 0.67 0.236 2.22 0.083 0.319 0.38 1.31 0.075 0.262 0.17 0.093 1.02 0.55 0.039 0.126 0.82 0.106 0.33 0.103 0.75 0.25 0.94 0.015 0.21 0.042 1.27 0.19 1.04 0.24 0.15 0.32 0.41 0.26 0.04 0.10 Appendix A. Appendix

A–16 Hydrogeology, Hydrologic Budget, and Water Chemistry of the Medina Lake area, Texas 2 (Smt) C-mi/hr) Stability ° parameter ( )) a -e 0 (e 2 product (u (mbar-mi/hr) Mass transfer ) 2 (u Wind speed a -e 0 e (mbar) ) a (mbar) of air at 2.0 m (e Vapor pressure Vapor (RH) 43.848.553.241.7 10.6778.1 12.6186.1 14.35 9.04 19.76 6.08 21.02 4.23 3.37 4.30 7.58 -2.92 3.90 -3.52 7.60 7.80 6.50 26.14 4.00 16.49 25.61 -18.99 59.14 -14.09 0.321 0.455 0.117 0.153 0.069 0.331 Relative humidity (percent) ) s (mbar) pressure of pressure air at 2.0 m (e m 2.0 at air Saturation vapor C) 0.94.3 6.54 8.32 ° Air ( -1.7-2.1-1.8 5.38 5.25 5.36 20.721.722.318.821.3 24.36 25.99 26.98 21.67 25.29 temperature ) 0 (mbar) Saturation vapor pressure at water- surface temperature (e C) ° ( 12.311.110.8 14.34 13.22 12.93 14.7 16.75 Water temperature Evaporation—Continued Date 3/1/19963/2/19963/3/19963/4/1996 13.73/5/1996 13.73/6/1996 13.73/7/1996 13.93/8/1996 15.03/9/1996 15.5 12.7 15.68 12.7 15.68 12.7 15.68 15.88 17.05 17.61 14.69 14.69 5.1 14.69 9.2 12.7 16.7 20.0 17.8 3.6 8.78 11.64 4.1 14.69 5.0 19.01 23.38 20.38 89.1 67.9 7.91 65.7 8.19 91.7 8.72 82 71 7.83 7.90 9.65 43.9 17.43 31.3 19.17 33.5 14.47 7.85 7.78 6.03 -1.55 3.47 2.56 3.80 -2.12 5.37 2.92 6.71 3.14 9.62 11.21 5.14 12.12 29.85 41.74 8.95 11.76 -14.92 40.45 17.67 -10.91 6.04 2.68 28.09 -0.595 198.18 -0.156 -0.022 0.030 73.21 0.189 31.58 0.029 -0.029 -0.236 -1.069 2/3/1996 2/4/19962/5/1996 10.9 13.04 2/1/19962/2/1996 11.3 11.52/6/19962/7/19962/8/19962/9/1996 10.5 10.7 13.39 11.4 13.57 12.6 12.70 12.87 13.48 -0.2 14.59 13.8 15.1 6.02 16.0 14.9 15.78 86.6 17.16 18.18 16.94 5.21 73.2 71.6 77.1 8.18 12.56 13.02 13.06 6.71 0.30 0.46 54.88 1.53 8.28 6.49 2.91 -0.255 2.52 2.99 4.44 0.064 0.109 0.272 2/22/19962/23/19962/24/19962/25/1996 14.82/26/1996 15.62/27/1996 14.62/28/1996 14.82/29/1996 15.4 16.0 14.5 16.83 13.8 17.72 16.62 16.83 17.50 18.18 16.51 15.783/10/19963/11/19963/12/19963/13/1996 12.6 20.73/14/1996 12.5 21.03/15/1996 12.73/16/1996 9.4 13.23/17/1996 3.9 14.53/18/1996 16.23/19/1996 17.1 24.41 14.593/20/1996 16.9 24.87 14.49 15.4 11.79 14.69 15.1 15.17 8.08 15.1 16.51 18.41 76.3 19.50 19.25 50.7 8.2 11.1 17.50 73.9 14.0 17.16 18.97 17.6 17.16 20.5 5.98 19.7 18.9 5.97 10.87 13.21 -0.79 18.2 15.98 15.4 10.53 20.12 12.1 24.11 3.58 10.8 9.81 22.95 11.86 41.9 21.83 59.2 20.90 70.7 6.71 17.50 -2.84 73.1 124.86 14.12 61.2 4.56 12.95 65.4 7.82 11.30 71 65.84 14.71 56.6 0.390 14.76 46.8 -0.036 10.03 15.01 42.5 6.67 43.3 3.38 15.50 -0.220 11.83 0.46 6.04 1.75 8.19 9.84 3.41 8.28 6.00 10.74 5.61 4.00 7.42 6.49 60.60 2.68 65.66 9.31 28.01 11.16 3.13 4.97 11.55 5.14 11.37 14.99 -0.121 8.72 9.14 -0.014 4.47 12.51 0.019 38.20 139.50 0.038 0.143 97.38 51.69 0.486 0.184 0.049 0.000 -0.039 -0.215 1/31/1996 2/10/19962/11/19962/12/19962/13/1996 13.22/14/1996 11.62/15/1996 11.62/16/1996 11.72/17/1996 12.42/18/1996 12.12/19/1996 11.9 15.172/20/1996 11.8 13.662/21/1996 12.4 13.66 12.8 13.75 13.4 14.40 14.12 13.93 17.3 13.84 13.5 14.40 10.3 14.78 15.37 10.3 14.7 15.6 19.75 9.5 15.47 10.5 12.53 13.3 12.53 16.6 16.73 17.72 81.8 32.9 11.87 12.70 31.4 15.27 45.5 18.89 16.15 59.3 45.1 5.09 3.93 34.4 57.7 5.70 83.9 -0.98 9.92 53.3 7.99 8.57 9.73 4.08 3.80 7.33 8.05 12.81 11.86 4.48 10.07 6.12 4.92 4.03 -3.72 9.85 101.58 6.51 2.24 1.58 6.93 4.71 47.86 6.49 32.41 5.59 3.13 10.02 0.284 0.014 3.80 42.47 -0.054 63.88 36.43 -0.086 4.96 17.92 0.460 0.073 -0.057 -0.042 0.092 0.263 Appendix A. Appendix

Appendix A A–17 (acre-ft) (+/-error) Evaporation (cm) (in.) (acre-ft) Diversion Lake Mass transfer Mass coefficient (N) coefficient (Harbeck, 1962) (acres) Surface area Surface (acre-ft) (+/-error) Evaporation (cm) (in.) (acre-ft) Medina Lake Medina Mass transfer coefficient (N) (Harbeck, 1962) (acres) Evaporation—Continued Surface area Date 2/1/19962/2/19962/3/19962/4/1996 4,3132/5/1996 4,3132/6/1996 4,3032/7/1996 4,3032/8/1996 4,292 0.005652/9/1996 4,292 0.00565 4,281 0.00565 4,281 0.00565 4,281 0.00565 0.310 0.00565 0.00565 0.00565 0.122 0.00565 43.89 0.014 0.017 10.97 0.025 0.006 0.007 0.010 2.00 2.38 121 3.53 0.50 0.59 0.88 0.006763/1/19963/2/19963/3/1996 1223/4/1996 4,144 122 0.3713/5/1996 4,132 121 1213/6/1996 4,132 1203/7/1996 4,121 119 0.00676 0.1463/8/1996 4,121 0.00566 119 0.006763/9/1996 4,121 0.00566 121 0.00676 0.00676 4,109 0.00566 0.00676 1.47 4,099 0.00567 0.00676 0.017 4,099 0.00567 0.169 0.00676 0.020 0.00567 0.236 0.37 0.00676 0.030 0.00567 0.229 0.007 0.00567 -0.085 0.067 0.008 0.00567 -0.062 0.093 0.012 0.090 0.159 0.07 -0.033 22.99 1.123 0.08 -0.024 32.06 0.415 0.12 31.07 -11.43 0.063 0.02 5.75 0.179 -8.35 0.442 0.02 8.01 -2.86 0.163 0.03 7.77 21.51 151.38 0.070 -2.09 55.80 5.38 37.85 122 24.06 122 13.95 124 124 6.02 124 0.00676 124 124 0.00676 0.00675 0.00675 124 0.00675 124 0.202 0.00675 0.282 0.00675 -0.101 0.273 0.00675 0.079 -0.074 0.111 0.00675 -0.040 0.108 0.190 1.338 -0.029 0.81 0.494 -0.41 1.13 0.075 1.11 0.527 0.213 -0.30 0.20 -0.10 0.195 0.28 0.28 -0.07 0.084 0.77 5.44 2.01 0.19 1.36 0.87 0.50 0.22 1/31/1996 4,324 0.005652/10/19962/11/19962/12/19962/13/1996 4,2712/14/1996 4,2712/15/1996 4,2712/16/1996 4,2502/17/1996 4,250 0.005662/18/1996 4,239 0.005662/19/1996 4,229 0.005662/20/1996 4,229 0.005662/21/1996 4,218 0.00566 -0.0212/22/1996 4,208 0.00566 0.5742/23/1996 4,208 0.00566 0.271 -0.0082/24/1996 4,197 0.00566 0.1832/25/1996 4,197 0.00566 0.226 0.0572/26/1996 4,186 0.00566 -2.95 0.107 0.2402/27/1996 4,186 0.00566 0.072 0.361 80.502/28/1996 4,176 0.00566 0.022 0.206 37.93 -0.742/29/1996 4,165 0.00566 0.095 0.028 25.56 4,155 20.13 0.00566 0.142 0.101 4,155 0.00566 7.91 0.081 9.48 33.42 4,144 0.00566 120 0.011 6.39 0.148 50.15 0.00566 0.040 0.093 28.60 1.98 122 0.00566 8.35 0.145 12.54 0.00566 3.89 122 0.058 0.335 14.01 0.00566 -0.108 0.037 7.15 0.00676 122 -0.080 0.057 122 20.37 0.97 -0.016 0.132 0.00676 3.50 -0.042 12.853/10/1996 122 0.707 122 -0.031 19.91 0.006763/11/1996 122 5.09 0.373 -0.006 45.98 -14.733/12/1996 0.00676 3.21 124 -10.913/13/1996 4,087 0.00676 -0.025 0.278 4.983/14/1996 4,087 11.49 124 -2.19 -3.68 0.147 0.00676 122 0.6863/15/1996 4,076 0.00676 -2.73 96.39 0.00676 -0.0103/16/1996 4,076 0.323 122 50.70 -0.553/17/1996 4,065 0.00567 0.00675 0.219 0.270 1223/18/1996 4,065 24.10 0.00567 -0.10 0.00675 122 0.0683/19/1996 4,053 12.67 0.127 0.00567 0.00676 124 0.287 124 0.4323/20/1996 4,053 0.086 0.00567 124 2.75 4,042 -0.03 0.00567 0.00676 0.246 0.343 0.027 124 4,021 0.113 0.00567 0.00676 1.29 0.372 0.170 0.034 4,008 0.00567 122 0.00676 0.88 124 0.121 0.159 0.69 0.00675 0.00675 0.097 0.00567 124 0.135 0.028 0.27 0.32 0.00675 0.00567 1.15 0.177 0.147 0.064 0.013 1.73 0.22 0.048 0.00567 0.111 0.063 0.00675 0.052 46.05 0.00567 1.00 0.173 0.011 0.07 0.071 0.00676 49.90 0.00675 -0.128 0.399 0.29 0.070 0.025 0.217 0.43 0.14 21.23 0.00675 -0.095 11.51 0.044 0.48 0.020 0.791 0.25 12.48 0.068 3.76 -0.019 0.028 -0.050 0.552 0.157 8.60 0.71 0.085 -0.037 0.03 5.31 0.293 0.843 0.12 6.91 0.45 0.311 -0.008 0.444 0.94 -0.52 9.43 0.69 0.217 28.80 1.62 2.15 0.18 -0.39 122 104.91 0.115 0.332 1.73 0.11 122 -0.08 -0.13 0.175 72.87 2.36 0.17 7.20 0.41 26.23 -0.10 122 38.56 3.43 18.22 -0.02 121 0.00676 1.81 121 9.64 0.00676 121 0.86 121 0.00676 0.45 122 122 0.00676 0.409 122 0.00676 0.444 0.00676 122 0.189 0.00676 0.161 0.00676 0.00676 0.175 0.034 0.077 0.00676 0.074 0.062 1.64 0.00676 0.013 0.085 1.78 0.258 0.942 0.030 0.76 0.024 0.41 0.658 0.033 0.44 0.13 0.102 0.371 0.349 0.31 0.19 0.25 0.259 0.03 0.34 0.137 1.03 3.77 0.08 0.06 2.63 0.08 0.26 0.94 1.40 0.66 0.35 Appendix A. Appendix

A–18 Hydrogeology, Hydrologic Budget, and Water Chemistry of the Medina Lake area, Texas 2 (Smt) C-mi/hr) Stability ° parameter ( )) a -e 0 (e 2 product (u (mbar-mi/hr) Mass transfer ) 2 7.40 6.7 19.52 0.047 (u Wind speed a -e 0 e (mbar) ) a (mbar) of air at 2.0 m (e Vapor pressure Vapor (RH) 58.878.973.146.5 17.3747.4 22.9264.3 22.7784.284 8.31 8.80 8.74 15.14 3.52 21.15 2.3581.4 16.82 9.90 23.7686.9 15.79 5.6078.5 8.98 7.10 13.00 3.04 24.45 87.12 5.10 23.84 0.61 19.69 5.10 23.97 16.68 218.63 4.70 6.40 80.52 1.81 0.020 45.78 2.50 0.050 14.30 2.91 -0.032 0.071 6.60 3.89 6.70 -0.175 -0.015 0.028 11.94 16.78 0.060 0.051 0.015 Relative humidity (percent) ) s (mbar) pressure of pressure air at 2.0 m (e m 2.0 at air Saturation vapor C) ° Air ( 23.823.624.715.716.220.1 29.54 21.2 29.05 23.1 31.15 17.86 18.44 23.54 24.1 25.12 22.6 28.28 24.4 30.04 27.44 30.54 temperature ) 0 (mbar) Saturation vapor pressure at water- surface temperature (e C) ° ( 21.822.021.221.220.820.520.6 26.17 20.7 26.44 25.12 25.12 24.53 21.9 24.11 21.9 24.20 22.3 24.36 26.26 26.35 26.89 Water temperature Evaporation—Continued Date 5/1/1996 5/2/1996 5/3/1996 5/4/1996 5/5/1996 5/6/1996 5/7/1996 5/8/1996 5/9/1996 4/1/19964/2/19964/3/19964/4/1996 15.14/5/1996 15.14/6/1996 15.24/7/1996 15.84/8/1996 15.24/9/1996 14.8 15.5 17.16 16.7 17.16 17.1 17.27 17.95 17.27 16.83 17.61 16.1 19.01 15.1 19.50 18.0 20.2 9.1 9.9 18.30 11.4 17.16 15.9 20.64 18.6 23.67 11.56 42.5 12.20 13.48 57.1 18.07 76.8 21.43 71.7 7.78 89.1 9.80 60.9 15.85 60.6 16.97 60 58 10.30 9.39 7.36 7.43 1.42 8.17 0.98 10.84 2.91 12.43 6.97 8.50 10.29 9.41 4.03 9.44 11.63 27.29 8.17 62.58 14.64 7.07 8.50 3.36 3.94 2.46 81.13 2.46 0.118 79.95 0.000 0.026 31.68 20.11 0.271 -0.045 17.40 -0.068 -0.364 -0.132 0.248 4/27/1996 4/28/1996 4/29/1996 4/30/1996 3/21/19963/22/19963/23/19963/24/1996 15.13/25/1996 15.33/26/1996 15.33/27/1996 16.13/28/1996 15.13/29/1996 14.13/30/1996 13.7 17.163/31/1996 14.7 17.38 14.4 17.38 14.9 18.30 15.0 17.16 16.09 15.68 13.3 16.73 17.5 16.40 17.1 16.94 19.5 17.054/10/1996 10.44/11/19964/12/1996 5.6 15.274/13/1996 5.9 17.5 20.00 12.44/14/1996 16.6 19.50 14.34/15/1996 18.1 22.67 20.44/16/1996 18.2 12.61 16.44/17/1996 18.5 53.64/18/1996 9.09 17.9 71.64/19/1996 9.29 18.1 14.40 84 20.004/20/1996 18.2 16.30 76.9 18.894/21/1996 20.0 23.97 50.6 8.19 20.774/22/1996 20.5 18.65 14.32 20.904/23/1996 20.3 73.2 21.304/24/1996 16.38 20.2 94.6 17.43 67.1 20.514/25/1996 20.3 89.5 6.38 20.774/26/1996 20.2 8.98 60 20.5 3.07 20.90 20.4 46.1 20.7 6.66 23.38 20.1 1.01 22.5 8.78 0.87 9.66 24.11 7.61 11.63 14.59 21.4 10.78 23.82 22.8 23.67 14.99 14.38 17.4 6.93 8.60 23.82 9.43 24.11 11.63 17.0 23.67 68.27 35.66 6.89 7.06 24.41 19.8 1.82 23.97 27.25 23.53 10.51 23.5 15.07 25.48 2.56 125.40 25.0 6.01 9.62 8.45 4.25 27.75 22.8 6.04 19.87 -0.031 57.9 24.4 0.016 19.38 99.16 74.1 7.83 21.7 7.38 23.09 61.1 0.008 19.1 66.29 30.02 -0.035 28.95 58.1 10.98 20.6 0.071 31.67 13.96 50 20.07 27.75 18.09 36 -0.077 62.41 30.56 16.65 44.7 25.96 -0.084 14.81 -0.127 69.1 -0.003 22.11 68.9 6.04 13.88 24.26 71.1 0.80 0.090 56.8 7.15 0.026 4.12 8.66 15.96 74.2 6.09 6.71 14.32 19.95 77.8 22.52 7.42 53.6 7.83 15.76 13.35 49.2 12.11 7.61 22.67 40.51 4.94 10.96 11.45 20.19 3.43 11.63 11.85 32.23 1.59 7.83 11.41 11.94 46.33 66.9 8.05 81.32 1.00 4.70 0.067 155.34 3.62 0.020 7.83 11.82 94.79 4.70 56.38 0.072 12.03 13.42 0.055 10.51 16.12 5.82 0.036 12.48 -0.004 7.61 37.84 -0.018 13.37 0.012 38.10 68.75 0.159 91.48 0.073 0.113 0.023 0.013 -0.033 10.07 0.003 -0.198 Appendix A. Appendix

Appendix A A–19 (acre-ft) (+/-error) Evaporation (cm) (in.) (acre-ft) Diversion Lake Mass transfer Mass coefficient (N) coefficient (Harbeck, 1962) (acres) Surface area Surface (acre-ft) (+/-error) Evaporation (cm) (in.) (acre-ft) Medina Lake Medina Mass transfer coefficient (N) (Harbeck, 1962) (acres) Evaporation—Continued Surface area Date 4/1/19964/2/19964/3/19964/4/1996 3,8224/5/1996 3,8104/6/1996 3,7984/7/1996 3,7864/8/1996 3,786 0.005694/9/1996 3,786 0.00569 3,775 0.00569 3,775 0.00569 3,763 0.00569 0.155 0.00569 0.356 0.00569 0.083 0.00569 0.061 0.022 0.00569 0.140 0.462 0.033 0.455 19.46 0.009 0.180 44.50 0.182 0.114 10.38 0.179 4.87 0.099 11.12 2.78 0.071 57.34 0.045 2.59 56.50 0.039 22.32 0.70 14.33 14.17 14.13 130 12.22 130 5.58 3.54 130 3.06 130 128 0.00673 127 0.006735/1/1996 1265/2/1996 0.00673 1255/3/1996 0.00673 122 0.006745/4/1996 3,550 0.184 0.00674 0.4215/5/1996 3,5315/6/1996 3,522 0.00674 0.0995/7/1996 3,513 0.072 0.00675 0.166 0.027 0.5475/8/1996 3,504 0.00571 0.00676 0.5395/9/1996 3,495 0.039 0.00571 3,477 0.00571 0.78 0.214 0.010 0.215 1.80 3,468 0.00571 0.136 0.212 3,468 0.00571 0.42 0.118 0.261 0.20 0.084 0.00571 0.082 0.45 0.11 2.30 0.053 0.00571 0.022 2.25 0.11 0.046 0.00571 0.103 0.00571 0.88 0.032 0.03 0.57 0.56 0.009 0.56 30.43 0.47 0.068 0.22 9.46 0.096 0.14 2.56 7.61 0.112 0.12 0.027 2.36 0.038 0.64 0.044 7.78 10.91 128 12.69 1.95 128 2.73 128 3.17 0.00674 0.00674 128 0.00674 128 132 0.309 0.096 128 0.00674 0.026 0.121 128 0.00674 128 0.00673 0.038 0.010 1.30 0.00674 0.080 0.113 0.40 0.00674 0.131 0.11 0.00674 0.32 0.032 0.045 0.10 0.052 0.03 0.34 0.47 0.57 0.08 0.12 0.14 3/21/19963/22/19963/23/19963/24/1996 3,9943/25/1996 3,9943/26/1996 3,9173/27/1996 3,9023/28/1996 3,886 0.005673/29/1996 3,872 0.005673/30/1996 3,859 0.005683/31/1996 3,859 0.00568 3,846 0.00568 0.387 3,846 0.00568 0.202 3,834 0.00568 0.086 0.00568 0.153 0.034 0.00569 0.080 0.713 0.00569 0.034 0.564 50.76 0.00569 0.013 0.377 26.51 0.281 0.171 11.00 12.69 0.222 0.0624/10/1996 4.37 0.148 6.63 0.114 90.844/11/1996 0.067 2.75 0.355 71.594/12/1996 0.025 47.714/13/1996 1.09 3,752 22.71 0.045 21.614/14/1996 3,740 17.90 124 0.1404/15/1996 3,740 11.93 7.87 125 14.404/16/1996 3,728 5.40 126 44.634/17/1996 3,717 0.005694/18/1996 1.97 3,705 126 0.00569 127 3.60 0.006754/19/1996 3,693 11.16 0.00569 1284/20/1996 3,682 0.00569 0.00675 1284/21/1996 3,671 0.00569 0.00674 0.231 1284/22/1996 3,671 0.00570 0.065 0.00674 0.00674 0.4614/23/1996 3,660 129 0.00570 0.183 130 0.006744/24/1996 3,649 0.00570 130 0.241 0.091 0.264 0.006744/25/1996 3,627 0.00570 0.102 0.026 0.463 0.1814/26/1996 3,627 0.00570 0.00674 0.072 0.885 0.041 28.38 0.8454/27/1996 3,617 0.095 0.00570 0.104 0.540 0.00674 0.6684/28/1996 3,607 0.040 0.00570 8.00 0.00673 0.182 0.321 22.51 0.00673 1.87 0.4474/29/1996 3,588 0.00570 0.348 7.10 0.092 0.016 0.333 32.274/30/1996 3,578 0.00570 0.99 0.202 0.213 0.071 0.263 56.48 2.00 3,568 0.00570 0.42 107.55 0.126 5.63 0.216 0.47 0.176 0.074 3,559 0.00570 0.135 0.036 8.07 0.076 0.17 65.43 3.52 0.420 0.25 3,559 14.12 0.080 0.00570 0.028 0.217 26.89 38.80 2.81 0.11 0.00571 0.085 0.392 0.029 124 11.07 1.88 16.36 0.053 0.00571 0.030 0.04 0.522 0.88 0.165 124 0.00571 8.56 0.85 0.086 9.70 0.70 124 25.89 0.00571 0.154 2.77 0.497 0.47 0.31 124 129 9.12 0.58 124 0.205 0.112 25.85 1.79 124 2.14 0.21 0.00675 6.47 0.095 46.65 125 0.196 0.08 1.248 0.00675 61.91 2.28 0.14 0.00675 0.044 6.46 0.460 0.45 126 11.66 0.00675 0.037 0.00674 126 58.51 0.00675 15.48 0.273 0.491 0.00675 13.19 126 0.181 126 0.077 11.14 0.00675 14.63 0.218 145.70 0.108 127 0.00674 0.313 3.30 127 53.66 0.549 0.00674 128 1.049 2.79 0.030 36.42 0.086 128 0.00674 0.640 13.42 0.123 0.00674 1.11 0.216 0.413 129 0.380 0.00674 0.31 0.00674 0.89 0.109 0.252 129 0.00674 0.28 1.27 129 0.084 0.00674 2.23 129 0.150 0.255 4.27 0.08 0.22 0.043 128 0.090 0.00674 2.62 0.32 0.257 0.033 0.56 0.463 0.100 1.07 0.00674 1.57 0.617 0.00674 0.45 0.00674 0.035 0.66 0.101 0.35 0.182 0.00674 0.587 0.39 1.05 0.243 0.11 0.133 0.38 1.07 0.112 1.473 0.09 0.231 1.95 0.26 2.59 0.543 0.052 0.09 0.27 0.044 0.580 0.49 2.48 0.65 0.214 0.56 0.48 6.23 0.62 2.28 0.14 0.12 1.56 0.57 Appendix A. Appendix

A–20 Hydrogeology, Hydrologic Budget, and Water Chemistry of the Medina Lake area, Texas 2 (Smt) C-mi/hr) Stability ° parameter ( )) a -e 0 (e 2 product (u (mbar-mi/hr) Mass transfer ) 2 4.94.75.94.7 49.59 56.11 77.10 67.53 -0.138 -0.184 -0.046 -0.086 (u Wind speed a -e 0 e (mbar) ) a (mbar) of air at 2.0 m (e Vapor pressure Vapor (RH) 90.189.574.171.7 29.01 28.63 27.11 25.81 10.12 11.94 13.07 14.37 Relative humidity (percent) ) s (mbar) pressure of pressure air at 2.0 m (e m 2.0 at air Saturation vapor C) ° Air ( 25.325.227.427.2 32.20 31.99 36.59 36.00 temperature ) 0 (mbar) Saturation vapor pressure at water- surface temperature (e C) ° ( 29.229.129.1 40.57 40.18 40.18 Water temperature Evaporation—Continued Date 6/1/19966/2/19966/3/19966/4/1996 26.56/5/1996 27.36/6/1996 27.96/7/1996 27.46/8/1996 27.46/9/1996 27.0 26.9 34.62 27.1 36.28 27.1 37.57 36.49 36.49 35.65 35.44 26.0 35.86 27.0 35.86 25.8 26.9 27.2 27.0 33.61 24.8 35.65 25.0 33.21 25.7 35.44 36.07 35.65 74.5 31.30 71.1 31.67 65.9 33.02 62.7 25.04 65.4 25.35 69.2 21.89 74.8 22.22 59.2 23.59 55.2 9.58 10.93 24.67 15.69 23.41 14.27 18.75 8.95 12.90 3.58 18.23 10.98 4.03 12.03 6.49 17.11 8.28 85.69 12.97 39.14 17.63 63.16 7.83 92.59 4.25 106.81 142.45 5.37 -0.006 -0.023 94.18 -0.130 72.71 -0.012 -0.003 94.66 0.000 -0.034 -0.116 -0.049 5/10/1996 5/11/1996 5/12/19965/13/19965/14/19965/15/1996 24.65/16/1996 24.15/17/1996 23.95/18/1996 23.65/19/1996 24.05/20/1996 24.15/21/1996 24.2 30.93 5/22/1996 24.4 30.01 5/23/1996 24.8 29.66 5/24/1996 25.4 29.135/25/1996 25.4 29.845/26/1996 25.4 30.015/27/1996 25.3 30.205/28/1996 25.1 30.565/29/1996 25.1 31.305/30/1996 25.5 32.445/31/1996 26.0 25.6 32.44 26.3 26.1 32.44 26.4 26.1 32.24 26.2 26.4 31.86 26.2 31.86 26.8 32.63 32.82 27.2 33.61 33.81 27.2 34.21 33.81 26.7 34.41 34.41 26.4 34.016/10/1996 34.01 27.26/11/1996 35.23 27.16/12/1996 36.07 69.5 25.06/13/1996 27.0 36.07 68 27.36/14/1996 26.9 35.03 68 29.16/15/1996 27.2 34.41 69.1 28.16/16/1996 27.8 36.07 23.50 69.6 26.86/17/1996 28.2 35.86 66.66/18/1996 22.99 28.1 31.67 65.16/19/1996 23.40 28.4 36.28 23.50 71.1 35.656/20/1996 29.2 40.28 24.52 72.1 6.34 35.446/21/1996 29.5 38.01 24.02 70.8 36.076/22/1996 29.4 35.23 23.48 7.02 74.9 37.366/23/1996 29.8 13.20 24.90 6.79 87.9 14.32 7.06 38.246/24/1996 29.7 24.81 80.2 6.78 38.016/25/1996 14.32 29.0 25.54 71.9 8.41 38.68 15.21 28.9 15.21 26.86 69.1 28.0 8.96 40.52 83.65 29.1 11.86 27.84 74.8 26.6 7.53 41.22 28.6 100.57 29.10 27.9 7.43 8.95 40.99 103.36 11.63 28.96 107.37 28.4 6.33 41.94 11.86 26.27 28.7 5.01 41.70 80.34 12.75 26.35 28.5 4.79 0.012 40.05 37.79 14.32 75.29 104.17 28.3 4.51 39.82 0.010 34.82 13.20 29.3 5.25 40.28 0.010 89.31 0.010 37.57 0.008 39.13 29.3 8.14 4.03 94.77 38.68 30.3 7.66 0.014 4.25 90.57 39.36 30.7 4.70 66.06 0.022 38.91 0.013 56.8 29.8 9.17 38.46 69 19.28 27.8 0.009 7.83 40.75 67 19.18 27.5 0.007 40.75 67.1 24.65 27.8 0.010 43.16 21.47 67.2 74.70 0.011 44.16 66 59.94 -0.031 24.03 41.94 66.7 25.17 0.072 37.36 25.96 63.6 0.127 36.71 14.18 26.45 63.6 0.020 37.36 62.2 11.41 25.68 0.010 25.65 62.9 10.89 11.40 9.40 25.92 64.8 11.79 25.92 75.5 8.05 26.85 75 12.34 7.38 13.03 6.04 27.78 76.7 133.24 14.60 5.82 27.18 15.31 28.20 91.91 7.38 14.14 6.93 80.42 27.53 68.85 14.17 4.47 28.65 68.54 14.52 0.011 4.47 11.85 7.16 91.06 90.36 -0.005 4.92 12.29 65.31 11.63 3.80 0.013 0.016 68.47 8.05 101.22 0.015 8.05 69.71 6.93 0.007 -0.002 55.23 0.005 95.40 -0.010 0.018 98.97 80.65 0.037 0.007 -0.019 -0.022 -0.027 6/26/1996 6/27/1996 6/28/1996 Appendix A. Appendix

Appendix A A–21 (acre-ft) (+/-error) Evaporation (cm) (in.) (acre-ft) Diversion Lake Mass transfer Mass coefficient (N) coefficient (Harbeck, 1962) (acres) Surface area Surface (acre-ft) (+/-error) Evaporation (cm) (in.) (acre-ft) Medina Lake Medina Mass transfer coefficient (N) (Harbeck, 1962) (acres) Evaporation—Continued Surface area Date 6/1/19966/2/19966/3/19966/4/1996 3,2576/5/1996 3,2496/6/1996 3,2496/7/1996 3,2416/8/1996 3,233 0.005736/9/1996 3,209 0.00573 3,201 0.00573 3,194 0.00573 3,180 0.00573 0.491 0.00574 0.224 0.00574 0.362 0.00574 0.193 0.531 0.00574 0.088 0.613 0.143 0.817 52.49 0.209 0.540 23.92 0.241 0.417 38.60 13.12 0.322 0.543 56.45 0.213 5.98 64.97 0.164 9.65 86.04 14.11 0.214 56.75 16.24 43.72 21.51 130 56.68 14.19 130 10.93 131 14.17 131 131 0.00673 131 0.00673 131 0.00673 131 0.00673 130 0.00673 0.577 0.00673 0.264 0.00673 0.425 0.227 0.00673 0.623 0.00673 0.719 0.104 0.959 0.167 0.245 2.46 0.634 0.283 0.489 1.12 0.378 0.637 1.83 0.62 0.250 2.68 0.193 3.09 0.28 0.251 4.12 0.46 0.67 2.72 0.77 2.10 1.03 2.72 0.68 0.53 0.68 5/10/19965/11/19965/12/19965/13/1996 3,4595/14/1996 3,4595/15/1996 3,4505/16/1996 3,4415/17/1996 3,432 0.005725/18/1996 3,423 0.005725/19/1996 3,423 0.005725/20/1996 3,415 0.005725/21/1996 3,407 0.005725/22/1996 3,398 0.005725/23/1996 3,390 0.005725/24/1996 3,381 0.005725/25/1996 3,373 0.005725/26/1996 3,364 0.005725/27/1996 3,348 0.00572 0.4785/28/1996 3,331 0.00572 0.5755/29/1996 3,323 0.00572 0.5915/30/1996 3,306 0.00572 0.188 0.6145/31/1996 3,306 0.00572 0.226 0.460 3,289 0.00573 0.233 0.431 53.72 3,281 0.00573 0.242 0.596 64.44 3,273 0.00573 0.181 0.511 66.08 13.43 0.00573 0.170 0.543 68.48 16.11 0.00573 0.235 0.519 51.12 16.52 0.00573 0.201 0.378 47.79 17.12 0.00573 0.214 0.110 65.97 12.78 0.204 0.110 56.41 11.95 124 0.149 0.141 59.596/10/1996 16.49 127 0.043 0.428 56.676/11/1996 14.10 133 126 0.043 0.344 41.246/12/1996 14.90 132 126 0.056 11.986/13/1996 3,165 14.17 131 125 0.169 11.92 0.006756/14/1996 3,151 10.31 131 126 0.135 15.24 0.006746/15/1996 3,144 130 127 2.99 0.00673 46.08 0.006746/16/1996 3,129 129 128 2.98 0.00673 36.89 0.006746/17/1996 3,123 0.00574 129 3.81 0.00673 0.00675 0.5656/18/1996 3,109 11.52 0.00574 129 0.00673 0.00674 0.6786/19/1996 3,102 0.00574 130 9.22 0.00673 0.00674 0.6976/20/1996 3,088 0.00574 0.222 0.00674 130 0.00674 0.7246/21/1996 3,075 0.00574 0.765 0.267 130 0.00674 0.5426/22/1996 3,069 0.00575 0.528 0.274 130 0.00674 0.5086/23/1996 3,050 0.00575 130 0.462 0.285 0.00673 2.30 0.7026/24/1996 3,044 0.00575 0.301 0.395 0.213 130 2.83 0.6026/25/1996 3,032 0.00575 0.00673 0.208 0.394 0.200 2.88 0.6386/26/1996 3,020 0.00575 0.00673 0.182 0.523 0.57 0.277 79.43 2.99 0.6106/27/1996 3,007 0.00575 0.00673 0.156 0.519 0.71 0.237 54.56 0.00673 2.22 0.4456/28/1996 3,001 0.00575 0.155 0.375 0.72 0.251 47.64 2.10 2,989 19.86 0.00575 0.00673 0.130 0.206 0.394 0.75 0.240 40.60 2.93 2,983 13.64 0.00575 0.129 0.204 0.582 0.56 0.175 40.34 2.53 2,972 11.91 0.00576 0.166 0.148 0.401 0.52 53.37 2.70 0.503 10.15 0.051 0.00576 0.155 0.318 0.73 52.85 2.58 10.09 0.051 0.00576 0.404 0.229 0.549 0.63 38.03 1.90 13.34 0.065 0.00576 130 0.158 0.569 0.68 0.198 39.72 13.21 0.00576 0.55 130 0.125 0.464 0.65 58.60 0.159 0.55 130 0.216 9.51 0.285 0.47 40.12 0.71 130 0.224 9.93 0.323 31.72 2.15 0.14 14.65 130 0.183 0.444 54.60 0.00673 0.14 10.03 1.72 130 0.112 0.389 56.43 0.00673 0.18 130 0.127 7.93 0.54 45.80 0.00673 13.65 0.175 130 28.11 0.00673 0.43 14.11 0.153 130 31.68 0.00673 0.897 11.45 131 43.45 0.00673 0.619 131 7.03 37.92 0.00673 0.542 7.92 0.353 131 0.464 10.86 0.00673 131 0.244 0.462 0.00673 131 9.48 0.213 0.00673 0.613 131 0.183 0.00673 3.83 0.609 0.182 131 2.64 0.00673 0.440 0.241 131 0.00673 2.31 131 0.461 0.96 0.240 0.00673 1.98 0.681 0.66 131 0.00673 1.97 0.469 0.173 0.58 2.62 0.182 0.00673 0.372 0.49 0.268 2.60 0.642 0.00673 0.49 0.185 0.00673 0.666 1.88 0.65 0.543 0.146 0.00673 1.97 0.65 0.253 2.93 0.334 0.262 2.02 0.47 0.378 0.214 0.519 0.49 1.60 0.73 2.76 0.131 0.455 0.50 2.86 0.149 0.204 2.33 0.40 0.69 0.179 1.43 0.72 1.62 0.58 2.23 0.36 1.95 0.41 0.56 0.49 Appendix A. Appendix

A–22 Hydrogeology, Hydrologic Budget, and Water Chemistry of the Medina Lake area, Texas 2 (Smt) C-mi/hr) Stability ° parameter ( )) a -e 0 (e 2 product (u (mbar-mi/hr) Mass transfer ) 2 4.73.32.83.6 74.06 62.73 54.36 67.34 -0.088 -0.173 -0.198 -0.066 4.84.1 4.9 4.3 4.7 78.205.2 4.9 3.9 4.1 -0.131 6.7 7.6 7.2 5.7 4.9 3.6 3.0 3.2 4.7 86.09 -0.074 (u Wind speed a -e 0 e (mbar) ) a (mbar) of air at 2.0 m (e Vapor pressure Vapor (RH) 68.259.858.758.2 24.55 21.95 22.47 23.24 15.76 19.01 19.41 66.4 18.71 82 28.01 27.40 13.69 14.06 8.28 3.58 113.3273.1 50.3369.963.7 0.003 64 25.8960.1 -0.289 24.44 62.6 23.69 5659.2 24.98 16.29 23.46 60.7 24.59 62.864.1 22.72 23.63 64 24.94 62.5 26.14 66.3 25.76 67.163.4 25.88 25.03 63 25.71 61.9 24.55 23.96 23.89 23.62 18.32 Relative humidity (percent) ) s (mbar) pressure of pressure air at 2.0 m (e m 2.0 at air Saturation vapor C) ° Air ( 27.227.528.228.9 36.00 36.71 38.29 39.92 26.926.727.728.628.628.7 35.42 29.2 34.96 28.9 37.19 29.4 39.03 29.7 39.03 29.1 39.29 29.2 40.57 29.0 39.92 28.4 41.09 27.4 41.62 28.0 40.18 28.1 40.44 28.2 40.05 38.78 28.5 36.59 37.79 37.92 38.16 38.91 65.5 25.48 16.94 temperature ) 0 (mbar) Saturation vapor pressure at water- surface temperature (e C) ° ( 29.129.429.8 40.31 40.96 41.89 Water temperature Evaporation—Continued Date 7/1/1996 7/2/19967/3/19967/4/19967/5/1996 29.87/6/1996 29.47/7/1996 29.47/8/1996 29.47/9/1996 29.5 29.8 29.7 41.94 29.7 40.99 40.99 40.99 41.22 41.94 41.70 41.70 29.5 29.7 28.9 29.7 29.7 29.8 41.22 29.9 41.70 39.82 41.70 41.70 41.94 59.8 42.18 57.38/1/1996 60.38/2/1996 63.18/3/1996 24.65 638/4/1996 23.89 66.38/5/1996 24.018/6/1996 26.318/7/1996 16.338/8/1996 26.27 17.09 27.818/9/1996 16.97 14.91 3.58 3.36 15.67 13.89 5.14 5.82 58.46 5.37 57.35 7.16 87.33 86.72 84.12 0.008 99.45 0.027 -0.019 0.006 -0.003 0.002 7/10/19967/11/19967/12/19967/13/1996 29.67/14/1996 29.57/15/1996 29.67/16/1996 29.87/17/1996 30.17/18/1996 30.27/19/1996 29.7 41.467/20/1996 29.5 41.227/21/1996 29.5 41.467/22/1996 29.5 41.947/23/1996 29.6 42.677/24/1996 29.6 42.917/25/1996 29.6 41.70 29.7 25.9 41.22 29.8 27.8 41.22 29.9 28.8 41.22 28.7 41.46 29.2 41.46 29.3 41.46 33.41 29.1 41.70 37.36 28.8 41.94 39.59 42.18 29.2 39.36 29.4 40.52 29.2 40.75 29.0 40.28 74.8 29.2 39.59 67 29.9 40.52 66.9 29.6 40.99 65.2 40.52 27.94 65.7 40.05 66.1 26.53 40.52 26.33 67 42.18 26.42 67.6 41.46 13.28 26.77 67.9 26.63 64.6 14.94 15.61 64.3 26.53 16.25 7.38 27.39 68.1 16.14 27.83 65.8 8.05 15.07 6.26 26.17 68.6 5.59 25.75 14.70 98.04 13.83 5.82 27.59 120.27 13.39 9.40 27.76 97.75 15.29 28.44 8.28 90.89 15.71 8.95 93.87 13.87 9.84 -0.031 141.61 13.94 8.72 -0.012 121.64 13.50 8.05 -0.028 123.78 7.61 -0.029 131.82 6.71 -0.027 133.37 -0.007 7.61 126.50 105.48 -0.010 -0.004 -0.001 93.58 102.66 -0.005 -0.009 -0.007 0.004 -0.003 6/29/1996 6/30/1996 7/26/1996 7/27/1996 7/28/1996 7/29/1996 7/30/1996 7/31/1996 8/10/1996 8/11/19968/12/19968/13/1996 29.8 30.7 30.0 41.94 44.16 42.42 8/14/19968/15/19968/16/19968/17/1996 29.4 29.3 29.2 29.1 40.99 40.75 40.52 40.28 26.9 26.9 28.3 28.5 35.44 35.44 38.46 38.91 76.8 72.6 66.9 66.2 27.22 25.73 25.73 25.76 13.77 15.02 14.79 14.53 4.03 5.37 6.71 8.28 55.44 80.64 99.23 120.22 -0.154 -0.083 -0.020 -0.009 Appendix A. Appendix

Appendix A A–23 (acre-ft) (+/-error) Evaporation (cm) (in.) (acre-ft) Diversion Lake Mass transfer Mass coefficient (N) coefficient (Harbeck, 1962) (acres) Surface area Surface (acre-ft) (+/-error) Evaporation (cm) (in.) (acre-ft) Medina Lake Medina Mass transfer coefficient (N) (Harbeck, 1962) (acres) Evaporation—Continued Surface area Date 7/1/19967/2/19967/3/19967/4/1996 2,9427/5/1996 2,9307/6/1996 2,9257/7/1996 2,9147/8/1996 2,903 0.005767/9/1996 2,887 0.00576 2,876 0.00576 2,865 0.00576 2,855 0.00577 0.313 0.00577 0.388 0.00577 0.337 0.00577 0.123 0.331 0.00577 0.153 0.504 0.133 0.500 30.23 0.130 0.485 37.31 0.198 0.574 32.34 0.197 7.56 0.654 31.61 0.191 9.33 47.96 0.226 8.08 47.37 0.257 7.90 45.79 11.99 53.93 11.84 131 61.25 11.45 131 13.48 131 15.31 131 131 0.00673 131 0.00673 1318/1/1996 0.00673 1318/2/1996 0.00673 131 0.006738/3/1996 0.366 0.006738/4/1996 2,669 0.453 0.006738/5/1996 2,658 0.394 0.006738/6/1996 2,646 0.144 0.386 0.00673 0.5888/7/1996 2,635 0.178 0.5848/8/1996 2,624 0.155 0.00579 0.5668/9/1996 2,612 0.152 0.00579 1.57 0.231 0.669 2,600 0.00579 1.95 0.230 0.763 2,594 0.00579 1.69 0.223 0.39 2,576 0.00579 1.66 0.264 2.53 0.49 0.00580 0.300 2.51 0.42 0.00580 2.43 0.41 0.00580 0.63 2.88 0.00580 0.63 3.28 0.61 0.72 0.82 130 131 130 131 131 0.00673 131 0.00673 131 0.00673 131 0.00673 131 0.00673 0.00673 0.00673 0.00673 0.00673 6/29/19966/30/1996 2,966 2,954 0.00576 0.005767/10/1996 0.4277/11/1996 0.3617/12/19967/13/1996 2,855 0.1687/14/1996 2,845 0.1427/15/1996 2,839 41.517/16/1996 2,834 35.027/17/1996 2,829 0.005777/18/1996 2,823 10.38 0.005777/19/1996 2,818 0.00577 8.767/20/1996 2,807 0.005777/21/1996 2,802 0.00577 0.2907/22/1996 2,791 0.00577 0.5667/23/1996 2,781 0.00577 132 0.6947/24/1996 2,776 0.00578 0.114 0.564 1317/25/1996 2,766 0.00578 0.223 0.5257/26/1996 2,760 0.00578 0.273 0.542 27.217/27/1996 2,750 0.00578 0.222 0.818 52.81 0.006737/28/1996 2,740 0.00578 0.207 0.703 64.667/29/1996 2,729 0.00578 0.00673 0.213 6.80 0.715 52.477/30/1996 2,719 13.20 0.00578 0.322 0.762 48.707/31/1996 2,708 16.17 0.00578 0.277 0.771 50.20 0.498 2,702 13.12 0.00578 0.281 0.731 75.60 2,691 12.17 0.00578 0.422 0.300 0.610 64.70 2,680 12.55 0.00578 0.303 0.541 0.196 133 65.73 18.90 0.00579 135 0.288 0.594 69.73 16.17 0.166 0.00579 134 0.240 0.452 70.31 16.43 0.00579 131 0.213 66.57 2.16 17.43 0.00579 130 0.234 55.33 17.58 0.00673 1.81 131 0.178 48.98 0.00672 16.64 130 0.54 53.55 0.006728/10/1996 13.83 130 40.65 0.006738/11/1996 0.45 12.24 130 0.006738/12/1996 13.39 130 0.339 0.00673 0.6598/13/1996 2,564 10.16 130 0.00673 0.8098/14/1996 2,558 130 0.00673 0.6588/15/1996 2,545 0.133 130 0.259 0.00673 0.6128/16/1996 2,524 129 0.318 0.00673 0.6328/17/1996 2,517 0.00580 129 0.259 0.00673 0.954 2,504 0.00580 1.48 129 0.241 0.00673 2.92 0.819 2,490 0.00580 0.249 0.00673 3.56 0.834 2,476 0.00581 0.375 0.00674 2.83 0.888 0.37 0.00581 0.73 0.323 0.00674 2.61 0.898 0.00581 0.500 0.89 0.328 0.00674 2.72 0.852 0.00581 0.71 0.350 4.07 0.710 0.00581 0.65 0.354 3.49 0.630 0.197 0.322 0.68 0.335 3.56 0.692 0.468 1.02 0.280 3.79 0.527 129 0.577 0.87 0.248 41.92 3.83 130 0.127 0.699 0.89 0.272 3.63 130 0.184 0.95 0.207 3.03 10.48 130 0.227 0.96 26.58 2.67 130 0.275 0.91 0.00674 38.48 2.93 130 0.76 0.00673 47.10 2.23 6.65 0.67 0.00673 56.76 9.62 0.73 0.00673 11.78 131 0.56 0.00673 14.19 0.00673 130 130 0.00673 130 130 131 0.00673 0.580 131 0.00673 0.00673 130 0.00673 0.228 0.00673 0.373 0.543 0.00673 0.668 0.00673 2.49 0.810 0.147 0.214 0.263 0.27 0.319 1.59 2.32 2.85 3.45 0.17 0.25 0.31 0.38 Appendix A. Appendix

A–24 Hydrogeology, Hydrologic Budget, and Water Chemistry of the Medina Lake area, Texas 2 (Smt) C-mi/hr) Stability ° parameter ( )) a -e 0 (e 2 product (u (mbar-mi/hr) Mass transfer ) 2 (u Wind speed a -e 0 e (mbar) ) a (mbar) of air at 2.0 m (e Vapor pressure Vapor (RH) Relative humidity (percent) ) s (mbar) pressure of pressure air at 2.0 m (e m 2.0 at air Saturation vapor C) ° Air ( 26.224.122.424.324.424.9 33.94 25.6 29.94 25.7 27.07 24.7 30.44 24.0 30.64 23.7 31.57 24.7 32.74 25.3 33.06 26.5 31.05 27.0 29.84 29.24 26.8 31.15 25.0 32.20 24.4 34.62 25.8 35.65 26.425.6 35.19 31.67 30.54 33.28 16.4 34.50 17.4 32.74 18.70 19.93 temperature ) 0 (mbar) Saturation vapor pressure at water- surface temperature (e C) ° ( Water temperature Evaporation—Continued Date 9/1/19969/2/19969/3/1996 28.2 28.3 38.24 38.46 25.1 26.5 31.86 34.62 85.2 76.8 27.15 26.59 11.09 11.87 2.91 3.80 32.25 45.15 -0.367 -0.124 9/4/1996 9/5/1996 9/6/1996 9/7/1996 9/8/1996 9/9/1996 8/18/19968/19/19968/20/19968/21/1996 28.98/22/1996 28.78/23/1996 28.88/24/1996 28.68/25/1996 28.18/26/1996 28.08/27/1996 28.0 39.828/28/1996 27.9 39.368/29/1996 27.9 39.598/30/1996 27.9 39.138/31/1996 28.1 38.01 28.3 37.79 28.2 37.79 28.1 28.0 37.57 27.2 37.57 26.9 37.57 26.4 38.01 24.6 38.46 24.9 38.24 37.79 24.8 38.01 36.07 23.5 35.44 23.9 34.41 25.6 30.93 27.1 31.49 69.4 26.6 31.30 73 24.2 28.95 76.6 25.2 29.66 74.9 32.82 26.23 85.5 35.86 89.6 26.33 34.82 27.15 89.9 30.20 25.78 93.6 32.05 13.59 26.44 90.6 28.21 85.1 13.03 12.44 28.14 77.6 13.36 9.40 27.10 80.4 11.57 26.87 92.5 9.40 5.14 27.93 85.5 9.58 4.47 27.83 127.69 9.66 10.48 3.58 28.00 122.43 10.71 27.93 3.36 64.02 27.41 9.64 3.80 59.77 10.19 2.24 -0.010 41.42 10.46 4.03 10.31 32.15 -0.017 7.16 10.61 8.28 -0.072 36.72 23.43 5.37 -0.110 43.11 2.46 -0.273 2.68 69.02 -0.275 84.33 -0.221 56.17 -0.879 25.36 -0.247 28.48 -0.045 -0.015 -0.059 -0.661 -0.402 9/10/1996 9/11/1996 9/12/1996 9/13/1996 9/14/1996 9/15/1996 9/16/1996 9/17/1996 9/18/1996 9/19/1996 9/20/1996 9/21/1996 9/22/1996 9/23/1996 9/24/1996 9/25/1996 9/26/1996 9/27/1996 9/28/1996 9/29/1996 9/30/1996 Appendix A. Appendix

Appendix A A–25 (acre-ft) (+/-error) Evaporation (cm) (in.) (acre-ft) Diversion Lake Mass transfer Mass coefficient (N) coefficient (Harbeck, 1962) (acres) Surface area Surface (acre-ft) (+/-error) Evaporation (cm) (in.) (acre-ft) Medina Lake Medina Mass transfer coefficient (N) (Harbeck, 1962) (acres) Evaporation—Continued Surface area Date 9/1/19969/2/19969/3/19969/4/1996 2,3929/5/1996 2,3929/6/1996 2,3929/7/1996 2,3859/8/1996 2,385 0.005829/9/1996 2,385 0.00582 2,385 0.00582 2,385 0.00582 2,385 0.00582 0.188 0.00582 0.263 0.00582 0.00582 0.074 0.00582 0.103 14.73 20.63 3.68 5.16 121 120 0.00676 0.00676 0.218 119 0.305 116 0.086 114 0.120 112 111 0.00676 110 0.87 0.00677 109 1.20 0.00678 0.00678 0.09 0.00679 0.13 0.00679 0.00679 8/18/19968/19/19968/20/19968/21/1996 2,4628/22/1996 2,4558/23/1996 2,4418/24/1996 2,4278/25/1996 2,412 0.005818/26/1996 2,405 0.005818/27/1996 2,399 0.005828/28/1996 2,399 0.005828/29/1996 2,392 0.00582 0.7428/30/1996 2,392 0.00582 0.7128/31/1996 2,392 0.00582 0.372 2,385 0.00582 0.292 0.348 2,392 0.00582 0.280 0.241 2,392 0.00582 0.147 0.187 59.96 0.00582 0.137 0.214 57.34 0.00582 0.095 0.136 29.82 14.99 0.00582 0.074 0.251 27.69 14.33 0.00582 0.084 0.402 19.07 0.054 7.45 0.491 14.77 0.099 6.92 0.327 16.829/10/1996 0.158 4.77 0.148 10.749/11/1996 129 0.193 3.69 0.166 19.699/12/1996 129 0.129 4.21 31.539/13/1996 2,385 0.058 2.68 130 38.539/14/1996 2,385 0.065 4.92 131 25.599/15/1996 2,385 7.88 131 11.59 0.006749/16/1996 2,377 9.63 129 13.01 0.006749/17/1996 2,377 0.00582 6.40 1289/18/1996 2,377 0.00582 0.00673 2.90 1289/19/1996 2,377 0.00582 0.00673 3.25 128 0.8609/20/1996 2,377 0.00582 0.00673 126 0.8259/21/1996 2,377 0.00582 0.00674 1259/22/1996 2,377 0.00582 0.00674 0.431 0.339 1229/23/1996 2,377 0.00582 0.00674 0.402 0.325 1229/24/1996 2,377 0.00582 0.00674 0.279 1219/25/1996 2,370 0.170 0.00582 0.00674 0.217 3.649/26/1996 2,370 0.158 0.00582 0.00675 0.247 3.499/27/1996 2,363 0.110 0.00582 0.00676 0.1589/28/1996 2,363 0.085 0.00582 0.00676 1.84 0.291 0.40 9/29/1996 2,356 0.097 0.00582 0.00676 1.73 0.466 0.38 9/30/1996 2,349 0.062 0.00582 1.20 0.569 0.20 2,342 0.114 0.00583 0.92 0.380 0.19 2,335 0.183 0.00583 1.04 0.171 0.13 2,335 0.224 0.00583 0.66 0.192 0.10 0.149 0.00583 1.22 0.11 0.067 0.00583 1.92 0.07 0.076 0.00583 2.33 0.13 0.00583 1.52 0.21 0.69 0.25 0.76 0.17 0.07 0.08 108 107 107 106 105 0.00680 105 0.00680 105 0.00680 104 0.00680 104 0.00681 105 0.00681 106 0.00681 108 0.00681 109 0.00681 110 0.00681 113 0.00680 115 0.00680 117 0.00679 117 0.00679 117 0.00678 117 0.00678 117 0.00677 0.00677 0.00677 0.00677 0.00677 Appendix A. Appendix

A–26 Hydrogeology, Hydrologic Budget, and Water Chemistry of the Medina Lake area, Texas (acre-ft) (+\- error) Medina in Lake total Lake SW (acre-ft) (acre-ft) (+\- error) Creek (site 10) 08179280 Cypress /s) (acre-ft) 3 (ft , surface-water inflow] , surface-water in (acre-ft) (+\- error) (site 3) 08179300 Elm Creek /s) (acre-ft) 3 (ft (acre-ft) (+\- error) Creek (site 2) /s, cubic feet per second; acre-ft, acre-feet; SW acre-ft, second; feet per cubic /s, 08179110 RedBluff Appendix A 3 /s) (acre-ft) 3 (ft (acre-ft) (+\- error) Hydrogeology, Hydrologic Budget, Hydrogeology, Chemistry the of Water and Texas area, Lake Medina English Crossing (site 1) (site Crossing English 08178990 Medina River at /s) (acre-ft) 3 Surface-water inflow, Medina Lake—Continued Surface-water inflow, (ft Surface-water inflow, Medina Lake Medina inflow, Surface-water Date 8/1/19958/2/19958/3/19958/4/19958/5/19958/6/19958/7/19958/8/1995 08/9/1995 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 09/1/19959/2/19959/3/1995 0.99/4/1995 1.29/5/1995 0.989/6/1995 0.71 1.799/7/1995 0.73 2.389/8/1995 0 1.94 0.829/9/1995 0 1.41 0.22 0.82 0 1.45 0.30 0.91 0 0.24 1.63 0 1 0 0.18 1.63 0 0 0.18 1.80 0 0 0.20 0 0 0.20 1.98 0 0 0 0.23 0 0 0 0 0.25 0 0 0 0 0 0 0 0 1 1 1 1 1.98 1 1.98 1 1.98 1 0.25 1.98 1 0.25 1.98 0.85 0.25 1.98 0.25 1.98 1.69 0.25 1.98 0.25 0.25 0.21 0.25 8/10/19958/11/19958/12/19958/13/19958/14/19958/15/19958/16/19958/17/1995 08/18/1995 08/19/1995 08/20/1995 0 08/21/1995 0 08/22/1995 0 08/23/1995 0 08/24/1995 0 0 08/25/1995 0 0 08/26/1995 0 0 08/27/1995 0 0 08/28/1995 0 0 08/29/1995 0 0 08/30/1995 0 0 08/31/1995 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 09/10/1995 0 09/11/1995 09/12/1995 0 19/13/1995 0 1.19/14/1995 0 1.39/15/1995 1.39/16/1995 1.98 2.18 1.2 0 2.58 1.4 0 2.58 1.5 0 0.25 0.27 1.2 2.38 0 0 0.32 1 2.78 0 0 0.32 1 2.98 0 0 0.30 2.38 1 0 0 0.35 1.1 1.98 0 0 0.37 1 1.98 0 0 0.30 1 1.98 0 0 1 2.18 0.25 0 1 0.25 1.98 0 1 0.25 1.98 0 0.27 1 1.98 0 1 0.25 1.98 1 0.25 1.98 1 0.25 1.98 1 0.25 1.98 0.25 1.98 0.25 1.98 0.25 1.98 0.25 0.25 0.25 0.82 0.71 0.7 1.63 0.87 1.41 1 1.39 1 0.20 1.73 1 0.18 1.98 0.17 0.22 1.98 1.98 0.25 0.25 0.25 Appendix A. Appendix Appendix A.Appendix 2. ft table 3 and figure to correspond numbers [Site

Appendix A A–27 (acre-ft) (+\- error) Medina in Lake total Lake SW (acre-ft) (acre-ft) (+\- error) Creek (site 10) 08179280 Cypress /s) (acre-ft) 3 (ft (acre-ft) (+\- error) (site 3) 08179300 Elm Creek /s) (acre-ft) 3 (ft (acre-ft) (+\- error) Creek (site 2) 08179110 RedBluff /s) (acre-ft) 3 (ft (acre-ft) (+\- error) English Crossing (site 1) (site Crossing English 08178990 Medina River at /s) (acre-ft) 3 Surface-water inflow, Medina Lake—Continued Surface-water inflow, (ft Date 9/17/19959/18/19959/19/19959/20/19959/21/19959/22/19959/23/19959/24/1995 09/25/1995 09/26/1995 09/27/1995 97 09/28/1995 20 09/29/1995 8.9 0 192.409/30/1995 1.410/1/1995 0.58 39.67 17.65 010/2/1995 0.36 19.24 114 010/3/1995 2.78 0.26 1.15 111 010/4/1995 0.19 3.97 1.77 0.71 10810/5/1995 0.12 226.12 0.52 10310/6/1995 0.28 0.05 220.17 0.12 0.3810/7/1995 0 99 214.21 0.07 0.24 22.6110/8/1995 93 204.30 0.05 0.10 22.0210/9/1995 90 0.04 21.42 196.36 85 0.02 0 20.43 184.46 89 0 0.01 178.51 19.64 0 168.59 18.45 0 176.53 17.85 0 0 0 16.86 0 0 17.65 0 0 0 0 0 0 0 0 0 27 0 1 0 0 1 0 15 7.8 0 1 53.55 0 0 8.3 0 0.39 1.98 6.6 15.47 0 0.34 29.75 1.98 5.5 6.69 0 0.28 1.98 16.46 5.3 0.77 13.09 0 0.26 0.25 4.9 1.93 0.67 10.91 3.72 0.25 5.3 0.22 0.56 10.51 0.25 2.06 4.8 0.18 0.12 0.52 1.64 9.72 0.12 0.10 1.36 10.51 0.44 0.11 0.0811/1/1995 1.31 0.36 9.52 0.09 0.0811/2/1995 0.24 4.5 1.21 120 4.411/3/1995 1.31 0.07 0.22 4.7 17611/4/1995 0.05 0.18 3.9 1.19 190 0.04 238.02 8.93 3.9 140 8.73 0.03 349.09 9.32 3.9 0.03 376.86 7.74 23.80 3.6 1.12 277.69 7.74 34.91 1.09 3.5 1.17 37.69 7.74 3.4 0.97 27.77 7.14 3.4 0 0.97 235.81 6.94 0 0.97 230.16 6.74 0 0.89 222.51 6.74 0 23.84 0.87 212.55 0 23.28 0.84 0 204.54 22.47 0.84 0 191.96 21.47 0 185.69 20.67 0 175.56 19.39 0 183.45 18.75 0 17.74 0 18.52 2.7 2 1.3 5.36 3.97 2.58 0.80 0.60 0.39 6.7 4.6 4.4 13.29 17 9.12 8.73 1.66 33.72 1.14 1.09 4.21 367.74 389.95 288.99 37.37 271.74 39.42 29.25 28.02 10/10/199510/11/199510/12/1995 8810/13/1995 8510/14/1995 79 174.5510/15/1995 74 168.5910/16/1995 69 156.6910/17/1995 65 17.45 146.7810/18/1995 62 16.86 136.8610/19/1995 69 15.67 128.9310/20/1995 72 14.68 0 122.9810/21/1995 73 13.69 0 136.8610/22/1995 69 12.89 0 142.8110/23/1995 66 12.30 0 144.7910/24/1995 50 13.69 0 0 136.8610/25/1995 50 14.28 0 0 130.9110/26/1995 52 14.48 0 010/27/1995 52 13.69 99.17 0 010/28/1995 52 13.09 99.17 0 0 0 103.1410/29/1995 52 0 0 0 103.1410/30/1995 9.92 52 0 0 0 103.1410/31/1995 9.92 55 10.31 0 0 0 103.14 62 10.31 0 0 103.14 77 10.31 0 0 0 0.09 109.09 10.31 0 0 0 0 0.07 122.98 10.31 0 0 0 0.07 152.73 10.91 0 0.18 0 0.07 12.30 0 0 0.14 0 0.05 15.27 0 0 0 0.14 0 0.05 0.03 0 0 0.14 0 0.04 0.02 0 0.10 0 0.04 0 0.02 0 0.10 0 0.04 0 0.02 0 0 0.08 0.04 3.4 0.01 0 0 0.08 0.03 3.4 0.01 0 0 0.08 0.03 3.4 0.01 0 0 0.08 3.4 6.74 0.01 0 0.06 0.04 6.74 3.2 0.01 0 0.06 0.04 0.03 6.74 2.6 0.01 0 0.03 0.84 6.74 2.2 0.08 0.01 0 0.03 0.84 2.4 6.35 0.08 0.01 0.06 0.03 0.84 2.5 5.16 0.06 0.03 0.84 2.2 4.36 0.01 181.47 0.06 0.03 0.79 4.76 2.2 0.01 0.01 175.48 0.06 0.03 0.64 4.96 2.2 0.01 163.58 0.06 18.32 0.55 4.36 0.01 153.66 0.06 17.72 2.2 0.60 4.36 0.01 143.31 0.06 16.53 2.2 0.62 2.2 4.36 0.01 134.18 15.54 0.55 2.2 0.01 127.42 14.49 4.36 0.55 2.2 0.01 141.70 13.55 4.36 0.55 4.36 2.2 147.85 12.85 4.36 2.2 149.24 0.55 14.29 2.2 4.36 141.28 0.55 14.91 0.55 2.2 4.36 135.33 15.04 0.55 4.36 14.24 0.55 4.36 103.62 13.65 0.55 4.36 103.62 107.56 0.55 107.56 10.47 0.55 107.56 4.1 10.47 10.87 0.55 107.56 10.87 107.56 10.87 113.51 8.13 10.87 127.40 10.87 11.46 1.02 12.85 160.86 16.29 Appendix A. Appendix

A–28 Hydrogeology, Hydrologic Budget, and Water Chemistry of the Medina Lake area, Texas (acre-ft) (+\- error) Medina in Lake total Lake SW (acre-ft) (acre-ft) (+\- error) Creek (site 10) 08179280 Cypress /s) (acre-ft) 3 (ft (acre-ft) (+\- error) (site 3) 08179300 Elm Creek /s) (acre-ft) 3 (ft (acre-ft) (+\- error) Creek (site 2) 08179110 RedBluff /s) (acre-ft) 3 (ft (acre-ft) (+\- error) English Crossing (site 1) (site Crossing English 08178990 Medina River at /s) (acre-ft) 3 Surface-water inflow, Medina Lake—Continued Surface-water inflow, (ft Date 11/5/199511/6/1995 11511/7/1995 11011/8/1995 10311/9/1995 228.10 94 218.18 86 204.30 22.81 21.82 186.45 20.43 170.58 18.64 0 17.06 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0.87 0.7612/1/1995 0.71 1.7312/2/1995 1.98 0.63 1.5112/3/1995 6512/4/1995 67 1.41 0.26 0.3012/5/1995 69 1.25 0.23 128.9312/6/1995 72 132.8912/7/1995 70 0.21 136.8612/8/1995 67 12.89 0.19 3.3 3.8 142.8112/9/1995 65 13.29 3 138.84 64 13.69 132.89 3 64 14.28 6.55 7.54 0 128.93 3 13.88 0 126.94 13.29 5.95 0 126.94 12.89 0.82 0.94 5.95 0 12.69 0 5.95 0 0.74 12.69 0 0 0 0.74 0 226.45 237.62 0 0.74 0 0 0 211.76 0 0 0 22.90 24.05 193.80 0 0 177.78 21.40 0 0 0 0 19.60 0 17.99 0.3 0 0.29 0 0.24 0 0.23 0.60 0.58 0.23 0.48 0.22 0.46 0.09 0.19 0.09 0.46 0.17 0.07 0.44 0.13 0.07 0.38 0.07 0.34 3 3 0.07 0.26 3.3 0.06 3.4 0.05 3.4 5.95 0.04 5.95 3.4 6.55 3.4 6.74 6.74 0.74 3.4 0.74 0.82 6.74 3.1 0.84 6.74 0.84 6.74 135.47 0.84 6.15 139.42 143.88 0.84 150.01 0.84 13.73 146.04 14.12 14.58 0.77 140.07 15.19 136.05 14.80 134.02 14.20 133.35 13.79 13.59 13.50 11/10/199511/11/199511/12/1995 8111/13/1995 8211/14/1995 72 160.6611/15/1995 73 162.6411/16/1995 74 142.8111/17/1995 67 16.07 144.7911/18/1995 65 16.26 146.7811/19/1995 79 14.28 132.8911/20/1995 93 14.48 0 128.9311/21/1995 96 14.68 0 156.6911/22/1995 97 13.29 0 184.4611/23/1995 92 12.89 0 190.4111/24/1995 86 15.67 0 0 192.4011/25/1995 85 18.45 0 0 182.4811/26/1995 78 19.04 0 0 170.5811/27/1995 70 19.24 0 0 168.5911/28/1995 65 18.25 0 0 0 154.7111/29/1995 64 17.06 0 0 0 138.8411/30/1995 62 16.86 0 0 0 128.93 60 15.47 0 0 0 126.94 62 13.88 0 0 0 122.98 12.89 0 0 0 0.66 119.01 12.69 0 0 0 0.59 122.98 12.30 0 0 0 0.52 11.90 0 0 1.31 0 0.51 12.30 0 0 1.17 0 0.41 0 0 1.03 0 0.29 0.20 0 0 1.01 0 0.212/10/1995 0.18 0 0 0.81 0 0.6812/11/1995 0.15 0 0 0.58 0.9312/12/1995 65 0.15 0 0 0.63 0.4012/13/1995 3 67 0.12 0 0 1.35 0.52 2.612/14/1995 69 0.09 0 0 1.84 0.43 128.93 2.612/15/1995 72 0 1.25 0.06 0.43 132.89 2.612/16/1995 72 0.20 0 1.03 5.95 0.41 136.8612/17/1995 5.16 2.6 72 12.89 0.28 0 0.85 0.38 142.8112/18/1995 5.16 2.6 73 13.29 0.19 0 0.85 0.39 142.8112/19/1995 5.16 74 13.69 0.15 0.81 2.6 0.74 0.39 0.64 142.81 4.112/20/1995 5.16 78 14.28 0.13 0.75 0 0.39 0.64 144.79 7.212/21/1995 5.16 82 14.28 0.13 0.77 0 0.37 0.64 146.78 5.612/22/1995 85 14.28 0.12 0.77 5.16 0 0.33 0.64 154.71 8.13 4.912/23/1995 167.92 72 14.48 0.11 168.97 0.77 14.28 0 0.3 0.64 162.64 4.4 65 14.68 0.12 149.00 0 0.73 11.11 0 168.59 4.1 64 15.47 0.12 0.64 150.96 0 0.65 17.01 0 17.08 1.02 142.81 4.1 9.72 16.26 0.12 152.75 0 1.79 0 0.60 15.08 128.93 3.9 8.73 16.86 0.11 138.62 0 1.39 0 15.28 126.94 3.9 8.13 14.28 0.10 0 0 0 134.48 15.44 1.21 8.13 3.9 12.89 166.18 0 0 0 0.09 14.02 1.09 200.59 7.74 3.9 12.69 0 0 0 1.02 202.77 7.74 3.8 13.60 0 0 0 16.89 1.02 3.5 7.74 203.15 0 0 20.51 0 0.97 7.74 192.06 0 0 20.62 3 0 0.1 0.97 7.54 179.56 0 0 0.1 20.61 0.97 6.94 177.54 0 0 0.13 19.47 0.97 163.20 0 0 0.13 0.20 18.20 0.94 5.95 147.35 0 0 0.12 0.20 18.00 0.87 137.43 0 0.26 0.11 16.55 135.45 0 0.26 0.03 0.12 14.97 0.74 131.25 0 0.24 0.03 0.14 13.98 0.04 126.60 0 0.22 0.14 13.78 0.04 0.24 0.11 13.35 0.04 0.28 3 129.52 0.11 12.87 0.03 0.28 3 0.11 3 0.04 0.22 0.1 13.13 3 0.04 0.22 0.08 3 5.95 0.04 0.22 3 5.95 0.03 5.95 0.20 3 0.03 0.16 5.95 3 0.74 0.03 5.95 0.74 2.7 0.74 5.95 0.03 2.2 0.02 0.74 5.95 2.2 135.07 0.74 5.95 5.36 2.2 139.04 0.74 4.36 143.07 2.2 0.74 13.67 4.36 2.2 149.02 0.74 0.67 14.06 4.36 149.00 14.47 0.55 148.98 4.36 15.06 0.55 4.36 150.98 15.06 0.55 153.00 160.34 15.06 0.55 167.23 15.26 0.55 173.18 15.46 16.18 147.39 16.84 133.49 17.44 131.46 14.86 13.47 13.26 Appendix A. Appendix

Appendix A A–29 (acre-ft) (+\- error) Medina in Lake total Lake SW (acre-ft) (acre-ft) (+\- error) Creek (site 10) 08179280 Cypress /s) (acre-ft) 3 (ft (acre-ft) (+\- error) (site 3) 08179300 Elm Creek /s) (acre-ft) 3 (ft (acre-ft) (+\- error) Creek (site 2) 08179110 RedBluff /s) (acre-ft) 3 (ft (acre-ft) (+\- error) English Crossing (site 1) (site Crossing English 08178990 Medina River at /s) (acre-ft) 3 Surface-water inflow, Medina Lake—Continued Surface-water inflow, (ft Date 1/1/19961/2/19961/3/1996 691/4/1996 691/5/1996 58 136.861/6/1996 56 136.861/7/1996 54 115.041/8/1996 52 13.69 111.071/9/1996 51 13.69 107.11 53 11.50 103.14 54 11.11 0 101.16 10.71 0 105.12 10.31 0 107.11 10.12 0 10.51 0 0 10.71 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0.09 0 0.08 0 0.07 0 0.18 0.08 0.16 0.07 0.14 0.06 0.03 0.16 0.06 0.02 0.14 0.052/1/1996 0.02 0.12 0.052/2/1996 0.02 0.12 2.12/3/1996 43 0.02 0.10 1.62/4/1996 45 0.02 0.10 1.62/5/1996 45 0.02 4.17 1.62/6/1996 43 0.01 85.29 1.6 3.172/7/1996 44 0.01 89.26 1.6 3.172/8/1996 46 89.26 0.52 1.6 3.172/9/1996 8.53 48 85.29 0.40 3.17 1.6 8.93 51 87.27 0.40 3.17 1.6 8.93 51 91.24 0.40 3.17 8.53 141.20 95.21 0 0.40 101.16 3.17 8.73 140.19 0 0.40 101.16 3.17 9.12 118.35 0 14.23 0.40 9.52 10.12 114.41 0 14.11 0.40 10.12 0 110.42 0 11.92 0.40 0 106.43 0 11.53 0 104.45 0 0 11.13 0 108.40 0 10.73 0 0 110.38 10.53 0 0 10.92 0 0 0 11.12 0 0 0 0 0.05 0 0 0.06 0 0.04 0.10 0.03 0.12 0.03 0.08 0.03 0.01 0.06 0.04 0.04 0.02 0.06 0.04 0.01 0.06 0.01 0.08 0.08 1.3 0.01 0.08 1.3 0.01 1.3 0.01 0.01 1.3 2.58 0.01 1.3 2.58 1.3 2.58 0.32 2.58 1.3 1.3 0.32 2.58 1.3 0.32 2.58 0.32 2.58 2.58 87.97 0.32 2.58 91.95 0.32 91.91 0.32 0.32 8.87 87.93 0.32 9.27 89.91 9.26 93.88 103.81 8.86 97.86 103.81 9.06 9.46 10.45 9.85 10.45 1/10/19961/11/19961/12/1996 551/13/1996 541/14/1996 52 109.091/15/1996 50 107.111/16/1996 50 103.141/17/1996 51 10.911/18/1996 51 10.71 99.171/19/1996 51 10.31 99.17 101.161/20/1996 50 0 101.161/21/1996 9.92 49 0 101.161/22/1996 9.92 48 10.12 01/23/1996 49 10.12 99.171/24/1996 50 10.12 97.19 0 01/25/1996 51 95.21 0 0 01/26/1996 9.92 51 97.19 0 01/27/1996 9.72 49 99.17 0 101.161/28/1996 9.52 48 0 0 101.161/29/1996 9.72 47 0 0 0 01/30/1996 9.92 46 10.12 97.19 0 0 01/31/1996 45 10.12 95.21 0 0 45 0 93.22 0 9.72 43 0 0 91.24 0 0 0 0.05 9.52 0 89.26 0 0 0.06 9.32 0 89.26 0 0.05 9.12 0 85.29 0.10 0 8.93 0 0 0 0.12 0 0.05 8.93 0 0 0.10 0 0.05 0.05 8.53 0 0.01 0 0.05 0 0 0.10 0.02 0 0.072/10/1996 0 0 0.10 0.01 0 0.10 0 0 0 0.10 0 0.06 1.6 51 0.01 0 0.14 0.05 1.6 0.01 0 0 0.01 0.05 1.6 0 0 0.12 0.01 0.05 101.16 3.17 0 0 0.10 0.02 0.05 0.05 1.6 3.17 0 0.10 0.05 1.6 3.17 1.4 0.02 10.12 0 0.10 0.40 1.3 0.01 0 0.10 0.10 0.05 3.17 0.40 1.4 0.01 0 0.10 0.05 3.17 0.40 2.78 0.01 0.04 0 1.3 2.58 0.01 0.10 0.01 112.36 0.04 0.40 1.5 2.78 0.10 0.01 110.40 0.05 0.40 1.9 0.35 0.08 106.41 0.04 11.32 2.58 1.9 0.32 0.01 0.08 0 0.05 11.13 2.98 1.8 0.35 1.9 0.01 102.45 0.10 10.73 3.77 1.9 0.01 102.45 0.08 104.03 0.32 3.77 0.01 0.10 103.83 10.33 0.37 1.9 3.57 3.77 0.01 104.07 0 10.33 0.47 10.48 1.8 3.77 0.01 0.47 10.45 1.5 0.01 101.87 0.45 10.48 3.77 1.3 0.47 100.26 1.3 3.57 0.47 99.07 10.26 1.3 2.98 101.06 10.11 0.47 0.05 1.3 2.58 102.84 105.02 0.45 2.58 10.01 105.02 10.20 0.37 2.58 0.10 10.38 0.32 10.60 2.58 101.06 0.32 10.60 98.88 0.32 0.01 96.28 10.20 0.32 93.90 9.98 91.93 9.71 91.91 1.3 9.46 87.97 9.26 9.26 2.58 8.87 0.32 103.83 10.45 12/24/199512/25/199512/26/1995 6412/27/1995 6512/28/1995 63 126.9412/29/1995 61 128.9312/30/1995 59 124.9612/31/1995 60 12.69 120.99 62 12.89 117.02 65 12.50 119.01 12.10 0 122.98 11.70 0 128.93 11.90 0 12.30 0 12.89 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0.08 0 0.08 0 0.08 0.16 0.09 0.16 0.08 0.16 0.08 0.02 0.18 0.08 0.02 0.16 0.08 0.02 0.16 0.03 0.16 2.2 0.02 0.16 2.2 0.02 2.2 0.02 4.36 2.2 0.02 4.36 2.2 4.36 2.2 0.55 2.2 4.36 0.55 2.2 4.36 0.55 4.36 0.55 4.36 131.46 0.55 4.36 133.45 0.55 129.48 13.26 0.55 125.53 13.46 0.55 121.55 13.07 123.53 12.67 127.50 12.27 133.45 12.47 12.87 13.46 Appendix A. Appendix

A–30 Hydrogeology, Hydrologic Budget, and Water Chemistry of the Medina Lake area, Texas (acre-ft) (+\- error) Medina in Lake total Lake SW (acre-ft) (acre-ft) (+\- error) Creek (site 10) 08179280 Cypress /s) (acre-ft) 3 (ft (acre-ft) (+\- error) (site 3) 08179300 Elm Creek /s) (acre-ft) 3 (ft (acre-ft) (+\- error) Creek (site 2) 08179110 RedBluff /s) (acre-ft) 3 (ft (acre-ft) (+\- error) English Crossing (site 1) (site Crossing English 08178990 Medina River at /s) (acre-ft) 3 Surface-water inflow, Medina Lake—Continued Surface-water inflow, (ft Date 3/1/19963/2/19963/3/1996 503/4/1996 493/5/1996 473/6/1996 45 99.173/7/1996 48 97.193/8/1996 51 93.223/9/1996 9.92 53 89.26 9.72 46 95.21 101.16 9.32 39 105.12 8.93 0 9.52 10.12 91.24 0 10.51 77.36 0 0 9.12 0 0 0 7.74 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0.05 0.04 0 0.04 0 0.10 0.04 0.08 0.04 0.04 0.08 0.02 0.01 0.08 0.01 0.08 0.08 0.02 0.01 0.04 0.02 0.01 1 0.01 0.04 0.01 0.79 0.04 0.01 0.61 0.62 0.01 1.57 1.98 0.6 0.6 0.01 1.21 0.64 1.23 0.20 0.25 1 1.19 1.19 0.15 1.27 1 0.15 0.15 101.26 0.15 98.84 0.16 1.98 94.51 1.98 90.57 10.18 9.93 102.43 0.25 96.48 106.43 9.49 0.25 9.09 10.28 10.68 9.68 93.26 79.38 9.38 7.99 2/11/19962/12/19962/13/1996 502/14/1996 442/15/1996 402/16/1996 40 99.172/17/1996 42 87.272/18/1996 44 79.342/19/1996 9.92 39 79.342/20/1996 8.73 40 83.312/21/1996 7.93 43 87.272/22/1996 7.93 44 77.36 02/23/1996 8.33 44 79.34 02/24/1996 8.73 44 85.29 02/25/1996 7.74 44 87.27 02/26/1996 7.93 43 0 87.27 02/27/1996 8.53 41 0 87.27 02/28/1996 8.73 40 0 87.27 02/29/1996 8.73 40 0 85.29 0 8.73 45 0 0 81.32 0 8.73 50 0 0 79.34 0 8.53 0 0 79.34 0 8.13 0 0 89.26 0 7.93 0 0 99.17 0 7.93 0 0 0 0.04 8.93 0 0 0 0.03 9.92 0 0 0 0.03 0 0 0.08 0 0.043/10/1996 0 0 0.06 0 0.043/11/1996 0 0 0.06 0 0.053/12/1996 37 0.01 0 0 0.08 0.043/13/1996 38 0.01 0 0 0.08 0.063/14/1996 39 0.01 0 0 0.10 0.073/15/1996 40 0.01 0 0 0.08 73.39 0.07 1.33/16/1996 40 0.01 0 0.12 75.37 0.05 1.33/17/1996 40 0.01 0 0.14 77.36 0.04 1.33/18/1996 7.34 39 0.01 0 0.14 79.34 0.05 2.58 1.33/19/1996 7.54 39 0.02 0 0.10 79.34 0.04 2.58 1.33/20/1996 7.74 38 0.02 0.08 79.34 0.04 2.58 1.33/21/1996 7.93 37 0.02 0.10 77.36 0 0.04 0.32 1.3 2.583/22/1996 7.93 35 0.01 0.08 77.36 0 0.04 0.32 1.3 2.583/23/1996 7.93 32 0.01 0.08 75.37 0 0.04 0.32 1 2.583/24/1996 7.74 32 0.01 0.08 73.39 0 0.17 0.32 2.58 0.823/25/1996 7.74 32 0.01 101.83 0 0.08 69.42 0 0.32 2.58 0.823/26/1996 7.54 32 0.01 0 0.08 63.47 0 89.91 0.32 0.833/27/1996 7.34 33 0.01 0 0.34 63.47 1.63 1.98 0 81.98 10.25 0.32 0.823/28/1996 6.94 34 0.01 0 63.47 1.63 0 82.00 0.32 1.13/29/1996 6.35 36 0.01 0 0 63.47 1.65 9.06 0 85.96 0.83/30/1996 6.35 38 0.05 0 0 0.20 65.45 1.63 0.25 8.27 0 89.95 0.71 6.35 39 0 0 0.20 67.44 8.27 0 80.01 2.18 0.68 6.35 40 0 0 0.21 71.40 8.66 0 82.04 1.59 0.6 6.55 0 0 0.20 75.37 1.41 9.06 0 0.94 6.74 89.04 0 0 87.41 77.36 1.35 8.07 0 0.02 0.27 7.14 89.00 0 0 79.34 8.27 0 0.02 0.20 1.19 7.54 89.00 0 0 0.18 1.86 0 0.02 7.74 8.95 89.00 8.80 0 0 0.04 0.17 0 0.02 7.93 8.95 0 0 0.04 0 87.55 0.02 0.15 8.94 0 0 0.04 0.23 0 82.99 0.02 8.95 0.01 80.83 0 0 0.04 0 0.01 0.01 80.77 0 0 0.04 8.81 0 0.01 0.01 0 0 0.04 8.34 0 90.53 101.38 8.12 0.01 0 0 0.02 0 1 8.11 0.01 0 0 0.02 0 1 0.01 0 0 10.20 9.09 0 1 0 0 0 0 1.1 0 0 0 1.98 0 0.99 0 0 1.98 0 0.92 0 0 1.98 0 2.18 0 0 1.96 0.25 0 0.9 0 0 1.82 0.25 0.01 0.81 0 0 0.25 0.01 0.27 0.25 0 0 0.01 1.79 0.02 0.23 75.41 0 0 1.61 0.01 0.71 0.02 77.39 0 0.73 0.02 79.38 0 81.56 0.22 0.75 0 81.34 7.59 0.02 0 0.20 1.41 0.95 0 81.20 7.79 0 1.45 1.1 0 7.99 8.21 1.49 1.1 8.19 0 0.18 1.88 79.16 1 8.17 78.98 0.18 1 1 2.18 0.19 1 1 2.18 0.24 7.96 1 7.94 76.78 1.98 0.8 0.27 74.84 1.98 1.98 0.27 70.91 1.98 1.98 7.71 65.36 1.98 0.25 1.59 7.52 0.25 0.25 65.65 7.13 0.25 0.25 65.65 6.58 0.25 0.20 65.45 6.62 73.41 67.44 6.62 77.38 69.42 79.36 6.60 80.95 7.39 6.79 7.79 6.99 7.99 8.14 Appendix A. Appendix

Appendix A A–31 (acre-ft) (+\- error) Medina in Lake total Lake SW (acre-ft) (acre-ft) (+\- error) Creek (site 10) 08179280 Cypress /s) (acre-ft) 3 (ft (acre-ft) (+\- error) (site 3) 08179300 Elm Creek /s) (acre-ft) 3 (ft (acre-ft) (+\- error) Creek (site 2) 08179110 RedBluff /s) (acre-ft) 3 (ft (acre-ft) (+\- error) English Crossing (site 1) (site Crossing English 08178990 Medina River at /s) (acre-ft) 3 Surface-water inflow, Medina Lake—Continued Surface-water inflow, (ft Date 4/1/19964/2/19964/3/1996 414/4/1996 364/5/1996 324/6/1996 33 81.324/7/1996 36 71.404/8/1996 45 63.474/9/1996 8.13 62 65.45 7.14 71 71.40 6.35 69 89.26 122.98 6.55 0 140.83 7.14 0 136.86 8.93 12.30 0 14.08 0 13.69 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0.03 0 0.01 05/1/1996 0 05/2/1996 0.06 0 05/3/1996 27 0.02 05/4/1996 26 0 05/5/1996 23 0.01 0 05/6/1996 22 0 0 53.55 05/7/1996 22 51.575/8/1996 1 21 45.62 0 1.25/9/1996 5.36 1.3 21 43.64 0 5.16 1.3 23 43.64 0 1.3 4.56 1.3 23 41.65 1.98 2.38 4.36 2.58 41.65 0 4.36 2.58 1.3 45.62 0 2.58 4.17 2.58 1.3 45.62 0 0.25 0.30 0.32 4.17 1.1 0 0.32 4.56 2.58 0 0 0.32 0.32 4.56 2.58 0 0 2.18 0 83.31 0 73.84 73.98 0.32 0 0 66.05 0.32 0 0 2.5 91.85 68.03 0.27 0 0 8.38 7.45 7.46 0 0 125.55 6.67 0 0 4.96 143.40 9.25 6.87 0 139.04 12.62 0 0 14.40 0 0.50 0 13.96 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0.83 0 0 0.82 0 0.84 0 1.65 0.82 1.63 0.82 1.67 0.82 1 0.21 1.63 0.88 0.20 1.63 1 0.21 1.63 0.20 1.75 1.98 55.20 0.20 53.20 0.20 1.98 47.29 0.22 0.25 5.56 45.26 5.36 45.26 0.25 4.77 43.28 4.57 43.40 52.56 4.57 4.37 47.60 4.38 5.31 4.81 3/31/1996 40 79.34 7.934/10/19964/11/1996 04/12/1996 634/13/1996 574/14/1996 51 124.964/15/1996 47 0 113.064/16/1996 46 101.164/17/1996 43 12.504/18/1996 39 11.31 93.224/19/1996 36 10.12 0 91.244/20/1996 32 85.29 04/21/1996 9.32 29 77.36 04/22/1996 9.12 29 71.40 04/23/1996 8.53 28 63.474/24/1996 7.74 27 57.52 0 0 04/25/1996 7.14 27 57.52 0 04/26/1996 6.35 26 55.54 0 04/27/1996 5.75 26 53.55 04/28/1996 5.75 26 0 0 53.55 0 04/29/1996 5.55 25 0 51.57 0 04/30/1996 5.36 24 0 51.57 0 0 5.36 25 0 51.57 0 5.16 26 0 0 0 49.59 0 5.16 0 0 47.60 0 0 5.16 0 0 49.59 0 0 4.96 0 0 51.57 0 0 4.76 0 0 0 4.96 0.77 0 0 0 0 0 5.16 0 0 0 0 0 0 0 0 0 1.53 05/10/1996 0 0 0 05/11/1996 0 0 0 0 0 05/12/1996 23 0 0 0 0 0.19 05/13/1996 24 0 0 0 0 05/14/1996 25 0 0 0 05/15/1996 26 0 0 0 0 45.62 05/16/1996 26 0 1.1 0 0 47.60 80.87 05/17/1996 26 0 1.3 0 0 49.59 05/18/1996 4.56 24 1 0 0 0 51.57 0 4.76 22 0 2.18 0 0 51.57 8.12 0 4.96 0.96 20 2.58 0 0 51.57 0 5.16 0.82 0 0 47.60 0.5 0 1.98 5.16 0.82 0.27 0 0 43.64 0.22 1.90 0.05 5.16 0.93 0.32 0 0 39.67 0.14 1.63 0 4.76 0.96 0 0 0.07 0.99 0 1.63 0.25 4.36 0.85 0.44 0.10 0 0 0.24 0 127.14 1.84 3.97 0.85 0.28 0 0.20 0 115.64 1.90 0.82 0.14 0 0 0.10 0.20 0 1.69 0.04 12.77 1.2 0.01 103.14 0 0 0.23 0 1.69 0.03 11.63 1 0 0 95.13 0.24 0 1.63 0.01 0.82 0 92.87 0.21 10.36 0.83 2.38 0 0 86.92 0.21 0.05 0.87 0.82 0 0 9.56 0.16 79.20 0.20 1.63 1.98 0.95 0 0 9.33 0.01 73.31 1.65 0.30 0.86 0 8.73 0 1.73 0.10 65.16 1.63 0.32 0 7.97 59.21 0.20 1.88 0.25 0.02 0.88 0 7.38 59.15 0.21 1.71 0.83 0 0.22 0.01 6.56 0.20 0.05 57.92 0 5.96 0.24 0 1.75 0 5.96 55.18 0.21 55.54 1.65 0 53.22 0 5.85 0.6 49.43 53.20 0.6 0.22 0 0 0 5.56 53.45 5.60 0.21 0 0 5.36 51.29 0.6 1.19 4.99 0 5.36 1.19 0 5.39 51.33 0 0 5.17 53.22 1.19 0.61 0.15 0 0.15 0 5.18 0 5.36 1.21 0.15 0 47.90 0.55 49.55 0.59 0.15 0.54 51.07 1.09 4.82 0.54 5.00 1.17 0.56 1.07 52.92 5.14 0.14 1.07 0.15 1.11 0.13 5.32 0.13 52.66 0.14 52.74 48.67 5.29 44.71 5.30 40.78 4.89 4.50 4.11 Appendix A. Appendix

A–32 Hydrogeology, Hydrologic Budget, and Water Chemistry of the Medina Lake area, Texas (acre-ft) (+\- error) Medina in Lake total Lake SW (acre-ft) (acre-ft) (+\- error) Creek (site 10) 08179280 Cypress /s) (acre-ft) 3 (ft (acre-ft) (+\- error) (site 3) 08179300 Elm Creek /s) (acre-ft) 3 (ft (acre-ft) (+\- error) Creek (site 2) 08179110 RedBluff /s) (acre-ft) 3 (ft (acre-ft) (+\- error) English Crossing (site 1) (site Crossing English 08178990 Medina River at /s) (acre-ft) 3 Surface-water inflow, Medina Lake—Continued Surface-water inflow, (ft Date 6/1/19966/2/19966/3/1996 196/4/1996 236/5/1996 176/6/1996 15 37.696/7/1996 13 45.626/8/1996 11 33.726/9/1996 3.77 12 29.75 4.56 11 25.79 3.37 10 21.82 2.98 23.80 0 2.58 21.82 0 2.18 19.83 0 2.38 0 2.18 0 0 1.98 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 07/1/1996 0 07/2/1996 0 07/3/1996 0 0 6.9 07/4/1996 0 0 6.77/5/1996 0 0 6.27/6/1996 13.69 0 0 5.7 13.29 0 0 5.1 0.28 12.30 0 5.2 1.37 0.28 11.31 0 1.33 0.28 10.12 0 0.56 1.23 0.28 10.31 0 0.56 1.13 0.28 0 0.56 1.01 0.26 0 0.07 0.56 1.03 0.21 0 0.07 0.56 0.13 0 0.07 0.52 0 0.16 0 0.07 0.42 0 0 38.24 0.07 0.26 0 46.18 0.06 0.32 0 34.27 0.05 0 0 3.84 30.31 0.03 0 0 4.63 26.34 0.04 0 3.44 22.33 0 3.04 24.22 0 2.65 22.08 0 2.25 0 20.15 2.43 0 2.21 0 2.02 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0.16 0 0.16 0.16 0.32 0.16 0.32 0.16 0.32 0.16 0.04 0.32 0.04 0.32 0.04 0.32 0.04 14.00 0.04 13.61 0.04 12.61 1.41 11.62 1.37 10.43 1.27 10.63 1.17 1.05 1.07 5/19/19965/20/19965/21/1996 185/22/1996 165/23/1996 165/24/1996 15 35.705/25/1996 14 31.745/26/1996 13 31.745/27/1996 3.57 13 29.755/28/1996 3.17 13 27.775/29/1996 3.17 15 25.795/30/1996 2.98 15 25.79 05/31/1996 2.78 15 25.79 0 2.58 15 29.75 0 2.58 16 29.75 0 2.58 0 29.75 0 2.98 0 29.75 0 2.98 0 31.74 0 2.98 0 0 2.98 0 0 0 3.17 0 0 0 0 0 06/10/1996 0 0 06/11/1996 0 0 06/12/1996 0 0 9.8 06/13/1996 10 0 0 06/14/1996 11 0 0 06/15/1996 19.44 0 0 9.9 06/16/1996 10 0 0 19.83 06/17/1996 0 0 21.82 9 0 1.946/18/1996 19.64 0 0 7.4 06/19/1996 1.98 0 0 19.83 7.2 06/20/1996 2.18 0 0 7.4 0.05 17.85 1.966/21/1996 14.68 0 0 0 7 06/22/1996 1.98 14.28 0 0 7.6 0 06/23/1996 14.68 0.10 0 0 1.79 0 7.3 0 1.476/24/1996 0 0 7.2 0 13.88 1.436/25/1996 0 0.58 15.07 0 0 0 5 1.476/26/1996 0.6 14.48 0.01 0 0 0 5.16/27/1996 0 0.56 14.28 0 0 0 0 1.39 7.7 1.15 1.516/28/1996 0 0.47 0 0 9.3 1.456/29/1996 0 1.19 0.47 10.12 12 9.92 0 0 0 1.11 0.42 1.436/30/1996 0.57 15.27 10 0 0 0.14 0.93 0 0 0 0.6 18.45 0 0 0 9.7 0.93 1.01 0.99 0.15 0 0 0.44 0 23.80 0 0.83 0.14 7.8 1.13 1.53 0 0 19.83 0 0.12 1.84 1.19 0.42 19.24 0 36.85 0.12 0.87 0 0 0 0 2.38 0.42 15.47 0.10 0 0 0.14 0 32.93 0 0 1.98 0.31 0 32.85 0 0.83 1.92 0.15 0 0 0.28 0 3.71 0 30.68 0.11 0.83 1.55 0 28.70 0 0 0 0.61 3.32 0 0 0 30.68 0 3.31 26.92 0.10 0 0.56 0 0 0 0 0 3.09 0 0.10 26.98 0 0 0 0 2.89 0 26.66 0.08 0 3.09 0 0 2.72 0 0.07 0 0 0 0 30.59 0 2.73 0 0 0 0 0 2.69 0 30.59 0 0 0 0 0 30.37 0 0 0 3.08 0 32.29 0.23 0 3.08 0 0 0 0.2 0 0 3.05 0 0 0 0.16 0 0 3.24 0.09 0.46 0.16 0 0 0 0.16 0.40 0.32 0 0 0.18 0 0 0 0.06 0.32 0.16 0 0.14 0 0 0.32 0.12 0.05 0 0 0 0.04 0.11 0.03 0.32 0 0.04 0.28 0 0 19.89 0 0.24 0.11 0.04 0.13 0 0.22 0.14 20.23 0.04 0 0 0.03 22.14 0.2 0.18 0.22 2.00 19.95 0 0.03 0.26 0 0.03 0.28 20.15 2.03 0.16 0.16 0 2.22 0.36 0.40 18.17 0.03 0 2.00 14.96 0.03 0.36 14.52 0.03 2.02 0.32 0.32 0.28 14.90 0.04 0.05 1.82 0.28 1.50 0.71 0.28 14.10 1.46 15.33 0.04 0.04 0.56 0.26 1.50 14.76 0.56 14.64 0.09 15.85 0.56 1.42 1.54 0.52 0.07 1.48 10.43 10.23 0.07 1.47 1.60 0.07 19.16 0.06 1.05 1.03 24.36 20.39 1.93 19.80 15.99 2.45 2.05 1.99 1.61 Appendix A. Appendix

Appendix A A–33 (acre-ft) (+\- error) Medina in Lake total Lake SW (acre-ft) (acre-ft) (+\- error) Creek (site 10) 08179280 Cypress /s) (acre-ft) 3 (ft (acre-ft) (+\- error) (site 3) 08179300 Elm Creek /s) (acre-ft) 3 (ft (acre-ft) (+\- error) Creek (site 2) 08179110 RedBluff /s) (acre-ft) 3 (ft (acre-ft) (+\- error) English Crossing (site 1) (site Crossing English 08178990 Medina River at /s) (acre-ft) 3 Surface-water inflow, Medina Lake—Continued Surface-water inflow, (ft Date 7/7/19967/8/19967/9/1996 4.8 4.5 4.2 9.52 8.93 8.33 0.95 0.89 0.83 0 0 0 0 0 0 0 0 0 08/1/1996 08/2/1996 08/3/1996 2.78/4/1996 0 2.68/5/1996 0 2.48/6/1996 0 5.36 2.48/7/1996 5.16 2.38/8/1996 0 2.3 4.768/9/1996 0.54 0 4.76 2.3 0.52 0 4.56 2.2 0.48 4.56 2.2 0.48 4.56 0 0.16 0.46 4.36 0 0.16 0.46 4.36 0 0.16 0.46 0 0.32 0.44 0 0 0.32 0.44 0 0 0.32 0 0.04 0 0 0.04 0 0 0 0.04 0 0 0 0 0 9.84 0 0 9.24 0 0 8.65 0 0 0.99 0 0 0.93 0 0.87 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0.16 0 0.17 0 0.2 0 0.32 0.16 0 0.34 0.16 0.16 0.40 0.04 0.32 0.14 0.04 0.32 0.15 0.32 0.13 0.05 0.04 0.28 0.04 0.30 5.67 0.04 0.26 5.49 0.03 0.04 5.16 0.58 5.08 0.03 0.56 4.88 4.88 0.53 0.52 4.84 0.50 4.66 0.50 4.62 0.49 0.47 0.47 7/10/19967/11/19967/12/1996 5.27/13/1996 5.37/14/1996 5.37/15/1996 10.31 5.67/16/1996 10.51 5.47/17/1996 10.51 4.7 1.037/18/1996 11.11 4.3 1.057/19/1996 10.71 4 1.057/20/1996 9.32 3.8 1.117/21/1996 0 8.53 3.6 1.077/22/1996 0 3.47/23/1996 7.93 0.93 0 7.54 3.17/24/1996 0.85 0 7.14 2.97/25/1996 0 0 6.74 2.9 0.797/26/1996 0 0.75 6.15 2.9 07/27/1996 0 0.71 5.75 2.9 07/28/1996 0 0.67 5.75 4.17/29/1996 0 0 0.61 0 5.75 4.8 07/30/1996 0 0.58 0 5.75 3 07/31/1996 0 0.58 0 8.13 3.1 0 0 0.58 9.52 3 0 0 0 0.58 0 2.9 0 5.95 0.81 0 0 0.16 6.15 0 0.95 0 0 0 0 5.95 0 0 5.75 0 0.60 0.32 0 0.61 0 0 0 0 0 0 0 0 0.60 0 0.58 0 0 0 0.05 0 0 0 0 0 08/10/1996 0 0 08/11/1996 0 0 0 0 0 0 08/12/1996 0 0 0 2.2 0.84 08/13/1996 0 0 0 0 0 2.1 08/14/1996 0 0 2.1 08/15/1996 0 0 1.67 0 0 0 0 4.36 2.5 08/16/1996 0 0 4.17 2.5 0 0.498/17/1996 0 0 0 0 4.17 2.3 0 0.228/18/1996 0.21 0.44 0 4.96 2.3 0 0.168/19/1996 0 0 0.42 0 0.97 0 0 4.96 2.3 0 0.168/20/1996 0.42 0.44 0 0 4.56 2.3 08/21/1996 0.50 0.16 0.32 0 0 4.56 2.3 08/22/1996 12.30 0.50 0.16 0.12 0.32 0 0 0 4.56 2.4 0 08/23/1996 0.46 0.05 0 0 4.56 2.4 0 0.328/24/1996 0.15 0.46 0.16 0.04 0 0 0 4.56 2.6 0 0 0.32 1.29 0.46 0.16 0.04 0 0 4.76 2.9 0 0 0.46 11.48 0.15 0 2.9 0 0.30 0 4.76 0.04 0 0.32 0.46 10.95 0.14 0 0 5.16 0.04 0 0.32 0 11.42 0.48 0.13 0 0 0 5.75 0 0.30 1.17 11.03 0.48 0.15 0.04 0 0 5.75 0 0.04 0.28 1.11 0 0.52 0.15 0 0 0 0.04 0 0.26 9.64 1.15 0.58 0.21 0 0 0.04 0 0.30 8.85 1.11 0.58 0 0.25 0 0 0 0.03 0 0.30 0.19 0 0 0.03 8.23 0 0.42 0.97 7.85 0 0 0.04 0 0.50 0 0.17 0.89 7.46 0.17 0 0 0 0.04 0.38 0 7.04 0 0 0.83 0.05 0 0.17 0.79 6.43 0.16 0 0 0.34 0.06 0 0.34 0.75 6.01 0 0 0 0.05 0 0.71 6.05 0 0 0.34 0 0.32 0 0.65 6.05 0.04 0 0 0.04 0 0.61 6.17 0 0 0 0.61 8.63 0.04 0 0 0 0.04 0 0.61 9.90 0 0 0 0 0.63 0 0 6.29 0 0.88 6.49 0 0 0 1.00 0 0 6.29 0 6.07 0.13 0 0 0.64 0 0.66 0.14 0 0 0.02 0.14 0 0 0.64 0.26 0.61 0.16 0 0 0.28 0.04 0.21 0 0 0.28 0.26 0 0.03 0.32 0.21 0 0.03 0.42 0.01 0.26 0 0.03 0.52 0.28 0 0.04 0.42 0.3 0.05 0.52 4.62 1.5 0.06 0.38 0.56 4.44 0.81 0.05 4.44 0.60 0.44 0.06 0.47 5.28 2.98 0.44 0.75 0.07 1.61 0.45 5.38 0.87 0.45 5.08 0.07 0.87 0.54 4.98 0.37 0.09 0.20 0.55 5.08 0.11 0.52 5.12 0.11 0.51 5.16 0.52 6.55 7.74 0.53 6.37 6.03 0.53 6.62 0.68 0.85 0.68 0.62 0.68 Appendix A. Appendix

A–34 Hydrogeology, Hydrologic Budget, and Water Chemistry of the Medina Lake area, Texas (acre-ft) (+\- error) Medina in Lake total Lake SW (acre-ft) (acre-ft) (+\- error) Creek (site 10) 08179280 Cypress /s) (acre-ft) 3 (ft (acre-ft) (+\- error) (site 3) 08179300 Elm Creek /s) (acre-ft) 3 (ft (acre-ft) (+\- error) Creek (site 2) 08179110 RedBluff /s) (acre-ft) 3 (ft (acre-ft) (+\- error) English Crossing (site 1) (site Crossing English 08178990 Medina River at /s) (acre-ft) 3 Surface-water inflow, Medina Lake—Continued Surface-water inflow, (ft Date 9/1/19969/2/19969/3/1996 159/4/1996 149/5/1996 129/6/1996 12 29.759/7/1996 31 27.779/8/1996 61 23.809/9/1996 2.98 48 23.80 2.78 42 61.49 120.99 2.38 36 2.38 95.21 0 6.15 12.10 83.31 0 71.40 0 9.52 0 8.33 0 0 0 7.14 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0.03 0 0.01 0 0 0 0.06 0 0.02 0 0 0.01 0 0 0 0 0 0 0 0 23 0 0 0 0 3.8 0 0 0 45.62 0 7.54 1.5 0 5.70 0.9 0 0.93 0.82 0.94 2.98 0.82 1.79 75.43 1.84 1.63 3.1 0.37 1.7 1.63 35.33 0.22 8.69 0.23 0.20 6.15 3.37 0.20 3.72 26.78 25.59 0.77 122.62 63.33 0.42 2.75 96.83 12.30 2.60 6.38 89.45 74.78 9.72 9.10 7.56 8/25/19968/26/19968/27/1996 4.58/28/1996 6.78/29/1996 8.98/30/1996 8.93 7.98/31/1996 13.29 7.3 17.65 7.1 15.67 12 0.89 1.33 14.48 1.77 14.08 1.57 23.80 0 1.45 0 1.41 0 2.38 0 0 09/10/1996 0 09/11/1996 0 09/12/1996 0 309/13/1996 0 28 09/14/1996 0 0 269/15/1996 0 23 0 59.509/16/1996 0 21 55.549/17/1996 0 26 51.579/18/1996 0 5.95 99 45.62 105 09/19/1996 5.55 0 41.65 0.099/20/1996 5.16 71 51.57 0 196.369/21/1996 4.56 60 0 208.26 09/22/1996 0.18 4.17 53 0.02 0 0 140.839/23/1996 5.16 48 19.64 0.43 0 20.83 119.019/24/1996 0 42 0 0.26 105.12 0.039/25/1996 0.04 0 38 14.08 0 09/26/1996 0.85 36 11.90 0 95.21 0 0 09/27/1996 37 10.51 0 0.52 0 83.31 0.019/28/1996 0 37 0 75.37 0.42 0 0.139/29/1996 9.52 0 37 0 0 71.40 09/30/1996 8.33 34 0.08 0 0 73.39 0 0 0 7.54 32 0.83 0 0.47 73.39 0.46 7.14 30 0 73.39 0 0 1.6 0.42 7.34 0 67.44 0 0 1.3 0.93 0.42 7.34 0.10 0.91 0 63.47 0 0 0 0 0 7.34 59.50 0.83 0 3.17 0 6.74 0 0 0.83 0 0 0.12 2.58 6.35 0.11 0 0 0 0 14.30 5.95 0 0 0.10 0 0.40 0 0 0 0 0.10 0 0.05 0.32 0 0 0 0 0 0 1.46 15.43 9.86 0 0 0 0 0 0 0 0.10 18.49 0 0 18.11 0 0 0 16.50 0 0 26.90 0 1.57 0 1.01 0 0 0 0.01 1.87 0 0 0 1.93 0 0 1.67 0 0 0 2.78 0 1.3 0 0 0 0 0 1.1 0 0.06 3.9 0.82 0 0 0 0.52 0.82 2.58 0 0 0.02 0.82 2.18 0.12 0 0 1.63 0.01 7.74 1.3 1.03 1.63 0 1.3 0.32 0.04 0 1.63 0 0.27 0.02 1.3 0.02 0 0.20 0 0.97 0.15 1.2 2.58 0 0.20 2.58 0.01 1.2 0 0.20 62.08 0 2.58 0 0.82 57.72 0.95 0.32 2.38 0 53.20 59.40 0.32 0.82 1.2 2.38 47.25 6.27 0.82 0.83 0.32 0 1.63 43.28 1.88 5.83 0.30 0 5.36 1.63 6.14 198.94 0.82 2.38 0.30 210.84 0 4.77 1.63 1.65 0.20 4.37 0.24 143.40 19.96 0.20 1.63 121.39 21.15 0.30 0.82 0.20 0.21 107.50 14.40 0.82 12.20 0.82 73.15 0.20 97.09 1.63 10.81 76.05 1.63 85.69 75.05 77.02 1.63 7.36 9.76 0.20 7.70 75.03 0.20 8.63 7.55 7.74 0.20 7.55 69.06 65.10 61.13 6.95 6.55 6.15 Appendix A. Appendix

Appendix A A–35 (acre-ft) (+\- error) Diversion Lake total Lake Diversion in SW (acre-ft) (acre-ft) (+\- error) , surface-water inflow] , surface-water in (site 6) /s) (acre-ft) 08179520 Medina River below Medina Lake 3 137137137137140 271.74144 271.74143 271.74143 271.74143 277.69143 285.62143 27.17 283.64143 27.17 283.64144 27.17 283.64143 27.17 283.64143 27.77 283.64143 28.56 283.64143 28.36 285.62 28.36 283.64 28.36 283.64 28.36 283.64 28.36 283.64 28.36 28.56 28.36 28.36 28.36 28.36 (ft (acre-ft) (+\- error) /s, cubic feet per second; acre-ft, acre-feet; SW acre-ft, second; feet per cubic /s, Appendix A 3 (site 5) Hydrogeology, Hydrologic Budget, Hydrogeology, Chemistry the of Water and Texas area, Lake Medina 08179530Creek Koenig /s) (acre-ft) 3 (ft Surface-water inflow, Diversion Lake—Continued inflow, Surface-water Surface-water inflow, Diversion Lake Diversion inflow, Surface-water Date 9/1/19959/2/19959/3/19959/4/19959/5/1995 0.749/6/1995 0.739/7/1995 0.739/8/1995 0.739/9/1995 0.73 0.72 1.47 0.72 1.45 0.72 1.45 0.72 1.45 1.45 1.43 1.43 0.22 1.43 0.22 1.43 0.22 0.22 0.22 0.21 0.21 0.21 143 0.21 143 143 143 143 283.64 143 283.64 143 283.64 143 283.64 143 283.64 283.64 28.36 283.64 28.36 283.64 28.36 283.64 28.36 28.36 28.36 28.36 28.36 285.10 28.36 285.08 285.08 285.08 285.08 285.06 285.06 28.58 285.06 28.58 285.06 28.58 28.58 28.58 28.58 28.58 28.58 28.58 8/2/1995 8/3/1995 8/4/1995 8/5/1995 8/6/1995 8/7/1995 8/8/1995 8/9/1995 8/1/1995 8/10/1995 8/11/1995 8/12/1995 8/13/1995 8/14/1995 8/15/1995 8/16/1995 8/17/1995 8/18/19958/19/19958/20/19958/21/19958/22/1995 0.778/23/1995 0.768/24/1995 0.768/25/1995 0.768/26/1995 0.768/27/1995 0.75 1.538/28/1995 0.75 1.518/29/1995 0.75 1.518/30/1995 0.74 1.518/31/1995 0.74 1.51 0.74 1.49 0.74 1.49 0.23 0.74 1.49 0.23 0.74 1.47 0.23 1.47 0.23 1.47 0.23 1.47 0.22 1.47 0.22 1.47 0.229/10/1995 143 0.229/11/1995 143 0.229/12/1995 143 0.229/13/1995 143 0.229/14/1995 0.72 143 0.229/15/1995 0.72 283.64 143 0.229/16/1995 0.72 283.64 143 0.71 283.64 143 0.71 283.64 143 0.71 283.64 143 1.43 0.70 283.64 143 28.36 1.43 283.64 143 28.36 1.43 283.64 143 28.36 1.41 283.64 143 28.36 1.41 283.64 28.36 1.41 283.64 28.36 1.39 0.21 283.64 28.36 0.21 283.64 28.36 0.21 283.64 285.16 28.36 0.21 285.14 28.36 0.21 285.14 28.36 0.21 28.36 285.14 0.21 28.36 285.14 143 285.12 28.36 135 285.12 28.59 112 285.12 28.59 112 285.10 28.59 112 285.10 28.59 283.64 112 285.10 28.59 267.77 112 285.10 28.59 222.15 285.10 28.59 222.15 285.10 28.59 222.15 28.58 222.15 28.36 28.58 222.15 26.78 28.58 22.21 28.58 22.21 28.58 22.21 28.58 22.21 22.21 285.06 269.20 223.58 223.56 223.56 223.56 223.54 28.58 26.99 22.43 22.43 22.43 22.43 22.42 Appendix A. Appendix Appendix A.Appendix 2. ft table 3 and figure to correspond numbers [Site

A–36 Hydrogeology, Hydrologic Budget, and Water Chemistry of the Medina Lake area, Texas (acre-ft) (+\- error) Diversion Lake total Lake Diversion in SW (acre-ft) (acre-ft) (+\- error) (site 6) /s) (acre-ft) 08179520 Medina River below Medina Lake 3 (ft (acre-ft) (+\- error) (site 5) 08179530Creek Koenig /s) (acre-ft) 3 (ft Surface-water inflow, Diversion Lake—Continued inflow, Surface-water Date 9/17/19959/18/19959/19/19959/20/19959/21/1995 0.709/22/1995 0.709/23/1995 0.709/24/1995 0.709/25/1995 0.709/26/1995 0.70 1.399/27/1995 0.70 1.399/28/1995 0.69 1.399/29/1995 0.69 1.399/30/1995 0.69 1.3910/1/1995 0.69 1.3910/2/1995 0.68 1.39 0.2110/3/1995 0.68 1.37 0.2110/4/1995 0.68 1.37 0.2110/5/1995 0.68 1.37 0.2110/6/1995 0.68 1.37 0.2110/7/1995 0.67 1.35 0.2110/8/1995 0.66 1.35 0.2110/9/1995 0.66 1.35 0.21 0.66 112 1.35 0.21 0.66 112 1.35 0.21 0.66 120 1.33 0.21 0.66 1.31 0.20 1.31 34 0.20 222.15 1.31 34 0.20 222.15 1.31 33 0.20 238.02 1.31 33 0.20 1.31 33 0.20 33 0.20 67.44 22.21 33 0.20 67.44 22.21 33 0.20 65.45 23.80 33 0.20 65.45 32 0.20 65.45 32 0.20 65.45 32 6.74 65.45 32 6.74 65.45 32 6.55 65.45 223.54 32 6.55 63.47 223.54 32 6.55 63.47 239.40 32 6.55 63.47 32 6.5511/1/1995 63.47 32 6.5511/2/1995 63.47 6.5511/3/1995 63.47 68.83 6.3511/4/1995 63.47 22.42 68.83 6.35 63.47 22.42 0.62 66.84 6.35 63.47 24.01 0.61 66.82 6.35 63.47 0.61 66.82 6.35 0.60 66.82 6.35 66.82 6.35 6.95 66.80 1.23 6.35 6.95 66.80 1.21 6.35 6.75 64.82 1.21 6.35 6.75 64.82 1.19 6.75 64.82 6.75 64.80 6.75 64.78 0.18 6.75 64.78 0.18 6.75 64.78 0.18 6.55 64.78 0.18 6.55 64.78 6.55 64.78 6.55 6.54 6.54 53 6.54 32 6.54 32 6.54 32 6.54 105.12 63.47 63.47 63.47 10.51 6.35 6.35 6.35 106.35 64.68 64.68 64.66 10.70 6.53 6.53 6.53 10/10/199510/11/199510/12/199510/13/199510/14/1995 0.6610/15/1995 0.6510/16/1995 0.6510/17/1995 0.6310/18/1995 0.6410/19/1995 0.64 1.3110/20/1995 0.63 1.2910/21/1995 0.63 1.2910/22/1995 0.63 1.2610/23/1995 0.63 1.2710/24/1995 0.63 1.2710/25/1995 0.63 1.25 0.2010/26/1995 0.63 1.25 0.1910/27/1995 0.63 1.25 0.1910/28/1995 0.62 1.25 0.1910/29/1995 0.62 1.25 0.1910/30/1995 0.62 1.25 0.1910/31/1995 0.62 1.25 0.19 0.62 1.25 0.19 0.62 1.23 32 0.19 0.62 1.23 45 0.19 0.62 1.23 71 0.19 1.23 83 0.19 1.23 83 0.19 1.23 83 0.19 63.47 104 1.23 0.18 89.26 126 140.83 1.23 0.18 126 164.63 0.18 126 164.63 0.18 126 164.63 0.18 206.28 126 6.35 0.18 249.92 127 8.93 0.18 14.08 249.92 126 0.18 16.46 249.92 126 16.46 249.92 116 16.46 249.92 20.63 86 251.90 24.99 70 249.92 24.99 70 249.92 24.99 70 230.08 64.78 24.99 68 142.12 90.55 170.58 24.99 61 165.89 138.84 25.19 165.90 138.84 24.99 165.90 138.84 24.99 207.53 134.88 251.17 23.01 120.99 251.17 17.06 6.54 14.28 251.17 13.88 9.12 16.65 251.17 13.88 16.65 251.17 13.88 16.65 253.15 20.82 13.49 251.17 25.18 12.10 251.15 25.18 231.31 25.18 25.18 171.81 25.18 140.07 25.38 140.07 25.18 140.07 25.18 136.11 23.19 122.22 17.24 14.07 14.07 14.07 13.67 12.28 Appendix A. Appendix

Appendix A A–37 (acre-ft) (+\- error) Diversion Lake total Lake Diversion in SW (acre-ft) (acre-ft) (+\- error) (site 6) /s) (acre-ft) 08179520 Medina River below Medina Lake 3 (ft (acre-ft) (+\- error) (site 5) 08179530Creek Koenig /s) (acre-ft) 3 (ft Surface-water inflow, Diversion Lake—Continued inflow, Surface-water Date 11/5/199511/6/199511/7/199511/8/199511/9/1995 0.60 0.60 0.60 0.60 0.60 1.19 1.19 1.19 1.19 1.19 0.18 0.18 0.18 0.18 0.18 31 31 3112/1/1995 3112/2/1995 3112/3/199512/4/1995 61.4912/5/1995 61.49 0.5612/6/1995 61.49 0.5612/7/1995 61.49 0.5612/8/1995 61.49 0.5612/9/1995 0.56 6.15 0.55 1.11 6.15 0.55 1.11 6.15 0.54 1.11 6.15 0.54 1.11 6.15 1.11 1.09 1.09 0.17 1.07 0.17 62.68 1.07 0.17 62.68 0.17 62.68 0.17 62.68 0.16 62.68 0.16 0.16 30 0.16 6.33 30 6.33 30 6.33 30 6.33 30 6.33 30 59.50 30 59.50 30 59.50 29 59.50 59.50 59.50 5.95 59.50 5.95 59.50 5.95 57.52 5.95 5.95 5.95 5.95 5.95 5.75 60.61 60.61 60.61 60.61 60.61 60.60 60.60 6.12 60.58 6.12 58.59 6.12 6.12 6.12 6.11 6.11 6.11 5.91 11/10/199511/11/199511/12/199511/13/199511/14/1995 0.6011/15/1995 0.6011/16/1995 0.6011/17/1995 0.6011/18/1995 0.6011/19/1995 0.60 1.1911/20/1995 0.60 1.1911/21/1995 0.59 1.1911/22/1995 0.59 1.1911/23/1995 0.58 1.1911/24/1995 0.58 1.1911/25/1995 0.58 1.19 0.1811/26/1995 0.58 1.17 0.1811/27/1995 0.58 1.17 0.1811/28/1995 0.58 1.15 0.1811/29/1995 0.58 1.15 0.1811/30/1995 0.58 1.15 0.18 0.57 1.15 0.18 0.57 1.15 0.18 0.57 1.15 31 0.18 0.57 1.15 30 0.17 1.15 30 0.17 1.13 30 0.17 1.13 30 0.17 1.13 30 0.17 61.49 1.13 30 0.1712/10/1995 59.50 33 0.1712/11/1995 59.50 32 0.1712/12/1995 59.50 31 0.1712/13/1995 59.50 31 0.1712/14/1995 59.50 0.54 31 6.15 0.1712/15/1995 59.50 0.54 30 5.95 0.1712/16/1995 65.45 0.54 30 5.9512/17/1995 63.47 0.53 30 5.9512/18/1995 61.49 0.52 30 5.9512/19/1995 61.49 0.52 1.07 30 5.9512/20/1995 61.49 0.52 1.07 30 5.9512/21/1995 59.50 0.52 1.07 30 6.5512/22/1995 59.50 0.51 1.05 30 6.3512/23/1995 59.50 0.51 62.68 1.03 30 6.15 59.50 0.51 60.69 1.03 6.15 59.50 0.50 60.69 1.03 6.15 0.16 59.50 0.50 60.69 1.03 5.95 0.16 59.50 0.49 60.69 1.01 5.95 0.16 59.50 60.69 1.01 5.95 0.16 59.50 60.69 1.01 5.95 0.15 6.33 66.62 0.99 5.95 0.15 6.13 64.64 0.99 5.95 0.15 6.13 62.64 0.97 5.95 0.15 6.13 62.64 30 5.95 0.15 6.13 62.64 30 5.95 0.15 6.13 60.65 30 0.15 6.13 60.65 30 0.15 6.72 60.65 30 0.15 6.52 60.65 30 0.15 59.50 6.32 60.65 29 59.50 6.32 60.63 29 59.50 6.32 60.63 29 59.50 6.12 60.63 29 59.50 6.12 60.63 29 59.50 6.12 29 5.95 57.52 6.12 29 5.95 57.52 6.12 29 5.95 57.52 6.12 5.95 57.52 6.12 5.95 57.52 6.12 5.95 57.52 6.12 5.75 57.52 5.75 57.52 5.75 60.58 5.75 60.58 5.75 60.58 5.75 60.56 5.75 60.54 5.75 60.54 58.55 6.11 58.55 6.11 58.53 6.11 58.53 6.11 58.53 6.11 58.51 6.11 58.51 5.91 58.49 5.91 5.90 5.90 5.90 5.90 5.90 5.90 Appendix A. Appendix

A–38 Hydrogeology, Hydrologic Budget, and Water Chemistry of the Medina Lake area, Texas (acre-ft) (+\- error) Diversion Lake total Lake Diversion in SW (acre-ft) (acre-ft) (+\- error) (site 6) /s) (acre-ft) 08179520 Medina River below Medina Lake 3 (ft (acre-ft) (+\- error) (site 5) 08179530Creek Koenig /s) (acre-ft) 3 (ft Surface-water inflow, Diversion Lake—Continued inflow, Surface-water Date 1/1/19961/2/19961/3/19961/4/19961/5/1996 0.451/6/1996 0.451/7/1996 0.451/8/1996 0.441/9/1996 0.44 0.43 0.89 0.43 0.89 0.42 0.89 0.42 0.87 0.87 0.85 0.85 0.13 0.83 0.13 0.83 0.13 0.13 0.13 0.13 0.13 0.12 29 0.12 29 29 29 29 29 57.52 29 57.52 292/1/1996 57.52 292/2/1996 57.522/3/1996 57.522/4/1996 57.52 5.752/5/1996 57.52 0.33 5.752/6/1996 57.52 0.32 5.752/7/1996 57.52 0.32 5.752/8/1996 0.32 5.752/9/1996 0.32 5.75 0.31 0.65 5.75 0.31 0.63 5.75 0.30 0.63 5.75 0.30 58.41 0.63 58.41 0.63 58.41 0.61 58.39 0.61 0.10 58.39 0.60 0.10 58.37 0.60 0.10 58.37 0.10 5.89 58.35 0.10 5.89 58.35 0.09 5.89 0.09 5.88 0.09 5.88 82 0.09 5.88 64 5.88 59 5.88 59 5.88 74 104 162.64 126.94 92 117.02 85 117.02 88 146.78 206.28 16.26 182.48 12.69 168.59 11.70 174.55 11.70 14.68 20.63 18.25 16.86 163.30 17.45 127.58 117.66 117.66 147.41 206.90 183.09 16.36 169.19 12.79 175.14 11.80 11.80 14.77 20.72 18.34 16.95 17.54 1/10/19961/11/19961/12/19961/13/19961/14/1996 0.411/15/1996 0.411/16/1996 0.411/17/1996 0.401/18/1996 0.401/19/1996 0.40 0.811/20/1996 0.39 0.811/21/1996 0.39 0.811/22/1996 0.38 0.791/23/1996 0.38 0.791/24/1996 0.37 0.791/25/1996 0.37 0.77 0.121/26/1996 0.37 0.77 0.121/27/1996 0.36 0.75 0.121/28/1996 0.36 0.75 0.121/29/1996 0.36 0.73 0.121/30/1996 0.35 0.73 0.121/31/1996 0.35 0.73 0.12 0.35 0.71 0.12 0.34 0.71 51 0.11 0.34 0.71 70 0.11 0.34 0.69 57 0.11 0.69 57 0.11 0.69 57 0.11 101.16 0.67 57 0.11 138.84 0.67 57 0.11 113.06 0.67 54 0.112/10/1996 113.06 48 0.10 113.06 51 0.10 113.06 58 0.10 10.12 113.06 58 0.10 13.88 0.30 107.11 58 0.10 11.31 58 0.10 95.21 11.31 101.16 53 11.31 115.04 53 11.31 115.04 64 11.31 115.04 0.60 71 10.71 115.04 71 101.97 105.12 71 9.52 139.66 10.12 105.12 74 113.87 11.50 126.94 87 113.85 11.50 140.83 113.85 11.50 140.83 0.09 11.50 113.85 140.83 10.51 113.83 10.24 146.78 107.88 10.51 14.01 172.56 12.69 11.43 101.91 14.08 95.96 11.42 115.78 14.08 11.42 14.08 115.78 11.42 14.68 115.78 11.42 99 115.76 17.26 10.83 105.84 105.84 10.23 127.64 9.63 11.61 141.52 11.61 196.36 141.52 11.61 141.50 11.61 147.45 10.62 173.24 10.62 12.80 19.64 14.19 14.19 14.18 14.78 17.36 196.96 19.73 12/24/199512/25/199512/26/199512/27/199512/28/1995 0.4912/29/1995 0.4912/30/1995 0.4812/31/1995 0.48 0.47 0.47 0.97 0.46 0.97 0.46 0.95 0.95 0.93 0.93 0.91 0.15 0.91 0.15 0.14 0.14 0.14 0.14 0.14 0.14 29 29 29 29 29 29 57.52 29 57.52 29 57.52 57.52 57.52 57.52 5.75 57.52 5.75 57.52 5.75 5.75 5.75 5.75 5.75 5.75 58.49 58.49 58.47 58.47 58.45 58.45 58.43 5.90 58.43 5.90 5.89 5.89 5.89 5.89 5.89 5.89 Appendix A. Appendix

Appendix A A–39 (acre-ft) (+\- error) Diversion Lake total Lake Diversion in SW (acre-ft) (acre-ft) (+\- error) (site 6) /s) (acre-ft) 08179520 Medina River below Medina Lake 3 (ft (acre-ft) (+\- error) (site 5) 08179530Creek Koenig /s) (acre-ft) 3 (ft Surface-water inflow, Diversion Lake—Continued inflow, Surface-water Date 3/1/19963/2/19963/3/19963/4/19963/5/1996 0.233/6/1996 0.233/7/1996 0.233/8/1996 0.233/9/1996 0.22 0.22 0.46 0.22 0.46 0.21 0.46 0.21 0.46 0.44 0.44 0.44 0.07 0.42 0.07 0.42 0.07 0.07 0.07 0.07 0.07 0.06 76 0.06 76 76 76 76 150.74 75 150.74 73 150.74 68 150.74 68 150.74 148.76 15.07 144.79 15.07 134.88 15.07 134.88 15.07 15.07 14.88 14.48 13.49 151.20 13.49 151.20 151.20 151.20 151.18 149.20 145.23 15.14 135.29 15.14 135.29 15.14 15.14 15.14 14.94 14.54 13.55 13.55 2/11/19962/12/19962/13/19962/14/19962/15/1996 0.292/16/1996 0.292/17/1996 0.292/18/1996 0.292/19/1996 0.282/20/1996 0.28 0.582/21/1996 0.27 0.582/22/1996 0.27 0.582/23/1996 0.27 0.582/24/1996 0.26 0.562/25/1996 0.26 0.562/26/1996 0.26 0.54 0.092/27/1996 0.25 0.54 0.092/28/1996 0.25 0.54 0.092/29/1996 0.25 0.52 0.09 0.24 0.52 0.08 0.24 0.52 0.08 0.24 0.50 0.08 0.24 0.50 0.08 0.50 99 0.08 102 0.48 0.08 106 0.48 0.08 105 0.48 0.08 109 0.48 0.073/10/1996 117 196.36 0.073/11/1996 202.31 118 0.073/12/1996 210.25 118 0.073/13/1996 208.26 114 0.073/14/1996 0.21 216.20 107 0.073/15/1996 0.20 232.07 108 0.073/16/1996 19.64 0.20 234.05 111 20.233/17/1996 0.19 234.05 118 21.023/18/1996 0.19 226.12 124 20.833/19/1996 0.19 212.23 124 21.62 0.423/20/1996 0.18 214.21 124 23.21 0.403/21/1996 0.18 220.17 124 23.40 0.403/22/1996 0.18 234.05 121 23.40 0.383/23/1996 0.17 245.95 104 22.61 0.383/24/1996 196.94 0.17 245.95 202.89 21.22 0.383/25/1996 0.16 245.95 210.82 21.42 0.36 0.063/26/1996 0.16 245.95 208.84 22.02 0.36 0.063/27/1996 0.16 240.00 23.40 216.75 0.36 0.063/28/1996 0.15 206.28 24.60 232.62 0.34 0.063/29/1996 0.15 234.58 24.60 0.34 0.063/30/1996 0.15 19.72 234.58 24.60 0.32 0.06 20.32 0.14 226.65 24.60 0.32 0.05 21.11 0.14 212.75 24.00 0.32 0.05 20.91 0.14 20.63 214.73 0.30 68 0.05 21.70 0.13 220.68 0.30 68 0.05 23.29 234.55 0.30 68 0.05 23.49 246.45 0.28 74 0.05 23.49 246.45 0.28 78 0.05 22.69 134.88 246.43 0.28 84 0.05 21.30 103 134.88 246.43 0.26 0.04 21.50 103 134.88 240.48 0.04 22.09 104 146.78 206.76 0.04 23.48 110 154.71 0.04 24.67 116 166.61 0.04 24.67 13.49 204.30 135 0.04 24.67 13.49 204.30 150 0.04 24.67 13.49 206.28 150 24.07 14.68 218.18 150 20.70 15.47 230.08 143 16.66 267.77 125 20.43 297.52 114 20.43 297.52 121 20.63 135.29 297.52 139 21.82 135.27 283.64 139 23.01 135.27 247.93 26.78 147.15 226.12 29.75 155.09 240.00 29.75 166.99 275.70 29.75 204.65 275.70 13.55 28.36 204.65 13.55 206.64 24.79 13.55 218.52 22.61 14.73 230.42 24.00 15.53 268.09 27.57 16.72 297.84 27.57 20.48 297.84 20.48 297.82 20.68 283.93 21.87 248.23 23.06 226.39 26.82 240.28 29.80 275.98 29.80 275.96 29.80 28.41 24.84 22.65 24.04 27.61 27.61 Appendix A. Appendix

A–40 Hydrogeology, Hydrologic Budget, and Water Chemistry of the Medina Lake area, Texas (acre-ft) (+\- error) Diversion Lake total Lake Diversion in SW (acre-ft) (acre-ft) (+\- error) (site 6) /s) (acre-ft) 08179520 Medina River below Medina Lake 3 (ft (acre-ft) (+\- error) (site 5) 08179530Creek Koenig /s) (acre-ft) 3 (ft Surface-water inflow, Diversion Lake—Continued inflow, Surface-water Date 4/1/19964/2/19964/3/19964/4/19964/5/1996 0.134/6/1996 0.124/7/1996 0.124/8/1996 0.124/9/1996 0.11 0.11 0.26 0.11 0.24 0.10 0.24 0.10 0.24 0.22 0.22 0.22 0.04 0.20 0.04 0.20 0.04 0.04 0.03 0.03 0.03 0.03 138 0.03 138 138 108 90 273.72 89 273.72 895/1/1996 273.72 895/2/1996 214.21 1015/3/1996 178.515/4/1996 176.53 27.375/5/1996 0.05 176.53 27.375/6/1996 0.05 176.53 27.375/7/1996 0.05 200.33 21.425/8/1996 0.045/9/1996 17.85 0.04 17.65 0.04 0.10 17.65 0.04 0.09 17.65 0.04 273.98 20.03 0.09 0.04 273.96 0.09 273.96 0.08 214.45 0.08 0.08 0.01 178.73 0.07 0.01 176.75 0.07 0.01 27.41 176.75 0.01 27.41 176.73 200.53 0.01 27.41 0.01 21.46 0.01 17.88 0.01 17.69 171 0.01 17.69 174 17.68 180 20.06 186 187 339.17 188 345.12 191 357.02 368.93 154 370.91 372.89 33.92 378.84 34.51 35.70 305.45 36.89 37.09 37.29 37.88 339.27 30.55 345.22 357.12 369.01 370.99 372.97 378.92 33.93 34.53 305.52 35.72 36.91 37.10 37.30 37.90 30.56 3/31/1996 0.13 0.264/10/19964/11/19964/12/19964/13/19964/14/1996 0.104/15/1996 0.10 0.044/16/1996 0.094/17/1996 0.094/18/1996 0.094/19/1996 0.09 0.204/20/1996 0.08 0.194/21/1996 0.05 0.194/22/1996 0.08 0.184/23/1996 0.08 138 0.174/24/1996 0.07 0.174/25/1996 0.07 0.16 0.034/26/1996 0.07 0.10 0.034/27/1996 0.07 0.15 0.034/28/1996 0.07 273.72 0.15 0.034/29/1996 0.06 0.15 0.034/30/1996 0.06 0.14 0.03 0.06 0.14 0.02 0.06 0.13 0.01 0.05 114 27.37 0.13 0.02 0.05 120 0.12 0.02 119 0.12 0.02 124 0.12 0.02 127 0.11 0.02 226.12 139 0.11 0.02 238.02 146 0.10 0.025/10/1996 236.03 146 0.025/11/1996 245.95 145 273.98 0.025/12/1996 251.90 151 0.025/13/1996 275.70 171 22.61 0.025/14/1996 0.03 289.59 171 23.80 0.025/15/1996 0.03 289.59 171 23.60 0.025/16/1996 0.03 287.60 171 24.605/17/1996 0.03 299.50 171 25.195/18/1996 27.41 0.03 339.17 170 27.57 0.03 339.17 170 28.96 0.07 0.03 339.17 170 28.96 0.07 0.02 339.17 171 28.76 226.31 0.06 0.02 339.17 171 29.95 238.21 0.06 337.19 171 236.22 33.92 0.06 337.19 246.13 33.92 0.05 337.19 252.08 33.92 0.05 0.01 339.17 275.87 33.92 0.05 0.01 339.17 33.92 289.75 0.05 0.01 22.64 339.17 33.72 289.69 0.01 23.83 287.76 33.72 0.01 23.63 299.65 33.72 0.01 24.62 339.32 33.92 0.01 25.22 339.32 33.92 0.01 27.60 33.92 339.31 91 0.01 28.98 339.31 91 28.97 339.30 91 28.78 337.31 91 29.97 337.31 91 33.94 180.50 337.30 91 33.94 180.50 339.28 91 33.94 180.50 339.28 91 33.94 109 180.50 339.28 33.94 180.50 33.74 180.50 33.74 18.05 180.50 33.74 18.05 180.50 33.93 18.05 216.20 33.93 18.05 33.93 18.05 18.05 18.05 18.05 21.62 180.56 180.56 180.56 180.56 180.55 180.55 180.55 18.06 180.54 18.06 216.24 18.06 18.06 18.06 18.06 18.06 18.06 21.63 Appendix A. Appendix

Appendix A A–41 (acre-ft) (+\- error) Diversion Lake total Lake Diversion in SW (acre-ft) (acre-ft) (+\- error) (site 6) /s) (acre-ft) 08179520 Medina River below Medina Lake 3 (ft (acre-ft) (+\- error) (site 5) 08179530Creek Koenig /s) (acre-ft) 3 (ft Surface-water inflow, Diversion Lake—Continued inflow, Surface-water Date 6/1/19966/2/19966/3/19966/4/19966/5/1996 0.016/6/1996 0.016/7/1996 06/8/1996 06/9/1996 0 0 0.02 0 0.02 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 7/1/19967/2/19967/3/19967/4/19967/5/1996 07/6/1996 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 5/19/19965/20/19965/21/19965/22/19965/23/1996 0.025/24/1996 0.025/25/1996 0.025/26/1996 0.025/27/1996 0.025/28/1996 0.02 0.045/29/1996 0.02 0.045/30/1996 0.02 0.045/31/1996 0.02 0.04 0.01 0.03 0.01 0.03 0.01 0.03 0.01 0.01 0.03 0.01 0.03 0.01 0.03 0.01 0.03 0 0.03 0.01 0.02 0 6/10/1996 0 6/11/1996 127 0 6/12/1996 145 0 6/13/1996 179 0 6/14/1996 0 194 0 6/15/1996 0 0 6/16/1996 0 251.906/17/1996 0 287.606/18/1996 0 355.046/19/1996 0 384.796/20/1996 0 06/21/1996 0 25.19 06/22/1996 0 28.76 06/23/1996 0 35.50 06/24/1996 0 38.48 06/25/1996 0 06/26/1996 0 06/27/1996 0 06/28/1996 0 0 06/29/1996 0 0 251.94 06/30/1996 0 0 287.64 0 0 0 355.08 0 0 0 384.83 0 0 0 0 0 0 0 0 0 25.20 0 0 28.77 0 0 35.51 0 0 38.48 0 0 0 0 0 0 0 0 0 0 0 0 Appendix A. Appendix

A–42 Hydrogeology, Hydrologic Budget, and Water Chemistry of the Medina Lake area, Texas (acre-ft) (+\- error) Diversion Lake total Lake Diversion in SW (acre-ft) (acre-ft) (+\- error) (site 6) /s) (acre-ft) 08179520 Medina River below Medina Lake 3 (ft (acre-ft) (+\- error) (site 5) 08179530Creek Koenig /s) (acre-ft) 3 (ft Surface-water inflow, Diversion Lake—Continued inflow, Surface-water Date 7/7/19967/8/19967/9/1996 0 0 0 0 0 0 0 0 0 8/1/19968/2/19968/3/19968/4/19968/5/1996 08/6/1996 08/7/1996 08/8/1996 08/9/1996 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 7/10/19967/11/19967/12/19967/13/19967/14/1996 07/15/1996 07/16/1996 07/17/1996 07/18/1996 07/19/1996 07/20/1996 0 07/21/1996 0 07/22/1996 0 07/23/1996 0 07/24/1996 0 07/25/1996 0 07/26/1996 0 07/27/1996 0 07/28/1996 0 0 07/29/1996 0 0 07/30/1996 0 0 07/31/1996 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 110 0 0 124 0 0 150 08/10/1996 0 159 08/11/1996 0 1628/12/1996 0 218.18 1668/13/1996 0 245.95 1698/14/1996 0 0 297.52 1768/15/1996 0 0 315.37 1828/16/1996 0 0 321.32 1898/17/1996 0 0 329.26 196 21.828/18/1996 0 0 335.21 197 24.608/19/1996 0 349.09 29.758/20/1996 0 360.99 0 31.548/21/1996 0 374.88 0 32.138/22/1996 0 388.76 0 32.938/23/1996 0 390.74 0 33.528/24/1996 0 0 34.91 0 0 36.10 218.18 0 0 245.95 37.49 0 0 297.52 38.88 0 0 0 315.37 39.07 0 0 321.32 0 0 329.26 0 0 335.21 0 21.82 0 349.09 0 24.60 0 360.99 0 29.75 0 374.88 0 31.54 388.76 0 32.13 390.74 0 32.93 0 33.52 0 34.91 0 36.10 0 37.49 0 38.88 39.07 122 62 241.98 122.98 24.20 12.30 241.98 122.98 24.20 12.30 Appendix A. Appendix

Appendix A A–43 (acre-ft) (+\- error) Diversion Lake total Lake Diversion in SW (acre-ft) (acre-ft) (+\- error) (site 6) /s) (acre-ft) 08179520 Medina River below Medina Lake 3 (ft (acre-ft) (+\- error) (site 5) 08179530Creek Koenig /s) (acre-ft) 3 (ft Surface-water inflow, Diversion Lake—Continued inflow, Surface-water Date 9/1/19969/2/19969/3/19969/4/19969/5/1996 09/6/1996 09/7/1996 09/8/1996 09/9/1996 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 16 15 15 15 15 15 31.74 15 29.75 15 29.75 15 29.75 29.75 29.75 3.17 29.75 2.98 29.75 2.98 29.75 2.98 2.98 2.98 2.98 2.98 2.98 31.74 29.75 29.75 29.75 29.75 29.75 29.75 3.17 29.75 2.98 29.75 2.98 2.98 2.98 2.98 2.98 2.98 2.98 8/25/19968/26/19968/27/19968/28/19968/29/1996 08/30/1996 08/31/1996 0 0 0 0 0 0 0 0 0 0 09/10/1996 09/11/19969/12/1996 09/13/1996 09/14/1996 0 09/15/1996 0 09/16/1996 0 09/17/1996 0 09/18/1996 0 09/19/1996 09/20/1996 0 09/21/1996 0 61 09/22/1996 0 34 09/23/1996 0 15 09/24/1996 0 15 09/25/1996 0 15 0 120.999/26/1996 0 16 09/27/1996 0 16 67.44 09/28/1996 0 0 29.75 09/29/1996 0 0 29.75 09/30/1996 0 0 29.75 0 0 0 31.74 12.10 0 0 0 31.74 0 0 0 6.74 0 0 0 2.98 0 0 2.98 0 0 2.98 0 0 15 3.17 0 0 15 3.17 0 0 15 120.99 0 0 15 0 0 15 67.44 0 16 29.75 29.75 0 15 29.75 29.75 0 15 29.75 29.75 0 30 29.75 31.74 12.10 0 44 29.75 31.74 0 43 31.74 0 43 2.98 29.75 6.74 43 2.98 29.75 2.98 64 2.98 59.50 2.98 87 2.98 87.27 2.98 87 2.98 85.29 3.17 87 3.17 85.29 3.17 77 2.98 85.29 126.94 57 2.98 172.56 57 5.95 29.75 172.56 64 8.73 29.75 172.56 8.53 29.75 152.73 8.53 29.75 113.06 8.53 12.69 29.75 113.06 17.26 31.74 126.94 17.26 29.75 17.26 2.98 29.75 15.27 2.98 59.50 11.31 2.98 87.27 11.31 2.98 85.29 12.69 2.98 85.29 126.94 3.17 85.29 172.56 2.98 172.56 2.98 172.56 5.95 152.73 8.73 113.06 8.53 113.06 8.53 12.69 126.94 8.53 17.26 17.26 17.26 15.27 11.31 11.31 12.69 Appendix A. Appendix

A–44 Hydrogeology, Hydrologic Budget, and Water Chemistry of the Medina Lake area, Texas (acre-ft) (+\- error) Diversion Lake (site8)(A) 08180015 Medina River below /s) (acre-ft) 3 (ft Diversion Lake (acre-ft) (+\- error) (+\- , surface-water outflow] surface-water , out canal (site 7) 08179990 Medina /s) (acre-ft) 3 (ft (acre-ft) (+\- error) Medina out Lake total SW (acre-ft) /s, cubic feet per second; acre-ft, acre-feet; SW acre-ft, second; feet per cubic /s, Appendix A 3 Medina Lake Medina (acre-ft) (+\- error) Hydrogeology, Hydrologic Budget, Hydrogeology, Chemistry the of Water and Texas area, Lake Medina Medina Lake (site 6) 08179520 Medina Riverbelow /s) (acre-ft) 3 (ft Surface-water outflow, Medina and Diversion Lakes—Continued Surface-water outflow, Surface-water outflow, Medina and Diversion Lakes Diversion and Medina outflow, Surface-water Date 8/1/19958/2/19958/3/1995 1378/4/1995 1378/5/1995 1378/6/1995 1378/7/1995 271.74 1408/8/1995 271.74 1448/9/1995 271.74 143 271.74 27.17 143 277.69 27.17 143 285.62 27.17 283.64 27.17 283.64 27.77 283.64 28.56 271.74 28.36 271.74 28.36 271.74 28.36 271.74 27.17 277.69 27.17 285.62 27.17 283.64 27.17 283.64 27.77 283.64 28.56 28.36 28.36 28.36 9/1/19959/2/19959/3/1995 1439/4/1995 1439/5/1995 1439/6/1995 1439/7/1995 283.64 1439/8/1995 283.64 1439/9/1995 283.64 143 283.64 28.36 143 283.64 28.36 143 283.64 28.36 283.64 28.36 283.64 28.36 283.64 28.36 283.64 28.36 283.64 28.36 283.64 28.36 283.64 28.36 283.64 28.36 283.64 28.36 283.64 28.36 283.64 28.36 283.64 126.00 28.36 123.00 28.36 121.00 28.36 118.00 28.36 249.92 116.00 243.97 113.00 240.00 111.00 234.05 113.00 24.99 230.08 106.00 24.40 224.13 24.00 220.17 23.40 224.13 23.01 210.25 22.41 5.70 22.02 5.60 22.41 5.60 21.02 11.31 5.60 11.11 5.50 11.11 5.40 11.11 5.40 1.13 10.91 5.40 1.11 10.71 5.20 1.11 10.71 1.11 10.71 1.09 10.31 1.07 1.07 1.07 1.03 8/10/19958/11/19958/12/1995 1438/13/1995 1438/14/1995 1438/15/1995 1448/16/1995 283.64 1438/17/1995 283.64 1438/18/1995 283.64 1438/19/1995 285.62 28.36 1438/20/1995 283.64 28.36 1438/21/1995 283.64 28.36 1438/22/1995 283.64 28.56 1438/23/1995 283.64 28.36 1438/24/1995 283.64 28.36 283.64 1438/25/1995 283.64 28.36 283.64 1438/26/1995 283.64 28.36 283.64 1438/27/1995 283.64 28.36 285.62 1438/28/1995 283.64 28.36 28.36 283.64 1438/29/1995 283.64 28.36 28.36 283.64 1438/30/1995 283.64 28.36 28.36 283.64 1438/31/1995 283.64 28.56 28.36 283.64 143 283.64 28.36 28.36 283.64 143 283.64 28.36 28.36 283.64 143 283.64 28.36 28.36 283.64 283.64 28.36 28.36 283.64 283.64 28.36 28.36 283.64 283.64 28.36 28.36 283.64 28.36 28.36 283.64 28.36 28.36 283.64 28.36 28.36 283.649/10/1995 28.36 283.649/11/1995 28.36 283.649/12/1995 28.36 283.64 1439/13/1995 141.00 28.36 283.64 1359/14/1995 141.00 28.36 283.64 1129/15/1995 141.00 28.36 112 283.64 141.00 28.36 112 267.77 279.67 140.00 28.36 112 222.15 279.67 137.00 28.36 222.15 279.67 139.00 28.36 222.15 279.67 140.00 26.78 27.97 222.15 277.69 133.00 22.21 27.97 271.74 131.00 22.21 27.97 275.70 128.00 22.21 27.97 277.69 22.21 27.77 283.64 263.80 27.17 267.77 259.83 27.57 222.15 253.88 27.77 222.15 28.36 26.38 222.15 26.78 25.98 222.15 22.21 25.39 22.21 22.21 103.00 22.21 103.00 102.00 5.70 101.00 204.30 100.00 204.30 99.00 11.31 202.31 200.33 20.43 198.35 20.43 1.13 196.36 20.23 20.03 19.83 5.30 19.64 5.30 5.30 10.51 5.20 10.51 4.90 10.51 4.90 10.31 1.05 9.72 1.05 1.05 9.72 1.03 0.97 0.97 Appendix A. Appendix A.Appendix 2. ft table 3 and figure to correspond numbers [Site

Appendix A A–45 (acre-ft) site 8 (A) to site 9 (B) Increasestreamflow in (acre-ft) (+\- error) (+\- (B) Diversion Lake total out SW (acre-ft) (acre-ft) (+\- error) Diversion Lake (A) Diversion Lake total Lake out SW (acre-ft) (acre-ft) (+\- error) 08180500 Medina River near Riomedina (site 9) (B) 9) (site Riomedina near /s) (acre-ft) 3 (ft Surface-water outflow, Medina and Diversion outflow, Lakes—ContinuedSurface-water Surface-water outflow, Medina and Diversion Lakes—Continued Surface-water outflow, Date 8/1/19958/2/19958/3/19958/4/1995 23.008/5/1995 23.008/6/1995 22.008/7/1995 21.008/8/1995 21.008/9/1995 45.62 21.00 45.62 21.00 43.64 21.00 41.65 21.00 41.65 41.65 4.56 41.65 4.56 41.65 4.36 41.65 4.17 4.17 4.17 4.17 4.17 4.17 9/1/19959/2/19959/3/19959/4/1995 21.009/5/1995 20.009/6/1995 21.009/7/1995 23.009/8/1995 22.009/9/1995 41.65 22.00 39.67 22.00 41.65 22.00 45.62 22.00 43.64 43.64 4.17 43.64 3.97 43.64 4.17 43.64 4.56 4.36 4.36 261.22 4.36 255.07 4.36 251.11 4.36 245.16 240.99 26.12 234.84 25.51 230.88 25.11 234.84 24.52 220.56 24.10 23.48 291.57 23.09 283.64 23.48 281.65 22.06 279.67 273.72 29.16 267.77 28.36 263.80 28.17 267.77 27.97 253.88 27.37 26.78 26.38 26.78 25.39 30.35 28.56 30.55 34.51 32.73 32.93 32.93 32.93 33.32 8/10/19958/11/19958/12/19958/13/1995 21.008/14/1995 21.008/15/1995 21.008/16/1995 21.008/17/1995 21.008/18/1995 41.65 21.008/19/1995 41.65 21.008/20/1995 41.65 21.008/21/1995 41.65 21.008/22/1995 41.65 21.008/23/1995 41.65 4.17 21.008/24/1995 41.65 4.17 21.008/25/1995 41.65 4.17 21.008/26/1995 41.65 4.17 21.008/27/1995 41.65 4.17 21.008/28/1995 41.65 4.17 21.008/29/1995 41.65 4.17 21.008/30/1995 41.65 4.17 22.008/31/1995 41.65 4.17 21.00 41.65 4.17 21.00 41.65 4.17 21.00 41.65 4.17 21.00 43.64 4.17 41.65 4.17 41.65 4.17 41.65 4.17 4.17 41.65 4.369/10/1995 4.179/11/1995 4.179/12/1995 4.179/13/1995 4.17 22.009/14/1995 22.009/15/1995 22.00 22.00 22.00 43.64 22.00 265.19 43.64 43.64 43.64 43.64 43.64 4.36 321.32 26.52 4.36 321.32 4.36 321.32 4.36 321.32 4.36 319.34 32.13 4.36 313.39 214.81 32.13 295.54 319.34 214.81 32.13 319.34 212.83 32.13 305.45 210.64 31.93 301.49 208.07 31.34 21.48 206.08 31.93 29.55 21.48 31.93 21.28 30.55 21.06 30.15 20.81 20.61 247.93 247.93 245.95 243.97 241.98 30.35 24.79 240.00 24.79 24.60 24.40 24.20 24.00 33.12 33.12 33.12 33.32 33.92 33.92 Appendix A. Appendix A.Appendix

A–46 Hydrogeology, Hydrologic Budget, and Water Chemistry of the Medina Lake area, Texas (acre-ft) (+\- error) Diversion Lake (site8)(A) 08180015 Medina River below /s) (acre-ft) 3 (ft Diversion Lake (acre-ft) (+\- error) (+\- canal (site 7) 08179990 Medina /s) (acre-ft) 3 (ft 46 91.24 9.12 6.4 12.69 1.27 (acre-ft) (+\- error) Medina out Lake total SW (acre-ft) Medina Lake Medina (acre-ft) (+\- error) Medina Lake (site 6) 08179520 Medina Riverbelow /s) (acre-ft) 3 (ft Surface-water outflow, Medina and Diversion Lakes—Continued Surface-water outflow, Date 9/16/19959/17/19959/18/1995 1129/19/1995 1129/20/1995 112 120 222.15 222.15 222.15 238.02 22.21 22.21 22.21 23.80 222.15 222.15 222.15 238.02 22.21 22.21 22.21 23.80 99.00 99.00 98.00 99.00 196.36 196.36 194.38 196.36 19.64 19.64 19.44 19.64 4.90 4.90 4.90 4.90 9.72 9.72 9.72 9.72 0.97 0.97 0.97 0.97 9/21/19959/22/19959/23/19959/24/1995 349/25/1995 349/26/1995 339/27/1995 33 67.449/28/1995 33 67.449/29/1995 33 65.459/30/1995 33 65.4510/1/1995 33 6.74 65.4510/2/1995 33 6.74 65.4510/3/1995 32 6.55 65.4510/4/1995 32 6.55 65.4510/5/1995 32 6.55 65.4510/6/1995 32 6.55 63.4710/7/1995 32 67.44 6.55 63.4710/8/1995 32 67.44 6.55 63.4710/9/1995 32 65.45 6.55 63.47 32 65.45 6.35 63.47 32 6.74 65.45 6.35 63.47 32 6.74 65.45 6.35 63.47 6.55 65.45 6.35 63.47 6.55 65.45 6.35 63.47 6.55 65.45 6.35 63.47 6.55 63.47 6.35 0 6.55 63.47 6.35 0 6.55 63.47 6.35 0 6.55 63.47 6.35 0 6.35 63.47 0 6.35 63.47 16.00 6.35 63.47 67.00 0 6.35 63.47 51.00 0 6.35 63.47 50.00 0 6.35 63.47 49.00 0 31.74 6.35 132.89 48.00 0 6.35 101.16 46.00 0 6.35 65.00 99.17 0 6.35 76.00 3.17 97.19 0 13.29 73.00 95.21 0 10.12 71.0011/1/1995 91.24 0 128.93 71.0011/2/1995 9.92 150.74 70.00 9.72 7.30 144.79 69.00 9.52 53 8.40 8.80 7.60 140.83 9.12 12.89 32 8.80 8.00 140.83 15.07 14.48 8.40 138.84 16.66 14.48 17.45 15.07 105.12 8.60 8.40 136.86 14.08 17.45 15.87 8.40 63.47 14.08 16.66 8.40 1.45 17.06 13.88 16.66 8.40 7.90 1.67 1.75 1.51 10.51 16.66 13.69 7.60 1.75 1.59 16.66 7.10 6.35 1.67 16.66 15.67 6.80 1.71 1.67 15.07 6.20 1.67 14.08 5.70 1.67 105.12 13.49 5.20 1.67 1.57 12.30 1.51 11.31 63.47 1.41 10.31 10.51 1.35 1.23 1.13 6.35 1.03 17.00 18.00 33.72 35.70 3.37 3.57 6.10 12.10 6.50 12.89 1.21 1.29 10/10/199510/11/199510/12/199510/13/1995 3210/14/1995 4510/15/1995 7110/16/1995 83 63.4710/17/1995 83 89.2610/18/1995 83 140.83 10410/19/1995 164.63 12610/20/1995 164.63 6.35 12610/21/1995 164.63 8.93 126 14.0810/22/1995 206.28 126 16.4610/23/1995 249.92 126 16.4610/24/1995 249.92 127 16.4610/25/1995 249.92 20.63 12610/26/1995 249.92 63.47 24.99 12610/27/1995 249.92 140.83 89.26 24.99 11610/28/1995 251.90 164.63 24.9910/29/1995 249.92 164.63 86 24.9910/30/1995 249.92 164.63 70 6.35 24.99 14.08 206.2810/31/1995 230.08 70 8.93 25.19 16.46 249.92 70 170.58 24.99 16.46 249.92 68 138.84 24.99 16.46 249.92 20.63 61 138.84 23.01 249.92 24.99 138.84 249.92 69.00 17.06 57.00 24.99 134.88 251.90 56.00 13.88 67.00 24.99 120.99 249.92 13.88 73.00 24.99 249.92 13.88 75.00 24.99 79.00 136.86 230.08 13.49 113.06 25.19 93.00 111.07 12.10 132.89 102.00 170.58 24.99 144.79 107.00 138.84 24.99 148.76 109.00 138.84 13.69 23.01 11.31 156.69 109.00 138.84 11.11 13.29 184.46 17.06 202.31 110.00 134.88 14.48 13.88 212.23 111.00 120.99 14.88 13.88 15.67 216.20 111.00 13.88 18.45 216.20 101.00 20.23 4.60 13.49 4.60 218.18 21.22 4.60 12.10 4.60 86.00 220.17 21.62 4.60 80.00 220.17 21.62 9.12 4.70 9.12 79.00 200.33 4.80 21.82 9.12 9.12 75.00 4.90 22.02 9.12 170.58 5.30 72.00 22.02 9.32 158.68 5.70 44.00 0.91 9.52 0.91 20.03 156.69 5.70 0.91 9.72 0.91 10.51 148.76 5.70 17.06 0.91 11.31 142.81 5.70 15.87 0.93 11.31 5.70 0.95 87.27 15.67 11.31 5.70 0.97 1.05 14.88 11.31 5.70 1.13 14.28 11.31 1.13 11.31 5.70 1.13 8.73 11.31 5.70 1.13 5.30 1.13 11.31 4.90 1.13 11.31 4.90 1.13 10.51 5.00 9.72 1.13 9.72 1.13 1.05 9.92 0.97 0.97 0.99 Appendix A.

Appendix A A–47 (acre-ft) site 8 (A) to site 9 (B) Increasestreamflow in (acre-ft) (+\- error) (+\- (B) Diversion Lake total out SW (acre-ft) (acre-ft) (+\- error) Diversion Lake (A) Diversion Lake total Lake out SW (acre-ft) (acre-ft) (+\- error) 08180500 Medina River near Riomedina (site 9) (B) 9) (site Riomedina near /s) (acre-ft) 3 (ft Surface-water outflow, Medina and Diversion outflow, Lakes—ContinuedSurface-water Date 9/16/19959/17/19959/18/19959/19/1995 22.009/20/1995 22.009/21/1995 22.009/22/1995 22.009/23/1995 22.009/24/1995 43.64 33.009/25/1995 43.64 27.009/26/1995 43.64 26.009/27/1995 43.64 26.009/28/1995 43.64 26.009/29/1995 65.45 4.36 27.009/30/1995 53.55 4.36 27.0010/1/1995 51.57 4.36 27.0010/2/1995 51.57 4.36 27.0010/3/1995 51.57 4.36 27.0010/4/1995 53.55 6.55 27.0010/5/1995 206.08 53.55 5.36 27.0010/6/1995 206.08 53.55 5.16 27.0010/7/1995 204.10 53.55 5.16 26.0010/8/1995 206.08 53.55 5.16 26.0010/9/1995 103.93 53.55 5.36 25.00 20.61 53.55 5.36 24.00 14.48 20.61 53.55 5.36 22.00 15.07 20.41 51.57 5.36 20.00 15.87 20.61 51.57 5.36 16.66 10.39 49.59 5.36 16.66 47.60 5.36 48.40 240.00 1.45 150.35 43.64 5.36 240.00 1.51 118.61 39.67 5.16 238.02 1.59 116.23 5.16 240.00 1.67 113.85 4.96 134.88 1.67 111.87 24.00 4.76 4.84 15.03 107.90 24.00 4.36 11.86 65.45 144.59 23.80 3.97 11.62 53.55 165.82 24.00 11.39 51.57 158.88 13.49 11.19 51.57 154.31 10.79 51.57 153.12 186.45 14.46 85.29 6.55 150.15 154.71 16.58 5.36 147.17 152.73 15.89 5.16 150.74 15.43 5.16 33.92 148.76 15.31 5.16 33.92 18.64 144.7911/1/1995 15.01 8.53 33.92 15.47 182.4811/2/1995 14.72 33.92 15.27 202.31 30.94 15.07 196.36 14.88 24.00 190.41 14.48 24.00 188.43 50.98 18.25 182.48 38.48 20.23 176.53 35.70 19.64 34.91 47.60 19.04 34.91 36.10 47.60 18.84 36.89 36.10 18.25 36.50 17.65 36.89 36.89 4.76 36.89 4.76 37.88 36.50 37.49 36.10 35.31 45.82 32.33 48.60 29.36 4.58 4.86 81.32 83.31 8.13 8.33 35.50 34.71 10/10/199510/11/199510/12/199510/13/1995 19.0010/14/1995 19.0010/15/1995 19.0010/16/1995 17.0010/17/1995 17.0010/18/1995 37.69 18.0010/19/1995 37.69 18.0010/20/1995 37.69 18.0010/21/1995 33.72 19.0010/22/1995 33.72 21.0010/23/1995 35.70 3.77 21.0010/24/1995 35.70 3.77 22.0010/25/1995 35.70 3.77 23.0010/26/1995 37.69 3.37 23.0010/27/1995 41.65 3.37 23.0010/28/1995 41.65 3.57 23.0010/29/1995 145.98 43.64 3.57 23.0010/30/1995 120.20 45.62 3.57 23.0010/31/1995 122.18 45.62 3.77 23.00 142.02 45.62 4.17 24.00 153.92 45.62 4.17 24.00 14.60 158.08 45.62 4.36 24.00 12.02 166.21 45.62 4.56 12.22 194.18 45.62 4.56 14.20 212.83 47.60 4.56 15.39 223.54 47.60 4.56 15.81 227.50 47.60 4.56 174.55 16.62 227.50 4.56 148.76 19.42 229.49 4.56 150.74 21.28 231.47 4.76 166.61 22.35 231.47 4.76 178.51 22.75 211.64 17.45 4.76 184.46 22.75 181.88 14.88 192.40 22.95 169.98 15.07 220.17 23.15 167.21 16.66 240.00 23.15 158.48 17.85 253.88 21.16 152.53 18.45 257.85 18.19 19.24 97.19 259.83 17.00 22.02 263.80 16.72 24.00 265.78 15.85 25.39 265.78 15.25 28.56 25.79 245.95 28.56 25.98 216.20 9.72 28.56 26.38 204.30 24.60 26.58 202.31 24.60 26.58 196.36 26.38 24.60 190.41 26.18 21.62 25.98 20.43 134.88 27.17 20.23 30.35 19.64 30.35 19.04 32.33 13.49 34.31 34.31 34.31 34.31 34.31 34.31 35.11 37.88 37.88 37.69 Appendix A.

A–48 Hydrogeology, Hydrologic Budget, and Water Chemistry of the Medina Lake area, Texas (acre-ft) (+\- error) Diversion Lake (site8)(A) 08180015 Medina River below /s) (acre-ft) 3 (ft Diversion Lake (acre-ft) (+\- error) (+\- canal (site 7) 08179990 Medina /s) (acre-ft) 3 (ft (acre-ft) (+\- error) Medina out Lake total SW (acre-ft) Medina Lake Medina (acre-ft) (+\- error) Medina Lake (site 6) 08179520 Medina Riverbelow /s) (acre-ft) 3 (ft Surface-water outflow, Medina and Diversion Lakes—Continued Surface-water outflow, Date 11/3/199511/4/199511/5/199511/6/1995 3211/7/1995 3211/8/1995 3111/9/1995 31 63.47 31 63.47 31 61.49 31 61.49 6.35 61.49 6.35 61.49 6.15 61.49 6.15 6.15 6.15 63.47 6.15 63.47 61.49 61.49 6.35 61.49 6.35 61.49 6.15 61.49 6.15 6.15 6.15 19.00 6.15 19.00 20.0012/1/1995 14.0012/2/1995 21.0012/3/1995 37.69 36.0012/4/1995 37.69 30 37.0012/5/1995 39.67 3012/6/1995 27.77 3012/7/1995 3.77 41.65 30 59.5012/8/1995 3.77 71.40 30 59.5012/9/1995 3.97 73.39 30 59.50 2.78 30 59.50 4.17 30 5.95 59.50 7.14 29 6.80 5.95 59.50 7.34 7.00 5.95 59.50 7.20 5.95 59.50 13.49 7.50 5.95 57.52 13.88 7.60 5.95 14.28 7.60 59.50 5.95 14.88 7.20 59.50 1.35 5.95 15.07 59.50 1.39 5.75 15.07 59.50 1.43 14.28 5.95 59.50 1.49 5.95 59.50 1.51 5.95 59.50 1.51 5.95 59.50 1.43 5.95 57.52 5.95 39.00 5.95 41.00 5.95 40.00 5.75 39.00 38.00 77.36 48.00 81.32 51.00 79.34 44.00 77.36 39.00 7.74 75.37 8.13 95.21 101.16 7.93 7.74 87.27 7.54 77.36 9.52 10.12 7.20 7.20 8.73 6.80 7.74 14.28 6.80 14.28 6.80 13.49 6.10 6.00 13.49 1.43 13.49 5.60 1.43 12.10 11.90 5.30 1.35 1.35 11.11 1.35 10.51 1.21 1.19 1.11 1.05 11/10/199511/11/199511/12/199511/13/1995 3111/14/1995 3011/15/1995 3011/16/1995 30 61.4911/17/1995 30 59.5011/18/1995 30 59.5011/19/1995 30 59.5011/20/1995 33 6.15 59.5011/21/1995 32 5.95 59.5011/22/1995 31 5.95 59.5011/23/1995 31 5.95 65.4511/24/1995 31 5.95 63.4711/25/1995 30 5.95 61.4911/26/1995 30 61.49 5.95 61.4911/27/1995 30 59.50 6.55 61.4911/28/1995 30 59.50 6.35 59.5011/29/1995 30 59.50 6.15 59.5011/30/1995 30 6.15 59.50 6.15 59.50 30 5.95 59.50 6.15 59.50 30 5.95 59.50 5.95 59.50 30 5.95 65.45 5.95 59.50 5.95 63.47 5.95 59.50 5.95 61.49 45.00 5.95 59.50 5.95 61.49 44.00 5.95 59.50 6.55 61.49 42.00 5.95 6.35 59.50 41.00 5.95 6.15 59.50 45.00 5.9512/10/1995 89.26 6.15 59.50 59.00 5.9512/11/1995 87.27 6.15 59.50 57.0012/12/1995 83.31 5.95 59.50 17.0012/13/1995 81.32 30 5.95 59.5012/14/1995 8.93 89.26 0 30 5.95 59.50 117.0212/15/1995 8.73 0 30 5.95 59.50 113.0612/16/1995 8.33 0 30 5.95 59.50 59.5012/17/1995 8.13 33.72 0 30 5.95 59.5012/18/1995 8.93 0 11.70 30 5.95 59.5012/19/1995 0 11.31 29 5.95 6.80 59.5012/20/1995 0 0 29 5.95 6.80 5.95 59.50 3.37 0 0 29 6.80 5.95 59.50 0 13.49 0 29 6.80 5.95 57.52 0 13.49 0 29 6.80 6.60 5.95 57.52 0 13.49 0 6.00 37.00 5.95 57.52 0 13.49 0 1.35 40.00 5.95 57.52 0 13.49 0 13.09 5.40 59.50 1.35 5.75 57.52 0 0 11.90 59.50 1.35 5.75 0 0 59.50 1.35 5.75 0 10.71 73.39 0 59.50 1.35 5.75 1.31 0 79.34 0 5.95 59.50 5.75 1.19 0 5.95 59.50 5.80 0 5.95 57.52 6.00 1.07 7.34 0 5.95 57.52 6.30 7.93 0 11.50 5.95 57.52 6.80 0 11.90 5.95 57.52 6.80 38.00 12.50 5.75 57.52 6.80 46.00 13.49 5.75 7.20 46.00 1.15 13.49 5.75 7.60 7.20 42.00 1.19 13.49 5.75 7.40 7.20 39.00 1.25 75.37 14.28 5.75 7.20 37.00 1.35 15.07 91.24 14.28 7.20 34.00 1.35 14.68 91.24 14.28 33.00 1.35 83.31 14.28 37.00 1.43 7.54 77.36 14.28 1.51 35.00 1.43 9.12 73.39 1.47 33.00 1.43 9.12 67.44 1.43 8.33 65.45 1.43 7.74 73.39 7.34 69.42 4.90 6.74 65.45 4.90 6.55 4.90 7.34 4.60 9.72 6.94 4.20 9.72 6.55 4.20 9.72 4.20 9.12 0.97 4.20 8.33 0.97 3.90 8.33 0.97 3.60 8.33 0.91 3.50 8.33 0.83 7.74 0.83 7.14 0.83 6.94 0.83 0.77 0.71 0.69 Appendix A.

Appendix A A–49 (acre-ft) site 8 (A) to site 9 (B) Increasestreamflow in (acre-ft) (+\- error) (+\- (B) Diversion Lake total out SW (acre-ft) (acre-ft) (+\- error) Diversion Lake (A) Diversion Lake total Lake out SW (acre-ft) (acre-ft) (+\- error) 08180500 Medina River near Riomedina (site 9) (B) 9) (site Riomedina near /s) (acre-ft) 3 (ft Surface-water outflow, Medina and Diversion outflow, Lakes—ContinuedSurface-water Date 11/3/199511/4/199511/5/199511/6/1995 26.0011/7/1995 27.0011/8/1995 27.0011/9/1995 27.00 27.00 51.57 27.00 53.55 27.00 53.55 53.55 53.55 53.55 5.16 53.55 5.36 5.36 5.36 5.36 5.36 5.36 51.17 51.57 53.95 42.64 56.73 86.48 5.12 87.67 5.16 5.40 4.2612/1/1995 5.6712/2/1995 8.6512/3/1995 8.7712/4/1995 89.26 26.0012/5/1995 91.24 27.0012/6/1995 93.22 27.0012/7/1995 81.32 26.0012/8/1995 95.21 124.96 24.0012/9/1995 8.93 51.57 126.94 24.00 9.12 53.55 24.00 9.32 53.55 23.00 8.13 51.57 23.00 9.52 12.50 47.60 12.69 47.60 5.16 47.60 5.36 45.62 5.36 45.62 5.16 4.76 38.08 4.76 39.67 4.76 91.64 39.27 4.56 95.60 38.68 4.56 92.83 38.48 38.48 90.84 39.27 88.86 107.31 9.16 113.06 9.56 98.38 9.28 87.87 9.08 8.89 10.73 11.31 128.93 134.88 9.84 132.89 8.79 128.93 122.98 142.81 12.89 148.76 13.49 13.29 132.89 12.89 122.98 12.30 14.28 14.88 13.29 12.30 37.29 39.27 40.07 38.08 34.12 35.50 35.70 34.51 35.11 11/10/199511/11/199511/12/199511/13/1995 27.0011/14/1995 27.0011/15/1995 27.0011/16/1995 26.0011/17/1995 24.0011/18/1995 53.55 24.0011/19/1995 53.55 23.0011/20/1995 53.55 22.0011/21/1995 51.57 22.0011/22/1995 47.60 22.0011/23/1995 47.60 5.36 22.0011/24/1995 45.62 5.36 22.0011/25/1995 43.64 5.36 22.0011/26/1995 43.64 5.16 22.0011/27/1995 43.64 4.76 23.0011/28/1995 43.64 4.76 24.0011/29/1995 102.74 43.64 4.56 24.0011/30/1995 100.76 43.64 4.36 24.00 43.64 4.36 24.00 96.79 45.62 4.36 26.00 94.81 102.74 47.60 4.36 27.00 10.27 130.12 47.60 4.36 10.08 124.96 47.60 4.36 47.60 4.36 44.43 9.68 51.57 4.56 11.50 9.48 10.27 53.55 4.76 11.90 13.01 4.76 12.50 142.8112/10/1995 12.50 4.76 13.49 140.8312/11/1995 4.76 13.49 4.4412/12/1995 5.16 136.86 13.49 1.1512/13/1995 5.36 132.89 21.00 14.28 136.86 1.1912/14/1995 14.28 21.00 14.28 164.63 1.2512/15/1995 14.08 21.00 14.28 158.68 1.3512/16/1995 21.00 14.28 1.3512/17/1995 13.69 21.00 14.28 1.3512/18/1995 77.36 13.29 41.65 13.69 19.00 88.46 1.4312/19/1995 43.64 41.65 16.46 19.00 94.02 1.4312/20/1995 43.64 41.65 15.87 19.00 1.43 43.64 41.65 19.00 1.43 43.64 41.65 19.00 1.43 43.64 7.74 37.69 4.17 19.00 8.85 43.64 4.36 40.07 37.69 4.17 9.40 45.62 4.36 40.07 37.69 4.17 47.60 4.36 37.69 4.17 47.60 4.36 40.07 37.69 4.17 47.60 4.36 38.08 34.12 37.69 3.77 47.60 4.36 34.51 3.77 124.96 85.09 4.56 100.96 33.72 3.77 132.89 4.76 100.96 3.77 4.76 3.77 92.43 32.93 4.76 3.77 85.69 32.13 4.76 12.50 81.72 8.51 10.10 31.74 13.29 75.77 10.10 31.14 73.79 30.15 81.12 9.24 30.15 76.56 8.57 30.15 72.40 8.17 31.34 117.02 132.89 7.58 33.32 132.89 7.38 33.32 8.11 33.32 124.96 7.66 33.32 36.50 119.01 7.24 38.88 11.70 13.29 111.07 13.29 105.12 103.14 12.50 111.07 11.90 107.11 11.11 103.14 10.51 10.31 11.11 10.71 31.93 10.31 31.93 31.93 32.53 33.32 29.36 29.36 29.36 29.95 30.55 30.74 Appendix A.

A–50 Hydrogeology, Hydrologic Budget, and Water Chemistry of the Medina Lake area, Texas (acre-ft) (+\- error) Diversion Lake (site8)(A) 08180015 Medina River below /s) (acre-ft) 3 (ft Diversion Lake (acre-ft) (+\- error) (+\- canal (site 7) 08179990 Medina /s) (acre-ft) 3 (ft (acre-ft) (+\- error) Medina out Lake total SW (acre-ft) Medina Lake Medina (acre-ft) (+\- error) Medina Lake (site 6) 08179520 Medina Riverbelow /s) (acre-ft) 3 (ft Surface-water outflow, Medina and Diversion Lakes—Continued Surface-water outflow, Date 1/1/19961/2/19961/3/19961/4/1996 291/5/1996 291/6/1996 291/7/1996 29 57.521/8/1996 29 57.521/9/1996 29 57.52 29 57.52 29 5.75 57.52 29 5.75 57.52 5.75 57.52 5.75 57.52 5.75 57.52 5.75 57.52 5.75 57.52 5.75 57.52 5.75 57.52 5.75 57.52 5.75 57.52 5.75 57.52 5.75 57.52 5.75 57.52 5.75 29.00 5.75 28.00 5.75 28.00 5.75 31.00 33.00 57.52 31.002/1/1996 55.54 29.002/2/1996 55.54 28.002/3/1996 61.49 28.002/4/1996 5.75 65.45 822/5/1996 5.55 61.49 642/6/1996 5.55 57.52 59 6.15 55.54 59 162.64 6.55 55.54 74 126.94 104 6.15 117.02 4.40 5.75 117.02 4.60 16.26 5.55 146.78 4.60 12.69 206.28 5.55 4.60 8.73 11.70 4.50 9.12 11.70 4.10 9.12 14.68 3.90 20.63 9.12 0.87 162.64 3.90 8.93 0.91 126.94 3.90 8.13 0.91 117.02 7.74 0.91 117.02 7.74 16.26 0.89 146.78 7.74 12.69 206.28 0.81 11.70 0.77 11.70 0.77 14.68 0.77 20.63 62.00 58.00 59.00 56.00 122.98 56.00 71.00 115.04 117.02 111.07 12.30 111.07 11.50 140.83 11.70 11.11 11.11 14.08 5.30 5.30 5.30 10.51 5.30 10.51 4.90 5.10 10.51 10.51 1.05 9.72 10.12 1.05 1.05 1.05 0.97 1.01 1/10/19961/11/19961/12/19961/13/1996 511/14/1996 701/15/1996 571/16/1996 57 101.161/17/1996 57 138.841/18/1996 57 113.061/19/1996 57 113.06 10.121/20/1996 54 113.06 13.881/21/1996 48 113.06 11.311/22/1996 51 113.06 11.311/23/1996 58 107.11 11.311/24/1996 58 95.21 11.311/25/1996 101.16 58 101.16 11.311/26/1996 138.84 58 115.04 10.711/27/1996 113.06 53 115.041/28/1996 113.06 53 115.04 10.12 9.52 10.121/29/1996 113.06 64 115.04 13.88 11.501/30/1996 113.06 71 105.12 11.31 11.501/31/1996 113.06 71 105.12 11.31 11.50 107.11 71 126.94 11.31 11.50 74 140.83 11.31 10.51 31.00 101.16 87 140.83 95.21 11.31 10.51 44.00 115.04 140.83 10.71 12.69 48.00 115.04 146.78 14.08 50.00 115.04 172.56 10.12 14.08 51.00 115.04 61.49 9.52 11.50 14.08 51.00 105.12 87.27 11.50 14.68 51.00 105.12 95.21 11.50 17.26 50.00 126.94 99.17 11.50 101.16 140.83 6.15 10.51 101.16 44.00 140.83 8.73 10.51 45.00 101.16 47.00 140.83 9.52 12.69 49.00 146.78 9.92 99.17 10.12 14.08 49.00 172.56 10.12 14.08 50.00 87.27 10.12 14.08 3.90 47.00 89.26 93.22 14.68 4.30 46.00 9.92 97.19 17.26 4.60 50.00 97.19 4.40 7.74 4.20 53.00 8.73 99.17 8.53 4.20 56.00 8.93 9.32 93.22 9.12 4.20 60.00 9.72 91.24 8.73 8.33 62.00 9.72 99.17 0.77 4.20 8.33 105.12 66.00 9.92 0.85 8.33 111.07 9.32 0.91 4.20 119.01 9.12 0.87 4.20 0.83 4.20 8.33 122.98 9.92 10.51 0.83 4.20 130.91 11.11 0.83 4.20 8.33 11.90 8.33 4.20 8.33 0.83 12.30 4.20 8.33 13.09 4.40 8.33 0.83 4.60 8.33 4.60 0.83 0.83 8.33 4.60 0.83 8.73 4.60 0.83 9.12 4.70 9.12 0.83 5.30 9.12 0.83 9.12 0.87 9.32 0.91 10.51 0.91 0.91 0.91 0.93 1.05 12/21/199512/22/199512/23/199512/24/1995 2912/25/1995 2912/26/1995 2912/27/1995 29 57.5212/28/1995 29 57.5212/29/1995 29 57.5212/30/1995 29 57.5212/31/1995 29 5.75 57.52 29 5.75 57.52 29 5.75 57.52 29 5.75 57.52 5.75 57.52 5.75 57.52 57.52 5.75 57.52 57.52 5.75 57.52 5.75 57.52 5.75 5.75 57.52 5.75 5.75 57.52 5.75 57.52 5.75 57.52 5.75 57.52 5.75 57.52 31.00 5.75 57.52 11.00 5.75 0 5.75 0 5.75 61.49 0 5.75 21.82 0 20.00 31.00 33.00 6.15 0 32.00 2.18 0 31.00 0 39.67 0 61.49 65.45 63.47 0 3.50 3.97 61.49 0 3.50 6.15 0 6.55 0 6.94 6.35 6.94 6.15 4.90 3.50 0.69 4.90 3.90 0.69 4.90 4.20 4.90 9.72 4.70 6.94 4.80 9.72 7.74 9.72 8.33 9.72 9.32 0.97 0.69 9.52 0.97 0.77 0.97 0.83 0.97 0.93 0.95 Appendix A.

Appendix A A–51 (acre-ft) site 8 (A) to site 9 (B) Increasestreamflow in (acre-ft) (+\- error) (+\- (B) Diversion Lake total out SW (acre-ft) (acre-ft) (+\- error) Diversion Lake (A) Diversion Lake total Lake out SW (acre-ft) (acre-ft) (+\- error) 08180500 Medina River near Riomedina (site 9) (B) 9) (site Riomedina near /s) (acre-ft) 3 (ft Surface-water outflow, Medina and Diversion outflow, Lakes—ContinuedSurface-water Date 1/1/19961/2/19961/3/19961/4/1996 17.001/5/1996 17.001/6/1996 17.001/7/1996 17.001/8/1996 17.001/9/1996 33.72 17.00 33.72 17.00 33.72 16.00 33.72 16.00 33.72 33.72 3.37 33.72 3.37 31.74 3.37 31.74 3.37 3.37 3.37 3.37 66.25 3.17 64.66 3.17 64.66 70.61 74.38 69.62 6.62 65.26 6.47 63.27 6.47 63.27 7.06 7.44 6.96 6.532/1/1996 91.24 6.332/2/1996 89.26 6.332/3/1996 89.262/4/1996 95.21 17.002/5/1996 99.17 18.002/6/1996 95.21 9.12 18.00 91.24 8.93 17.00 87.27 8.93 17.00 87.27 9.52 33.72 17.00 9.92 35.70 9.52 35.70 9.12 33.72 8.73 33.72 8.73 33.72 3.37 3.57 24.99 3.57 24.60 3.37 24.60 3.37 24.60 3.37 24.79 133.49 25.59 125.55 25.98 127.54 24.00 121.59 24.00 120.79 13.35 150.94 12.56 12.75 12.16 12.08 15.09 156.69 150.74 152.73 144.79 144.79 15.67 174.55 15.07 15.27 14.48 14.48 17.45 23.21 25.19 25.19 23.21 24.00 23.60 1/10/19961/11/19961/12/19961/13/1996 16.001/14/1996 16.001/15/1996 16.001/16/1996 16.001/17/1996 16.001/18/1996 31.74 16.001/19/1996 31.74 16.001/20/1996 31.74 16.001/21/1996 31.74 16.001/22/1996 31.74 16.001/23/1996 31.74 3.17 16.001/24/1996 31.74 3.17 16.001/25/1996 31.74 3.17 17.001/26/1996 31.74 3.17 17.001/27/1996 31.74 3.17 17.001/28/1996 31.74 3.17 17.001/29/1996 31.74 3.17 17.00 69.221/30/1996 33.72 3.17 17.00 95.801/31/1996 104.33 33.72 3.17 17.00 107.90 33.72 3.17 17.00 33.72 109.49 3.17 17.00 109.49 33.72 3.17 17.00 6.92 109.49 33.72 3.37 9.58 10.43 107.50 33.72 3.37 10.79 33.72 3.37 97.59 10.95 3.37 33.72 95.60 10.95 101.55 33.72 3.37 10.95 105.52 3.37 10.75 93.22 105.52 3.37 119.01 126.94 107.50 3.37 130.91 9.76 101.55 3.37 132.89 9.56 10.16 99.97 3.37 132.89 10.55 108.30 132.89 10.55 9.32 114.25 11.90 12.69 130.91 10.75 120.20 13.09 10.16 128.13 13.29 120.99 10.00 132.30 13.29 119.01 124.96 10.83 141.42 13.29 128.93 11.42 13.09 130.91 12.02 132.89 12.81 12.10 126.94 13.23 11.90 12.50 124.96 14.14 12.89 132.89 24.00 23.21 22.61 13.09 138.84 23.01 13.29 144.79 23.40 12.69 152.73 23.40 12.50 156.69 23.40 13.29 164.63 23.40 13.88 14.48 23.40 15.27 23.40 23.40 15.67 23.40 16.46 25.39 25.39 25.39 24.99 24.60 24.60 24.60 24.60 24.40 23.21 12/21/199512/22/199512/23/199512/24/1995 19.0012/25/1995 19.0012/26/1995 17.0012/27/1995 16.0012/28/1995 16.0012/29/1995 37.69 16.0012/30/1995 37.69 17.0012/31/1995 33.72 17.00 31.74 17.00 31.74 17.00 31.74 3.77 17.00 33.72 3.77 33.72 3.37 33.72 3.17 33.72 3.17 33.72 3.17 3.37 68.43 3.37 28.76 3.37 6.94 3.37 7.74 3.37 8.33 6.84 9.32 49.39 2.88 71.21 0.69 75.17 0.77 73.19 0.83 71.01 0.93 4.94 99.17 7.12 59.50 7.52 33.72 7.32 31.74 7.10 31.74 9.92 31.74 73.39 5.95 95.21 3.37 99.17 3.17 97.19 3.17 95.21 3.17 7.34 9.52 9.92 9.72 30.74 9.52 30.74 26.78 24.00 23.40 22.41 24.00 24.00 24.00 24.00 24.20 Appendix A.

A–52 Hydrogeology, Hydrologic Budget, and Water Chemistry of the Medina Lake area, Texas (acre-ft) (+\- error) Diversion Lake (site8)(A) 08180015 Medina River below /s) (acre-ft) 3 (ft Diversion Lake (acre-ft) (+\- error) (+\- canal (site 7) 08179990 Medina /s) (acre-ft) 3 (ft (acre-ft) (+\- error) Medina out Lake total SW (acre-ft) Medina Lake Medina (acre-ft) (+\- error) Medina Lake (site 6) 08179520 Medina Riverbelow /s) (acre-ft) 3 (ft Surface-water outflow, Medina and Diversion Lakes—Continued Surface-water outflow, Date 2/7/19962/8/19962/9/1996 92 85 88 182.48 168.59 174.55 18.25 16.86 17.45 182.48 168.59 174.55 18.25 16.86 17.453/1/19963/2/1996 76.003/3/1996 75.003/4/1996 75.00 763/5/1996 76 150.743/6/1996 76 148.763/7/1996 76 150.74 148.763/8/1996 76 150.743/9/1996 75 150.74 15.07 73 150.74 14.88 15.07 68 150.74 14.88 15.07 68 148.76 15.07 144.79 15.07 134.88 5.30 15.07 134.88 5.30 14.88 150.74 5.30 14.48 150.74 10.51 13.49 150.74 10.51 13.49 150.74 10.51 15.07 150.74 15.07 1.05 148.76 15.07 1.05 144.79 15.07 1.05 134.88 15.07 134.88 14.88 71.00 14.48 52.00 13.49 55.00 13.49 63.00 140.83 65.00 103.14 63.00 109.09 58.00 124.96 54.00 14.08 128.93 54.00 10.31 124.96 10.91 115.04 12.50 107.11 12.89 107.11 12.50 5.30 11.50 5.30 10.71 5.30 10.71 10.51 5.30 10.51 5.30 10.51 5.30 10.51 5.30 1.05 10.51 5.30 1.05 10.51 5.30 1.05 10.51 1.05 10.51 1.05 10.51 1.05 1.05 1.05 1.05 2/10/19962/11/19962/12/19962/13/1996 992/14/1996 99 1022/15/1996 1062/16/1996 196.36 1052/17/1996 196.36 1092/18/1996 202.31 1172/19/1996 210.25 118 19.642/20/1996 208.26 118 19.642/21/1996 216.20 20.23 1142/22/1996 232.07 21.02 1072/23/1996 234.05 20.83 1082/24/1996 234.05 21.62 1112/25/1996 226.12 196.36 23.21 1182/26/1996 212.23 196.36 23.40 202.31 1242/27/1996 214.21 23.40 210.25 1242/28/1996 220.17 22.61 19.64 208.26 1242/29/1996 234.05 21.22 19.64 216.20 124 245.95 20.23 21.42 232.07 121 245.95 21.02 22.02 234.05 104 245.95 20.83 23.40 234.05 245.95 21.62 24.60 226.12 240.00 80.00 23.21 24.60 212.23 206.28 81.00 23.40 24.60 82.00 214.21 23.40 24.60 86.00 220.17 22.61 24.00 90.00 234.05 158.68 21.22 20.63 91.00 245.95 160.663/10/1996 21.42 162.64 96.00 245.953/11/1996 22.02 170.58 98.00 245.953/12/1996 23.40 15.87 178.51 98.00 245.953/13/1996 24.60 68 16.07 180.50 99.00 240.003/14/1996 16.26 24.60 68 190.41 95.00 206.283/15/1996 17.06 24.60 68 194.38 93.003/16/1996 17.85 24.60 74 134.88 194.38 92.003/17/1996 18.05 24.00 78 134.88 196.36 94.00 5.303/18/1996 19.04 20.63 84 134.88 188.43 98.00 5.30 1033/19/1996 19.44 101.00 146.78 5.30 184.46 103 13.493/20/1996 19.44 103.00 154.71 5.30 10.51 182.48 104 13.493/21/1996 19.64 104.00 166.61 5.30 10.51 186.45 110 13.493/22/1996 204.30 18.84 10.51 104.00 5.30 194.38 116 14.683/23/1996 204.30 18.45 10.51 200.33 101.00 5.30 135 15.473/24/1996 206.28 18.25 10.51 204.30 1.05 5.30 150 16.663/25/1996 218.18 18.64 10.51 206.28 1.05 134.88 5.30 20.43 1.05 150 230.08 19.44 10.51 206.28 134.88 5.40 20.43 20.03 1.05 150 267.77 10.51 200.33 134.88 5.30 20.63 20.43 1.05 143 297.52 10.51 146.78 5.30 21.82 20.63 1.05 13.49 297.52 10.71 154.71 5.30 23.01 20.63 1.05 13.49 297.52 10.51 166.61 5.30 26.78 20.03 1.05 13.49 204.30 283.64 10.51 5.30 29.75 1.05 14.68 204.30 5.30 10.51 29.75 1.07 15.47 206.28 5.30 10.51 29.75 1.05 16.66 218.18 5.30 54.00 10.51 20.43 28.36 10.51 1.05 230.08 5.30 54.00 20.43 10.51 1.05 267.77 5.40 71.00 20.63 10.51 1.05 297.52 70.00 21.82 10.51 1.05 297.52 107.11 69.00 1.05 23.01 10.71 297.52 107.11 70.00 1.05 26.78 81.00 283.64 140.83 1.05 29.75 84.00 138.84 1.05 29.75 10.71 87.00 136.86 1.07 29.75 10.71 91.00 138.84 28.36 14.08 160.66 94.00 13.88 166.61 95.00 13.69 172.56 95.00 13.88 180.50 95.00 5.30 16.07 186.45 95.00 5.30 16.66 188.43 95.00 5.30 17.26 10.51 188.43 5.30 18.05 10.51 188.43 5.30 18.64 10.51 188.43 5.30 18.84 5.30 10.51 188.43 18.84 1.05 5.30 10.51 18.84 1.05 5.30 10.51 18.84 10.51 1.05 5.50 18.84 10.51 1.05 5.70 10.51 1.05 5.70 10.91 1.05 5.70 1.05 11.31 5.30 1.05 11.31 5.30 1.05 11.31 5.30 1.09 10.51 1.13 10.51 1.13 10.51 1.13 1.05 1.05 1.05 Appendix A.

Appendix A A–53 (acre-ft) site 8 (A) to site 9 (B) Increasestreamflow in (acre-ft) (+\- error) (+\- (B) Diversion Lake total out SW (acre-ft) (acre-ft) (+\- error) Diversion Lake (A) Diversion Lake total Lake out SW (acre-ft) (acre-ft) (+\- error) 08180500 Medina River near Riomedina (site 9) (B) 9) (site Riomedina near /s) (acre-ft) 3 (ft Surface-water outflow, Medina and Diversion outflow, Lakes—ContinuedSurface-water Date 2/7/19962/8/19962/9/1996 19.00 19.00 19.00 37.69 37.69 37.69 3.77 3.77 3.77 161.26 159.27 159.273/1/19963/2/1996 16.133/3/1996 15.933/4/1996 15.93 19.003/5/1996 18.003/6/1996 18.003/7/1996 19.00 188.433/8/1996 19.00 186.453/9/1996 37.69 20.00 186.45 35.70 19.00 35.70 19.00 37.69 18.84 19.00 37.69 18.64 39.67 18.64 3.77 37.69 3.57 37.69 3.57 37.69 3.77 3.77 3.97 151.34 3.77 113.65 3.77 119.60 27.17 3.77 135.47 27.17 139.44 27.17 15.13 135.47 11.37 125.55 11.96 117.62 13.55 117.62 13.94 13.55 178.51 12.56 138.84 11.76 144.79 11.76 162.64 166.61 17.85 164.63 13.88 152.73 14.48 144.79 16.26 144.79 16.66 16.46 15.27 14.48 14.48 27.17 25.19 25.19 27.17 27.17 29.16 27.17 27.17 27.17 2/10/19962/11/19962/12/19962/13/1996 19.002/14/1996 19.002/15/1996 19.002/16/1996 19.002/17/1996 19.002/18/1996 37.69 19.002/19/1996 37.69 19.002/20/1996 37.69 19.002/21/1996 37.69 19.002/22/1996 37.69 19.002/23/1996 37.69 3.77 19.002/24/1996 37.69 3.77 18.002/25/1996 37.69 3.77 18.002/26/1996 37.69 3.77 18.002/27/1996 37.69 3.77 18.002/28/1996 37.69 3.77 18.002/29/1996 169.19 35.70 3.77 18.00 171.17 35.70 3.77 19.00 173.16 35.70 3.77 19.00 181.09 35.70 3.77 19.00 189.02 35.70 3.77 16.92 191.01 35.70 3.57 17.12 200.93 37.69 3.57 17.32 204.89 37.69 3.57 18.11 204.89 37.69 3.57 18.90 207.07 3.573/10/1996 19.10 198.94 3.57 196.363/11/1996 20.09 194.98 3.77 198.353/12/1996 20.49 192.99 3.77 200.333/13/1996 20.49 196.96 3.77 18.00 208.263/14/1996 20.71 204.89 18.00 216.203/15/1996 19.89 210.84 19.64 18.00 218.183/16/1996 19.50 214.81 19.83 18.00 228.103/17/1996 19.30 216.79 20.03 18.00 232.073/18/1996 19.70 216.79 35.70 20.83 18.00 232.073/19/1996 20.49 211.04 35.70 21.62 18.00 234.053/20/1996 21.08 35.70 21.82 18.00 226.123/21/1996 21.48 35.70 22.81 18.00 220.173/22/1996 21.68 35.70 23.21 18.00 218.183/23/1996 21.68 35.70 23.21 3.57 18.00 222.153/24/1996 21.10 35.70 23.40 3.57 18.00 230.083/25/1996 27.17 35.70 22.61 3.57 19.00 236.03 27.17 35.70 22.02 3.57 19.00 240.00 27.17 35.70 21.82 3.57 19.00 243.97 27.17 35.70 22.21 3.57 20.00 243.97 117.62 27.17 35.70 23.01 3.57 238.02 117.62 27.17 37.69 23.60 3.57 151.34 27.17 37.69 24.00 3.57 149.36 27.17 37.69 24.40 3.57 147.37 27.17 39.67 24.40 3.57 11.76 149.36 26.98 23.80 3.57 11.76 171.17 27.17 3.77 15.13 177.12 25.19 3.77 14.94 183.07 25.19 3.77 14.74 191.40 25.19 3.97 14.94 197.75 25.19 142.81 17.12 199.74 25.19 142.81 17.71 199.74 25.19 176.53 18.31 198.94 27.17 174.55 19.14 198.94 27.17 172.56 19.78 198.94 26.98 14.28 174.55 19.97 14.28 196.36 19.97 17.65 202.31 19.89 17.45 208.26 19.89 17.26 216.20 19.89 17.45 222.15 19.64 224.13 20.23 226.12 20.83 226.12 21.62 226.12 25.19 22.21 228.10 25.19 22.41 25.19 22.61 25.19 22.61 25.19 22.61 25.19 22.81 25.19 25.19 25.19 24.79 24.40 24.40 26.38 27.17 27.17 29.16 Appendix A.

A–54 Hydrogeology, Hydrologic Budget, and Water Chemistry of the Medina Lake area, Texas (acre-ft) (+\- error) Diversion Lake (site8)(A) 08180015 Medina River below /s) (acre-ft) 3 (ft Diversion Lake (acre-ft) (+\- error) (+\- canal (site 7) 08179990 Medina /s) (acre-ft) 3 (ft (acre-ft) (+\- error) Medina out Lake total SW (acre-ft) Medina Lake Medina (acre-ft) (+\- error) Medina Lake (site 6) 08179520 Medina Riverbelow /s) (acre-ft) 3 (ft Surface-water outflow, Medina and Diversion Lakes—Continued Surface-water outflow, Date 4/1/19964/2/19964/3/1996 1384/4/1996 1384/5/1996 1384/6/1996 1084/7/1996 273.724/8/1996 273.72 904/9/1996 273.72 89 214.21 89 27.37 89 178.51 27.37 101 176.53 27.37 176.53 21.42 176.53 17.85 200.33 273.72 17.65 273.72 17.65 273.72 17.65 20.03 214.21 27.37 178.51 27.37 176.53 27.37 176.53 21.42 176.53 17.85 200.33 107.00 17.65 110.00 17.65 114.00 17.65 106.00 20.03 212.23 96.00 218.18 95.00 226.125/1/1996 95.00 210.25 21.225/2/1996 95.00 92.00 21.82 190.415/3/1996 22.61 171 188.435/4/1996 21.02 174 188.435/5/1996 180 188.435/6/1996 19.04 182.48 1865/7/1996 339.17 6.40 18.84 1875/8/1996 345.12 6.70 18.84 1885/9/1996 357.02 7.00 18.84 12.69 191 368.93 7.00 18.25 33.92 13.29 370.91 34.51 13.88 6.80 154 372.89 35.70 13.88 6.60 378.84 1.27 36.89 6.20 1.33 13.49 37.09 6.00 305.45 1.39 5.70 13.09 37.29 339.17 1.39 12.30 37.88 345.12 11.90 357.02 11.31 1.35 30.55 368.93 1.31 132.00 33.92 370.91 1.23 34.51 372.89 1.19 35.70 1.13 378.84 36.89 261.82 37.09 305.45 136.00 37.29 141.00 37.88 144.00 26.18 147.00 30.55 269.75 147.00 279.67 147.00 285.62 149.00 291.57 26.98 6.80 291.57 75.00 27.97 291.57 28.56 295.54 29.16 13.49 29.16 148.76 29.16 6.80 29.55 6.80 1.35 6.80 13.49 6.80 14.88 13.49 6.80 13.49 6.80 13.49 6.80 1.35 13.49 1.35 13.49 1.35 7.30 13.49 1.35 1.35 14.48 1.35 1.35 1.45 3/26/19963/27/19963/28/1996 1253/29/1996 1143/30/1996 1213/31/1996 139 247.93 139 226.12 138 240.00 275.70 24.79 275.70 22.61 273.72 24.00 27.57 27.57 27.37 247.934/10/1996 226.124/11/1996 240.004/12/1996 275.70 1144/13/1996 24.79 275.70 1204/14/1996 22.61 273.72 1194/15/1996 24.00 1244/16/1996 226.12 27.57 1274/17/1996 238.02 27.57 1394/18/1996 236.03 27.37 93.00 1464/19/1996 245.95 22.61 88.00 1464/20/1996 251.90 23.80 93.00 1454/21/1996 275.70 103.00 23.60 1514/22/1996 289.59 105.00 24.60 184.46 1714/23/1996 289.59 107.00 25.19 174.55 1714/24/1996 287.60 27.57 184.46 226.12 1714/25/1996 299.50 204.30 28.96 238.02 1714/26/1996 339.17 18.45 208.26 28.96 236.03 1714/27/1996 339.17 17.45 212.23 28.76 245.95 1704/28/1996 339.17 18.45 22.61 29.95 20.43 251.90 1704/29/1996 339.17 23.80 33.92 20.83 275.70 1704/30/1996 339.17 23.60 33.92 21.22 289.59 171 337.19 24.60 6.40 33.92 289.59 171 337.19 25.19 6.40 33.92 287.60 171 337.19 27.57 6.40 33.92 92.00 299.50 339.17 6.40 12.69 28.96 33.72 97.00 339.17 339.17 6.40 12.69 102.00 28.96 33.72 339.17 339.17 6.40 12.69 104.00 28.76 33.72 12.69 339.17 106.00 29.95 33.92 182.48 12.69 1.27 339.17 108.00 33.92 33.92 192.40 12.69 1.27 339.17 202.31 114.00 33.92 33.92 1.27 337.195/10/1996 206.28 118.00 1.27 33.92 337.195/11/1996 18.25 210.25 120.00 1.27 33.92 337.195/12/1996 19.24 214.21 121.00 1.27 33.92 20.23 339.17 226.12 129.00 33.72 91 20.63 339.17 234.05 132.00 33.72 91 21.02 339.17 238.02 132.00 33.72 91 21.42 240.00 131.00 33.92 180.50 5.70 22.61 255.87 130.00 33.92 180.50 5.70 23.40 5.40 261.82 132.00 33.92 180.50 23.80 5.30 11.31 261.82 136.00 24.00 18.05 5.30 11.31 259.83 138.00 25.59 10.71 18.05 5.40 257.85 138.00 26.18 10.51 18.05 5.80 261.82 139.00 26.18 10.51 1.13 6.00 269.75 137.00 25.98 10.71 1.13 6.00 273.72 1.07 25.79 11.50 6.00 273.72 180.50 1.05 26.18 11.90 6.00 275.70 180.50 1.05 26.98 11.90 6.00 271.74 180.50 1.07 27.37 11.90 6.20 1.15 27.37 11.90 18.05 6.80 1.19 27.57 11.90 18.05 6.80 1.19 27.17 12.30 18.05 6.80 1.19 13.49 6.80 1.19 13.49 6.80 1.19 13.49 6.80 80.00 1.23 13.49 6.80 82.00 1.35 13.49 6.80 82.00 1.35 13.49 1.35 13.49 158.68 1.35 13.49 162.64 1.35 162.64 1.35 1.35 15.87 1.35 16.26 16.26 7.60 7.60 7.60 15.07 15.07 15.07 1.51 1.51 1.51 Appendix A.

Appendix A A–55 (acre-ft) site 8 (A) to site 9 (B) Increasestreamflow in (acre-ft) (+\- error) (+\- (B) Diversion Lake total out SW (acre-ft) (acre-ft) (+\- error) Diversion Lake (A) Diversion Lake total Lake out SW (acre-ft) (acre-ft) (+\- error) 08180500 Medina River near Riomedina (site 9) (B) 9) (site Riomedina near /s) (acre-ft) 3 (ft Surface-water outflow, Medina and Diversion outflow, Lakes—ContinuedSurface-water Date 4/1/19964/2/19964/3/19964/4/1996 22.004/5/1996 22.004/6/1996 22.004/7/1996 22.004/8/1996 22.004/9/1996 43.64 22.00 43.64 22.00 43.64 22.00 43.64 22.00 43.64 43.64 4.36 43.64 4.36 43.64 4.36 43.64 4.36 4.36 4.36 224.93 4.36 231.47 4.36 240.00 4.36 224.13 203.90 22.49 201.52 23.15 200.73 24.00 200.33 22.41 193.79 20.39 20.15 255.875/1/1996 20.07 261.825/2/1996 20.03 269.755/3/1996 19.38 253.885/4/1996 22.00 234.055/5/1996 25.59 22.00 232.075/6/1996 26.18 22.00 232.075/7/1996 26.98 22.00 232.075/8/1996 25.39 22.00 226.125/9/1996 43.64 23.40 22.00 43.64 23.21 22.00 43.64 23.21 23.00 43.64 23.21 24.00 43.64 22.61 43.64 4.36 30.94 43.64 4.36 30.35 45.62 4.36 29.75 47.60 4.36 29.75 4.36 30.15 4.36 283.24 30.55 4.36 293.16 31.34 4.56 299.11 31.74 4.76 305.06 32.33 305.06 28.32 305.06 29.32 309.02 29.91 275.31 30.51 163.24 30.51 30.51 313.39 30.90 323.31 27.53 329.26 16.32 335.21 335.21 31.34 335.21 32.33 339.17 32.93 307.44 33.52 196.36 33.52 33.52 33.92 30.74 19.64 30.15 30.15 30.15 30.15 30.15 30.15 30.15 32.13 33.12 3/26/19963/27/19963/28/19963/29/1996 21.003/30/1996 21.003/31/1996 21.00 21.00 21.00 41.65 22.00 41.65 41.65 41.65 41.65 43.64 4.17 4.174/10/1996 4.174/11/1996 4.174/12/1996 4.174/13/1996 4.36 21.004/14/1996 197.16 19.004/15/1996 187.24 19.004/16/1996 197.16 19.004/17/1996 216.99 19.004/18/1996 220.96 41.65 18.004/19/1996 19.72 224.93 37.69 19.004/20/1996 18.72 37.69 19.004/21/1996 19.72 37.69 19.004/22/1996 21.70 37.69 22.004/23/1996 22.10 35.70 4.17 22.004/24/1996 22.49 37.69 3.77 22.00 226.124/25/1996 37.69 3.77 22.00 216.204/26/1996 37.69 3.77 22.00 226.124/27/1996 43.64 3.77 22.00 245.954/28/1996 43.64 3.57 22.00 249.924/29/1996 193.79 43.64 22.61 3.77 22.00 255.874/30/1996 203.70 43.64 21.62 3.77 22.00 213.02 43.64 22.61 3.77 22.00 216.79 43.64 24.60 4.36 22.00 220.76 43.64 24.99 4.36 22.00 19.38 224.93 43.64 25.59 4.36 20.37 237.62 43.64 4.36 21.30 245.95 43.64 4.36 21.68 249.92 43.64 4.36 22.08 251.90 43.64 4.36 22.49 267.77 28.96 4.36 224.135/10/1996 23.76 273.72 28.96 4.36 230.085/11/1996 24.60 274.12 28.96 4.36 240.005/12/1996 24.99 273.32 28.96 4.36 243.97 25.19 271.34 28.96 4.36 26.00 247.93 26.78 275.31 30.94 22.41 26.00 249.92 27.37 283.24 23.01 26.00 263.80 27.41 287.21 24.00 271.74 27.33 287.21 24.40 275.70 27.13 289.19 51.57 24.79 283.64 27.53 285.22 51.57 24.99 299.50 28.32 51.57 26.38 305.45 28.72 27.17 305.45 28.72 27.57 303.47 28.92 28.36 5.16 301.49 28.52 30.35 29.95 5.16 305.45 26.38 30.55 5.16 313.39 26.98 30.55 317.36 27.17 30.35 317.36 27.17 30.15 319.34 173.75 24.99 30.55 315.37 177.72 26.18 31.34 177.72 25.79 31.74 25.79 31.74 31.74 31.93 17.38 31.74 31.54 17.77 31.74 17.77 31.34 30.15 30.15 30.15 210.25 30.15 214.21 30.15 214.21 30.15 30.15 30.15 21.02 21.42 21.42 36.50 36.50 36.50 Appendix A.

A–56 Hydrogeology, Hydrologic Budget, and Water Chemistry of the Medina Lake area, Texas (acre-ft) (+\- error) Diversion Lake (site8)(A) 08180015 Medina River below /s) (acre-ft) 3 (ft Diversion Lake (acre-ft) (+\- error) (+\- canal (site 7) 08179990 Medina /s) (acre-ft) 3 (ft 147.00160.00161.00161.00 291.57165.00 317.36164.00 319.34164.00 319.34167.00 29.16 327.27168.00 31.74 325.29169.00 31.93 325.29171.00 31.93 331.24174.00 32.73 333.22174.00 32.53 6.80 335.21174.00 32.53 6.80 339.17174.00 33.12 6.80 345.12173.00 33.32 13.49 7.00 345.12172.00 33.52 13.49 7.50 345.12171.00 33.92 13.49 7.60 345.12170.00 34.51 13.88 7.60 343.14171.00 1.35 34.51 14.88 7.60 341.16172.00 1.35 34.51 15.07 7.60 339.17173.00 1.35 34.51 15.07 7.60 337.19174.00 1.39 34.31 15.07 7.60 339.17177.00 1.49 34.12 15.07 7.60 341.16179.00 1.51 33.92 15.07 7.60 343.14179.00 1.51 33.72 15.07 7.60 345.12179.00 1.51 33.92 15.07 7.60 351.07185.00 1.51 34.12 15.07 7.60 355.04186.00 1.51 34.31 15.07 7.60 355.04187.00 1.51 34.51 15.07 7.60 355.04188.00 1.51 35.11 15.07 7.60 366.94190.00 1.51 35.50 15.07 7.60 368.93189.00 1.51 35.50 15.07 7.60 370.91189.00 1.51 35.50 15.07 7.60 372.89190.00 1.51 36.69 15.07 7.60 376.86190.00 1.51 36.89 15.07 7.60 374.88189.00 1.51 37.09 15.07 7.60 374.88187.00 1.51 37.29 15.07 7.60 376.86 1.51 37.69 15.07 7.60 376.86 1.51 37.49 15.07 7.60 374.88 1.51 37.49 15.07 7.60 370.91 1.51 37.69 15.07 7.60 1.51 37.69 15.07 7.60 1.51 37.49 15.07 7.60 1.51 37.09 15.07 7.60 1.51 15.07 7.60 1.51 15.07 7.60 1.51 15.07 7.60 1.51 15.07 7.60 1.51 15.07 7.60 1.51 15.07 1.51 15.07 1.51 15.07 1.51 1.51 1.51 1.51 (acre-ft) (+\- error) Medina out Lake total SW (acre-ft) Medina Lake Medina (acre-ft) (+\- error) Medina Lake (site 6) 08179520 Medina Riverbelow /s) (acre-ft) 3 (ft Surface-water outflow, Medina and Diversion Lakes—Continued Surface-water outflow, Date 6/1/1996 6/2/1996 6/3/1996 6/4/1996 6/5/1996 6/6/1996 6/7/1996 6/8/1996 6/9/1996 5/13/19965/14/19965/15/19965/16/1996 915/17/1996 915/18/1996 915/19/1996 91 180.505/20/1996 91 180.50 1095/21/1996 180.50 1275/22/1996 180.50 145 18.055/23/1996 180.50 179 18.05 216.20 194 18.05 251.90 18.05 287.60 18.05 355.04 21.62 384.79 180.50 25.19 180.50 28.76 180.50 35.50 180.50 38.48 18.05 180.50 18.05 216.20 18.05 251.90 18.05 287.60 18.05 355.04 21.62 384.79 84.00 25.19 88.00 28.76 89.00 35.50 86.00 38.48 166.61 94.00 100.00 174.55 106.00 176.53 112.00 170.58 122.00 16.66 186.45 198.35 134.00 17.45 210.25 17.65 222.15 17.06 241.98 18.64 19.83 265.78 21.02 7.60 22.21 7.60 24.20 7.40 15.07 26.58 6.90 15.07 6.80 6.60 14.68 6.40 13.69 6.20 1.51 13.49 13.09 6.20 1.51 12.69 6.60 1.47 12.30 1.37 12.30 1.35 1.31 13.09 1.27 1.23 1.23 1.31 5/24/1996 5/25/1996 5/26/1996 5/27/1996 5/28/1996 5/29/1996 5/30/1996 5/31/1996 6/10/1996 6/11/1996 6/12/1996 6/13/1996 6/14/1996 6/15/1996 6/16/1996 6/17/1996 6/18/1996 6/19/1996 6/20/1996 6/21/1996 6/22/1996 6/23/1996 6/24/1996 6/25/1996 6/26/1996 6/27/1996 6/28/1996 6/29/1996 Appendix A.

Appendix A A–57 (acre-ft) site 8 (A) to site 9 (B) Increasestreamflow in (acre-ft) (+\- error) (+\- (B) Diversion Lake total out SW (acre-ft) (acre-ft) (+\- error) Diversion Lake (A) Diversion Lake total Lake out SW (acre-ft) (acre-ft) (+\- error) 08180500 Medina River near Riomedina (site 9) (B) 9) (site Riomedina near /s) (acre-ft) 3 (ft Surface-water outflow, Medina and Diversion outflow, Lakes—ContinuedSurface-water Date 6/1/19966/2/19966/3/19966/4/1996 27.006/5/1996 27.006/6/1996 27.006/7/1996 27.006/8/1996 27.006/9/1996 53.55 27.00 53.55 28.00 53.55 28.00 53.55 28.00 53.55 53.55 5.36 55.54 5.36 55.54 5.36 55.54 5.36 5.36 5.36 350.28 5.55 354.25 5.55 360.20 5.55 360.20 360.20 35.03 360.20 35.42 358.21 36.02 356.23 36.02 354.25 36.02 36.02 388.76 35.82 392.73 35.62 398.68 35.42 398.68 398.68 38.88 398.68 39.27 398.68 39.87 396.69 39.87 394.71 39.87 39.87 39.87 39.67 39.47 38.48 38.48 38.48 38.48 38.48 38.48 40.46 40.46 40.46 5/13/19965/14/19965/15/19965/16/1996 26.005/17/1996 25.005/18/1996 24.005/19/1996 24.005/20/1996 24.005/21/1996 51.57 22.005/22/1996 49.59 22.005/23/1996 47.60 22.005/24/1996 47.60 22.005/25/1996 47.60 22.005/26/1996 43.64 5.16 24.005/27/1996 43.64 4.96 24.005/28/1996 43.64 4.76 24.005/29/1996 43.64 4.76 26.005/30/1996 43.64 4.76 27.005/31/1996 47.60 4.36 26.00 181.69 47.60 4.36 26.00 189.62 47.60 4.36 27.00 191.21 51.57 4.36 27.00 184.26 53.55 4.36 199.93 51.57 4.76 18.17 211.44 51.57 4.76 18.96 222.94 53.55 4.76 19.12 234.45 53.55 5.16 18.43 254.28 5.366/10/1996 19.99 278.88 5.166/11/1996 21.14 305.06 5.16 218.186/12/1996 22.29 330.84 5.36 224.136/13/1996 23.44 332.83 5.36 28.00 224.136/14/1996 25.43 333.22 27.00 218.186/15/1996 27.89 342.15 27.00 234.056/16/1996 30.51 340.36 21.82 27.00 241.986/17/1996 33.08 340.36 22.41 27.00 253.886/18/1996 33.28 346.31 55.54 22.41 27.00 265.786/19/1996 33.32 348.30 53.55 21.82 28.00 285.626/20/1996 34.21 53.55 23.40 29.00 309.426/21/1996 34.04 53.55 24.20 29.00 339.176/22/1996 34.04 53.55 25.39 29.00 364.966/23/1996 34.63 53.55 26.58 5.55 29.00 366.946/24/1996 34.83 55.54 28.56 5.36 29.00 370.916/25/1996 57.52 30.94 5.36 30.00 380.836/26/1996 36.50 57.52 33.92 5.36 30.00 376.866/27/1996 34.51 57.52 36.50 5.36 29.00 376.866/28/1996 32.93 57.52 36.69 5.36 29.00 384.796/29/1996 352.26 33.92 57.52 37.09 5.55 28.00 386.78 354.25 34.12 59.50 38.08 5.75 28.00 356.23 30.55 59.50 37.69 5.75 29.00 358.21 30.94 57.52 37.69 5.75 29.00 360.20 31.34 57.52 38.48 5.75 35.23 366.15 31.34 55.54 38.68 5.75 35.42 370.12 30.55 55.54 5.95 35.62 370.12 34.12 57.52 5.95 35.82 370.12 34.12 57.52 5.75 36.02 382.02 34.12 5.75 36.61 384.00 37.69 5.55 392.73 37.01 385.98 38.68 5.55 392.73 37.01 387.97 36.50 5.75 394.71 37.01 391.93 36.50 5.75 396.69 38.20 389.95 38.48 398.68 38.40 389.95 38.48 39.27 404.63 38.60 391.93 39.27 410.58 38.80 391.93 39.47 412.56 39.19 389.95 39.67 412.56 39.00 385.98 39.87 424.46 39.00 40.46 426.45 39.19 41.06 428.43 39.19 41.26 432.40 39.00 41.26 436.36 38.60 42.45 432.40 40.46 42.64 432.40 38.48 42.84 432.40 38.48 43.24 432.40 38.48 43.64 432.40 38.48 43.24 428.43 38.48 43.24 40.46 43.24 42.45 43.24 42.45 43.24 42.45 42.84 42.45 42.45 44.43 44.43 42.45 42.45 40.46 40.46 42.45 42.45 Appendix A.

A–58 Hydrogeology, Hydrologic Budget, and Water Chemistry of the Medina Lake area, Texas (acre-ft) (+\- error) Diversion Lake (site8)(A) 08180015 Medina River below /s) (acre-ft) 3 (ft Diversion Lake (acre-ft) (+\- error) (+\- canal (site 7) 08179990 Medina /s) (acre-ft) 3 (ft 187.00187.00186.00186.00 370.91188.00 370.91189.00 368.93190.00 368.93190.00 37.09 372.89190.00 37.09 374.88192.00 36.89 376.86159.00 36.89 376.86113.00 37.29 376.86 37.49 7.60 380.83 37.69 7.60 315.37 37.69 7.60 224.13 37.69 15.07 7.60 38.08 15.07 7.60 31.54 15.07 7.60 22.41 15.07 7.60 1.51 15.07 7.60 1.51 15.07 7.60 1.51 15.07 7.60 1.51 15.07 7.90 1.51 15.07 7.90147.00 1.51 15.07156.00 1.51 15.67162.00 1.51 15.67163.00 1.51 291.57163.00 1.51 309.42165.00 1.57 321.32169.00 1.57 323.31171.00 29.16 323.31175.00 30.94 327.27178.00 32.13 335.21179.00 32.33 339.17179.00 32.33 347.11179.00 32.73 7.00 353.06178.00 33.52 7.20 355.04178.00 33.92 7.20 355.04175.00 34.71 13.88 7.20 355.04172.00 35.31 14.28 7.30 353.06170.00 35.50 14.28 7.60 353.06168.00 35.50 14.28 7.60 347.11167.00 1.39 35.50 14.48 7.60 341.16166.00 1.43 35.31 15.07 7.80 337.19159.00 1.43 35.31 15.07 8.00 333.22154.00 1.43 34.71 15.07 7.90 331.24125.00 1.45 34.12 15.47 8.00 329.26 1.51 33.72 15.87 8.00 315.37 1.51 33.32 15.67 8.00 305.45 1.51 33.12 15.87 8.00 247.93 1.55 32.93 15.87 8.00 1.59 31.54 15.87 8.00 1.57 30.55 15.87 8.00 1.59 24.79 15.87 8.00 1.59 15.87 8.00 1.59 15.87 8.00 1.59 15.87 7.70 1.59 15.87 7.20 1.59 15.87 7.20 1.59 15.27 1.59 14.28 1.59 14.28 1.59 1.53 1.43 1.43 (acre-ft) (+\- error) Medina out Lake total SW (acre-ft) Medina Lake Medina (acre-ft) (+\- error) Medina Lake (site 6) 08179520 Medina Riverbelow /s) (acre-ft) 3 (ft Surface-water outflow, Medina and Diversion Lakes—Continued Surface-water outflow, Date 7/1/1996 7/2/1996 7/3/1996 7/4/1996 7/5/1996 7/6/1996 7/7/1996 7/8/1996 7/9/1996 8/1/1996 8/2/1996 8/3/1996 8/4/1996 8/5/1996 8/6/1996 8/7/1996 8/8/1996 8/9/1996 6/30/1996 7/10/1996 7/11/1996 7/12/19967/13/19967/14/1996 1107/15/1996 1247/16/1996 1507/17/1996 1597/18/1996 218.18 1627/19/1996 245.95 1667/20/1996 297.52 1697/21/1996 315.37 21.82 1767/22/1996 321.32 24.60 1827/23/1996 329.26 29.75 1897/24/1996 335.21 31.54 1967/25/1996 349.09 32.13 1977/26/1996 360.99 32.93 218.187/27/1996 374.88 33.52 245.957/28/1996 388.76 34.91 297.527/29/1996 390.74 36.10 315.377/30/1996 21.82 37.49 321.327/31/1996 24.60 38.88 329.26 29.75 39.07 335.21 31.54 349.09 32.13 360.99 103.00 32.93 374.88 107.00 33.52 388.76 108.00 34.91 390.74 108.00 36.10 204.30 116.00 37.49 212.23 122.00 38.888/10/1996 214.21 120.00 39.078/11/1996 214.21 124.00 20.438/12/1996 230.08 128.00 21.228/13/1996 241.98 133.00 21.428/14/1996 238.02 137.00 21.428/15/1996 245.95 140.00 23.018/16/1996 253.88 24.20 7.80 263.80 23.80 7.60 271.74 24.60 7.60 277.69 25.39 15.47 7.60 26.38 15.07 7.60 27.17 15.07 7.60 27.77 15.07 7.40 1.55 15.07 7.2 1.51 15.07 7.10 1.51 14.68 7.00 1.51 6.80 14.28 1.51 14.08 6.80 1.51 13.88 1.47 13.49 13.49 1.43 1.41 1.39 1.35 1.35 Appendix A.

Appendix A A–59 (acre-ft) site 8 (A) to site 9 (B) Increasestreamflow in (acre-ft) (+\- error) (+\- (B) Diversion Lake total out SW (acre-ft) (acre-ft) (+\- error) Diversion Lake (A) Diversion Lake total Lake out SW (acre-ft) (acre-ft) (+\- error) 08180500 Medina River near Riomedina (site 9) (B) 9) (site Riomedina near /s) (acre-ft) 3 (ft Surface-water outflow, Medina and Diversion outflow, Lakes—ContinuedSurface-water Date 7/1/19967/2/19967/3/19967/4/1996 28.007/5/1996 28.007/6/1996 29.007/7/1996 28.007/8/1996 28.007/9/1996 55.54 28.00 55.54 28.00 57.52 29.00 55.54 28.00 55.54 55.54 5.55 55.54 5.55 57.52 5.75 55.54 5.55 5.55 5.55 385.98 5.55 384.00 5.75 384.00 5.55 387.97 389.95 38.60 391.93 38.40 391.93 38.40 391.93 38.80 395.90 39.00 39.19 426.45 39.19 424.468/1/1996 39.19 426.458/2/1996 39.59 428.438/3/1996 430.418/4/1996 42.64 28.00 432.408/5/1996 42.45 28.00 432.408/6/1996 42.64 28.00 434.388/7/1996 42.84 28.00 436.368/8/1996 43.04 28.008/9/1996 55.54 43.24 28.00 55.54 43.24 28.00 55.54 43.44 28.00 55.54 43.64 28.00 55.54 40.46 55.54 5.55 40.46 55.54 5.55 42.45 55.54 5.55 40.46 55.54 5.55 40.46 5.55 40.46 5.55 362.58 40.46 5.55 368.93 42.45 5.55 370.71 40.46 5.55 370.91 370.91 36.26 368.93 36.89 368.93 37.07 362.98 37.09 357.02 37.09 36.89 402.64 36.89 408.59 36.30 410.58 35.70 410.58 410.58 40.26 408.59 40.86 408.59 41.06 402.64 41.06 396.69 41.06 40.86 40.86 40.26 39.67 40.07 39.67 39.87 39.67 39.67 39.67 39.67 39.67 39.67 6/30/1996 28.00 55.547/10/19967/11/19967/12/19967/13/1996 5.55 28.007/14/1996 28.007/15/1996 29.007/16/1996 29.007/17/1996 29.007/18/1996 55.54 28.007/19/1996 385.98 55.54 28.007/20/1996 57.52 29.007/21/1996 57.52 29.007/22/1996 57.52 29.007/23/1996 55.54 5.55 29.007/24/1996 38.60 55.54 5.55 29.007/25/1996 57.52 5.75 28.007/26/1996 57.52 5.75 28.007/27/1996 57.52 5.75 28.007/28/1996 57.52 5.55 27.007/29/1996 331.04 57.52 5.55 28.00 426.457/30/1996 239.80 55.54 5.75 28.007/31/1996 219.77 55.54 5.75 27.00 227.31 55.54 5.75 26.00 229.29 53.55 5.75 26.00 33.10 229.29 55.54 42.64 5.75 28.00 23.98 245.16 55.54 5.55 21.98 257.06 53.55 5.55 22.73 252.69 51.57 5.55 22.93 260.23 51.57 5.36 22.93 267.97 55.54 5.55 370.91 24.52 277.69 5.55 279.678/10/1996 25.71 285.22 5.36 261.828/11/1996 25.27 291.17 5.16 269.758/12/1996 26.02 305.45 5.16 271.748/13/1996 26.80 323.70 40.46 37.09 5.55 29.00 269.758/14/1996 27.77 335.60 27.97 29.00 285.628/15/1996 28.52 337.59 26.18 29.00 299.508/16/1996 29.12 337.78 26.98 28.00 295.54 30.55 342.35 27.17 26.00 303.47 32.37 350.28 57.52 26.98 28.00 311.40 33.56 354.25 57.52 28.56 28.00 321.32 33.76 57.52 29.95 327.27 33.78 55.54 29.55 333.22 34.23 51.57 30.35 347.11 35.03 39.87 55.54 31.14 5.75 362.98 35.42 39.87 55.54 32.13 5.75 376.86 42.05 32.73 5.75 378.84 42.45 33.32 5.55 376.86 42.45 34.71 5.16 378.84 40.46 36.30 5.55 386.78 353.06 40.46 37.69 5.55 394.71 349.09 42.45 37.88 347.11 42.84 37.69 345.12 43.24 37.88 330.64 43.44 38.68 35.31 319.74 43.64 39.47 34.91 262.21 42.05 34.71 42.05 34.51 41.65 33.06 39.27 31.97 41.26 394.71 26.22 41.26 390.74 39.07 388.76 36.50 384.79 36.50 366.94 40.46 39.47 360.99 39.07 303.47 38.88 38.48 36.69 36.10 30.35 41.65 41.65 41.65 39.67 36.30 41.26 41.26 Appendix A.

A–60 Hydrogeology, Hydrologic Budget, and Water Chemistry of the Medina Lake area, Texas (acre-ft) (+\- error) Diversion Lake (site8)(A) 08180015 Medina River below /s) (acre-ft) 3 (ft Diversion Lake (acre-ft) (+\- error) (+\- canal (site 7) 08179990 Medina /s) (acre-ft) 3 (ft 82.0084.00 162.64 166.61 16.26 16.66 7.20 7.20 14.28 14.28 1.43 1.43 131.00129.00128.00131.00 259.83 255.87 253.88 259.83 25.98 25.59 25.39 25.98 7.20 7.20 7.20 14.28 7.20 14.28 14.28 14.28 1.43 1.43 1.43 1.43 (acre-ft) (+\- error) Medina out Lake total SW (acre-ft) Medina Lake Medina (acre-ft) (+\- error) Medina Lake (site 6) 08179520 Medina Riverbelow /s) (acre-ft) 3 (ft Surface-water outflow, Medina and Diversion Lakes—Continued Surface-water outflow, Date 9/1/19969/2/19969/3/19969/4/1996 169/5/1996 159/6/1996 159/7/1996 15 31.749/8/1996 15 29.759/9/1996 15 29.75 15 29.75 15 3.17 29.75 15 2.98 29.75 2.98 29.75 2.98 29.75 2.98 29.75 2.98 31.74 2.98 29.75 2.98 29.75 2.98 29.75 3.17 29.75 2.98 29.75 2.98 29.75 2.98 29.75 2.98 29.75 2.98 0 2.98 0 2.98 12.00 2.98 25.00 22.00 16.00 11.00 0 23.80 0 49.59 6.00 43.64 0 31.74 2.38 21.82 4.96 0 11.90 4.36 0 3.17 0 2.18 5.00 1.19 4.60 4.00 5.30 3.70 9.92 5.30 0 3.50 9.12 10.51 7.93 3.50 10.51 7.34 0.99 6.94 0.91 1.05 6.94 0.79 1.05 0.73 3.50 0.69 0.69 6.94 0.69 8/17/1996 8/18/1996 8/19/1996 8/20/1996 8/21/1996 8/22/1996 8/23/19968/24/19968/25/1996 1228/26/19968/27/1996 628/28/1996 618/29/1996 241.98 348/30/1996 15 122.988/31/1996 15 120.99 15 24.20 67.44 16 29.75 12.30 16 29.75 12.10 29.75 6.74 31.74 241.98 2.98 31.74 2.98 122.98 2.98 120.99 3.179/10/1996 24.20 3.179/11/1996 67.44 12.309/12/1996 29.75 12.109/13/1996 15 29.759/14/1996 15 29.759/15/1996 15 6.74 31.74 68.009/16/1996 15 2.98 31.74 29.759/17/1996 55.00 15 2.98 29.759/18/1996 45.00 16 2.98 29.759/19/1996 15 3.17 134.88 29.759/20/1996 15 3.17 18.00 2.98 29.75 109.099/21/1996 30 2.98 31.749/22/1996 7.20 44 89.26 2.98 29.759/23/1996 13.49 0 43 2.98 29.759/24/1996 0 43 10.91 2.98 59.509/25/1996 35.70 0 43 3.17 87.279/26/1996 0 8.93 64 29.75 14.28 2.98 85.299/27/1996 87 29.75 2.98 85.299/28/1996 87 6.80 29.75 5.95 85.299/29/1996 0 3.57 87 126.94 29.75 8.73 6.409/30/1996 0 77 172.56 2.98 29.75 1.43 8.53 13.49 0 57 172.56 2.98 31.74 6.40 8.53 0 57 172.56 2.98 12.69 29.75 8.53 12.69 64 152.73 2.98 29.75 17.26 0 12.69 113.06 2.98 6.40 59.50 1.35 17.26 0 113.06 3.17 87.27 5.90 17.26 1.27 0 0 126.94 2.98 85.29 15.27 12.69 0 0 2.98 85.29 11.31 1.27 126.94 0 5.95 85.29 11.70 11.31 172.56 0 8.73 12.69 172.56 0 8.53 5.70 1.27 172.56 0 8.53 5.40 12.69 0 1.17 152.73 0 8.53 5.30 17.26 0 113.06 0 11.31 5.30 17.26 0 113.06 0 10.71 17.26 0 126.94 0 10.51 15.27 0 0 10.51 11.31 1.13 0 0 0 9.00 11.31 1.07 17.00 0 0 0 12.69 1.05 26.00 0 0 1.05 30.00 0 0 35.00 0 0 17.85 26.00 0 0 33.72 25.00 0 0 51.57 3.10 29.00 0 0 59.50 2.90 0 69.42 2.90 1.79 0 3.37 51.57 2.90 6.15 0 5.16 49.59 2.90 5.75 0 5.95 57.52 2.90 5.75 0 6.94 2.90 5.75 0.61 5.16 2.90 5.75 3.40 0.58 4.96 2.90 5.75 3.80 0.58 5.75 2.90 5.75 4.10 0.58 2.90 5.75 4.70 6.74 0.58 2.90 5.75 5.30 7.54 0.58 3.10 5.75 5.30 8.13 0.58 5.75 5.30 9.32 0.58 10.51 5.75 5.30 0.67 0.58 10.51 0.75 6.15 0.58 10.51 0.81 0.58 10.51 0.93 1.05 0.58 1.05 0.61 1.05 1.05 Appendix A.

Appendix A A–61 (acre-ft) site 8 (A) to site 9 (B) Increasestreamflow in (acre-ft) (+\- error) (+\- (B) Diversion Lake total out SW (acre-ft) (acre-ft) (+\- error) Diversion Lake (A) Diversion Lake total Lake out SW (acre-ft) (acre-ft) (+\- error) 08180500 Medina River near Riomedina (site 9) (B) 9) (site Riomedina near /s) (acre-ft) 3 (ft Surface-water outflow, Medina and Diversion outflow, Lakes—ContinuedSurface-water Date 9/1/19969/2/19969/3/19969/4/1996 23.009/5/1996 23.009/6/1996 21.009/7/1996 22.009/8/1996 21.009/9/1996 45.62 21.00 45.62 20.00 41.65 18.00 43.64 18.00 41.65 41.65 4.56 39.67 4.56 35.70 4.17 35.70 4.36 4.17 4.17 3.97 10.51 3.57 10.51 3.57 33.72 58.71 51.57 39.07 1.05 28.76 1.05 18.84 3.37 5.87 6.94 5.16 3.91 2.88 45.62 1.88 45.62 65.45 0.69 93.22 85.29 73.39 4.56 61.49 4.56 47.60 6.55 9.32 35.70 8.53 7.34 6.15 4.76 3.57 35.11 35.11 31.74 34.51 33.72 34.31 32.73 28.76 28.76 8/17/19968/18/19968/19/19968/20/1996 28.008/21/1996 27.008/22/1996 27.008/23/1996 26.008/24/1996 26.008/25/1996 55.54 28.008/26/1996 53.55 30.008/27/1996 53.55 29.008/28/1996 51.57 28.008/29/1996 51.57 28.008/30/1996 55.54 5.55 26.008/31/1996 59.50 5.36 24.00 57.52 5.36 24.00 55.54 5.16 23.00 55.54 5.16 23.00 51.57 5.55 274.12 47.60 5.95 270.15 47.60 5.75 268.17 45.62 5.55 274.12 45.62 5.55 176.93 5.169/10/1996 27.41 180.89 4.769/11/1996 27.01 148.36 4.769/12/1996 26.82 121.79 4.569/13/1996 27.41 101.95 4.56 17.009/14/1996 17.69 17.00 48.409/15/1996 18.09 16.00 25.98 315.379/16/1996 14.84 16.00 11.31 309.429/17/1996 12.18 16.00 10.71 307.449/18/1996 10.20 33.72 16.00 10.51 311.409/19/1996 33.72 15.00 10.51 214.21 4.849/20/1996 31.74 31.54 15.00 222.15 2.609/21/1996 31.74 30.94 15.00 194.38 1.139/22/1996 31.74 30.74 15.00 166.61 1.079/23/1996 31.74 31.14 3.37 15.00 144.79 1.059/24/1996 29.75 21.42 3.37 16.00 1.059/25/1996 29.75 22.21 3.17 16.009/26/1996 91.24 29.75 19.44 3.17 16.009/27/1996 65.85 29.75 16.66 3.17 18.009/28/1996 47.60 29.75 14.48 3.17 19.009/29/1996 47.60 31.74 2.98 21.009/30/1996 45.62 6.15 41.26 31.74 2.98 23.00 45.62 5.75 9.12 39.27 31.74 2.98 23.00 5.75 6.59 39.27 35.70 2.98 23.00 5.75 4.76 37.29 37.69 2.98 23.00 5.75 4.76 37.29 41.65 3.17 5.75 4.56 0.61 41.26 45.62 3.17 5.75 4.56 0.58 46.02 45.62 3.17 5.75 0.58 44.83 45.62 3.57 5.75 0.58 42.84 45.62 3.77 5.75 0.58 4.17 5.75 0.58 4.56 42.84 5.75 0.58 33.72 4.56 39.87 6.15 0.58 33.72 4.56 24.60 36.30 0.58 31.74 4.56 41.26 36.89 0.58 31.74 59.70 35.11 0.58 31.74 68.83 35.11 0.58 31.74 3.37 79.93 0.61 29.75 3.37 62.08 2.46 29.75 3.17 60.10 4.13 29.75 3.17 68.03 5.97 29.75 3.17 6.88 29.75 3.17 7.99 31.74 2.98 6.21 31.74 2.98 6.01 49.59 2.98 6.80 69.42 2.98 89.26 27.57 101.16 2.98 27.97 115.04 3.17 25.98 3.17 97.19 4.96 25.98 95.21 6.94 25.98 103.14 8.93 10.12 25.98 11.50 24.00 24.00 9.72 24.00 9.52 10.31 24.00 24.00 25.98 25.59 24.99 28.17 29.55 32.33 35.11 35.11 35.11 35.11 Appendix A.

A–62 Hydrogeology, Hydrologic Budget, and Water Chemistry of the Medina Lake area, Texas storage (acre-ft) (+/- error) storage (acre-ft) Storage (acre-ft) storage (acre-ft) (+/- error) storage (acre-ft) Storage (acre-ft) Appendix A storage (acre-ft) (+/- error) storage (acre-ft) Hydrogeology, Hydrologic Budget, Hydrogeology, Chemistry the of Water and Texas area, Lake Medina 08179505 Medina Lake (site 13) 08180010 Diversion Lake (site 15) Medina/Diversion Lakes combined Storage (acre-ft) Storage—Continued Storage Date 8/1/1995 8/2/1995 8/3/1995 8/4/1995 8/5/1995 8/6/1995 8/7/1995 8/8/1995 8/9/1995 9/1/1995 9/2/1995 9/3/1995 9/4/1995 9/5/1995 9/6/1995 9/7/1995 9/8/1995 9/9/1995 8/10/1995 8/11/1995 8/12/1995 8/13/1995 8/14/1995 8/15/1995 8/16/1995 8/17/1995 8/18/1995 8/19/1995 8/20/1995 8/21/1995 8/22/1995 8/23/1995 8/24/1995 8/25/1995 8/26/1995 8/27/1995 8/28/1995 8/29/1995 8/30/1995 8/31/1995 9/10/19959/11/19959/12/19959/13/1995 9/14/1995 9/15/1995 1,500 1,490 1,490 -10.0 0 -1.5 0 Appendix A. Appendix Appendix A.Appendix acre-feet; 2. acre-ft, table 3 and figure to correspond [Site numbers storage] in change storage,

Appendix A A–63

storage (acre-ft) (+/- error) storage (acre-ft)

Storage (acre-ft) storage (acre-ft) (+/- error) storage (acre-ft) Storage (acre-ft) storage (acre-ft) (+/- error) storage (acre-ft) 08179505 Medina Lake (site 13) 08180010 Diversion Lake (site 15) Medina/Diversion Lakes combined Storage (acre-ft) Storage—Continued Date 10/2/199510/3/199510/4/199510/5/1995 155,09010/6/1995 155,12710/7/1995 155,01510/8/1995 155,00210/9/1995 154,874 154,788 99 154,717 37 -112 154,651 -13 -128 -86 9.90 -71 -11.20 3.70 -66 -12.80 -1.30 -8.60 -7.10 -6.60 11/1/199511/2/1995 151,763 152,225 1,646 462 164.60 46.20 1,707 1,777 116.7 70.1 17.5 10.5 153,470 154,002 1,762.7 532.1 182.11 56.72 9/21/19959/22/19959/23/19959/24/1995 149,6019/25/1995 151,3959/26/1995 152,9679/27/1995 153,6219/28/1995 154,039 9749/29/1995 154,317 1,7949/30/1995 154,509 1,57210/1/1995 154,684 654 154,775 418 154,867 278 179.40 97.40 154,991 192 157.20 175 65.40 91 41.80 92 124 27.80 19.20 17.50 9.10 9.20 12.40 2,030 2,070 2,030 40.0 -40.0 6.0 -6.0 156,387 156,539 156,069 318.0 152.0 33.80 13.20 9/16/1995 9/17/1995 9/18/1995 9/19/1995 9/20/1995 148,627 10/10/199510/11/199510/12/199510/13/1995 154,60010/14/1995 154,60410/15/1995 154,48310/16/1995 154,33210/17/1995 154,15510/18/1995 -51 153,82510/19/1995 153,581 -121 410/20/1995 153,281 -15110/21/1995 153,019 -17710/22/1995 152,774 -33010/23/1995 152,484 -5.10 -24410/24/1995 152,039 -12.10 -30010/25/1995 151,708 0.40 -15.10 -26210/26/1995 151,448 -17.70 -24510/27/1995 151,079 -33.00 -29010/28/1995 150,785 -24.40 -44510/29/1995 150,587 -30.00 -33110/30/1995 1,549 150,461 -26.20 -26010/31/1995 150,241 1,522 -24.50 -369 1,518 150,044 1,548 -29.00 -294 149,933 1,563 -44.50 -198 150,117 1,570 -33.10 -126 1,580 -26.00 -220 1,615 -36.90 4.6 -197 -31.4 25.8 1,638 -29.40 -111 15.4 1,650 -19.80 184 1,656 -12.60 6.5 10.2 1,658 -22.00 34.5 1,660 -19.70 23.4 1,663 -4.7 0.7 -11.10 3.9 12.0 1,662 2.3 18.40 1,664 6.0 1,662 1.0 2.0 1.5 1,644 2.1 5.2 1,618 2.8 3.5 1,600 -1.0 156,122 156,005 1.8 155,880 1,589 2.1 156,149 155,718 -2.0 0.9 1,591 -17.6 0.3 155,395 -26.9 155,161 0.3 -116.4 -17.7 -27.4 -125.2 154,896 0.4 -10.4 -0.2 -161.6 154,657 154,424 0.3 -323.5 -0.3 -233.8 1.2 -2.6 154,140 -265.5 -4.0 153,697 -11.41 -238.6 -11.23 -2.7 -4.31 153,368 -233.0 -15.39 -1.6 153,111 152,741 -284.0 -32.03 -22.87 -443.0 152,449 152,249 0.2 -24.83 -328.9 152,105 -22.69 -257.2 151,859 -370.0 -22.70 151,644 -291.9 151,522 -28.10 -200.0 -143.6 -44.20 -246.9 -32.79 151,708 -214.7 -25.58 -37.05 -121.4 -29.09 -20.10 -15.24 185.2 -26.04 -22.36 -12.66 18.58 Appendix A. Appendix

A–64 Hydrogeology, Hydrologic Budget, and Water Chemistry of the Medina Lake area, Texas storage (acre-ft) (+/- error) storage (acre-ft) Storage (acre-ft) storage (acre-ft) (+/- error) storage (acre-ft) Storage (acre-ft) storage (acre-ft) (+/- error) storage (acre-ft) 08179505 Medina Lake (site 13) 08180010 Diversion Lake (site 15) Medina/Diversion Lakes combined Storage (acre-ft) Storage—Continued Date 11/3/199511/4/199511/5/199511/6/1995 152,40711/7/1995 152,37611/8/1995 152,42511/9/1995 152,499 152,578 182 152,581 -31 152,555 49 74 79 18.20 3 -26 -3.10 4.90 7.40 7.90 -2.60 0.30 1,823 1,858 1,886 1,908 1,935 45.6 35.4 1,915 1,927 27.312/1/1995 22.012/2/1995 27.512/3/1995 6.8 -11.912/4/1995 152,888 -8.2 5.312/5/1995 152,89012/6/1995 152,904 4.112/7/1995 152,861 3.312/8/1995 152,825 4.112/9/1995 -34 152,802 -1.8 154,230 -1.2 152,725 2 154,234 152,685 14 -43 152,645 154,311 -36 154,407 227.6 -23 -3.40 154,513 -77 154,470 154,508 -40 4.4 0.20 1.40 -40 76.3 -4.30 96.0 -3.60 106.5 -2.30 25.04 -37.9 -7.70 -5.2 1,922 -4.00 2.21 -4.00 1,887 8.99 1,855 10.70 1,825 12.03 1,797 -4.39 -30.0 1,766 -0.93 1,722 -35.1 1,686 -31.8 -30.1 1,659 -27.6 -31.2 -4.5 -44.5 -35.2 -5.3 -27.0 -4.8 -4.5 -4.1 -4.7 -6.7 154,810 -5.3 -4.1 154,777 154,759 154,686 154,622 -64.0 154,568 154,447 -33.1 -17.8 154,371 -73.1 154,304 -63.6 -54.2 -121.5 -7.90 -75.2 -5.06 -67.0 -3.37 -8.82 -7.74 -6.98 -14.38 -9.28 -8.05 11/10/199511/11/199511/12/199511/13/1995 152,58611/14/1995 152,60411/15/1995 152,41511/16/1995 152,39411/17/1995 152,35211/18/1995 152,334 3111/19/1995 152,294 18 -18911/20/1995 152,57611/21/1995 -21 152,99511/22/1995 -42 153,05011/23/1995 -18 153,143 3.1011/24/1995 -40 153,217 -18.90 282 1.8011/25/1995 153,231 41911/26/1995 153,254 -2.1011/27/1995 153,218 -4.20 5511/28/1995 153,158 -1.80 9311/29/1995 153,136 -4.00 7411/30/1995 28.20 153,171 14 1,894 41.90 153,120 1,836 23 1,865 -36 152,976 5.50 1,808 -60 152,922 9.30 1,780 -22 7.40 1,738 -21.6 35 -29.4 1.40 1,683 -51 -28.1 -144 1,674 2.30 -3.60 -27.7 1,721 -54 -6.00 -28.7 -2.20 1,763 -42.112/10/1995 1,801 -54.1 -3.2 3.5012/11/1995 -5.10 -4.4 -14.40 1,835 -9.3 -4.212/12/1995 1,864 47.312/13/1995 152,396 -4.2 -5.40 1,89212/14/1995 1,917 152,314 -4.3 41.612/15/1995 1,939 152,251 -6.3 38.312/16/1995 1,962 152,234 -8.1 33.312/17/1995 154,480 152,194 -1.4 154,251 29.7 1,984 -24912/18/1995 154,469 2,002 152,191 2,001 27.7 7.112/19/1995 24.8 -82 152,152 154,20212/20/1995 22.2 1,952 -63 152,145 154,132 6.2 23.0 -17 152,226 154,072 5.7 -218.4 -40 152,099 9.4 153,977 -10.1 5.0 -24.90 22.0 17.8 151,965 -0.5 4.5 -3 154,250 -48.7 -39 -8.20 4.2 -49.5 154,716 -70.7 3.7 -6.30 -7 -60.1 3.3 -1.70 81 154,813 -127 -23.31 -94.1 3.5 -4.00 154,944 -134 -0.14 272.7 -2.41 3.3 155,052 -0.30 -0.1 2.7 466.3 1,635 -3.90 -6.26 155,095 -7.4 -8.51 155,146 -0.70 155,135 1,610 96.6 -8.11 -12.70 131.3 8.10 155,097 1,578 -12.12 -13.40 107.3 155,098 1,552 26.81 -24.7 1,531 43.7 49.00 155,155 154,977 155,122 50.7 -11.2 1,516 -24.4 1,502 154,874 -37.8 -32.1 11.74 15.05 1,494 -26.3 1.0 1,469 12.40 1,485 -20.6 -144.5 1,459 57.0 -33.2 -3.7 -15.7 5.86 -103.5 -13.1 6.46 -3.7 0.12 -2.67 -4.8 -8.8 -15.9 -3.9 -8.3 -10.5 1.25 -14.48 -3.1 -2.43 6.80 154,031 -12.83 -2.4 -2.0 153,924 -1.3 153,829 -2.4 -1.2 153,786 -1.6 -273.7 153,725 -106.4 153,707 153,654 -95.1 -43.3 153,639 153,568 -28.61 -60.6 153,711 153,424 -18.7 -11.86 -52.1 -11.12 -142.9 -15.8 -5.64 -144.5 72.7 -7.09 -2.66 -5.86 -15.09 -2.02 -14.98 6.86 Appendix A. Appendix

Appendix A A–65 storage (acre-ft) (+/- error) storage (acre-ft) Storage (acre-ft) storage (acre-ft) (+/- error) storage (acre-ft) Storage (acre-ft) storage (acre-ft) (+/- error) storage (acre-ft) 08179505 Medina Lake (site 13) 08180010 Diversion Lake (site 15) Medina/Diversion Lakes combined Storage (acre-ft) Storage—Continued Date 1/1/19961/2/19961/3/19961/4/1996 151,1421/5/1996 150,9801/6/1996 150,7731/7/1996 150,6851/8/1996 150,6761/9/1996 -44 150,573 -162 150,314 -207 150,173 -88 150,097 -9 -103 -4.40 -16.20 -259 -20.70 -141 -76 -8.80 -10.30 -0.90 -25.90 -14.10 1,537.2 1,526.3 1,516.8 -7.60 1,509 -10.9 1,482 1,495 -9.6 1,471.1 -9.5 1,464 1,458.4 -7.8 -13.0 -14.0 -10.9 -1.6 -1.42/1/1996 -1.4 -7.12/2/1996 -5.62/3/1996 -1.22/4/1996 146,364 -2.0 -2.1 -1.62/5/1996 146,181 152,5062/6/1996 145,955 152,679 -1.1 145,738 152,290 -0.8 145,554 -267 145,359 -183 152,194 -172.9 152,055 -53.6 -226 152,171 151,785 -216.5 -217 -184 151,637 -26.70 -195 151,555 -95.8 -18.30 -116.0 -269.9 -17.84 -23.0 -22.60 -5.84 -21.70 -22.13 -148.1 -18.40 -19.50 -81.6 -12.25 -9.97 -27.54 1,578.3 -3.00 1,583.9 1,568.3 -15.17 1,555.2 1,549.8 -8.44 18.4 1,577.9 5.6 -15.6 -13.1 -5.4 28.1 2.8 -2.3 0.8 -2.0 -0.8 4.2 147,942 147,523 147,765 147,293 147,104 -248.6 146,937 -241.6 -177.4 -230.1 -189.4 -166.9 -23.94 -24.94 -17.46 -23.67 -19.21 -15.29 1/10/19961/11/19961/12/19961/13/1996 150,0001/14/1996 149,8721/15/1996 149,6751/16/1996 149,5111/17/1996 149,3631/18/1996 -97 149,233 -1281/19/1996 149,096 -1971/20/1996 148,983 -1641/21/1996 148,983 -1481/22/1996 148,591 -1301/23/1996 148,436 -9.70 -12.80 -1371/24/1996 148,300 -19.70 -1131/25/1996 148,145 -16.401/26/1996 148,089 -14.80 -392 01/27/1996 147,901 -13.00 -1551/28/1996 147,727 -13.70 -1361/29/1996 147,642 -11.30 -1551/30/1996 1,459.3 147,373 1,495.21/31/1996 -56 147,160 1,509 -39.20 -188 147,036 1,512 0 -15.50 -174 146,883 1,513 -13.60 -85 146,631 1,513.2 35.9 -15.50 -269 0.9 1,513.2 -213 13.8 1,513.7 -5.60 -18.80 -124 -17.40 3.0 -153 1,503.2 1.0 -252 0.2 1,506.6 -8.50 -26.90 0 1,510.1 1,511.5 5.4 -21.30 0.1 0.5 1,514.2 -12.40 2.1 -15.30 -6.9 1,517.2 1,517.1 0.5 -25.20 3.4 1,513.8 0.2 -3.6 0 4.9 2.7 1,518.9 1,531 0 151,367 151,459 0.1 1,541.6 -0.1 3.0 151,184 1,548.4 -1.0 -3.3 1,550.6 151,023 0.5 1,559.9 -0.5 150,876 5.1 0.7 -92.1 12.1 -96.1 10.6 150,746 0.4 -183.2 6.8 150,497 150,609 0 -161.0 0.5 2.2 -0.5 150,094 -147.0 9.3 -129.8 149,943 150,493 -7.41 0.8 -9.57 -112.5 149,812 1.8 -137.0 -17.63 1.6 149,659 -398.9 -15.95 1.0 -14.65 149,606 0.3 -151.6 149,418 149,241 -12.97 1.4 -131.1 -3.6 -152.3 -11.23 -13.70 149,161 148,904 148,702 -40.24 -53.0 -188.1 -177.3 148,584 -14.99 148,434 -12.87 -0.54 148,191 -256.9 -15.10 -79.9 -202.4 -117.2 -18.82 -17.90 -5.15 -150.8 -242.7 -25.09 -19.71 -7.73 -11.38 -14.97 -23.81 12/21/199512/22/199512/23/199512/24/1995 151,89512/25/1995 151,85312/26/1995 151,70312/27/1995 151,63312/28/1995 151,54812/29/1995 -70 151,47512/30/1995 -42 151,406 -15012/31/1995 151,303 -70 151,217 -85 151,214 -73 151,186 -7.00 -69 -4.20 -15.00 -103 -86 -7.00 -8.50 -3 -28 -7.30 -6.90 -10.30 1,452 1,457 1,488.4 -8.60 -0.30 1,521.7 -2.80 1,554.4 1,584.4 -7.3 31.7 1,603.6 1,591.5 5.1 33.3 1,573.3 32.7 30.0 1,559.1 1,546.8 -12.1 19.2 -1.1 4.8 -18.2 0.8 5.0 -14.2 -12.3 4.9 4.5 -1.8 2.9 153,347 153,191 -2.7 153,310 -2.1 153,155 -1.8 153,102 -77.3 153,059 -118.3 152,895 153,010 -36.9 152,790 -36.7 -52.3 152,773 152,733 -43.0 -115.1 -10.25 -49.8 -8.10 -104.2 -3.43 -2.01 -17.2 -40.3 -3.59 -12.12 -2.80 -4.02 -11.33 -2.43 -4.64 Appendix A. Appendix

A–66 Hydrogeology, Hydrologic Budget, and Water Chemistry of the Medina Lake area, Texas storage (acre-ft) (+/- error) storage (acre-ft) Storage (acre-ft) storage (acre-ft) (+/- error) storage (acre-ft) Storage (acre-ft) storage (acre-ft) (+/- error) storage (acre-ft) 08179505 Medina Lake (site 13) 08180010 Diversion Lake (site 15) Medina/Diversion Lakes combined Storage (acre-ft) Storage—Continued Date 2/7/19962/8/19962/9/1996 145,140 144,963 144,783 -219 -177 -180 -21.90 -17.70 -18.00 1,597.2 1,596.2 1,594.23/1/1996 19.33/2/1996 -1.03/3/1996 -2.03/4/1996 139,3653/5/1996 139,1553/6/1996 138,9383/7/1996 138,748 2.93/8/1996 138,614 -0.2 -1463/9/1996 138,576 -0.3 -210 138,294 -217 137,902 -190 137,675 -134 146,737 -14.60 -38 146,559 -21.00 -282 146,377 -21.70 -392 -19.00 -227 -199.7 -13.40 -178.0 -182.0 -3.80 -28.20 1,604.3 -39.20 1,613.5 -22.70 1,625.2 -19.01 1,631.8 -17.85 -22.7 1,627 -18.30 9.2 1,626.8 1,624.2 11.7 1,620.9 6.6 1,620 -4.8 -3.4 -0.2 -2.6 -3.3 1.4 1.8 -0.9 1.0 -0.7 140,969 -0.4 0 -0.5 140,769 140,563 -0.1 -168.7 140,380 140,241 -200.8 139,918 -205.3 140,203 139,523 -183.4 -138.8 139,295 -18.01 -284.6 -19.62 -395.3 -38.2 -19.95 -227.9 -18.01 -14.12 -28.59 -39.70 -3.83 -22.84 2/10/19962/11/19962/12/19962/13/1996 144,5772/14/1996 144,4782/15/1996 144,0342/16/1996 143,7812/17/1996 143,556 -2062/18/1996 143,2452/19/1996 -99 142,992 -4442/20/1996 142,697 -2532/21/1996 142,444 -2252/22/1996 142,150 -20.60 -3112/23/1996 141,897 -2532/24/1996 141,621 -9.90 -44.40 -2952/25/1996 141,400 -25.30 -2532/26/1996 141,175 -22.50 -2942/27/1996 140,826 -31.10 -2532/28/1996 140,519 -25.30 -2762/29/1996 140,254 1,599.5 -29.50 -221 140,005 -25.30 -225 1,605 139,811 1,606 -29.40 -349 139,511 1,612.6 -25.30 -307 1,614 -27.60 -265 5.3 1,614.2 -22.10 -249 1,619.1 -22.50 -194 1,620.5 5.5 -34.90 1.0 -300 6.6 1,621.2 -30.70 1,618 -26.50 1.4 0.23/10/1996 1,616 -24.90 0.8 4.93/11/1996 1,610.8 -19.40 1.43/12/1996 1,609.2 -30.00 0.73/13/1996 137,449 1,613.8 0.8 0.2 1.03/14/1996 137,253 1,622.8 -3.23/15/1996 137,001 1,630.1 -2.0 0.2 -5.2 03/16/1996 136,879 1,634.3 -1.6 0.7 146,1773/17/1996 136,705 1,636.2 -226 0.2 4.63/18/1996 136,543 1,636 -196 0.1 9.03/19/1996 136,311 1,627 146,083 145,640 -252 -0.5 7.3 145,3943/20/1996 136,080 -122 -0.3 -200.7 4.23/21/1996 135,845 -0.8 145,170 -174 1.93/22/1996 135,460 -0.2 -22.60 144,859 -162 144,6113/23/1996 135,105 -0.2 -19.60 -443.0 -232 0.7 -93.5 -246.4 144,3183/24/1996 134,769 -9.0 -25.20 -231 1.4 144,0653/25/1996 134,425 -12.20 -223.6 -235 1.1 143,768 -19.81 134,086 -17.40 -310.8 -385 0.6 -248.1 143,513 133,796 143,232 -16.20 -355 0.3 -293.6 133,561 143,009 -23.20 -336 -44.25 -252.3 -24.31 0 1,617.2 -23.10 -9.08 -344 -1.4 142,789 -297.2 1,614 -23.50 -339 -22.29 142,449 -255.0 1,608 -281.2 -38.50 -290 -31.07 142,149 -24.57 1,593.5 -222.6 -35.50 -235 141,888 -29.29 1,586.6 -33.60 -2.8 -220.4 141,641 -25.20 1,583.6 -34.40 -340.0 1,594 -29.88 -3.2 -33.90 -299.7 141,447 141,138 -14.5 1,604 -25.60 -6.0 -29.00 -28.38 -260.8 1,607 -23.50 -22.34 -6.9 -247.1 1,610.1 -3.0 -21.81 1,613 -0.4 -194.2 -309.0 10.4 -33.55 1,630 -0.5 -29.61 10.0 1,647 -2.2 -0.9 -25.87 1,664 3.0 3.1 -24.62 1,681 -1.0 1,698 -0.5 2.9 17.0 -19.43 -31.35 139,066 1.6 17.0 138,867 1.5 17.0 138,473 138,609 17.0 0.5 0.5 17.0 -228.8 138,292 138,127 0.4 -199.2 2.6 -136.5 -258.0 2.6 137,905 2.6 137,684 -180.9 2.6 -165.0 -23.02 137,452 137,070 2.6 -221.6 -20.08 136,718 -221.0 -14.38 136,399 -26.10 136,072 -18.44 -232.0 -381.9 135,750 -16.65 135,477 -352.1 -319.0 135,259 -21.64 -327.0 -21.60 -322.0 -23.05 -273.0 -38.04 -218.0 -35.07 -31.05 -31.85 -31.35 -26.45 -20.95 Appendix A. Appendix

Appendix A A–67 storage (acre-ft) (+/- error) storage (acre-ft) Storage (acre-ft) storage (acre-ft) (+/- error) storage (acre-ft) Storage (acre-ft) storage (acre-ft) (+/- error) storage (acre-ft) 08179505 Medina Lake (site 13) 08180010 Diversion Lake (site 15) Medina/Diversion Lakes combined Storage (acre-ft) Storage—Continued Date 4/1/19964/2/19964/3/19964/4/1996 131,3734/5/1996 131,0224/6/1996 130,7164/7/1996 130,5174/8/1996 130,385 -3734/9/1996 130,271 -351 129,988 -306 129,804 -199 129,402 -132 -37.30 -114 -35.10 -283 -30.60 -184 -19.90 -402 -13.20 -11.40 -28.30 1,775 -18.40 1,780 -40.20 1,778 1,768 1,731 1,705 6.4 1,671 4.9 1,645 -1.5 -10.5 1,619 -37.4 -25.5 -33.85/1/1996 1.0 -26.25/2/1996 0.7 -26.0 -0.25/3/1996 -1.65/4/1996 121,846 -5.65/5/1996 121,480 -3.85/6/1996 121,123 -5.15/7/1996 120,735 -3.9 133,1485/8/1996 120,383 -3.9 132,802 -620 132,4945/9/1996 119,988 132,285 -366 119,597 132,116 -357 119,239 -366.6 131,976 -388 118,946 -346.1 131,659 -352 -307.5 -62.00 -209.5 131,449 -395 -36.60 -169.4 131,021 -391 -35.70 -139.5 -358 -38.80 -316.8 -293 -36.34 -35.20 -210.2 -34.37 -30.83 -39.50 -428.0 -21.48 -39.10 -18.81 1,730 -35.80 -15.23 1,728 -29.30 -33.37 1,724 -22.33 1,722 -44.10 1,722 1,722 -2.0 1,722 -1.9 1,730 -4.7 1,819 -1.7 0 0 -0.3 -0.1 -0.3 8.0 -0.7 89.0 -0.3 0 123,576 0 0 123,208 1.2 13.4 122,847 122,457 -622.0 -367.9 122,105 -361.7 121,710 121,319 -389.7 120,969 120,765 -62.30 -352.0 -36.89 -395.0 -391.1 -36.41 -350.0 -204.0 -39.06 -35.20 -39.50 -39.12 -34.60 -15.95 3/26/19963/27/19963/28/19963/29/1996 133,1363/30/1996 132,7933/31/1996 132,588 132,287 132,046 -425 131,746 -343 -205 -301 -241 -42.50 -300 -34.30 -20.504/10/1996 -30.104/11/1996 -24.104/12/1996 -30.004/13/1996 129,3004/14/1996 128,990 1,7164/15/1996 128,747 1,7224/16/1996 128,465 1,7334/17/1996 128,117 1,744 -1024/18/1996 127,853 1,759 -3104/19/1996 18.0 127,402 1,769 -2434/20/1996 127,023 6.2 -2824/21/1996 10.6 126,692 -3484/22/1996 11.1 126,472 -10.20 -2644/23/1996 15.4 126,106 -31.00 -4514/24/1996 125,739 -24.30 9.3 -3794/25/1996 2.7 125,302 -28.20 -3314/26/1996 124,941 0.9 -34.80 -2204/27/1996 1.6 124,616 -26.40 -3664/28/1996 1.7 124,255 -45.10 -3674/29/1996 2.3 123,857 1,621 -37.90 -4374/30/1996 123,428 1,629 1.4 -33.10 -361 134,852 123,107 1,634 -22.00 -325 122,786 1,632 -36.60 134,515 -361 134,321 122,466 1,635 -36.70 -398 134,031 1,638 -43.70 2.0 -429 -407.0 133,805 1,650 -36.10 8.4 -321 1,657 -32.50 -336.8 4.9 133,515 -321 -194.4 1,662 -2.2 -36.10 -320 -289.9 1,664 -39.80 3.1 -225.6 1,680 -42.90 2.55/10/1996 12.4 1,692 -39.80 0.3 -32.10 -290.75/11/1996 1,706 1.3 -32.10 7.2 -33.37 5/12/1996 1,717 -18.91 0.7 -32.00 4.2 -0.3 118,706 1,727 -28.44 2.5 15.7 118,644 1,735 -21.79 0.5 12.1 118,367 1,741 0.4 -28.61 1.9 13.8 1,738 130,921 11.2 1,735 1.1 130,619 -240 10.0 1,738 0.6 130,381 130,097 -62 1,732 0.4 8.2 -277 2.4 -100.0 6.0 129,752 1.8 -2.9 -301.6 129,491 2.1 129,052 -3.0 -24.00 -238.1 -284.2 1.7 2.9 128,680 1.5 -5.7 -6.20 -27.70 -344.9 128,354 1.2 -261.5 128,136 -438.6 127,786 -9.90 0.9 -29.74 -0.4 127,431 -371.8 -23.57 -0.5 127,008 -28.53 -326.8 126,658 1,829 0.4 -217.5 -34.34 -0.9 -350.3 126,343 -26.03 1,820 -354.9 1,810 -43.24 125,990 -423.2 125,598 -36.82 125,166 -349.8 -32.47 124,842 -315.0 10.1 -21.63 -34.25 -352.8 124,524 -10.0 124,198 -9.0 -34.89 -392.0 -431.9 -41.63 -324.0 -34.42 -31.00 -318.1 -325.7 1.5 -34.87 -1.5 -1.4 -38.90 -43.34 -32.55 -31.67 -32.86 120,535 120,177 120,464 -229.9 -287.0 -71.0 -22.49 -29.20 -7.55 Appendix A. Appendix

A–68 Hydrogeology, Hydrologic Budget, and Water Chemistry of the Medina Lake area, Texas storage (acre-ft) (+/- error) storage (acre-ft) Storage (acre-ft) storage (acre-ft) (+/- error) storage (acre-ft) Storage (acre-ft) storage (acre-ft) (+/- error) storage (acre-ft) 08179505 Medina Lake (site 13) 08180010 Diversion Lake (site 15) Medina/Diversion Lakes combined Storage (acre-ft) Storage—Continued Date 6/1/19966/2/19966/3/19966/4/1996 110,8596/5/1996 110,3706/6/1996 110,5016/7/1996 110,0126/8/1996 109,432 -3926/9/1996 108,853 -489 108,498 131 108,052 -489 107,639 -580 -39.20 -579 -48.90 -355 -446 13.10 -48.90 -413 -58.00 -57.90 -35.50 1,760 -44.60 1,774 -41.30 1,786 1,784 1,789 1,787 -0.7 14.0 1,787 1,786 12.0 1,783 -2.3 5.3 -1.7 -0.1 -0.5 2.1 -1.1 -2.5 1.8 -0.3 0.8 -0.3 -0.1 112,619 -0.2 112,144 -0.4 112,287 111,796 -392.7 111,221 110,640 -475.0 110,285 -491.3 143.0 109,838 109,422 -574.7 -580.7 -39.31 -355.5 -46.80 -447.1 -415.5 -49.25 14.90 -57.21 -58.16 -35.58 -44.77 -41.68 5/13/19965/14/19965/15/19965/16/1996 118,1275/17/1996 117,8875/18/1996 117,5105/19/1996 117,3735/20/1996 117,065 -2405/21/1996 116,722 -2405/22/1996 116,349 -3775/23/1996 115,943 -1375/24/1996 115,707 -3085/25/1996 115,368 -24.00 -3435/26/1996 114,929 -24.00 -3735/27/1996 114,361 -37.70 -4065/28/1996 113,826 -13.70 -2365/29/1996 113,226 -30.80 -3395/30/1996 112,764 -34.30 -4395/31/1996 112,631 -37.30 -568 112,136 1,801 -40.60 -535 111,641 1,775 -23.60 -600 111,251 1,745 -33.90 -462 1,723 -43.90 -133 1,694 -56.80 -495 1,682 -9.0 -53.50 -495 -26.0 1,663 -60.00 -390 -30.0 1,647 -46.20 -21.9 1,670 -13.30 -29.16/10/1996 1,693 -49.50 -12.06/11/1996 1,717 -49.50 -19.0 -1.46/12/1996 1,740 -3.9 -39.00 -16.06/13/1996 106,906 1,749 -4.56/14/1996 23.0 106,371 1,765 -3.36/15/1996 23.0 105,899 1,779 -4.46/16/1996 24.0 105,427 1,782 -1.86/17/1996 23.0 104,958 1,776 -2.9 -7336/18/1996 119,928 104,430 1,767 -2.4 119,662 9.0 -5356/19/1996 16.4 103,900 1,761 119,255 -4726/20/1996 3.5 13.8 103,375 119,096 -4726/21/1996 3.5 102,882 118,759 3.0 -469 -249.06/22/1996 3.6 102,359 -6.3 -73.30 -266.0 118,404 -5286/23/1996 3.5 101,625 -9.1 -53.50 -407.0 118,012 -5306/24/1996 101,170 -6.1 1.4 -47.20 -158.9 117,590 -5256/25/1996 2.5 100,709 -47.20 -337.1 -4936/26/1996 2.1 117,377 100,108 -46.90 -355.0 -5236/27/1996 117,061 -25.35 0.5 -52.80 -392.0 99,572 -734 -27.90 -0.96/28/1996 116,646 -53.00 -422.0 99,107 -455 -42.20 -1.46/29/1996 116,101 1,782 -52.50 98,672 -461 -16.99 -0.9 -213.0 1,780 -49.30 115,575 98,199 -601 -35.17 -316.0 114,991 1,777 -52.30 97,700 -36.10 -536 -415.0 114,543 1,772 -73.40 97,228 -40.15 -465 -545.0 1,771 -45.50 114,413 -43.00 113,912 -435 1,780 -1.1 -46.10 -526.0 113,408 -583.6 -473 1,782 -1.7 -20.15 -60.10 113,012 -448.2 -499 1,783 -3.7 -30.45 -53.60 -472 1,785 -4.9 -40.30 -130.0 -46.50 -501.3 1,795 -0.6 -53.35 -43.50 -504.1 1,804 8.9 -52.15 -0.2 -47.30 -396.1 1,809 -57.54 2.1 -0.3 -49.90 1,811 -44.13 0.7 -0.6 -47.20 1,812 1.7 -12.85 -0.7 10.0 -50.45 1,808 -0.1 -50.87 9.3 1,809 -39.92 1.3 4.8 1,808 108,688 0.3 2.6 1,807 108,151 0.1 0.4 1,803 107,676 0.3 1,800 -4.2 107,199 1.5 -734.1 106,729 1.9 1.4 -1.3 -536.7 0.7 106,210 -1.0 -475.7 0.4 105,682 -4.1 -476.9 0.1 105,158 -3.4 -469.6 -0.6 104,667 104,154 -73.47 -519.1 0.3 -53.76 -0.2 -527.9 103,429 -47.76 -0.2 -524.3 102,979 -47.94 -0.6 -491.3 102,520 -513.0 -46.99 -0.5 101,920 101,380 -724.7 -51.47 -450.2 -52.69 100,916 100,480 -458.4 -52.40 100,006 -600.6 -49.05 -50.80 -540.2 99,503 -72.01 99,028 -463.1 -436.3 -44.78 -474.0 -45.71 -60.04 -503.1 -54.23 -475.4 -46.22 -43.70 -47.45 -50.52 -47.71 Appendix A. Appendix

Appendix A A–69 storage (acre-ft) (+/- error) storage (acre-ft) Storage (acre-ft) storage (acre-ft) (+/- error) storage (acre-ft) Storage (acre-ft) storage (acre-ft) (+/- error) storage (acre-ft) 08179505 Medina Lake (site 13) 08180010 Diversion Lake (site 15) Medina/Diversion Lakes combined Storage (acre-ft) Storage—Continued Date 7/1/19967/2/19967/3/19967/4/1996 96,0877/5/1996 95,6407/6/1996 95,1717/7/1996 94,6147/8/1996 94,0607/9/1996 -563 93,173 -447 92,656 -469 92,110 -557 91,538 -554 -56.30 -887 -44.70 -517 -46.90 -546 -55.70 -572 -55.40 -88.70 -51.70 1,797 -54.60 1,797 -57.20 1,798 1,801 1,806 1,807 -1.4 1,807 0 1,806 0.9 1,809 3.0 5.3 0.8 -0.28/1/1996 0 -0.28/2/1996 0 0.18/3/1996 2.9 0.58/4/1996 81,887 0.88/5/1996 81,443 0.18/6/1996 80,870 97,8848/7/1996 0 80,363 08/8/1996 79,808 0.48/9/1996 -469 96,969 79,356 97,437 -444 96,415 78,852 -564.4 -573 95,866 78,354 -507 94,980 77,675 -555 -468.1 -447.0 -46.90 -452 -554.0 94,463 93,916 -44.40 -504 -548.7 93,347 -57.30 -56.51 -498 -886.2 -50.70 -679 -55.50 -46.77 -517.0 -546.2 -45.20 -44.70 -569.1 -55.25 -50.40 1,781 -54.61 -49.80 1,786 -88.58 -67.90 1,784 1,787 -51.70 -54.63 1,787 -56.77 1,787 9.1 1,787 4.6 1,788 -2.0 1,795 3.1 0 0.2 -0.1 1.4 0.7 0.6 -0.3 7.7 0.5 0 0 0 83,668 0.1 83,229 82,654 1.2 82,150 -459.9 -439.4 81,595 -575.0 81,143 80,639 -503.9 80,142 79,470 -45.54 -555.0 -451.8 -43.71 -504.1 -57.60 -497.4 -671.3 -50.24 -55.50 -45.17 -50.42 -49.71 -66.75 6/30/1996 96,650 -5787/10/19967/11/19967/12/1996 -57.807/13/1996 91,4257/14/1996 90,9407/15/1996 90,7137/16/1996 90,3157/17/1996 9,00897/18/1996 -113 89,8927/19/1996 -485 89,452 1,7987/20/1996 -227 89,0607/21/1996 -398 88,6217/22/1996 -226 88,200 -11.307/23/1996 -197 87,690 -48.507/24/1996 -440 87,209 -1.6 -22.707/25/1996 -392 86,807 -39.807/26/1996 -439 86,403 -22.607/27/1996 -421 85,977 -19.707/28/1996 -510 85,401 -44.007/29/1996 -481 84,863 1,850 -39.207/30/1996 -402 -0.2 84,325 1,894 -43.907/31/1996 -404 83,866 1,860 -42.10 -426 83,364 1,808 -51.00 -576 82,866 1,782 -48.10 -538 40.6 82,356 1,786 -40.20 -538 44.3 1,784 -40.40 -459 -34.2 1,772 98,448 -42.60 -502 -51.7 1,764 -57.60 -498 -26.3 1,764 -53.80 -510 1,764 -53.80 3.5 6.1 1,764 -1.5 -579.6 -45.908/10/1996 -12.5 6.6 1,764 -5.1 -50.208/11/1996 1,757 -7.5 -7.8 -49.808/12/1996 1,751 -3.9 -51.008/13/1996 0 77,212 1,7518/14/1996 0 76,931 1,758 0.58/15/1996 0 -58.04 -0.2 76,451 1,761 -1.98/16/1996 0 93,275 75,760 1,763 -7.0 92,834 -1.1 92,573 75,357 1,765 -6.0 -463 92,123 74,881 1,768 -0.5 -281 91,871 0 74,405 1,772 7.6 -480 -72.4 0 -440.7 3.0 -691 -261.2 91,678 0 91,236 2.1 -403 -1.1 -449.7 90,832 0 -46.30 1.3 -476 -0.9 -252.3 90,385 -28.10 3.9 -476 -0.1 -48.00 3.7 -193.5 -441.5 1.1 -69.10 -5.21 -41.86 -404.5 -27.83 89,964 0.5 -40.30 -47.56 89,454 -446.5 0.3 -47.60 -26.55 88,973 88,160 0.2 -47.60 1,791 88,571 87,728 0.6 1,787 -19.18 -421.0 87,152 0.6 -44.23 1,786 -41.08 -510.0 86,621 1,782 -481.0 -411.0 -45.03 86,086 1,771 -402.0 -432.0 85,629 1,761 -4.4 -576.5 85,129 1,768 -4.1 -42.10 -530.4 84,634 -0.9 -51.00 -535.0 84,128 -4.1 -48.10 -41.45 -11.2 -456.9 -40.20 -43.50 -500.7 -9.5 -57.68 -0.7 -494.1 6.9 -0.6 -506.3 -52.66 -0.1 -53.35 -0.6 -45.59 -1.7 -50.01 -1.4 -49.22 -50.45 79,003 1.0 78,718 78,237 77,542 77,128 -467.4 -285.1 76,642 -480.9 76,173 -695.1 -414.2 -485.5 -46.96 -28.72 -469.1 -48.14 -69.72 -41.98 -49.03 -46.57 Appendix A. Appendix

A–70 Hydrogeology, Hydrologic Budget, and Water Chemistry of the Medina Lake area, Texas storage (acre-ft) (+/- error) storage (acre-ft) Storage (acre-ft) storage (acre-ft) (+/- error) storage (acre-ft) Storage (acre-ft) storage (acre-ft) (+/- error) storage (acre-ft) 08179505 Medina Lake (site 13) 08180010 Diversion Lake (site 15) Medina/Diversion Lakes combined Storage (acre-ft) Storage—Continued Date 9/1/19969/2/19969/3/19969/4/1996 70,9419/5/1996 70,9659/6/1996 70,8939/7/1996 70,7739/8/1996 70,7259/9/1996 -24 70797 70,749 24 -72 70,773 -120 70,797 -48 -2.40 72 -48 2.40 -7.20 24 -12.00 24 -4.80 7.20 -4.80 1,574 2.40 1,561 2.40 1,538 1,484 1,434 -12.0 1,357 1390 -12.6 -23.0 -54.6 1,332 1,315 -49.6 -1.8 -32.7 -44.3 -1.9 -24.5 -3.5 -8.2 -17.6 -7.4 -4.9 -6.6 72,515 -3.7 72,526 72,431 -2.6 72,257 72,159 -36.0 72,106 -174.6 72187 11.4 -95.0 72,105 -97.6 72,112 -4.20 -80.7 27.7 -20.19 -10.65 0.51 -0.5 -12.24 6.4 -9.70 0.55 -1.28 -0.24 8/17/19968/18/19968/19/19968/20/1996 73,9608/21/1996 73,5158/22/1996 73,0968/23/1996 72,6818/24/1996 72,1208/25/1996 -445 71,5908/26/1996 -445 71,3978/27/1996 -419 71,1818/28/1996 -415 71,1098/29/1996 -561 70,989 -44.508/30/1996 -530 70,965 -44.508/31/1996 -193 70,941 -41.90 -216 70,821 -41.50 -72 70,869 -56.10 -120 70,965 -53.00 -24 -19.30 -24 1,760 -21.60 -120 1,751 1,749 -7.20 48 -12.00 1,759 96 1,800 -2.409/10/1996 1,802 -7.6 -2.40 -12.009/11/1996 1,747 -9.09/12/1996 1,728 -2.49/13/1996 4.80 10.1 70,7499/14/1996 9.60 1,731 41.0 70,701 1,7239/15/1996 70,6549/16/1996 2.1 -55.4 -1.1 1,673 70,5369/17/1996 -19.3 -1.4 1,645 70,465 1,6189/18/1996 -0.4 -48 70,5369/19/1996 1.5 -48 70,512 -8.0 3.19/20/1996 1,599 6.2 -47 70,5369/21/1996 1,586 -118 -49.5 70,536 -8.3 0.39/22/1996 -28.4 -27.1 -71 70,512 75,720 -2.99/23/1996 70,488 -4.80 75,266 719/24/1996 -24 70,418 -19.0 -4.80 74,8459/25/1996 -1.2 70,347 -12.9 0.5 -4.70 24 -11.809/26/1996 74,440 70,276 -7.4 -452.69/27/1996 73,920 0 -24 70,110 -4.3 -7.10 -454.0 -4.19/28/1996 73,144 73,392 -24 69,968 -421.49/29/1996 7.10 72,909 -70 69,731 -2.409/30/1996 -404.9 -2.9 1,300 -71 69,496 -520.0 -1.9 2.40 1,285 -71 69,286 72,712 -45.64 -166 72,840 -248.4 -527.9 1,270 69,053 1,257 -2.40 0 -45.85 -142 72,638 -235.3 69,029 -2.40 -42.26 -237 72,586 72,439 1,244 -7.00 -235 -14.5 -39.99 -7.10 -128.0 1,240 -210 -15.0 -49.95 1,230 -68.9 -7.10 72,468 -16.60 -233 -15.6 -12.6 -27.61 -52.69 -73.5 72,551 -14.20 1,216 -147.1 -24 -24.50 -52.4 -23.70 -13.6 1,234 -23.50 1,262 1,210 -2.2 -21.00 -13.20 -10.0 -3.9 1,290 29.0 -2.3 -23.30 -6.74 1,314 83.1 -13.2 -2.3 -1.9 -9.83 1,344 1,405 -16.07 -2.40 -6.66 24.0 1,454 -2.0 27.8 1,506 -6.4 28.1 1,505 -1.5 -0.6 72,049 24.2 1.95 1,496 71,986 -2.0 30.3 7.67 60.6 1,489 71,924 71,793 49.0 3.6 1,484 52.0 -1.0 71,709 4.2 -1.4 -62.5 4.2 -8.6 -63.0 71,742 71,776 3.6 -130.6 -7.3 -62.6 4.5 9.1 71,752 7.4 -4.7 -84.6 7.8 71,746 -0.2 -6.98 -34.0 71,746 71,750 67.1 -1.3 -7.05 -13.69 71,708 -1.1 -7.04 10.8 71,661 71,620 71,515 -0.7 -9.14 71,422 0 -6.4 71,237 3.8 -41.9 -3.90 71,001 6.51 -46.8 70,782 -105.4 -40.7 0.42 70,542 -93.0 -185.0 70,513 -236.4 -0.96 1.20 -218.6 -2.78 1.77 -240.3 -3.47 -7.51 -2.55 -6.85 -28.7 -15.90 -23.71 -22.29 -24.40 -3.11 Appendix A. Appendix

Appendix A A–71 Blank Page Blank

A–72 Hydrogeology, Hydrologic Budget, and Water Chemistry of the Medina Lake area, Texas Appendix B

Appendix B— Hydrologic Budgets

Hydrogeology, Hydrologic Budget, and Water Chemistry of the Medina Lake area, Texas

Appendix B B–1 28.82 38.49 28.73 27.17 26.27 25.79 18.53 30.21 29.68 17.18 19.33 16.40 16.85 (acre-ft) (+/- error) out GW , ground-water ground-water , out -5.03 15.33 72.69 46.84 25.29 66.96 65.20 93.69 98.96 73.87 87.38 160.49 213.90 (acre-ft) ay] 9.90 3.70 0.40 4.90 7.40 7.90 0.30 3.10 1.80 -1.30 -8.60 -7.10 -6.60 -5.10 -3.10 -2.60 -2.10 -4.20 -1.80 -4.00 12.40 18.40 46.20 18.20 -11.20 -12.80 -12.10 -15.10 -17.70 -33.00 -24.40 -30.00 -26.20 -24.50 -29.00 -44.50 -33.10 -26.00 -36.90 -29.40 -19.80 -12.60 -22.00 -19.70 -11.10 -18.90 164.60 (acre-ft) (+/- error) storage 4 3 99 37 49 74 79 31 18 -13 -86 -71 -66 -51 -31 -26 -21 -42 -18 -40 124 184 462 182 -112 -128 -121 -151 -177 -330 -244 -300 -262 -245 -290 -445 -331 -260 -369 -294 -198 -126 -220 -197 -111 -189 1,646 (acre-ft) storage, change in storage; GW in storage; change storage,

8.25 2.56 4.69 9.07 5.81 6.90 24.01 13.61 11.03 11.49 15.59 24.12 16.15 . 1; acre-ft/d, acre-feet per d per acre-feet 1; acre-ft/d, . (acre-ft) (+/- error) (+/- Evaporation 33.02 96.03 54.44 44.13 45.98 62.35 10.23 96.49 64.60 18.77 36.28 23.25 27.59 (acre-ft) , surface-water outflow; outflow; surface-water , out 6.35 6.35 6.35 6.35 6.35 6.35 6.35 6.35 6.35 6.35 8.93 6.35 6.35 6.35 6.15 6.15 6.15 6.15 6.15 6.15 5.95 5.95 5.95 5.95 5.95 5.95 14.08 16.46 16.46 16.46 20.63 24.99 24.99 24.99 24.99 24.99 25.19 24.99 24.99 23.01 17.06 13.88 13.88 13.88 13.49 12.10 10.51 (acre-ft) (+/- error) out SW ntrol and Improvement District No Improvement and ntrol 63.47 63.47 63.47 63.47 63.47 63.47 63.47 63.47 63.47 63.47 89.26 63.47 63.47 63.47 61.49 61.49 61.49 61.49 61.49 61.49 59.50 59.50 59.50 59.50 59.50 59.50 140.83 164.63 164.63 164.63 206.28 249.92 249.92 249.92 249.92 249.92 251.90 249.92 249.92 230.08 170.58 138.84 138.84 138.84 134.88 120.99 105.12 (acre-ft) , surface-water inflow; SW inflow; , surface-water in 23.84 23.28 22.47 21.47 20.67 19.39 18.75 17.74 18.52 18.32 17.72 16.53 15.54 14.49 13.55 12.85 14.29 14.91 15.04 14.24 13.65 10.47 10.47 10.87 10.87 10.87 10.87 10.87 11.46 12.85 16.29 28.02 37.37 39.42 29.25 24.05 22.90 21.40 19.60 17.99 17.01 17.08 15.08 15.28 15.44 14.02 13.60 (acre-ft) (+/- error) in SW 235.81 230.16 222.51 212.55 204.54 191.96 185.69 175.56 183.45 181.47 175.48 163.58 153.66 143.31 134.18 127.42 141.70 147.85 149.24 141.28 135.33 103.62 103.62 107.56 107.56 107.56 107.56 107.56 113.51 127.40 160.86 271.74 367.74 389.95 288.99 237.62 226.45 211.76 193.80 177.78 167.92 168.97 149.00 150.96 152.75 138.62 134.48 (acre-ft) riod. SW acre-feet; riod. acre-ft, 4.78 10.58 73.52 79.95 (acre-ft) (+/- error) Precipitation 70.54 31.84 Medina hydrologic Lake budget—Continued Medina hydrologic Lake budget 490.13 533.00 (acre-ft) Date 10/01/95 10/02/95 10/03/95 10/04/95 10/05/95 10/06/95 10/07/95 10/08/95 10/09/95 10/10/95 10/11/95 10/12/95 10/13/95 10/14/95 10/15/95 10/16/95 10/17/95 10/18/95 10/19/95 10/20/95 10/21/95 10/22/95 10/23/95 10/24/95 10/25/95 10/26/95 10/27/95 10/28/95 10/29/95 10/30/95 10/31/95 11/01/95 11/02/95 11/03/95 11/04/95 11/05/95 11/06/95 11/07/95 11/08/95 11/09/95 11/10/95 11/11/95 11/12/95 11/13/95 11/14/95 11/15/95 11/16/95 outflow; ft, feet; BMA, Bexar-Medina-Atascosa Counties Water Co Water Counties feet; BMA, Bexar-Medina-Atascosa ft, outflow; Appendix B.Appendix pe budget indicates [Shading B.Appendix

B–2 Hydrogeology, Hydrologic Budget, and Water Chemistry of the Medina Lake area, Texas -62.00 (acre-ft/d) Average storage Average 34.10 (acre-ft/d) Average evaporationAverage out 59.50 (acre-ft/d) Average SWAverage in 145.16 (acre-ft/d) Average SWAverage 0 (acre-ft/d) Average precipitationAverage 1,044.79 sea level) Average stage (ft above mean above (ft out 19.89 (+/- error) (acre-ft/d) 113.56 (acre-ft/d) sea level) (ft above mean Stage Average GW Medina hydrologic Lake budget—Continued Medina hydrologic Lake budget—Continued (ft above (ft BMA datum) BMA Date 10/01/9510/02/95 1,053.1810/03/95 1,053.2010/04/95 1,053.21 1,045.38 10/05/95 1,053.19 1,045.40 10/06/95 1,053.18 1,045.41 10/07/95 1,053.15 1,045.39 10/08/95 1,053.14 1,045.38 10/09/95 1,053.12 1,045.35 10/10/95 1,053.10 1,045.34 10/11/95 1,053.09 1,045.32 10/12/95 1,053.09 1,045.30 10/13/95 1,053.07 1,045.29 10/14/95 1,053.03 1,045.29 10/15/95 1,053.00 1,045.27 10/16/95 1,052.92 1,045.23 10/17/95 1,052.87 1,045.20 10/18/95 1,052.80 1,045.12 10/19/95 1,052.74 1,045.07 10/20/95 1,052.69 1,045.00 10/21/95 1,052.62 1,044.94 10/22/95 1,052.52 1,044.89 10/23/95 1,052.45 1,044.82 10/24/95 1,052.39 1,044.72 10/25/95 1,052.31 1,044.65 10/26/95 1,052.24 1,044.59 10/27/95 1,052.20 1,044.51 10/28/95 1,052.17 1,044.44 10/29/95 1,052.12 1,044.40 10/30/95 1,052.07 1,044.37 10/31/95 1,052.05 1,044.32 11/01/95 1,052.09 1,044.27 11/02/95 1,052.46 1,044.25 11/03/95 1,052.56 1,044.29 11/04/95 1,052.61 1,044.66 11/05/95 1,052.60 1,044.76 11/06/95 1,052.61 1,044.81 11/07/95 1,052.63 1,044.80 11/08/95 1,052.64 1,044.81 11/09/95 1,052.64 1,044.83 11/10/95 1,052.64 1,044.84 11/11/95 1,052.65 1,044.84 11/12/95 1,052.65 1,044.84 11/13/95 1,052.61 1,044.85 11/14/95 1,052.60 1,044.85 11/15/95 1,052.59 1,044.81 11/16/95 1,052.59 1,044.80 1,052.58 1,044.79 1,044.79 1,044.78 Appendix B.Appendix ppendix B. ppendix

Appendix B B–3 (acre-ft) (+/- error) out (acre-ft) (acre-ft) (+/- error) (acre-ft) (acre-ft) (+/- error) (+/- Evaporation storage GW (acre-ft) (acre-ft) (+/- error) out SW (acre-ft) (acre-ft) (+/- error) in (acre-ft) (acre-ft) (+/- error) Precipitation SW Medina hydrologic Lake budget—Continued (acre-ft) Date 11/17/9511/18/9511/19/95 639.2411/20/9511/21/9511/22/95 95.8911/23/9511/24/9511/25/95 166.1811/26/9511/27/9511/28/9511/29/95 16.8911/30/9512/01/95 200.5912/02/95 202.7712/03/95 203.15 65.4512/04/95 192.06 20.5112/05/95 179.56 20.6212/06/95 177.54 20.6112/07/95 163.20 6.55 19.4712/08/95 147.35 18.20 63.4712/09/95 137.43 18.00 61.4912/10/95 135.45 16.55 61.49 33.5712/11/95 131.25 35.35 14.97 61.4912/12/95 126.60 13.98 6.35 59.5012/13/95 129.52 13.78 6.15 59.5012/14/95 135.47 5.04 13.35 6.15 59.5012/15/95 139.42 8.84 12.87 6.15 59.5012/16/95 143.88 13.13 5.95 59.50 20.4412/17/95 150.01 13.73 5.95 134.02 59.50 11.7712/18/95 146.04 14.12 5.95 59.5012/19/95 282 140.07 6.60 14.58 5.95 59.50 17.00 84.0912/20/95 136.05 15.19 5.95 5.11 59.50 28.87 39.0712/21/95 13.59 14.80 5.95 2.94 59.50 33.4512/22/95 133.35 14.20 5.95 28.20 59.50 62.31 12.6112/23/95 135.07 1.65 13.79 5.95 4.25 59.50 36.7312/24/95 139.04 5.86 419 5.95 7.22 59.50 23.9512/25/95 143.07 59.50 13.50 5.95 8.36 59.50 30.60 5512/26/95 149.02 153.00 15.58 182.08 422.61 13.67 5.95 59.5012/27/95 149.00 93 128.83 14.06 160.34 5.95 9.18 59.50 7412/28/95 41.90 148.98 14.47 5.95 5.99 20.63 1412/29/95 150.98 5.95 101.96 15.06 5.95 15.46 7.65 57.52 45.52 23 5.5012/30/95 -36 7.85 15.06 5.95 59.50 32.2112/31/95 16.18 1.42 9.30 15.06 -302.32 -60 5.95 59.50 30.47 7.4001/01/96 167.23 4.37 15.26 -22 5.16 59.50 36.60 1.4001/02/96 173.18 29.17 5.75 -51 59.50 24.03 57.52 35 -3.60 2.3001/03/96 147.39 1.96 74.52 -144 5.95 59.50 51.7401/04/96 47.36 133.49 0.35 57.52 -6.00 4.57 16.84 42.06 5.95 59.50 65.4201/05/96 131.46 1.09 39.58 -2.20 17.44 -54 5.95 9.15 57.52 131.46 77.19 7.29 140.60 -5.10 14.86 22.40 5.95 -14.40 6.01 5.75 3.50 -34 133.45 77.39 61.58 12.93 13.47 123.53 5.95 80.93 23.49 129.48 5.75 111.12 16.35 13.26 22.13 5.95 57.52 2 52.43 125.53 14 -5.40 13.26 75.99 -43 20.51 5.75 57.52 15.25 35.15 121.55 -40 -59.34 13.46 -36 23.77 20.85 57.52 10.05 -3.40 82.27 -0.90 12.47 -23 10.35 20.23 13.07 19.49 57.52 127.50 -77 13.11 6.91 86.12 12.67 5.75 57.52 10.08 0.20 16.47 133.45 103.39 -4.30 1.40 12.27 5.75 3.81 -40 57.52 31.77 48.08 -4.00 141.20 38.02 -3.60 102.11 17.20 5.75 -0.23 2.51 -249 57.52 -2.30 140.19 57.52 12.87 5.75 57.52 21.53 -7.70 118.35 1.73 -82 119.01 13.46 16.23 5.75 2.52 57.52 76.50 114.41 -4.00 14.23 -63 96.91 66.00 5.75 118.92 7.94 57.52 48.82 15.47 -24.90 110.42 14.11 98.51 -17 5.75 21.46 -7 5.75 51.83 11.92 5.75 57.52 29.75 71.52 -8.20 81 -40 88.12 15.33 11.53 5.75 57.52 41.62 19.19 -3 15.84 17.74 12.21 -6.30 -24.77 11.13 -39 5.75 57.52 32.01 243.64 17.42 -1.70 20.24 5.37 57.52 -0.70 25.59 17.88 -127 31.82 23.50 5.75 109.11 57.52 23.06 -4.00 8.10 10.41 5.75 -134 57.52 28.75 -0.30 38.30 131.31 35.38 -3.90 5.75 8.00 57.52 38.82 187.48 96.46 -70 5.75 -12.70 6.40 21.73 -42 7.96 122.59 5.75 5.77 -150 -25.22 -13.40 4.75 17.29 5.75 7.19 12.83 82.39 100.69 -70 5.75 9.70 70.94 20.78 16.48 135.74 -7.00 117.69 -85 -4.20 16.77 -15.00 -86 29.30 -73 59.98 200.83 1.19 16.39 -69 18.55 3.21 23.84 -103 17.73 -7.00 46.88 33.93 36.92 138.41 -8.50 182.32 -8.60 46.45 15.00 25.80 -7.30 -6.90 -3 -10.30 -28 5.96 111.94 -44 11.72 -162 18.21 135.34 23.29 23.49 150.66 -207 121.90 108.27 -0.30 128.21 -2.80 17.95 -88 -16.20 -4.40 18.10 -9 -20.70 18.62 17.04 17.11 19.59 -8.80 108.93 68.23 91.10 56.75 -0.90 207.85 40.57 14.15 15.25 121.05 23.86 28.79 15.02 16.70 17.18 Appendix B.Appendix

B–4 Hydrogeology, Hydrologic Budget, and Water Chemistry of the Medina Lake area, Texas -48.45 -70.75 -88.33 (acre-ft/d) Average storage Average 45.06 44.66 52.68 (acre-ft/d) Average evaporationAverage out 59.32 57.52 57.52 (acre-ft/d) Average SWAverage in 140.05 142.30 130.70 (acre-ft/d) Average SWAverage 1.53 5.08 10.26 (acre-ft/d) Average precipitationAverage 1,044.87 1,044.66 1,044.51 sea level) Average stage (ft above mean above (ft out 21.87 22.30 23.54 (+/- error) (acre-ft/d) 85.64 121.13 113.92 (acre-ft/d) sea level) (ft above mean Stage Average GW Medina hydrologic Lake budget—Continued (ft above (ft BMA datum) BMA Date 12/17/95 1,052.55 1,044.75 12/29/95 1,052.34 1,044.54 01/04/96 1,052.22 1,044.42 11/17/9511/18/95 1,052.6411/19/95 1,052.7411/20/95 1,052.75 1,044.84 11/21/95 1,052.77 1,044.94 11/22/95 1,052.79 1,044.95 11/23/95 1,052.79 1,044.97 11/24/95 1,052.79 1,044.99 11/25/95 1,052.79 1,044.99 11/26/95 1,052.77 1,044.99 11/27/95 1,052.77 1,044.99 11/28/95 1,052.78 1,044.97 11/29/95 1,052.76 1,044.97 11/30/95 1,052.73 1,044.98 12/01/95 1,052.72 1,044.96 12/02/95 1,052.71 1,044.93 12/03/95 1,052.71 1,044.92 12/04/95 1,052.72 1,044.91 12/05/95 1,052.71 1,044.91 12/06/95 1,052.70 1,044.92 12/07/95 1,052.69 1,044.91 12/08/95 1,052.68 1,044.90 12/09/95 1,052.67 1,044.89 12/10/95 1,052.66 1,044.88 12/11/95 1,052.60 1,044.87 12/12/95 1,052.58 1,044.86 12/13/95 1,052.57 1,044.80 12/14/95 1,052.57 1,044.78 12/15/95 1,052.56 1,044.77 12/16/95 1,052.56 1,044.77 1,052.55 1,044.76 12/18/95 1,044.76 12/19/95 1,052.56 1,044.75 12/20/95 1,052.5412/21/95 1,052.51 1,044.76 12/22/95 1,052.49 1,044.74 12/23/95 1,052.48 1,044.71 12/24/95 1,052.45 1,044.69 12/25/95 1,052.43 1,044.68 12/26/95 1,052.41 1,044.65 12/27/95 1,052.40 1,044.63 12/28/95 1,052.38 1,044.61 1,052.36 1,044.60 12/30/95 1,044.58 12/31/95 1,052.34 1,044.56 01/01/96 1,052.3301/02/96 1,052.32 1,044.54 01/03/96 1,052.28 1,044.53 1,052.24 1,044.52 01/05/96 1,044.48 1,052.22 1,044.44 1,044.42 Appendix B.

Appendix B B–5 (acre-ft) (+/- error) out (acre-ft) (acre-ft) (+/- error) (acre-ft) (acre-ft) (+/- error) (+/- Evaporation storage GW (acre-ft) (acre-ft) (+/- error) out SW (acre-ft) (acre-ft) (+/- error) in (acre-ft) (acre-ft) (+/- error) Precipitation SW Medina hydrologic Lake budget—Continued (acre-ft) Date 01/06/9601/07/9601/08/9601/09/9601/10/9601/11/9601/12/9601/13/9601/14/9601/15/9601/16/9601/17/9601/18/9601/19/96 106.4301/20/96 104.4501/21/96 108.4001/22/96 110.38 10.7301/23/96 112.36 10.5301/24/96 110.40 10.9201/25/96 106.41 11.1201/26/96 102.45 11.32 57.5201/27/96 102.45 11.13 57.5201/28/96 104.03 10.73 57.5201/29/96 103.83 10.33 57.5201/30/96 104.07 101.16 10.33 5.7501/31/96 101.87 138.84 10.48 5.7502/01/96 100.26 113.06 10.45 5.7502/02/96 113.06 99.07 10.48 5.75 10.1202/03/96 101.06 113.06 119.82 10.26 13.8802/04/96 102.84 113.06 10.11 11.31 52.4502/05/96 105.02 113.06 11.31 36.42 10.0102/06/96 105.02 107.11 10.20 11.31 29.96 19.91 26.0002/07/96 101.06 10.38 95.21 11.3102/08/96 13.11 101.16 98.88 10.60 11.3102/09/96 10.60 96.28 9.10 115.04 10.7102/10/96 -103 115.04 3.90 10.20 93.90 4.9802/11/96 115.04 91.93 9.52 -259 10.1202/12/96 115.04 9.98 91.91 10.0402/13/96 -141 11.50 105.12 9.71 87.97 -10.30 -12.09 11.5002/14/96 87.93 105.12 9.46 87.97 -76 11.5002/15/96 -25.90 9.26 91.95 11.50-39202/16/96 126.94 9.26 -14.10 91.91 10.51 2.5102/17/96 140.83 -3.02 8.87 10.51 9.71 32.09 8.86 27.0802/18/96 140.83 -97 -7.60 8.87 89.91 -19.34 -128 253.4802/19/96 140.83 -39.20 9.27 93.88 12.69 -19702/20/96 146.78 155.46 -137 5.94 9.26 97.86 14.08 -113 -164 42.7602/21/96 103.81 172.56 33.94 14.08 2.43 117.02 -148 6.77 31.3902/22/96 -9.70 0 103.81 -12.80 108.95 162.64 -4.83 31.41 9.06 14.08 -13002/23/96 103.83 -19.70 126.94 9.46 14.68 -13.70 20.84 31.5802/24/96 -11.30 101.83 -16.40 117.02 1.48 10.69 9.85 10.45 17.26 52.27 -14.80 11.70 -155 -136 89.91 10.45 15.47 16.26 -155 7.85 27.35 -13.00 146.78 0 81.98 10.45 12.69 206.28 117.74 10.25 82.00 11.70 7.89 122.05 -188 -56 182.48 13.07 168.59 -15.50 85.96 -13.60 -15.50 -174 174.55 9.06 89.95 14.68 6.84 43.89 196.36 8.27 80.01 20.63 20.76 -18.80 19.01 196.36 8.27 82.04 -85 18.25 -269 16.86 -5.60 129.32 8.66 87.41 -17.40 17.45 162.14 94.94 -213 202.31 10.97 9.06 89.04 19.64 210.25 8.07 89.00 19.64 145.14 -26.90 208.26 -8.50 8.27 89.00 21.88 40.04 216.20 2.00 22.44 21.62 2.38 138.55 8.80 -21.30 89.00 20.23 -267 232.07 3.53 8.95 87.55 21.02 -124 -2.95 234.05 26.28 8.95 20.83 -153 172.18 80.50 234.05 8.94 25.36 16.68 21.62 -252 24.06 -26.70 0.50 -217 226.12 0.59 138.72 8.95 23.21 37.93 -12.40 212.23 0.88 8.81 23.40 -183 -0.74 25.56 -15.30 214.21 34.45 20.13 23.40 -226 -25.20 19.88 220.17 7.91 -21.70 -219 22.61 -177 28.08 33.42 148.43 234.05 21.22 -184 9.48 -180 50.15 -18.30 -206 245.95 21.42 -195 6.39 28.60 -22.60 -99 22.02 -21.90 -17.70 1.98 3.89 34.30 23.40 8.35 14.01 -18.40 -18.00 -444 12.54 -20.60 24.60 -19.50 -253 7.15 20.37 -9.90 -225 132.39 12.85 109.84 0.97 -311 -44.40 3.50 -253 19.91 105.74 116.42 -25.30 45.98 -295 5.09 -22.50 -76.03 30.17 26.59 -31.10 -253 3.21 -25.30 -294 293.67 27.18 4.98 30.33 11.49 -29.50 99.16 -276 31.52 -25.30 90.83 -221 147.35 -29.40 50.52 -225 60.73 -253 -349 34.52 112.36 -27.60 -22.10 31.82 39.74 97.10 141.29 -22.50 37.66 -25.30 -34.90 39.17 130.41 35.46 38.28 76.98 60.04 144.62 36.42 32.61 34.04 45.09 Appendix B.Appendix

B–6 Hydrogeology, Hydrologic Budget, and Water Chemistry of the Medina Lake area, Texas -112.67 -159.00 -225.43 -271.83 (acre-ft/d) Average storage Average 49.89 23.19 21.28 23.00 (acre-ft/d) Average evaporationAverage out 57.52 119.89 190.13 225.12 (acre-ft/d) Average SWAverage in 97.58 84.56 109.08 100.35 (acre-ft/d) Average SWAverage 0 0 0 0 (acre-ft/d) Average precipitationAverage 1,044.36 1,043.77 1,043.00 1,042.61 sea level) Average stage (ft above mean above (ft out 22.59 23.93 32.97 37.02 (+/- error) (acre-ft/d) 114.34 116.27 111.60 108.28 (acre-ft/d) sea level) (ft above mean Stage Average GW Medina hydrologic Lake budget—Continued (ft above (ft BMA datum) BMA Date 01/10/9601/11/96 1,052.0601/12/96 1,052.0301/13/96 1,051.99 1,044.26 01/14/96 1,051.95 1,044.23 01/15/96 1,051.92 1,044.19 01/16/96 1,051.89 1,044.15 01/17/96 1,051.86 1,044.12 01/18/96 1,051.83 1,044.09 01/19/96 1,051.83 1,044.06 01/20/96 1,051.74 1,044.03 1,051.71 1,044.03 1,043.94 1,043.91 01/29/9601/30/96 1,051.3801/31/96 1,051.3502/01/96 1,051.29 1,043.58 02/02/96 1,051.23 1,043.55 02/03/96 1,051.19 1,043.49 02/04/96 1,051.13 1,043.43 02/05/96 1,051.08 1,043.39 02/06/96 1,051.04 1,043.33 02/07/96 1,051.00 1,043.28 1,050.94 1,043.24 1,043.20 1,043.14 02/14/96 1,050.57 1,042.77 02/20/9602/21/96 1,050.18 1,050.11 1,042.38 1,042.31 01/06/9601/07/96 1,052.1901/08/96 1,052.1301/09/96 1,052.10 1,044.39 1,052.08 1,044.33 1,044.30 1,044.28 01/21/9601/22/96 1,051.6701/23/96 1,051.6401/24/96 1,051.63 1,043.87 01/25/96 1,051.58 1,043.84 01/26/96 1,051.54 1,043.83 01/27/96 1,051.52 1,043.78 01/28/96 1,051.46 1,043.74 1,051.41 1,043.72 1,043.66 1,043.61 02/08/9602/09/96 1,050.9002/10/96 1,050.8602/11/96 1,050.81 1,043.10 02/12/96 1,050.79 1,043.06 02/13/96 1,050.68 1,043.01 1,050.63 1,042.99 02/15/96 1,042.88 02/16/96 1,050.50 1,042.83 02/17/96 1,050.4402/18/96 1,050.37 1,042.70 02/19/96 1,050.31 1,042.64 1,050.24 1,042.57 1,042.51 02/22/96 1,042.44 02/23/96 1,050.0602/24/96 1,050.01 1,049.92 1,042.26 1,042.21 1,042.12 Appendix B.

Appendix B B–7 (acre-ft) (+/- error) out (acre-ft) (acre-ft) (+/- error) (acre-ft) (acre-ft) (+/- error) (+/- Evaporation storage GW (acre-ft) (acre-ft) (+/- error) out SW (acre-ft) (acre-ft) (+/- error) in (acre-ft) (acre-ft) (+/- error) Precipitation SW Medina hydrologic Lake budget—Continued (acre-ft) Date 02/25/9602/26/9602/27/9602/28/9602/29/9603/01/96 19.6203/02/96 227.2303/03/9603/04/9603/05/96 2.94 34.0803/06/9603/07/9603/08/96 101.3803/09/96 90.53 82.9903/10/96 80.8303/11/96 80.7703/12/96 10.20 9.0903/13/96 8.3403/14/96 101.26 8.1203/15/96 8.11 98.84 206.2803/16/96 94.51 240.0003/17/96 245.95 90.57 10.1803/18/96 245.95 96.4803/19/96 102.43 245.95 20.63 9.9303/20/96 106.43 24.00 9.49 24.6003/21/96 150.74 9.09 93.26 24.6003/22/96 9.68 79.38 10.28 24.6003/23/96 150.74 75.41 10.68 50.7003/24/96 150.74 96.39 -14.73 77.39 15.0703/25/96 150.74 9.38 -10.91 79.3803/26/96 150.74 148.76 7.99 81.56 15.07 -2.1903/27/96 12.67 144.79 7.59 81.34 15.07 24.1003/28/96 -3.68 7.79 81.20 15.07 23.88 22.9903/29/96 -2.73 134.88 7.99 79.16 15.07 14.88 63.6703/30/96 134.88 8.21 -300 -0.55 78.98 14.48 32.0603/31/96 134.88 -194 8.19 76.78 -307 31.0704/01/96 134.88 3.58 8.17 -11.43 74.84 -265 13.49 5.7504/02/96 134.88 9.55 7.96 70.91 13.49 -30.00 21.51 -8.3504/03/96 -249 146.78 7.94 151.38 65.36 -19.40 13.49 8.01 -30.7004/04/96 154.71 7.71 65.65 13.49 7.77 -26.5004/05/96 69.42 -2.86 166.61 -146 7.52 65.65 13.49 55.8004/06/96 73.41 204.30 -24.90 7.13 -2.09 65.45 371.62 14.68 24.06 5.38 37.8504/07/96 -210 204.30 6.58 -32.24 198.13 67.44 15.47 158.77 46.0504/08/96 -217 206.28 6.62 -190 16.66 -14.60 110.78 49.90 6.9904/09/96 218.18 13.95 6.62 20.43 21.23 7.3904/10/96 -134 52.46 230.08 -282 6.60 -21.00 29.72 77.38 86.01 20.43 6.02 -38 40.30 04/11/96 40.38 267.77 11.51 3.76 6.79 -21.70 79.36 20.63 -19.0004/12/96 37.16 297.52 8.60 12.48 80.95 21.82 247.93 -392 73.5304/13/96 297.52 6.91 -13.40 80.87 23.01 226.12 5.31 -28.2004/14/96 35.93 -227 297.52 73.84 9.43 126.04 7.79 -3.80 83.31 26.78 -226 28.80 0.94 283.64 129.70 104.91 7.99 73.98 29.75 141.25 -196 -39.20 2.15 24.79 24.02 8.14 66.05 29.75 72.87 1.73 22.61 -252 8.12 -22.70 68.03 88.09 29.75 28.83 38.56 92.26 7.45 -22.60 2.36 240.00 8.38 -29.85 -122 28.36 7.20 29.13 50.76 26.23 -19.60 26.06 275.70 7.46 91.85 -174 26.51 294.59 125.55 275.70 18.22 71.59 6.67 -25.20 -162 11.00 22.47 143.40 273.72 147.44 47.71 50.51 6.87 -232 24.00 9.64 178.51 120.48 19.24 -12.20 139.04 -231 273.72 12.69 4.37 -235 27.57 90.84 -17.40 127.14 273.72 44.73 88.62 9.25 12.62 27.57 6.63 -385 17.90 -16.20 115.64 273.72 175.27 14.40 27.37 2.75 28.24 11.93 -23.20 103.14 -355 214.21 17.85 29.71 -23.10 13.96 27.37 -23.50 -336 21.61 1.09 53.02 22.71 12.77 95.13 27.37 27.97 -38.50 92.03 -344 176.53 -425 7.87 176.53 92.87 11.63 27.37 30.15 14.40 69.68 -339 -343 176.53 -35.50 10.36 21.42 44.63 -33.60 97.43 200.33 57.34 -290 20.80 5.40 76.88 -235 19.46 0.59 226.12 9.56 -34.40 24.77 -42.50 17.65 17.65 44.50 168.78 1.97 238.02 9.33 -33.90 24.69 -34.30 3.60 17.65 10.38 11.16 157.26 236.03 32.01 20.03 14.33 -29.00 -23.50 -205 32.65 2.78 82.83 4.87 41.54 22.61 245.95 11.12 48.44 198.78 -301 85.62 23.80 56.50 22.32 -241 251.90 206.26 2.59 43.97 96.13 -300 23.60 14.17 -132 -20.50 45.28 12.22 -72.04 0.70 -373 53.56 24.60 -351 52.94 28.38 -30.10 46.44 14.13 -24.10 25.19 44.45 5.58 -30.00 -306 45.67 8.00 -13.20 3.54 22.51 43.80 -37.30 -199 42.08 20.77 3.06 -35.10 -114 7.10 32.27 96.78 -283 -30.60 31.85 56.48 2.00 -184 62.51 168.13 5.63 -19.90 32.96 163.12 -402 106.77 -11.40 -102 41.64 -28.30 8.07 37.68 14.12 -18.40 87.95 -310 42.89 40.46 -243 -40.20 47.27 50.04 46.48 -10.20 -27.18 -282 209.70 -348 -31.00 41.67 136.71 -24.30 328.49 30.04 26.96 -28.20 -25.36 36.10 -34.80 179.62 29.50 47.13 87.59 28.79 98.91 132.49 40.83 35.87 39.45 46.17 Appendix B.Appendix

B–8 Hydrogeology, Hydrologic Budget, and Water Chemistry of the Medina Lake area, Texas -270.29 -209.50 -214.60 -194.00 -285.82 -304.40 -202.83 (acre-ft/d) Average storage Average 10.18 36.96 48.88 25.91 40.45 28.49 31.82 (acre-ft/d) Average evaporationAverage out 236.03 174.88 142.81 141.22 243.07 257.45 189.09 (acre-ft/d) Average SWAverage in 85.59 96.18 95.60 79.02 71.95 75.27 116.81 (acre-ft/d) Average SWAverage 0 0 0 0 8.76 41.14 33.02 (acre-ft/d) Average precipitationAverage 1,042.12 1,041.75 1,041.49 1,041.21 1,040.72 1,039.89 1,039.37 sea level) Average stage (ft above mean above (ft

out 37.38 33.47 33.04 26.68 40.60 41.80 34.82 (+/- error) (acre-ft/d) 74.25 109.66 134.98 118.50 105.88 102.48 131.75 (acre-ft/d) sea level) (ft above mean Stage Average GW Medina hydrologic Lake budget—Continued (ft above (ft BMA datum) BMA Date 02/28/96 1,049.68 1,041.88 03/05/96 1,049.39 1,041.59 03/10/96 1,049.11 1,041.31 03/15/96 1,048.89 1,041.09 03/26/96 1,048.03 1,040.23 04/05/96 1,047.31 1,039.51 04/11/96 1,046.94 1,039.14 02/25/9602/26/96 1,049.8502/27/96 1,049.79 1,049.73 1,042.05 02/29/96 1,041.99 03/01/96 1,049.61 1,041.93 03/02/96 1,049.5703/03/96 1,049.52 1,041.81 03/04/96 1,049.47 1,041.77 1,049.42 1,041.72 03/06/96 1,041.67 03/07/96 1,049.38 1,041.62 03/08/96 1,049.3103/09/96 1,049.22 1,041.58 1,049.16 1,041.51 03/11/96 1,041.42 03/12/96 1,049.06 1,041.36 03/13/96 1,049.0003/14/96 1,048.97 1,041.26 1,048.93 1,041.20 03/16/96 1,041.17 03/17/96 1,048.83 1,041.13 03/18/96 1,048.7703/19/96 1,048.71 1,041.03 03/20/96 1,048.62 1,040.97 03/21/96 1,048.53 1,040.91 03/22/96 1,048.44 1,040.82 03/23/96 1,048.36 1,040.73 03/24/96 1,048.27 1,040.64 03/25/96 1,048.20 1,040.56 1,048.14 1,040.47 03/27/96 1,040.40 03/28/96 1,047.94 1,040.34 03/29/96 1,047.8903/30/96 1,047.81 1,040.14 03/31/96 1,047.75 1,040.09 04/01/96 1,047.67 1,040.01 04/02/96 1,047.57 1,039.95 04/03/96 1,047.48 1,039.87 04/04/96 1,047.40 1,039.77 1,047.34 1,039.68 04/06/96 1,039.60 04/07/96 1,047.28 1,039.54 04/08/96 1,047.2004/09/96 1,047.16 1,039.48 04/10/96 1,047.05 1,039.40 1,047.02 1,039.36 04/12/96 1,039.25 04/13/96 1,046.87 1,039.22 04/14/96 1,046.80 1,046.71 1,039.07 1,039.00 1,038.91 Appendix B.

Appendix B B–9 (acre-ft) (+/- error) out (acre-ft) (acre-ft) (+/- error) (acre-ft) (acre-ft) (+/- error) (+/- Evaporation storage GW (acre-ft) (acre-ft) (+/- error) out SW (acre-ft) (acre-ft) (+/- error) in (acre-ft) (acre-ft) (+/- error) Precipitation SW Medina hydrologic Lake budget—Continued (acre-ft) Date 04/15/9604/16/9604/17/9604/18/9604/19/9604/20/9604/21/9604/22/9604/23/9604/24/96 29.6204/25/9604/26/9604/27/9604/28/96 4.44 86.9204/29/96 79.2004/30/96 195.05 73.3105/01/96 65.1605/02/96 55.54 8.73 59.2105/03/96 7.97 29.26 59.1505/04/96 7.38 57.9205/05/96 6.56 5.6005/06/96 275.70 5.96 55.1805/07/96 289.59 49.43 5.96 53.2205/08/96 289.59 5.85 53.2005/09/96 287.60 53.45 27.57 339.1705/10/96 299.50 5.56 102.60 51.29 28.9605/11/96 4.99 339.17 5.36 28.9605/12/96 339.17 5.36 51.33 28.7605/13/96 33.92 107.55 5.39 15.39 53.22 29.9505/14/96 339.17 5.17 55.20 33.92 339.17 65.4305/15/96 339.17 53.20 33.92 38.8005/16/96 337.19 5.18 47.29 26.89 11.0705/17/96 337.19 47.60 25.85 5.36 45.26 33.9205/18/96 337.19 16.36 8.56 33.92 5.56 45.26 33.92 25.8905/19/96 5.36 43.28 33.72 9.7005/20/96 339.17 9.12 -264 4.77 43.40 33.72 2.7705/21/96 4.81 339.17 6.46 4.57 33.72 -451 46.6505/22/96 2.14 339.17 4.57 11.14 52.56 6.47 61.9105/23/96 -379 345.12 4.37 47.90 33.92 -26.40-36105/24/96 2.28 -331 357.02 4.38 49.55 33.92 -437 58.5105/25/96 -45.10 368.93 11.66 51.07 -220 33.92 13.1905/26/9610.91 -366 370.91 15.48 2.79 5.31 -37.90 52.92 34.5105/27/96 372.89 -36.10 145.70 4.82 -33.10 -32.34 52.66 -367 35.7005/28/96 -43.70 378.84 14.63 5.00 52.74 36.89 -361 53.66 175.19 -22.0005/29/96 5.14 190.10 -36.60 48.67 37.09 3.30 -325 -321 30.43 2.7305/30/96 305.45 123.92 5.32 44.71 37.29 36.42 -36.70 47.5005/31/96 180.50 9.46 5.29 40.78 37.88 97.49 -398 157.1406/01/96 -36.10 180.50 2.56 13.42 56.60 5.30 28.51 36.85 -28.8606/02/96 -32.50 -429 -32.10 180.50 -358 4.89 32.93 30.55 7.61 49.23 60.08 41.8206/03/96 180.50 -321 4.50 32.85 18.05 41.62 -39.80 2.36 76.62 44.42 180.50 56.15 4.11 30.68 18.05 -320 0.64 180.50 30.68 7.78 30.36 37.70 3.71 -42.90 28.70 18.05 -35.80 215.16 -22.86 -620 50.67 180.50 6.27 3.32 26.92 18.05 -32.10 12.69 180.50 6.24 3.31 26.98 50.37 -366 18.05 -32.00 216.20 55.76 3.09 26.66 -357 18.05 51.19 3.09 1.95 251.90 129.91 55.40 2.89 49.75 -62.00 18.05 32.29 -112.54 287.60 2.72 30.59 18.05 3.17 38.24 -36.60 355.04 2.73 30.59 21.62 54.44 -35.70 -19.62 384.79 2.69 30.37 -391 25.19 -388 54.91 305.59 59.45 28.76 -352 3.24 53.72 -293 3.08 35.50 -395 3.84 64.44 64.61 3.08 48.82 46.18 38.48 66.08 -39.10 -38.80 44.70 3.05 34.27 71.30 68.48 -35.20 13.43 -29.30 51.12 -39.50 16.11 50.65 -240 47.79 16.52 4.63 50.72 65.97 -62 47.77 17.12 3.44 -277 -137 12.78 -240 27.41 -308 -24.00 11.95 -240 -343 16.49 54.65 -377 -373 -6.20 -27.70 -13.70 -406 11.98 -24.00 -30.80 42.78 56.41 -236 -24.00 -34.30 59.59 -339 -37.70 -37.30 56.67 -48.54 -40.60 41.24 14.10 2.99 107.77 -23.60 36.89 14.90 101.50 -33.90 11.92 52.49 14.17 15.24 89.48 26.79 10.31 100.20 -439 -462 46.08 39.42 -133.98 -568 9.22 43.97 13.12 -81.08 2.98 -535 48.30 3.81 -600 23.92 51.48 -43.90 -46.20 11.52 44.40 38.60 -56.80 -390 -392 53.96 -53.50 -133 -60.00 -495 5.98 -495 -39.00 9.65 -39.20 -13.30 -49.50 -49.50 -489 131 -48.90 13.10 Appendix B.Appendix

B–10 Hydrogeology, Hydrologic Budget, and Water Chemistry of the Medina Lake area, Texas -316.33 -348.25 -391.50 -313.40 (acre-ft/d) Average storage Average 48.71 28.48 40.58 60.77 (acre-ft/d) Average evaporationAverage out 256.20 321.57 341.65 223.34 (acre-ft/d) Average SWAverage in 95.48 59.83 51.80 40.79 (acre-ft/d) Average SWAverage 0 3.70 0 24.38 (acre-ft/d) Average precipitationAverage 1,038.94 1,038.29 1,037.36 1,035.69 sea level) Average stage (ft above mean above (ft out 44.40 48.68 55.71 41.99 (+/- error) (acre-ft/d) 61.73 85.45 70.08 106.91 (acre-ft/d) sea level) (ft above mean Stage Average GW Medina hydrologic Lake budget—Continued (ft above (ft BMA datum) BMA Date 04/17/96 1,046.41 1,038.61 04/25/9604/26/96 1,045.65 1,045.54 1,037.85 1,037.74 05/04/9605/05/96 1,044.6605/06/96 1,044.5605/07/96 1,044.45 1,036.86 05/08/96 1,044.33 1,036.76 05/09/96 1,044.23 1,036.65 05/10/96 1,044.15 1,036.53 05/11/96 1,044.08 1,036.43 05/12/96 1,044.06 1,036.35 05/13/96 1,043.98 1,036.28 05/14/96 1,043.91 1,036.26 05/15/96 1,043.84 1,036.18 05/16/96 1,043.73 1,036.11 1,043.69 1,036.04 1,035.93 1,035.89 05/21/9605/22/96 1,043.2005/23/96 1,043.1005/24/96 1,042.97 1,035.40 05/25/96 1,042.80 1,035.30 05/26/96 1,042.64 1,035.17 05/27/96 1,042.46 1,035.00 05/28/96 1,042.32 1,034.84 05/29/96 1,042.28 1,034.66 05/30/96 1,042.13 1,034.52 05/31/96 1,041.98 1,034.48 06/01/96 1,041.86 1,034.33 06/02/96 1,041.74 1,034.18 06/03/96 1,041.59 1,034.06 1,041.63 1,033.94 1,033.79 1,033.83 04/15/9604/16/96 1,046.63 1,046.5104/18/96 1,038.83 04/19/96 1,046.32 1,038.71 04/20/96 1,046.2604/21/96 1,046.16 1,038.52 04/22/96 1,046.06 1,038.46 04/23/96 1,045.94 1,038.36 04/24/96 1,045.85 1,038.26 1,045.75 1,038.14 1,038.05 04/27/96 1,037.95 04/28/96 1,045.4204/29/96 1,045.3304/30/96 1,045.24 1,037.62 05/01/96 1,045.15 1,037.53 05/02/96 1,044.98 1,037.44 05/03/96 1,044.87 1,037.35 1,044.77 1,037.18 1,037.07 1,036.97 05/17/9605/18/96 1,043.6005/19/96 1,043.5005/20/96 1,043.39 1,035.80 1,043.27 1,035.70 1,035.59 1,035.47 Appendix B.

Appendix B B–11 (acre-ft) (+/- error) out (acre-ft) (acre-ft) (+/- error) (acre-ft) (acre-ft) (+/- error) (+/- Evaporation storage GW (acre-ft) (acre-ft) (+/- error) out SW (acre-ft) (acre-ft) (+/- error) in (acre-ft) (acre-ft) (+/- error) Precipitation SW Medina hydrologic Lake budget—Continued (acre-ft) Date 06/04/9606/05/9606/06/9606/07/9606/08/9606/09/9606/10/9606/11/9606/12/9606/13/9606/14/9606/15/9606/16/9606/17/96 30.3106/18/96 26.3406/19/96 22.3306/20/96 24.2206/21/96 3.04 22.0806/22/96 2.65 20.1506/23/96 2.25 19.8906/24/96 2.43 20.2306/25/96 2.21 22.1406/26/96 2.02 19.9506/27/96 2.00 164.55 20.1506/28/96 2.03 18.17 53.9706/29/96 2.22 14.9606/30/96 2.00 24.68 14.5207/01/96 2.02 14.9007/02/96 8.10 1.82 14.1007/03/96 1.50 15.3307/04/96 15.85 1.46 14.7607/05/96 1.50 14.6407/06/96 19.16 1.42 10.2307/07/96 56.45 1.54 10.4307/08/96 1.60 64.97 1.4807/09/96 86.04 1.47 1.9307/10/96 56.75 1.03 24.36 14.1107/11/96 43.72 1.05 20.39 16.24 40.4507/12/96 56.68 296.44 19.80 21.5107/13/96 79.43 15.99 14.1907/14/96 -489 54.56 2.45 14.00 10.9307/15/96 -580 47.64 6.07 2.05 44.47 13.61 14.1707/16/96 -579 40.60 1.99 12.61 19.8607/17/96 -355 40.34 1.61 -48.90 11.62 13.6407/18/96 -446 53.37 1.41 -58.00 10.43 11.9107/19/96 -413 52.85 12.30 8.65 1.37 -57.90 10.63 10.1507/20/96 -733 38.03 1.27 -35.50 10.09 9.8407/21/96 -535 39.72 1.17 -44.60 13.34 9.2407/22/96 -472 58.60 1.05 -41.30 13.2107/23/96 1.29 -472 0.87 40.12 1.07 -73.30 28.11 9.51 -469 31.72 -53.50 11.48 0.99 9.93 -528 54.60 -47.20 10.95 14.65 31.68 0.93 -530 56.43 -47.20 11.42 10.03 45.80 -46.90 -525 11.03 7.03 7.93 1.17 -52.80 -493 13.65 9.64 -523 1.11 -53.00 7.92 14.11 8.85 -734 43.45 1.15 11.45 -52.50 8.23 -465 37.92 1.11 -455 -49.30 7.85 -461 41.51 -52.30 0.97 7.46 -435 -601 218.18 35.02 -73.40 10.86 0.89 7.04 -536 245.95 30.23 -46.50 0.83 -45.50 6.43 9.48 297.52 37.31 -46.10 10.38 0.79 6.01 32.34 -43.50 -60.10 315.37 21.82 0.75 6.05 8.76 -473 31.61 -53.60 321.32 24.60 0.71 7.56 47.96 -499 329.26 29.75 61.25 27.21 0.65 9.33 -472 47.37 335.21 0.61 8.08 31.54 -47.30 -578 349.09 45.79 64.66 0.61 7.90 32.13 -563 11.99 360.99 53.93 52.47 -49.90 32.93 15.31 -47.20 -447 11.84 374.88 6.80 48.78 33.52 -469 388.76 -57.80 11.45 34.91 52.81 16.17 50.20 -557 390.74 -56.30 13.48 36.10 -554 75.60 13.12 -572 -44.70 37.49 -887 -113 64.70 12.20 -46.90 38.88 65.73 -517 13.20 12.55 -227 -55.70 39.07 69.73 -55.40 -546 18.90 -398 -57.20 70.31 -88.70 -11.30 16.17 -226 66.57 16.43 -51.70 -485 -22.70 -433 55.33 17.43 -54.60 -39.80 -440 48.98 17.58 -22.60 -392 16.64 -439 -48.50 -43.30 13.83 -44.90 -421 -44.00 12.24 111.01 -510 -39.20 -109.27 -481 -43.90 -402 35.41 -42.10 77.07 -404 48.60 -51.00 51.92 39.32 -48.10 6.28 -40.20 45.92 55.03 -40.40 57.68 9.63 85.74 53.69 45.98 57.63 -36.08 -29.67 57.41 64.91 63.22 57.61 57.53 Appendix B.Appendix

B–12 Hydrogeology, Hydrologic Budget, and Water Chemistry of the Medina Lake area, Texas -331.29 -443.60 (acre-ft/d) Average storage Average 60.29 62.18 (acre-ft/d) Average evaporationAverage out 294.69 372.89 (acre-ft/d) Average SWAverage in 9.71 6.60 (acre-ft/d) Average SWAverage 0 0 (acre-ft/d) Average precipitationAverage 1,026.95 1,026.07 sea level) Average stage (ft above mean above (ft out 47.37 60.13 (+/- error) (acre-ft/d) 13.98 15.12 (acre-ft/d) sea level) (ft above mean Stage Average GW Medina hydrologic Lake budget—Continued (ft above (ft BMA datum) BMA Date 07/19/96 1,034.21 1,026.41 06/04/9606/05/96 1,041.4806/06/96 1,041.3006/07/96 1,041.12 1,033.68 06/08/96 1,041.01 1,033.50 06/09/96 1,040.87 1,033.32 06/10/96 1,040.74 1,033.21 06/11/96 1,040.51 1,033.07 06/12/96 1,040.34 1,032.94 06/13/96 1,040.19 1,032.71 06/14/96 1,040.04 1,032.54 06/15/96 1,039.89 1,032.39 06/16/96 1,039.72 1,032.24 06/17/96 1,039.55 1,032.09 06/18/96 1,039.38 1,031.92 06/19/96 1,039.22 1,031.75 06/20/96 1,039.05 1,031.58 06/21/96 1,038.81 1,031.42 06/22/96 1,038.66 1,031.25 06/23/96 1,038.51 1,031.01 06/24/96 1,038.31 1,030.86 06/25/96 1,038.13 1,030.71 06/26/96 1,037.98 1,030.51 06/27/96 1,037.83 1,030.33 06/28/96 1,037.67 1,030.18 06/29/96 1,037.51 1,030.03 06/30/96 1,037.35 1,029.87 07/01/96 1,037.15 1,029.71 07/02/96 1,036.96 1,029.55 07/03/96 1,036.81 1,029.35 07/04/96 1,036.65 1,029.16 07/05/96 1,036.46 1,029.01 07/06/96 1,036.27 1,028.85 07/07/96 1,035.96 1,028.66 07/08/96 1,035.78 1,028.47 07/09/96 1,035.59 1,028.16 07/10/96 1,035.39 1,027.98 07/11/96 1,035.35 1,027.79 07/12/96 1,035.18 1,027.59 07/13/96 1,035.10 1,027.55 07/14/96 1,034.96 1,027.38 07/15/96 1,034.88 1,027.30 07/16/96 1,034.81 1,027.16 07/17/96 1,034.65 1,027.08 07/18/96 1,034.51 1,027.01 1,034.36 1,026.85 07/20/96 1,026.71 07/21/96 1,034.02 1,026.56 07/22/96 1,033.8507/23/96 1,033.71 1,026.22 1,033.56 1,026.05 1,025.91 1,025.76 Appendix B.

Appendix B B–13 (acre-ft) (+/- error) out (acre-ft) (acre-ft) (+/- error) (acre-ft) (acre-ft) (+/- error) (+/- Evaporation storage GW (acre-ft) (acre-ft) (+/- error) out SW (acre-ft) (acre-ft) (+/- error) in (acre-ft) (acre-ft) (+/- error) Precipitation SW Medina hydrologic Lake budget—Continued (acre-ft) Date 07/24/9607/25/9607/26/9607/27/9607/28/9607/29/9607/30/9607/31/9608/01/9608/02/9608/03/9608/04/9608/05/9608/06/96 6.0508/07/96 6.1708/08/96 8.6308/09/96 9.9008/10/96 0.6108/11/96 6.29 0.6308/12/96 6.49 0.88 6.2908/13/96 1.00 6.0708/14/96 0.64 5.6708/15/96 0.66 5.4908/16/96 0.6408/17/96 5.16 0.6108/18/96 5.08 0.58 4.8808/19/96 0.56 4.8808/20/96 0.53 4.8408/21/96 0.52 4.6608/22/96 0.50 89.5008/23/96 4.62 0.5008/24/96 4.62 0.49 56.68 4.4408/25/96 0.47 13.43 58.92 4.4408/26/96 53.55 0.47 44.65 5.2808/27/96 40.65 0.47 54.78 5.3808/28/96 8.50 122.09 0.4508/29/96 5.08 8.84 0.4508/30/96 4.98 13.39 7.74 6.70 0.54 5.0808/31/96 10.16 8.22 18.31 172.42 0.55 5.1209/01/96 6.03 326.51 0.52 5.1609/02/96 6.62 -426 0.51 0.8509/03/96 6.55 -576 25.86 0.52 92.6909/04/96 6.37 14.30 9.86 48.98 0.5309/05/96 0.62 0.53 -42.6009/06/96 0.68 29.81 -57.60 13.9009/07/96 15.43 0.68 108.52 0.6809/08/96 1.46 18.11 1.01 -53809/09/96 -538 18.4909/10/96 241.98 4.47 -459 16.28 16.50 75.43 09/11/96 1.57 122.98 -502 -53.80 1.93 120.99 67.44 -498 -53.80 -510 1.87 26.90 24.20 41.92 -45.90 25.59 63.33 -469 1.67 8.69 12.30 -50.20 29.75 -444 35.33 12.10 -49.80 6.74 31.74 -573 26.78 26.58 -51.00 10.48 2.78 -507 38.48 29.75 2.60 14.77 -46.90 6.38 -555 47.10 29.75 29.82 31.74 16.82 -44.40 122.62 2.98 -452 3.72 56.76 10.74 -57.30 3.17 19.69 -504 2.75 6.65 -281 96.83 59.96 -50.70 19.07 -498 9.62 2.98 89.45 57.34 31.74 3.69 -55.50 29.75 11.78 29.75 -679 2.98 12.30 74.78 7.45 3.17 4.21 -45.20 14.19 25.59 -463 62.08 27.69 29.75 2.68 -50.40 -28.10 -403 14.99 4.92 11.59 9.72 57.72 4.77 29.75 -49.80 -476 14.33 -193 -480 9.10 3.17 -476 2.98 31.53 -67.90 -415 -216 2.98 -691 7.56 -445 38.53 29.75 14.73 -46.30 6.40 -40.30 6.27 6.92 2.98 -445 -72 -120 -530 2.90 -47.60 5.83 -19.30 2.98 -419 29.75 -48.00 -47.60 -41.50 -21.60 7.88 29.75 13.01 -69.10 -44.50 9.63 2.98 29.75 3.68 -120 -44.50 -561 -12.00 -53.00 -7.20 29.75 20.63 -41.90 48 2.98 29.75 1.80 127.39 -24 2.98 3.25 -12.00 -56.10 -24 2.98 -24 169.26 2.98 5.16 4.91 2.98 4.80 32.41 26.09 -2.40 96 252.50 23.48 -2.40 -2.40 16.55 24 253.30 -120 -18.80 29.41 -48 9.60 145.65 -27.78 49.44 2.40 -12.00 -72 8.96 -113.85 -4.80 17.27 10.50 72 -7.20 -39.06 -48 10.98 24 24 7.20 -48 7.42 -4.80 -48 2.40 2.40 -4.80 -4.80 Appendix B.Appendix

B–14 Hydrogeology, Hydrologic Budget, and Water Chemistry of the Medina Lake area, Texas (acre-ft/d) Average storage Average (acre-ft/d) Average evaporationAverage out (acre-ft/d) Average SWAverage in (acre-ft/d) Average SWAverage (acre-ft/d) Average precipitationAverage sea level) Average stage (ft above mean above (ft out (+/- error) (acre-ft/d) (acre-ft/d) sea level) (ft above mean Stage Average GW Medina hydrologic Lake budget—Continued (ft above (ft BMA datum) BMA Date 07/24/9607/25/96 1,033.4107/26/96 1,033.2007/27/96 1,033.00 1,025.61 07/28/96 1,032.80 1,025.40 07/29/96 1,032.63 1,025.20 07/30/96 1,032.45 1,025.00 07/31/96 1,032.26 1,024.83 08/01/96 1,032.07 1,024.65 08/02/96 1,031.90 1,024.46 08/03/96 1,031.73 1,024.27 08/04/96 1,031.51 1,024.10 08/05/96 1,031.32 1,023.93 08/06/96 1,031.11 1,023.71 08/07/96 1,030.94 1,023.52 08/08/96 1,030.74 1,023.31 08/09/96 1,030.55 1,023.14 08/10/96 1,030.29 1,022.94 08/11/96 1,030.11 1,022.75 08/12/96 1,030.00 1,022.49 08/13/96 1,029.81 1,022.31 08/14/96 1,029.54 1,022.20 08/15/96 1,029.38 1,022.01 08/16/96 1,029.19 1,021.74 08/17/96 1,029.00 1,021.58 08/18/96 1,028.82 1,021.39 08/19/96 1,028.64 1,021.20 08/20/96 1,028.47 1,021.02 08/21/96 1,028.30 1,020.84 08/22/96 1,028.07 1,020.67 08/23/96 1,027.85 1,020.50 08/24/96 1,027.77 1,020.27 08/25/96 1,027.68 1,020.05 08/26/96 1,027.65 1,019.97 08/27/96 1,027.60 1,019.88 08/28/96 1,027.59 1,019.85 08/29/96 1,027.58 1,019.80 08/30/96 1,027.53 1,019.79 08/31/96 1,027.55 1,019.78 09/01/96 1,027.59 1,019.73 09/02/96 1,027.58 1,019.75 09/03/96 1,027.59 1,019.79 09/04/96 1,027.56 1,019.78 09/05/96 1,027.51 1,019.79 09/06/96 1,027.49 1,019.76 09/07/96 1,027.52 1,019.71 09/08/96 1,027.50 1,019.69 09/09/96 1,027.51 1,019.72 09/10/96 1,027.52 1,019.70 09/11/96 1,027.50 1,019.71 1,027.48 1,019.72 1,019.70 1,019.68 Appendix B.

Appendix B B–15 (acre-ft) (+/- error) out (acre-ft) (acre-ft) (+/- error) (acre-ft) (acre-ft) (+/- error) (+/- Evaporation storage GW (acre-ft) (acre-ft) (+/- error) out SW (acre-ft) (acre-ft) (+/- error) in (acre-ft) (acre-ft) (+/- error) Precipitation SW Medina hydrologic Lake budget—Continued (acre-ft) Date 09/12/9609/13/9609/14/9609/15/96 20.3009/16/9609/17/96 151.7309/18/9609/19/96 3.0509/20/96 22.7609/21/9609/22/96 47.25 29.7109/23/9609/24/96 59.4009/25/96 53.2009/26/96 4.46 4.77 61.7009/27/96 43.2809/28/96 6.1409/29/96 198.94 5.36 170.30 107.5009/30/96 210.84 9.26 29.75 143.40 4.37 121.39 31.74 25.55 19.96 10.81 21.15 29.75 73.15 14.40 97.09 2.98 12.20 85.69 29.75 3.17 75.03 77.02 29.75 85.29 2.98 29.75 7.36 9.76 76.05 59.50 8.63 2.98 75.05 87.27 7.55 7.74 2.98 8.53 69.06 2.98 172.56 7.70 65.10 5.95 85.29 7.55 61.13 8.73 85.29 152.73 126.94 17.26 6.95 172.56 6.55 8.53 172.56 15.27 6.15 8.53 12.69 113.06 -118 17.26 113.06 17.26 126.94 71 11.31 -11.80 -47 11.31 12.69 -71 7.10 -24 -24 -4.70 24 -7.10 0 -24 -2.40 -166 -2.40 2.40 -70 -235 -2.40 0 -71 -71 -16.60 -142 -237 -23.50 -7.00 -7.10 -7.10 -210 -14.20 -233 -23.70 -24 -21.00 -23.30 -2.40 Appendix B.Appendix

B–16 Hydrogeology, Hydrologic Budget, and Water Chemistry of the Medina Lake area, Texas (acre-ft/d) Average storage Average (acre-ft/d) Average evaporationAverage out (acre-ft/d) Average SWAverage in (acre-ft/d) Average SWAverage (acre-ft/d) Average precipitationAverage sea level) Average stage (ft above mean above (ft out (+/- error) (acre-ft/d) (acre-ft/d) sea level) (ft above mean Stage Average GW Medina hydrologic Lake budget—Continued (ft above (ft BMA datum) BMA Date 09/12/9609/13/96 1,027.4609/14/96 1,027.4109/15/96 1,027.38 1,019.66 09/16/96 1,027.41 1,019.61 09/17/96 1,027.40 1,019.58 09/18/96 1,027.41 1,019.61 09/19/96 1,027.41 1,019.60 09/20/96 1,027.40 1,019.61 09/21/96 1,027.39 1,019.61 09/22/96 1,027.36 1,019.60 09/23/96 1,027.33 1,019.59 09/24/96 1,027.30 1,019.56 09/25/96 1,027.23 1,019.53 09/26/96 1,027.17 1,019.50 09/27/96 1,027.07 1,019.43 09/28/96 1,026.97 1,019.37 09/29/96 1,026.88 1,019.27 09/30/96 1,026.78 1,019.17 1,026.77 1,019.08 1,018.98 1,018.97 Appendix B.

Appendix B B–17 (acre-ft) (+/- error) (site 8) out out (acre-ft) , surface-water outflow; outflow; , surface-water out (acre-ft) (+/- error) (acre-ft) , surface-water inflow; SW inflow; , surface-water in (acre-ft) (+/- error) (acre-ft) (acre-ft) (+/- error) (site 8) Evaporationstorage GW out out SW (acre-ft) ading indicates budget period. acre-ft, acre-feet; SW acre-feet; acre-ft, period. budget indicates ading Appendix B (acre-ft) (+/- error) in (acre-ft) , ground-water outflow; ft, feet; BMA, Bexar-Medina-Atascosa Counties Water Control and Improvement District No. 1; 1; No. District Improvement and Control Water Counties Bexar-Medina-Atascosa BMA, feet; ft, outflow; ground-water , out Hydrogeology, Hydrologic Budget, Hydrogeology, Chemistry the of Water and Texas area, Lake Medina (acre-ft) (+/- error) (+/- Precipitation SW Diversion hydrologic Lake budget Diversion Lake Diversion hydrologicLake budget—Continued (acre-ft) Date storage, change in storage; GW in storage; change storage, 10/01/9510/02/9510/03/9510/04/9510/05/9510/06/9510/07/9510/08/9510/09/9510/10/9510/11/9510/12/9510/13/9510/14/9510/15/95 64.8210/16/95 64.8210/17/95 64.8010/18/95 64.78 6.5510/19/95 64.78 6.5510/20/95 64.78 6.5510/21/95 64.78 6.5410/22/95 64.78 111.87 6.5410/23/95 64.78 107.90 6.5410/24/95 64.78 144.59 6.5410/25/95 90.55 165.82 6.54 11.19 142.1210/26/95 158.88 6.54 10.79 165.8910/27/95 154.31 6.54 14.46 165.9010/28/95 153.12 9.12 16.58 165.90 14.2810/29/95 150.15 15.89 207.53 16.6510/30/95 147.17 15.43 251.17 16.6510/31/95 145.98 15.31 251.17 16.65 1.2211/01/95 120.20 122.18 15.01 251.17 20.8211/02/95 17.55 14.72 142.02 251.17 25.1811/03/95 14.60 153.92 251.17 25.18 9.3111/04/95 158.08 12.02 253.15 0.18 25.18 12.2211/05/95 166.21 251.17 25.18 14.2011/06/95 2.63 194.18 251.15 25.18 15.3911/07/95 212.83 231.31 25.38 1.40 15.8111/08/95 223.54 140.07 171.81 25.18 16.6211/09/95 227.50 140.07 25.18 19.4211/10/95 122.22 227.50 140.07 23.19 21.2811/11/95 229.49 106.35 14.07 17.24 22.3511/12/95 231.47 136.11 14.07 22.7511/13/95 12.28 231.47 14.07 22.7511/14/95 211.64 10.70 22.95 158.48 181.88 13.67 23.15 64.68 169.98 23.15 64.68 97.19 167.21 21.16 64.66 15.85 18.19 45.82 62.68 6.53 152.53 17.00 -31.4 62.68 6.53 16.72 4.6 62.68 9.72 25.8 6.53 62.68 15.4 4.58 6.33 15.25 62.68 -4.7 6.33 48.60 6.5 62.68 0.7 10.2 6.33 51.17 3.9 60.69 34.5 6.33 51.57 2.3 60.69 23.4 6.33 53.95 60.69 1.0 4.86 12.0 6.33 42.64 1.5 60.69 5.12 6.13 56.73 6.0 5.2 5.16 6.13 86.48 2.0 3.5 5.40 6.13 87.67 2.1 1.8 102.74 4.26 6.13 2.8 0.9 100.76 5.67 -1.0 0.3 8.65 3.43 96.79 2.1 -17.7 0.3 8.77 10.27 -2.0 1.96 94.81 -17.6 0.4 102.74 10.08 -0.2 1.60 -26.9 1.68 -2.7 1.2 0.3 9.68 -0.3 0.86 2.26 116.7 -10.4 -2.6 9.48 10.27 0.49 0.37 -4.0 0.40 3.44 0.2 0.42 17.5 -1.6 0.57 2.29 35.4 0.66 0.09 1.26 27.3 70.1 0.86 22.0 45.6 27.5 5.3 0.57 10.5 -8.2 4.1 0.16 0.32 -21.6 3.3 6.8 -28.1 4.1 -1.2 -25.74 -29.4 -11.9 -3.2 -20.53 -27.7 -28.7 -4.2 -3.57 -23.23 -4.4 -1.8 9.91 -17.86 -4.2 -4.3 -18.83 9.28 -15.41 8.32 9.46 10.80 -8.99 12.49 -14.61 -7.07 12.55 12.29 12.72 12.03

Appendix B.Appendix 2. Sh table 3 and figure to corresponds number [Site acre-ft/d, acre-feet per day] day] per acre-feet acre-ft/d, Appendix B.

B–18 Hydrogeology, Hydrologic Budget, and Water Chemistry of the Medina Lake area, Texas (acre-ft/d) Average storage Average (acre-ft/d) Average evaporationAverage out (acre-ft/d) Average SW in (acre-ft/d) Average SW Average (acre-ft/d) Average precipitation sea level) Average stageAverage (ft above mean out (+/- error) (acre-ft/d) (acre-ft/d) sea level) (ft above mean Stage Average GW Diversion hydrologic Lake budget—Continued Diversion Lake Diversion hydrologicLake budget—Continued (ft above (ft BMA datum) BMA Date 10/01/95 10/02/95 10/03/95 10/04/95 10/05/95 10/06/95 10/07/95 10/08/95 10/09/95 10/10/9510/11/9510/12/95 919.3610/13/95 919.110/14/95 919.1410/15/95 911.56 919.3510/16/95 919.48 911.30 10/17/95 911.34 919.5310/18/95 911.55 919.6210/19/95 911.68 919.9010/20/95 911.73 920.0910/21/95 911.82 920.1910/22/95 912.10 920.2410/23/95 912.29 920.2510/24/95 912.39 920.2710/25/95 912.44 920.2910/26/95 912.45 920.2810/27/95 912.47 920.310/28/95 912.49 920.2810/29/95 912.48 920.1410/30/95 919.93 912.50 10/31/95 912.48 919.7811/01/95 912.34 919.6911/02/95 912.13 919.7111/03/95 911.98 920.6411/04/95 911.89 921.1811/05/95 911.91 921.5311/06/95 912.84 921.8011/07/95 913.38 922.0011/08/95 913.73 922.1611/09/95 914.00 922.3611/10/95 914.20 922.3011/11/95 914.36 922.2211/12/95 914.56 922.0611/13/95 914.50 921.8511/14/95 914.42 921.63 914.26 921.42 914.05 921.20 913.83 913.62 913.40 Appendix B.Appendix Appendix B.

Appendix B B–19 (acre-ft) (+/- error) (site 8) out out (acre-ft) (acre-ft) (+/- error) (acre-ft) (acre-ft) (+/- error) (acre-ft) (acre-ft) (+/- error) (site 8) Evaporationstorage GW out out SW (acre-ft) (acre-ft) (+/- error) in (acre-ft) (acre-ft) (+/- error) (+/- Precipitation SW Diversion Lake Diversion hydrologicLake budget—Continued (acre-ft) Date 11/15/9511/16/9511/17/9511/18/95 1.2711/19/95 11.2411/20/9511/21/9511/22/95 0.1911/23/95 1.6911/24/9511/25/9511/26/95 60.6911/27/95 66.6211/28/9511/29/95 60.6911/30/95 6.1312/01/95 6.7212/02/95 64.64 6.1312/03/95 62.6412/04/95 62.64 124.9612/05/95 62.64 44.43 6.5212/06/95 60.65 130.12 6.3212/07/95 60.65 12.50 6.3212/08/95 60.65 6.32 4.4412/09/95 60.65 6.12 13.01 11.5012/10/95 60.65 6.12 0.85 11.9012/11/95 60.63 6.12 0.94 12.5012/12/95 60.63 6.12 13.4912/13/95 60.63 1.19 1.15 6.12 13.49 0.8012/14/95 60.63 1.19 6.12 0.13 13.4912/15/95 60.61 1.25 6.12 0.23 14.2812/16/95 60.61 1.35 6.12 14.2812/17/95 60.61 0.30 1.35 6.12 0.70 14.28 0.2012/18/95 60.61 1.35 6.12 0.41 14.28 60.5812/19/95 60.61 1.43 6.12 0.23 14.28 -54.112/20/95 60.60 1.43 6.12 0.60 1.16 88.4612/21/95 60.60 1.43 6.12 0.17 1.03 -9.3 94.02 -42.112/22/95 1.43 6.11 6.12 0.10 1.20 2.88 91.6412/23/95 58.59 -8.1 1.43 6.11 0.06 2.25 95.6012/24/95 60.58 8.85 6.11 0.17 0.15 1.34 92.83 -1.412/25/95 60.58 -6.3 9.40 0.26 0.88 90.8412/26/95 60.58 47.3 9.16 5.91 0.43 0.30 1.13 98.38 88.8612/27/95 60.56 41.6 107.31 9.56 -9.83 6.11 0.56 6.7612/28/95 60.54 38.3 9.28 113.06 6.11 0.33 4.76 58.5312/29/95 60.54 33.3 -28.12 41.54 9.08 6.11 7.1 0.22 0.7512/30/95 58.55 29.7 9.84 8.89 6.11 10.73 6.2 0.28 0.28 16.11 87.87 58.5312/31/95 58.55 27.7 6.11 11.31 5.7 1.69 0.05 85.0901/01/96 24.8 100.96 15.71 5.90 6.11 5.0 1.19 0.16 8.35 01/02/96 58.53 22.2 100.96 5.91 4.5 0.19 1.2901/03/96 23.0 5.14 8.79 5.90 5.91 4.2 0.99 0.07 0.84 92.43 1.79 58.51 22.0 8.73 8.51 10.10 3.7 0.01 85.69 11.61 2.23 58.51 17.8 5.90 10.10 3.3 0.04 81.12 81.72 15.25 58.49 -0.5 3.5 0.32 -49.5 75.77 16.44 58.49 9.71 9.24 5.90 3.3 0.25 0.21 4.73 72.40 -30.0 73.79 18.27 0.45 58.49 8.96 8.57 5.90 2.7 8.63 2.69 -35.1 19.32 0.56 1.72 58.47 8.11 8.17 -0.1 5.90 8.17 -31.8 76.56 22.84 0.49 -7.4 58.47 7.58 5.90 7.70 -30.1 22.50 -4.5 58.45 7.24 7.38 5.90 7.53 1.18 0.32 -35.2 -27.6 68.43 23.23 -31.2 -5.3 58.45 5.89 7.33 0.67 0.22 28.76 21.80 0.43 -44.5 -4.8 58.43 7.66 -32.09 5.89 7.12 2.69 0.32 0.12 -4.5 58.43 6.94 15.37 5.89 7.18 1.00 -5.3 -4.1 58.41 -4.7 7.74 6.84 -1.31 -0.03 5.89 7.10 1.51 0.08 -27.0 58.41 -6.7 8.33 2.88 5.89 7.03 0.06 0.05 10.82 -24.7 -24.4 58.41 9.32 -0.57 5.89 13.45 0.67 0.08 3.72 49.39 0.69 -32.1 -1.42 5.89 0.25 11.90 71.21 0.77 -4.1 -17.30 -0.01 -2.75 -1.48 5.89 0.38 0.67 -26.3 75.17 0.83 -3.7 12.51 -3.7 -10.20 5.89 12.10 2.22 -20.6 73.19 0.93 -4.8 4.94 0.93 11.85 -15.7 71.01 1.31 -8.3 7.12 13.21 12.73 11.56 -13.1 66.25 -3.9 1.02 7.52 -7.01 14.49 -8.8 0.17 -10.5 64.66 -3.1 -17.70 0.82 7.32 -2.50 0.55 64.66 -2.4 0.75 -1.2 7.10 -8.78 0.94 -15.9 -2.0 0.33 6.62 11.40 1.27 -1.3 -1.6 0.25 6.47 -5.90 12.36 11.13 1.04 0.21 -7.3 6.47 -4.77 0.15 12.75 -2.4 0.19 -15.82 -5.80 5.1 0.24 0.41 -5.12 31.7 0.32 11.76 2.28 -6.40 -2.00 -1.1 33.3 0.26 10.97 4.33 32.7 10.13 0.04 10.47 1.92 0.8 -5.85 30.0 0.10 4.8 19.2 9.81 0.57 -12.1 5.0 9.54 9.49 1.08 -18.2 -3.28 4.9 0.48 10.00 -14.2 4.5 22.43 2.9 -12.3 -1.8 18.54 -2.7 -9.6 16.44 9.10 -10.9 -2.1 16.64 -1.8 6.63 -9.5 18.40 -11.06 7.61 -1.4 -1.92 -1.6 7.77 0.44 7.72 -1.4 -0.71 7.48 8.22 -0.69 9.42 -0.52 9.94 0.32 9.63 1.33 9.41 9.00 8.96 8.87 Appendix B.

B–20 Hydrogeology, Hydrologic Budget, and Water Chemistry of the Medina Lake area, Texas -0.87 20.62 -12.45 (acre-ft/d) Average storage Average 2.02 0.96 1.69 (acre-ft/d) Average evaporationAverage out 55.70 29.20 69.16 (acre-ft/d) Average SW in 58.52 58.48 58.43 (acre-ft/d) Average SW Average 0.67 0 0 (acre-ft/d) Average precipitation 910.87 911.74 911.51 sea level) Average stageAverage (ft above mean 8.83 8.12 9.30 out (+/- error) (acre-ft/d) 2.34 7.70 0.03 (acre-ft/d) sea level) (ft above mean Stage Average GW Diversion Lake Diversion hydrologicLake budget—Continued (ft above (ft BMA datum) BMA Date 12/24/95 919.13 911.33 11/15/9511/16/9511/17/95 920.8811/18/95 920.4511/19/95 920.3811/20/95 913.08 920.7511/21/95 912.65 921.0811/22/95 912.58 921.3711/23/95 912.95 921.6211/24/95 913.28 921.8411/25/95 913.57 922.0511/26/95 913.82 922.2311/27/95 914.04 922.3911/28/95 914.25 922.5511/29/95 914.43 922.7211/30/95 914.59 922.8512/01/95 914.75 922.8412/02/95 914.92 922.4812/03/95 915.05 922.2712/04/95 915.04 922.0112/05/95 914.68 921.7712/06/95 914.47 921.5412/07/95 914.21 921.3412/08/95 913.97 921.1012/09/95 913.74 920.7512/10/95 913.54 920.4712/11/95 913.30 920.2612/12/95 912.95 920.0712/13/95 912.67 919.8712/14/95 912.46 919.6012/15/95 912.27 919.3812/16/95 912.07 919.2112/17/95 911.80 919.0812/18/95 911.58 918.9712/19/95 911.41 918.8912/20/95 911.28 918.8212/21/95 911.17 918.6812/22/95 911.09 918.5912/23/95 911.02 918.52 910.88 918.5712/25/95 910.79 918.8512/26/95 910.72 12/27/95 910.77 919.4012/28/95 911.05 919.65 919.8112/30/95 911.60 919.7112/31/95 911.85 01/01/96 912.01 919.4401/02/96 911.91 919.3401/03/96 919.26 911.64 919.17 911.54 919.09 911.46 911.37 911.29 12/29/95 919.56 911.76 Appendix B.

Appendix B B–21 (acre-ft) (+/- error) (site 8) out out (acre-ft) (acre-ft) (+/- error) (acre-ft) (acre-ft) (+/- error) (acre-ft) (acre-ft) (+/- error) (site 8) Evaporationstorage GW out out SW (acre-ft) (acre-ft) (+/- error) in (acre-ft) (acre-ft) (+/- error) (+/- Precipitation SW Diversion Lake Diversion hydrologicLake budget—Continued (acre-ft) Date 01/04/9601/05/9601/06/9601/07/9601/08/9601/09/9601/10/9601/11/9601/12/9601/13/9601/14/9601/15/9601/16/9601/17/9601/18/96 58.3901/19/96 58.3901/20/96 58.3701/21/96 58.37 5.8801/22/96 58.35 5.8801/23/96 58.35 5.88 101.9701/24/96 5.88 139.6601/25/96 5.88 113.87 70.6101/26/96 5.88 113.85 10.24 74.3801/27/96 113.85 14.01 69.6201/28/96 113.85 11.43 65.2601/29/96 7.06 113.83 11.42 63.2701/30/96 7.44 107.88 11.42 63.27 69.2201/31/96 6.96 11.42 95.8002/01/96 95.96 6.53 104.33 101.91 11.4202/02/96 6.33 107.90 115.78 10.83 0.7602/03/96 6.33 6.92 109.49 115.78 1.4902/04/96 9.63 9.58 109.49 115.78 10.23 10.43 3.7702/05/96 109.49 115.76 11.61 10.79 1.6602/06/96 107.50 105.84 11.61 10.95 0.19 1.1402/07/96 105.84 11.61 10.95 0.37 0.6202/08/96 127.64 11.61 10.95 0.94 97.59 95.6002/09/96 101.55 141.52 10.62 10.75 0.4102/10/96 105.52 141.52 10.62 0.2802/11/96 -7.8 105.52 141.50 12.80 0.16 -14.002/12/96 9.76 107.50 9.56 147.45 14.19 10.16 -13.0 0.3202/13/96 101.55 173.24 14.19 10.55 -0.39 -10.902/14/96 -1.2 163.30 14.18 10.55 -2.1 99.9702/15/96 -7.1 108.30 127.58 14.78 10.75 -2.002/16/96 -5.6 114.25 117.66 17.36 10.16 -1.6 0.08 0.3102/17/96 -3.6 -0.10 -6.9 120.20 117.66 16.36 0.8802/18/96 10.00 -1.1 128.13 147.41 12.79 10.83 -0.63 -5.1702/19/96 -0.8 -3.47 132.30 206.90 11.80 11.42 0.9 0.1902/20/96 35.9 -0.5 13.8 -2.02 141.42 183.09 -1.0 11.80 12.02 0.08 1.3902/21/96 133.49 169.19 14.77 12.81 2.36 0 3.0 0.2202/22/96 0.5 -0.16 1.02 125.55 175.14 9.27 20.72 13.23 1.0 1.03 1.04 0.1 9.72 127.54 196.96 18.34 14.14 5.4 0.2 2.1 0.05 1.70 0.06 9.37 121.59 196.94 16.95 13.35 0.35 0.90 0.5 8.94 120.79 202.89 17.54 12.56 0.1 3.4 0 0.2 0.26 150.94 210.82 19.73 12.75 4.9 8.71 0.26 2.7 0 161.26 208.84 19.72 12.16 8.68 0.43 159.27 216.75 20.32 12.08 3.0 0.22 1.47 0.5 -0.1 159.27 232.62 21.11 15.09 0.7 0.27 169.19 234.58 20.91 16.13 0.4 -3.3 4.02 171.17 234.58 21.70 15.93 5.1 0.5 12.1 173.16 226.65 23.29 15.93 0 0.37 10.6 181.09 10.51 212.75 23.49 16.92 15.26 -0.5 189.02 214.73 15.82 23.49 17.12 4.48 0.07 0.8 8.18 191.01 220.68 22.69 17.32 1.8 0.08 200.93 21.30 18.11 1.6 15.44 5.06 0.12 18.4 204.89 21.50 18.90 -0.10 6.8 15.71 3.00 204.89 22.09 19.10 15.70 2.2 8.15 0.02 2.75 207.07 13.21 20.09 9.3 0.02 1.29 13.47 15.83 198.94 20.49 2.8 0.03 0.88 1.0 -0.03 194.98 9.82 20.49 14.70 5.6 0.27 -15.6 14.60 0.3 192.99 20.71 16.78 0.69 1.15 -13.1 1.4 19.3 18.31 19.89 0.32 1.73 -1.0 -5.4 19.50 18.66 0.22 1.00 -2.3 0.8 28.1 -2.0 9.94 19.30 0.07 0.14 5.3 -2.0 2.9 0.29 0.48 -0.2 -0.8 5.5 0.43 -0.3 1.0 4.2 21.30 0.25 0.71 0.8 6.6 0.03 0.45 1.4 0.12 0.8 2.47 0.2 10.84 0.2 4.9 17.75 0.18 1.0 1.4 22.57 0.11 0.2 0.7 24.59 0 23.26 -3.2 17.52 0.7 23.70 27.44 0.2 26.00 -5.2 22.26 0.1 -1.6 18.14 -0.5 26.14 -2.0 26.70 24.40 25.07 -0.8 27.83 27.29 -0.2 28.19 28.86 -0.3 22.29 28.91 30.77 31.17 24.25 31.17 28.84 30.72 29.03 29.34 Appendix B.

B–22 Hydrogeology, Hydrologic Budget, and Water Chemistry of the Medina Lake area, Texas 4.27 4.96 0.90 -9.73 (acre-ft/d) Average storage Average 1.57 0.75 0.73 0.79 (acre-ft/d) Average evaporationAverage out 67.74 107.15 167.77 199.64 (acre-ft/d) Average SW in 58.37 120.60 190.72 225.67 (acre-ft/d) Average SW Average 0 0 0 0 (acre-ft/d) Average precipitation 910.97 911.31 912.00 912.13 sea level) Average stageAverage (ft above mean 9.11 out 16.19 25.46 30.16 (+/- error) (acre-ft/d) 8.43 -1.20 17.26 24.34 (acre-ft/d) sea level) (ft above mean Stage Average GW Diversion Lake Diversion hydrologicLake budget—Continued (ft above (ft BMA datum) BMA Date 01/10/9601/11/9601/12/96 918.5901/13/96 918.9101/14/96 919.0301/15/96 910.79 919.0501/16/96 911.11 919.0601/17/96 911.23 919.0601/18/96 911.25 919.0601/19/96 911.26 919.0601/20/96 911.26 919.03 911.26 918.98 911.26 919.00 911.23 911.18 911.20 01/04/9601/05/9601/06/96 919.0201/07/96 918.9001/08/96 918.7901/09/96 911.22 918.69 911.10 918.63 910.99 918.58 910.89 910.83 910.78 01/21/9601/22/9601/23/96 919.0501/24/96 919.0701/25/96 919.0901/26/96 911.25 919.0901/27/96 911.27 919.0701/28/96 911.29 919.11 911.29 919.21 911.27 919.30 911.31 911.41 911.50 02/08/9602/09/9602/10/96 919.7502/11/96 919.7302/12/96 919.7802/13/96 911.95 919.83 911.93 919.8302/15/96 911.98 919.8902/16/96 912.03 02/17/96 912.03 919.9002/18/96 912.09 919.9402/19/96 919.95 912.10 919.96 912.14 919.9302/22/96 912.15 912.16 912.13 919.86 912.06 01/29/9601/30/9601/31/96 919.3502/01/96 919.3702/02/96 919.4502/03/96 911.55 919.6002/04/96 911.57 919.6502/05/96 911.65 919.5202/06/96 911.80 919.4102/07/96 911.85 919.36 911.72 919.60 911.61 919.76 911.56 911.80 911.96 02/14/96 919.90 912.10 02/20/9602/21/96 919.92 919.87 912.12 912.07 Appendix B.

Appendix B B–23 (acre-ft) (+/- error) (site 8) out out (acre-ft) (acre-ft) (+/- error) (acre-ft) (acre-ft) (+/- error) (acre-ft) (acre-ft) (+/- error) (site 8) Evaporationstorage GW out out SW (acre-ft) (acre-ft) (+/- error) in (acre-ft) (acre-ft) (+/- error) (+/- Precipitation SW Diversion Lake Diversion hydrologicLake budget—Continued (acre-ft) Date 02/23/9602/24/9602/25/9602/26/9602/27/9602/28/9602/29/9603/01/9603/02/96 6.3003/03/9603/04/9603/05/9603/06/96 0.9503/07/96 234.5503/08/96 246.4503/09/96 246.4503/10/96 206.76 246.43 23.4803/11/96 246.43 24.6703/12/96 240.48 24.6703/13/96 20.70 24.6703/14/96 196.96 151.20 24.6703/15/96 204.89 151.20 24.0703/16/96 210.84 151.2003/17/96 211.04 214.81 151.20 15.14 19.7003/18/96 216.79 151.18 15.14 20.4903/19/96 216.79 149.20 15.14 21.0803/20/96 145.23 21.10 15.14 21.4803/21/96 151.34 135.29 15.14 21.68 0.6903/22/96 113.65 135.29 14.94 21.68 1.6203/23/96 119.60 135.29 14.54 -0.5203/24/96 135.47 135.27 13.55 15.13 -0.39 1.8103/25/96 139.44 135.27 13.55 11.37 -0.08 0.1703/26/96 135.47 147.15 13.55 11.96 0.41 3.4303/27/96 -0.13 125.55 155.09 13.55 13.5503/28/96 -0.10 117.62 166.99 13.55 13.94 0.45 0.8103/29/96 -0.02 117.62 204.65 14.73 13.55 2.13 1.1303/30/96 117.62 204.65 15.53 12.56 4.6 0.86 1.1103/31/96 117.62 206.64 16.72 11.76 -0.41 9.004/01/96 7.3 151.34 218.52 20.48 11.76 -0.30 0.2004/02/96 4.2 -9.0 149.36 230.42 0.32 20.48 11.76 0.28 0.7704/03/96 1.9 0.7 147.37 268.09 20.68 11.76 0.28 5.4404/04/96 1.4 -0.10 -0.2 149.36 297.84 21.87 15.13 1.1 2.0104/05/96 -0.07 171.17 297.84 -1.4 23.06 14.94 0.6 0.8704/06/96 -22.7 177.12 226.39 297.82 26.82 14.74 0.3 0.19 1.6404/07/96 183.07 32.29 283.93 29.80 14.94 9.2 8.21 0 1.36 1.7804/08/96 11.7 191.40 30.93 248.23 29.80 17.12 28.82 0.50 0.7604/09/96 -3.4 6.6 197.75 22.65 29.80 17.71 -4.8 27.80 0.22 0.1304/10/96 9.21 199.74 240.28 28.41 18.31 30.65 27.81 0.41 0.3104/11/96 1.4 -0.2 199.74 275.98 1.23 24.84 19.14 1.8 32.10 0.44 0.2504/12/96 32.47 -2.6 198.94 275.96 19.78 1.0 20.45 0.19 0.34 -0.7 32.72 187.24 -3.3 198.94 21.75 273.98 24.04 19.97 29.61 0.03 1.03 32.84 -0.9 198.94 273.98 27.61 19.97 0 0.08 3.77 -2.8 197.16 178.73 27.22 273.96 27.61 -0.4 19.89 0.06 2.63 18.79 32.41 -3.2 273.96 18.72 27.41 19.89 -0.5 21.68 0.08 1.40 16.84 9.54 -6.0 197.16 214.45 27.41 19.89 -0.1 0.26 1.87 -14.5 216.99 17.88 27.41 19.72 -0.4 18.99 0.94 0.99 19.38 -6.9 220.96 176.75 27.41 -0.5 13.15 16.83 0.66 0.42 -3.0 224.93 176.75 21.46 -0.9 19.72 20.60 20.34 1.88 18.96 0.35 0.17 -2.2 10.4 224.93 176.73 21.70 17.71 0.47 3.52 10.0 203.90 231.47 200.53 17.69 22.10 -1.0 18.83 0.25 2.81 20.17 19.27 240.00 226.31 17.69 22.49 -0.5 3.0 19.08 0.11 17.96 224.13 238.21 17.68 22.49 -10.82 3.1 1.6 0.47 0.04 0.85 17.94 12.17 236.22 20.39 20.06 23.15 2.9 1.5 0.88 0.31 17.95 17.0 201.52 22.64 24.00 14.31 0.70 0.58 0.5 17.95 17.0 200.73 23.83 22.41 20.39 20.33 1.79 0.5 17.0 200.33 23.63 21.09 0.21 0.78 22.75 0.4 17.0 193.79 20.15 6.2 2.6 2.30 0.08 1.80 16.50 21.43 17.0 193.79 20.07 2.6 0.14 0.42 22.42 18.0 203.70 16.79 20.03 2.6 0.45 0.11 26.74 213.02 21.38 19.38 2.6 0.20 0.9 10.6 27.12 28.37 19.38 2.6 0.57 0.45 2.25 49.48 11.1 20.37 2.7 27.64 0.11 0.88 80.12 15.4 21.30 29.07 0.03 0.56 81.48 9.3 1.6 30.38 0.47 81.71 33.54 33.21 6.4 1.7 0.56 1.11 -37.4 64.47 35.97 4.9 2.3 0.22 0.31 30.27 35.92 -1.5 0.14 0.89 -10.5 1.4 35.92 29.41 0.12 31.67 -5.6 1.0 34.79 0.28 -25.5 47.58 0.7 31.83 -0.2 0.08 -33.8 39.03 -1.6 0.22 -26.2 31.13 37.96 -26.0 -3.8 35.16 18.15 41.87 -5.1 35.44 35.79 2.0 35.04 -3.9 8.4 35.49 0.71 -3.9 4.9 27.73 35.47 -1.52 35.88 0.3 36.43 8.94 1.3 31.07 2.04 0.7 32.27 27.09 27.23 29.42 27.01 25.79 28.16 17.41 29.80 31.38 31.82 Appendix B.

B–24 Hydrogeology, Hydrologic Budget, and Water Chemistry of the Medina Lake area, Texas 3.05 5.77 -0.36 -2.54 -1.00 13.63 -24.48 (acre-ft/d) Average storage Average 0.43 1.11 1.74 0.94 1.73 0.95 1.26 (acre-ft/d) Average evaporationAverage out 202.58 166.38 124.42 161.26 197.83 218.64 199.01 (acre-ft/d) Average SW in 234.88 185.49 140.97 174.35 267.84 258.77 189.30 (acre-ft/d) Average SW Average 0 0.90 0 0 0 0.24 1.37 (acre-ft/d) Average precipitation 912.15 912.19 912.16 911.96 912.45 913.24 912.51 sea level) Average stageAverage (ft above mean out 31.05 25.03 18.83 23.83 33.43 33.94 27.84 (+/- error) (acre-ft/d) 28.82 19.25 17.34 13.15 54.66 33.65 14.88 (acre-ft/d) sea level) (ft above mean Stage Average GW Diversion Lake Diversion hydrologicLake budget—Continued (ft above (ft BMA datum) BMA Date 03/05/96 920.01 912.21 03/12/96 919.85 912.05 03/19/96 919.87 912.07 02/23/9602/24/9602/25/96 919.9002/26/96 919.97 920.0302/28/96 912.10 920.0702/29/96 912.17 03/01/96 912.23 920.0803/02/96 912.27 920.0003/03/96 919.8203/04/96 912.28 919.90 912.20 919.9903/06/96 912.02 920.0503/07/96 912.10 03/08/96 912.19 920.0103/09/96 912.25 919.9803/10/96 919.9603/11/96 912.21 919.95 912.18 919.9203/13/96 912.16 919.9003/14/96 912.15 03/15/96 912.12 919.7303/16/96 912.10 919.6703/17/96 919.6503/18/96 911.93 919.73 911.87 919.8203/20/96 911.85 919.8403/21/96 911.93 03/22/96 912.02 919.8903/23/96 912.04 920.0303/24/96 920.1603/25/96 912.09 920.3003/26/96 912.23 920.43 912.36 920.5703/28/96 912.50 920.7103/29/96 912.63 03/30/96 912.77 920.8403/31/96 912.91 920.9304/01/96 921.0504/02/96 913.04 921.1204/03/96 913.13 921.1704/04/96 913.25 921.20 913.32 921.1904/06/96 913.37 921.1104/07/96 913.40 04/08/96 913.39 920.6204/09/96 913.31 920.3604/10/96 920.15 912.82 919.9404/12/96 912.56 919.96 912.35 912.14 920.07 912.16 912.27 04/11/96 920.03 912.23 03/27/96 920.76 912.96 02/27/96 920.08 912.28 04/05/96 920.82 913.02 Appendix B.

Appendix B B–25 (acre-ft) (+/- error) (site 8) out out (acre-ft) (acre-ft) (+/- error) (acre-ft) (acre-ft) (+/- error) (acre-ft) (acre-ft) (+/- error) (site 8) Evaporationstorage GW out out SW (acre-ft) (acre-ft) (+/- error) in (acre-ft) (acre-ft) (+/- error) (+/- Precipitation SW Diversion Lake Diversion hydrologicLake budget—Continued (acre-ft) Date 04/13/9604/14/9604/15/9604/16/9604/17/9604/18/9604/19/9604/20/9604/21/9604/22/9604/23/9604/24/9604/25/9604/26/96 246.1304/27/96 252.0804/28/96 275.8704/29/96 289.75 24.6204/30/96 289.69 25.22 5.7005/01/96 287.76 27.6005/02/96 299.65 28.9805/03/96 216.79 339.32 28.9705/04/96 220.76 339.32 0.85 28.7805/05/96 224.93 339.31 29.9705/06/96 237.62 339.31 33.94 21.6805/07/96 245.95 339.30 33.94 22.0805/08/96 249.92 339.28 337.31 33.94 22.4905/09/96 251.90 337.31 33.94 23.7605/10/96 267.77 337.30 33.94 24.60 4.69 1.2705/11/96 273.72 33.93 33.74 24.99 2.2305/12/96 274.12 339.28 33.74 25.19 4.2705/13/96 273.32 339.28 33.74 26.78 2.6205/14/96 271.34 339.27 0.70 27.37 0.32 1.5705/15/96 287.21 275.31 345.22 33.93 27.41 0.56 0.4505/16/96 283.24 357.12 33.93 27.33 1.07 0.3505/17/96 287.21 369.01 33.93 27.13 0.66 1.0505/18/96 370.99 28.72 34.53 27.53 0.39 0.3805/19/96 -2.2 289.19 372.97 35.72 28.32 0.11 1.0705/20/96 285.22 378.92 36.91 28.72 3.1 0.09 1.9505/21/96 283.24 37.10 2.5 0.26 2.5905/22/96 12.4 293.16 305.52 37.30 -0.3 28.92 0.48 0.0905/23/96 299.11 180.56 37.90 28.52 7.2 8.2 0.27 2.4805/24/96 0.5 305.06 180.56 28.32 4.2 0.49 0.5605/25/96 0.4 305.06 180.56 30.56 29.32 2.5 1.9 0.6505/26/96 15.7 305.06 180.56 18.06 29.91 0.12 30.26 6.2305/27/96 1.1 1.2 12.1 309.02 180.55 18.06 30.51 0.62 2.2805/28/96 0.6 13.8 25.98 180.55 18.06 30.51 0.14 1.3005/29/96 0.4 11.2 163.24 44.18 180.55 18.06 30.51 2.4 6.61 275.31 0.4005/30/96 37.11 32.81 10.0 173.75 180.54 18.06 30.90 1.8 1.56 0.1105/31/96 -3.0 177.72 34.96 216.24 18.06 2.1 33.52 0.5706/01/96 177.72 33.19 251.94 18.06 16.32 6.0 1.7 35.62 27.53 0.32 37.53 -2.9 181.69 44.91 287.64 0.99 18.06 17.38 1.5 0.10 54.80 189.62 355.08 -0.5 21.63 17.77 3.03 38.02 0.03 0.34 53.12 191.21 384.83 25.20 17.77 2.9 38.12 50.33 0.9 -5.7 184.26 28.77 18.17 -0.4 39.15 0.57 52.84 0.47 43.30 -2.0 199.93 35.51 18.96 55.37 43.64 -1.9 211.44 0.46 38.48 19.12 60.30 0.08 0.4 43.68 -4.7 222.94 18.43 -0.9 43.61 234.45 45.59 -0.3 19.99 52.44 0.14 0.12 43.48 254.28 -0.3 21.14 44.47 278.88 22.29 -0.7 -0.1 40.96 -1.7 23.44 44.06 57.47 2.30 44.31 25.43 0 56.74 2.83 89.0 27.89 0 53.56 2.88 8.0 -0.3 44.61 0 62.60 2.99 44.34 305.06 0.57 2.22 44.20 13.4 342.15 330.84 0 0.71 2.10 45.29 10.1 1.2 332.83 0 0.72 2.93 46.59 -9.0 333.22 0.75 30.51 -10.0 69.66 34.21 0.56 33.08 -21.9 -9.0 52.72 1.5 340.36 0.52 33.28 -29.1 -26.0 -1.4 350.28 340.36 0.73 33.32 -12.0 -30.0 -1.5 346.31 -19.0 -3.3 48.90 2.53 -1.4 348.30 37.13 34.04 -16.0 -4.4 -3.9 0.55 2.70 35.03 34.04 -1.8 -4.5 2.58 23.0 34.63 -2.9 1.90 23.0 34.83 -2.4 0.63 15.89 0.14 0.68 0.55 3.5 6.88 2.46 0.65 0.71 13.92 3.5 0.47 2.15 45.01 26.01 1.72 66.98 24.0 27.30 0.14 13.8 23.0 30.31 75.70 0.62 0.18 33.77 80.03 9.0 0.54 16.4 37.19 3.6 0.43 2.1 3.5 43.81 3.0 47.66 1.4 -0.7 -6.3 2.5 -9.1 -6.1 0.5 -0.1 -0.9 -1.4 -0.9 Appendix B.

B–26 Hydrogeology, Hydrologic Budget, and Water Chemistry of the Medina Lake area, Texas 4.85 9.59 -1.41 -7.43 (acre-ft/d) Average storage Average 1.93 1.18 1.73 2.61 (acre-ft/d) Average evaporationAverage out 219.47 263.50 288.45 226.60 (acre-ft/d) Average SW in 256.38 321.71 341.76 265.26 (acre-ft/d) Average SW Average

0 0 0.71 0 (acre-ft/d) Average precipitation 912.28 912.69 913.05 912.63 sea level) Average stageAverage (ft above mean out 33.78 41.63 44.74 35.15 (+/- error) (acre-ft/d) 30.12 47.44 53.71 43.49 (acre-ft/d) sea level) (ft above mean Stage Average GW Diversion Lake Diversion hydrologicLake budget—Continued (ft above (ft BMA datum) BMA Date 05/04/9605/05/9605/06/96 920.7605/07/96 920.7605/08/96 920.7505/09/96 912.96 920.7505/10/96 912.96 920.8205/11/96 912.95 921.5005/12/96 912.95 921.5805/13/96 913.02 921.5105/14/96 913.70 921.4305/15/96 913.78 921.3605/16/96 913.71 921.17 913.63 920.94 913.56 920.76 913.37 913.14 912.96 05/23/9605/24/9605/25/96 920.7205/26/96 920.9005/27/96 920.9605/28/96 912.92 921.0905/29/96 913.10 921.2005/30/96 913.16 921.2205/31/96 913.29 921.1706/01/96 913.40 921.10 913.42 921.06 913.37 921.12 913.30 913.26 913.32 04/13/9604/14/9604/15/96 920.0504/16/96 920.07 920.0904/18/96 912.25 920.1904/19/96 912.27 04/20/96 912.29 920.2804/21/96 912.39 920.3004/22/96 920.4204/23/96 912.48 920.5204/24/96 912.50 920.63 912.62 920.71 912.72 920.7904/27/96 912.83 04/28/96 912.91 04/29/96 912.99 920.8804/30/96 920.8605/01/96 920.8805/02/96 913.08 920.8405/03/96 913.06 920.82 913.08 920.81 913.04 920.77 913.02 913.01 912.97 05/17/9605/18/9605/19/96 920.5305/20/96 920.4405/21/96 920.2905/22/96 912.73 920.16 912.64 920.34 912.49 920.52 912.36 912.54 912.72 04/17/96 920.25 912.45 04/25/9604/26/96 920.85 920.91 913.05 913.11 Appendix B.

Appendix B B–27 (acre-ft) (+/- error) (site 8) out out (acre-ft) (acre-ft) (+/- error) (acre-ft) (acre-ft) (+/- error) (acre-ft) (acre-ft) (+/- error) (site 8) Evaporationstorage GW out out SW (acre-ft) (acre-ft) (+/- error) in (acre-ft) (acre-ft) (+/- error) (+/- Precipitation SW Diversion Lake Diversion hydrologicLake budget—Continued (acre-ft) Date 06/02/9606/03/9606/04/9606/05/9606/06/9606/07/9606/08/9606/09/9606/10/9606/11/9606/12/9606/13/9606/14/9606/15/9606/16/9606/17/9606/18/9606/19/9606/20/9606/21/9606/22/9606/23/9606/24/9606/25/9606/26/96 354.2506/27/96 360.2006/28/96 1.31 360.2006/29/96 360.20 35.4206/30/96 360.20 36.0207/01/96 358.21 36.0207/02/96 0.20 356.23 36.0207/03/96 354.25 36.0207/04/96 1.12 352.26 35.8207/05/96 1.83 354.25 35.6207/06/96 2.68 356.23 35.4207/07/96 3.09 358.21 35.2307/08/96 0.28 4.12 360.20 35.4207/09/96 0.46 2.72 366.15 35.6207/10/96 0.67 2.10 370.12 35.8207/11/96 0.77 2.72 1.31 370.12 36.0207/12/96 1.03 3.83 24.27 14.0 370.12 36.6107/13/96 0.68 2.64 12.0 1.35 382.02 37.0107/14/96 0.53 2.31 -2.3 384.00 37.0107/15/96 0.68 1.98 0.20 385.98 37.0107/16/96 5.3 2.1 3.64 0.96 1.97 -1.7 387.97 38.2007/17/96 1.8 0.66 2.62 0.20 391.93 -0.5 391.93 38.40 -0.307/18/96 0.58 2.60 -1.1 389.95 38.6007/19/96 0.49 1.88 0.8 -2.5 389.95 38.80 -0.307/20/96 0.49 1.97 -1.1 39.19 39.19 -0.107/21/96 0.65 2.93 -1.7 391.93 -0.2 39.00 0.65 2.02 -3.7 389.95 -0.4 39.00 0.47 1.60 -4.9 385.98 -0.2 0.49 2.76 -0.6 385.98 39.19 -0.3 0.73 2.86 218.18 385.98 39.00 -0.6 8.9 0.50 2.33 245.95 384.00 38.60 -0.7 2.1 0.40 297.52 384.00 -0.1 38.60 0.7 0.69 315.37 21.82 387.97 38.60 1.7 0.72 321.32 1.3 24.60 10.0 389.95 38.40 0.58 329.26 0.3 29.75 395.90 391.93 38.40 9.3 331.04 335.21 0.1 31.54 391.93 38.80 4.8 219.77 349.09 0.3 32.13 239.80 391.93 39.00 2.6 1.5 227.31 360.99 32.93 39.59 39.19 0.4 229.29 33.10 374.88 1.4 33.52 -4.2 39.19 1.69 229.29 0.7 34.91 21.98 23.98 39.19 1.66 245.16 0.4 36.10 22.73 -1.3 2.53 257.06 0.1 37.49 22.93 -0.6 3.28 2.51 252.69 22.93 1.48 1.9 0.42 2.43 260.23 24.52 -0.2 3.56 2.92 0.41 2.88 267.97 25.71 -1.0 2.83 0.63 277.69 25.27 -4.1 2.61 0.82 0.63 0.3 26.02 0.37 -3.4 2.72 0.61 26.80 -1.6 0.89 4.07 -0.2 0.9 0.73 0.72 27.77 -1.4 0.71 3.49 -0.6 3.0 0.65 3.56 -0.5 5.3 0 0.68 3.79 -0.2 2.9 0.8 40.6 0.1 1.02 3.83 -0.2 -34.2 0 0.5 44.3 -0.2 0.87 3.63 -51.7 0.8 0.89 -26.3 0 0.4 0.1 6.1 0.95 -5.1 3.5 0.96 6.6 -7.8 0 0 -1.5 0.91 -12.5 -3.9 -7.5 0.5 29.06 -0.2 0 -1.9 67.52 0 91.92 -1.1 0 31.40 79.87 34.38 0 73.60 81.20 37.77 0 0 86.46 39.00 40.43 41.82 85.07 42.00 89.19 93.56 43.55 44.97 46.66 Appendix B.

B–28 Hydrogeology, Hydrologic Budget, and Water Chemistry of the Medina Lake area, Texas -20.45 (acre-ft/d) Average storage Average 3.21 (acre-ft/d) Average evaporationAverage out 234.64 (acre-ft/d) Average SW in 287.93 (acre-ft/d) Average SW Average 0 (acre-ft/d) Average precipitation 913.55 sea level) Average stageAverage (ft above mean out 37.47 (+/- error) (acre-ft/d) 70.53 (acre-ft/d) sea level) (ft above mean Stage Average GW Diversion Lake Diversion hydrologicLake budget—Continued (ft above (ft BMA datum) BMA Date 06/02/9606/03/9606/04/96 921.1606/05/96 921.2506/06/96 921.2306/07/96 913.36 921.2706/08/96 913.45 921.2606/09/96 913.43 921.2606/10/96 913.47 921.2506/11/96 913.46 921.2306/12/96 913.46 921.2206/13/96 913.45 921.2106/14/96 913.43 921.1806/15/96 913.42 921.1406/16/96 913.41 921.1306/17/96 913.38 921.2106/18/96 913.34 921.2206/19/96 913.33 921.2306/20/96 913.41 921.2406/21/96 913.42 921.3206/22/96 913.43 921.3906/23/96 913.44 921.4206/24/96 913.52 921.4406/25/96 913.59 921.4406/26/96 913.62 921.4106/27/96 913.64 921.4306/28/96 913.64 921.4206/29/96 913.61 921.4106/30/96 913.63 921.3807/01/96 913.62 921.3507/02/96 913.61 921.3407/03/96 913.58 921.3307/04/96 913.55 921.3307/05/96 913.54 921.3407/06/96 913.53 921.3607/07/96 913.53 921.407/08/96 913.54 921.4107/09/96 913.56 921.4107/10/96 921.4 913.60 07/11/96 913.61 921.4307/12/96 913.61 921.7307/13/96 922.07 913.60 07/14/96 913.63 921.8107/15/96 913.93 921.4207/16/96 914.27 921.2207/17/96 914.01 921.25 913.62 921.2307/19/96 913.42 921.1407/20/96 913.45 07/21/96 913.43 921.08 913.34 921.08 921.08 913.28 913.28 913.28 07/18/96 921.08 913.28 Appendix B.

Appendix B B–29 (acre-ft) (+/- error) (site 8) out out (acre-ft) (acre-ft) (+/- error) (acre-ft) (acre-ft) (+/- error) (acre-ft) (acre-ft) (+/- error) (site 8) Evaporationstorage GW out out SW (acre-ft) (acre-ft) (+/- error) in (acre-ft) (acre-ft) (+/- error) (+/- Precipitation SW Diversion Lake Diversion hydrologicLake budget—Continued (acre-ft) Date 07/22/9607/23/9607/24/9607/25/9607/26/9607/27/9607/28/9607/29/9607/30/9607/31/9608/01/9608/02/9608/03/9608/04/96 388.7608/05/96 390.7408/06/9608/07/96 38.8808/08/96 39.0708/09/9608/10/9608/11/96 285.2208/12/96 291.1708/13/9608/14/96 28.52 4.3708/15/96 29.1208/16/9608/17/96 305.4508/18/96 0.66 323.70 3.0308/19/96 335.60 2.6708/20/96 337.59 30.5508/21/96 337.78 32.3708/22/96 342.35 0.76 33.5608/23/96 350.28 0.67 33.7608/24/96 3.49 354.25 33.7808/25/96 2.93 8.28 362.58 34.2308/26/96 2.23 368.93 35.0308/27/96 0 3.84 370.71 35.4208/28/96 -7.0 0.52 370.91 36.2608/29/96 0.73 1.24 2.94 370.91 36.8908/30/96 0.56 368.93 37.0708/31/96 0.58 -1.1 368.93 0 37.0909/01/96 5.39 362.98 37.0909/02/96 241.98 0.44 347.11 -6.0 357.02 36.8909/03/96 6.96 -0.5 353.06 36.8909/04/96 103.90 120.99 349.09 36.3009/05/96 100.51 24.20 0.81 34.71 35.70 -0.909/06/96 11.99 122.98 345.12 29.75 35.31 -0.109/07/96 12.10 1.04 48.75 330.64 34.9109/08/96 7.6 48.22 319.7409/09/96 67.44 3.0 148.36 12.30 262.21 31.74 34.51 2.1 1.80 2.98 274.12 33.06 29.75 1.3 101.95 1.1 270.15 31.74 31.97 29.75 3.9 2.49 6.74 14.84 0.5 180.89 268.17 26.22 3.7 3.17 121.79 0.3 274.12 27.41 31.74 9.1 2.98 29.75 10.20 0.2 25.98 176.93 27.01 4.6 1.59 3.17 2.98 0.6 -2.0 18.09 26.82 29.75 0.27 2.32 0.6 12.18 48.40 0.92 27.41 29.75 3.1 2.85 3.17 1.4 10.51 17.69 2.98 0 2.60 3.45 0.7 11.31 0.66 29.75 -0.3 0.2 0.17 3.64 2.98 10.51 10.71 -0.1 29.75 1.20 0.25 3.49 4.84 2.98 0.5 -4.1 0.10 1.04 29.75 0.6 0.31 1.05 1.84 10.51 -0.9 29.75 7.7 0 0.38 58.71 1.73 1.13 2.98 0 1.92 -4.4 0.07 29.75 0.40 1.05 0 1.07 -11.2 2.98 10.51 -0.6 0.13 0.38 2.98 0.1 1.22 33.72 -9.5 0.11 -0.1 -55.4 0.20 1.05 2.98 1.2 0.69 -4.1 5.87 -0.7 6.9 0.19 2.98 -1.7 0.21 2.33 51.57 -7.6 1.05 0.87 1.52 3.1 39.07 -9.0 -1.4 -8.3 3.37 0.13 28.76 -2.4 -0.6 -19.3 2.1 1.0 0.07 10.1 0.76 18.84 -1.1 5.16 41.0 0.25 -49.5 -1.4 0.5 6.94 3.91 0.09 0.17 1.20 -0.4 156.38 -2.9 2.88 0.3 1.5 -8.0 1.88 0.08 -19.0 -7.4 6.2 -28.4 0.69 29.60 19.12 0.13 -12.0 -27.1 -1.2 19.45 -2.9 -12.9 -4.3 54.28 15.84 -1.8 -4.1 -12.6 17.55 25.82 -1.9 44.93 -54.6 8.42 44.51 -1.9 39.32 44.62 -23.0 8.39 -8.2 4.47 33.36 -49.6 5.32 -44.3 3.94 -3.5 5.15 30.64 -32.7 -24.5 -7.4 3.86 -6.6 -17.6 -4.9 3.68 -3.7 -2.6 Appendix B.

B–30 Hydrogeology, Hydrologic Budget, and Water Chemistry of the Medina Lake area, Texas -2.42 -25.82 -18.67 (acre-ft/d) Average storage Average 3.42 1.15 1.23 (acre-ft/d) Average evaporationAverage out 89.30 10.68 272.50 (acre-ft/d) Average SW in 30.74 366.61 116.63 (acre-ft/d) Average SW Average 0 3.01 2.06 (acre-ft/d) Average precipitation 913.27 912.94 911.96 sea level) Average stageAverage (ft above mean 4.40 out 45.69 15.96 (+/- error) (acre-ft/d) 93.12 55.01 39.56 (acre-ft/d) sea level) (ft above mean Stage Average GW Diversion Lake Diversion hydrologicLake budget—Continued (ft above (ft BMA datum) BMA Date 07/24/9607/25/9607/26/96 920.9807/27/96 920.9807/28/96 921.0407/29/96 913.18 921.0607/30/96 913.18 921.0807/31/96 913.24 921.0908/01/96 913.26 921.1208/02/96 913.28 921.1408/03/96 913.29 921.2108/04/96 913.32 921.2508/05/96 913.34 921.2308/06/96 913.41 921.2608/07/96 913.45 921.2608/08/96 913.43 921.2608/09/96 913.46 921.2608/10/96 913.46 921.2608/11/96 913.46 921.3208/12/96 913.46 921.2908/13/96 913.46 921.2608/14/96 913.52 921.2508/15/96 913.49 921.2108/16/96 913.46 921.1308/17/96 913.45 921.0608/18/96 913.41 921.1108/19/96 913.33 921.0608/20/96 913.26 920.9908/21/96 913.31 920.9708/22/96 913.26 921.0508/23/96 913.19 921.36 913.17 921.37 913.25 920.95 913.56 913.57 913.15 07/22/9607/23/96 921.08 921.03 913.28 913.23 08/24/9608/25/9608/26/96 920.8008/27/96 920.82 920.7608/29/96 913.00 920.3708/30/96 913.02 08/31/96 912.96 919.9309/01/96 912.57 919.7709/02/96 919.66 912.13 919.56 911.97 919.46 911.86 911.76 911.66 08/28/96 920.15 912.35 09/03/9609/04/9609/05/96 919.2709/06/96 918.8009/07/96 918.3709/08/96 911.47 917.9809/09/96 911.00 917.68 910.57 917.46 910.18 917.30 909.88 909.66 909.50 Appendix B.

Appendix B B–31 (acre-ft) (+/- error) (site 8) out out (acre-ft) (acre-ft) (+/- error) (acre-ft) (acre-ft) (+/- error) (acre-ft) (acre-ft) (+/- error) (site 8) Evaporationstorage GW out out SW (acre-ft) (acre-ft) (+/- error) in (acre-ft) (acre-ft) (+/- error) (+/- Precipitation SW Diversion Lake Diversion hydrologicLake budget—Continued (acre-ft) Date 09/10/9609/11/9609/12/9609/13/9609/14/9609/15/9609/16/9609/17/96 8.7509/18/9609/19/9609/20/9609/21/96 1.3109/22/96 1.0609/23/9609/24/96 29.7509/25/96 29.75 31.7409/26/96 29.75 0.1609/27/96 29.75 2.9809/28/96 29.75 2.9809/29/96 3.17 2.9809/30/96 29.75 2.98 85.29 29.75 2.98 59.50 6.15 87.27 5.75 2.98 5.75 5.75 8.53 2.98 85.29 5.75 5.95 0.61 85.29 5.75 8.73 126.94 0.58 172.56 0.58 0.58 5.75 8.53 172.56 0.58 5.75 5.75 8.53 172.56 12.69 0.58 5.75 152.73 17.26 5.75 113.06 17.26 0.58 113.06 17.26 0.58 0.58 5.75 126.94 15.27 0.58 24.60 6.15 11.31 0.58 41.26 11.31 59.70 12.69 0.58 68.83 2.46 0.61 79.93 4.13 62.08 5.97 60.10 6.88 68.03 -14.5 7.99 -15.0 6.21 -15.6 6.01 -3.9 -12.6 -2.2 6.80 -13.6 -2.3 -2.3 -0.6 -10.0 -1.9 -13.2 -2.0 27.8 -6.4 -1.5 24.0 -2.0 4.2 28.1 -1.0 30.3 24.2 3.6 60.6 49.0 4.2 52.0 4.5 3.6 -1.4 9.1 -8.6 7.4 -7.3 7.8 -4.7 -0.2 -1.3 -1.1 -0.7 Appendix B.

B–32 Hydrogeology, Hydrologic Budget, and Water Chemistry of the Medina Lake area, Texas (acre-ft/d) Average storage Average (acre-ft/d) Average evaporationAverage out (acre-ft/d) Average SW in (acre-ft/d) Average SW Average (acre-ft/d) Average precipitation sea level) Average stageAverage (ft above mean out (+/- error) (acre-ft/d) (acre-ft/d) sea level) (ft above mean Stage Average GW Diversion Lake Diversion hydrologicLake budget—Continued (ft above (ft BMA datum) BMA Date 09/10/9609/11/9609/12/96 917.1709/13/96 917.0309/14/96 916.8809/15/96 909.37 916.7609/16/96 909.23 916.6309/17/96 909.08 916.6009/18/96 908.96 916.5009/19/96 908.83 916.3809/20/96 908.80 916.3109/21/96 908.70 916.5409/22/96 908.58 916.8109/23/96 908.51 917.0709/24/96 908.74 917.2909/25/96 909.01 917.5709/26/96 909.27 918.1109/27/96 909.49 918.5409/28/96 909.77 919.0009/29/96 910.31 918.9909/30/96 910.74 918.91 911.20 918.85 911.19 918.81 911.11 911.05 911.01 Appendix B.

Appendix B B–33 (acre-ft) (+/- error) storage Diversion Lake , ground-water ground-water , (acre-ft) out (acre-ft) (+/- error) storage Medina Lake ay] ay] (acre-ft) total ration Evapo- (acre-ft) storage, change in storage; GW in storage; change storage,

(acre-ft) (+/- error) Evaporation Diversion Lake . 1; acre-ft/d, acre-feet per d per acre-feet 1; acre-ft/d, . (acre-ft) (acre-ft) (+/- error) (+/- , surface-water outflow; outflow; surface-water , Evaporation Medina Lake out (acre-ft) (acre-ft) (+/- error) out SW ntrol and Improvement District No Improvement and ntrol Diversion Lake (acre-ft) , surface-water inflow; SW inflow; , surface-water in (acre-ft) in (+/- error) Appendix B SW Medina Lake Medina (acre-ft) (acre-ft) (+/- error) Hydrogeology, Hydrologic Budget, Hydrogeology, Chemistry the of Water and Texas area, Lake Medina Precipitation riod. SW acre-feet; riod. acre-ft, Diversion Lake Diversion (acre-ft) (acre-ft) (+/- error) Medina/Diversion Lakes combined hydrologic budget Medina/Diversion Lakes combined hydrologic budget—Continued Medina Lake Precipitation (acre-ft) Date 10/01/9510/02/9510/03/9510/04/9510/05/9510/06/9510/07/9510/08/9510/09/9510/10/9510/11/9510/12/9510/13/9510/14/9510/15/9510/16/9510/17/95 235.8110/18/95 230.1610/19/95 23.84 222.5110/20/95 23.28 212.5510/21/95 22.47 204.54 148.7610/22/95 21.47 191.96 144.7910/23/95 20.67 185.69 14.88 182.4810/24/95 19.39 175.56 14.48 202.3110/25/95 18.75 183.45 18.25 196.3610/26/95 33.02 17.74 181.47 20.23 190.4110/27/95 18.52 175.48 19.64 188.4310/28/95 18.32 8.25 163.58 19.04 182.4810/29/95 17.72 153.66 18.84 176.5310/30/95 70.54 16.53 143.31 18.25 174.5510/31/95 31.84 15.54 134.18 490.13 17.65 10.58 148.7611/01/95 14.49 127.42 533.00 17.45 150.7411/02/95 4.78 73.52 13.55 141.70 14.88 166.6111/03/95 1.22 79.95 12.85 147.85 15.07 178.5111/04/95 17.55 14.29 149.24 16.66 184.4611/05/95 0.18 14.91 141.28 17.85 9.31 192.4011/06/95 15.04 2.63 135.33 18.45 220.1711/07/95 14.24 103.62 113.51 19.24 240.00 1.4011/08/95 13.65 103.62 22.02 160.86 253.8811/09/95 10.47 11.46 107.56 24.00 257.8511/10/95 271.74 10.47 107.56 16.29 25.39 259.8311/11/95 10.87 107.56 25.79 124 263.80 196.3611/12/95 28.02 127.40 10.87 107.56 25.98 265.7811/13/95 134.88 10.87 107.56 26.38 19.64 265.78 12.8511/14/95 12.4 10.87 26.58 245.95 13.49 81.32 10.87 26.58 216.20 190.41 24.60 99 204.30 8.13 21.62 37 202.31 -112 19.04 367.74 20.43 -13 9.9 389.95 20.23 -128 -11.2 37.37 3.7 288.99 39.42 -86 237.62 -1.3 -12.8 29.25 -71 226.45 83.31 24.05 -66 211.76 -8.6 89.26 22.90 -51 193.80 -7.1 91.24 21.40 177.78 8.33 -6.6 -121 4 93.22 19.60 167.92 8.93 -5.1 -151 81.32 17.99 168.97 9.12 -177 -12.1 95.21 17.01 149.00 9.32 124.96 0.4 -330 -15.1 17.08 150.96 8.13 126.94 -244 -17.7 96.03 15.08 152.75 9.52 12.50 142.81 -300 4.6 -33.0 -31.4 54.44 15.28 25.8 12.69 140.83 24.01 -262 -24.4 44.13 15.44 15.4 14.28 136.86 13.61 -245 -30.0 45.98 -4.7 62.35 0.7 14.08 132.89 11.03 3.9 -290 6.5 -26.2 10.2 3.43 13.69 136.86 11.49 2.3 -445 -24.5 15.59 10.23 34.5 1.96 13.29 -331 -197 -29.0 96.49 1.0 0.86 23.4 1.60 13.69 1.5 -260 -44.5 64.60 184 2.56 0.49 12 1.68 2.26 5.2 -369 -33.1 24.12 -19.7 18.77 0.40 3.5 -294 6 99.47 -26.0 16.15 36.28 1646 0.42 0.57 18.4 -198 2 56.40 -36.9 0.37 -17.7 -111 4.69 1.8 3.44 -126 2.1 45.73 -29.4 164.6 -31 9.07 2.29 -220 2.8 47.66 -19.8 0.9 0.09 64.61 -2.7 -11.1 49 0.86 -1 1.2 -12.6 0.3 0.66 116.7 0.3 74 0.57 -3.1 2.1 -22.0 1.26 0.4 10.60 79 -2 -10.4 0.16 0.2 99.94 3 -17.6 17.5 4.9 -0.2 0.32 66.89 -26.9 35.4 0.3 7.4 -1.6 31 -2.6 7.9 -0.3 19.42 18 27.3 0.3 -189 462 -4.0 37.54 5.3 22 182 -21 27.5 3.1 -18.9 4.1 46.2 1.8 -8.2 -42 18.2 3.3 -21.6 -29.4 4.1 -2.1 -1.2 -28.1 70.1 -4.2 45.6 -3.2 -26 -4.4 -27.7 -4.2 10.5 -28.7 6.8 -4.2 -2.6 -4.3 -11.9 -1.8 outflow; ft, feet; BMA, Bexar-Medina-Atascosa Counties Water Co Water Counties feet; BMA, Bexar-Medina-Atascosa ft, outflow; Appendix B.Appendix pe budget indicates [Shading B.Appendix

B–34 Hydrogeology, Hydrologic Budget, and Water Chemistry of the Medina Lake area, Texas storage Average (acre-ft/d) (acre-ft/d) evaporation Average total out Sw Average (acre-ft/d) in Sw Average (acre-ft/d) Average (acre-ft/d) precipitation sea level) Lake stage (ft above mean Average Medina (acre-ft) (+/- error) out GW Average (acre-ft/d) sea level) sea (ftmean above Medina Lake stage (ft above (ft BMA datum) BMA (acre-ft) total (+/- error) (+/- out system GW (acre-ft) Medina/Diversion Lakes combined hydrologic budget—Continued Medina/Diversion Lakes combined hydrologic budget—Continued total storage (acre-ft) Date 10/01/9510/02/9510/03/9510/04/9510/05/9510/06/9510/07/9510/08/9510/09/9510/10/9510/11/9510/12/95 -27.410/13/95 -116.410/14/95 -125.210/15/95 -161.6 1,053.1810/16/95 -323.5 1,053.210/17/95 -233.8 1,053.2110/18/95 -265.5 1,045.38 1,053.1910/19/95 -238.6 1,045.4 1,053.1810/20/95 -233.0 1,045.41 1,053.1510/21/95 -284.0 1,045.39 1,053.1410/22/95 -443.0 1,045.38 1,053.1210/23/95 -328.9 1,045.35 1,053.110/24/95 1,053.09 -257.2 1,045.34 1,053.07 1,053.0910/25/95 -370.0 1,045.32 1,053.0310/26/95 -291.9 1,045.29 1,045.3 1,053 1,045.27 10/27/95 -200.0 1,045.29 1,052.92 1,045.23 10/28/95 -143.6 1,052.8710/29/95 -246.9 1,052.8 1,045.12 10/30/95 1,045.2 -214.7 1,052.74 1,045.07 10/31/95 -121.4 1,052.6911/01/95 1,045 185.2 1,052.62 1,044.94 1762.711/02/95 1,052.52 1,044.89 11/03/95 532.1 1,052.45 1,044.82 11/04/95 227.6 1,052.39 1,044.72 11/05/95 1,052.31 1,044.65 11/06/95 4.4 1,052.24 76.3 1,044.59 11/07/95 1,052.2 96.0 1,044.51 11/08/95 106.5 1,052.17 1,044.44 93.8911/09/95 11.69 1,052.1211/10/95 -5.2 1,044.4 -37.9 39.41 1,052.07 -37.61 1,044.37 3.4011/11/95 29.86 1,052.05 1,044.32 11/12/95 9.4 27.57 -10.1 27.89 1,052.09 1,044.27 11/13/95 9.43 -218.4 1,052.46 1,052.6 1,044.25 11/14/95 1,052.61 -48.7 28.02 -61.69 1,052.56 1,044.29 163.65 5.11 -70.7 1,052.64 1,044.66 1,052.63 1,052.61 33.07 1,044.8 1,044.81 32.44 22.80 47.35 1,044.76 1,044.84 1,052.64 1,044.83 49.05 1,044.81 21.30 23.33 1,052.65 1,052.61 1,052.65 1,044.84 1,052.64 1,052.6 1,044.85 1,044.81 1,044.85 1,052.59 1,044.84 1,044.8 1,044.79 Appendix B. Appendix B.Appendix

Appendix B B–35 (acre-ft) (+/- error) storage Diversion Lake (acre-ft) (acre-ft) (+/- error) storage Medina Lake (acre-ft) total ration Evapo- (acre-ft) (acre-ft) (+/- error) Evaporation Diversion Lake (acre-ft) (acre-ft) (+/- error) (+/- Evaporation Medina Lake (acre-ft) (acre-ft) (+/- error) out SW Diversion Lake (acre-ft) (acre-ft) in (+/- error) SW Medina Lake Medina (acre-ft) (acre-ft) (+/- error) Precipitation Diversion Lake Diversion (acre-ft) (acre-ft) (+/- error) Medina/Diversion Lakes combined hydrologic budget—Continued Medina Lake Precipitation (acre-ft) Date 11/15/9511/16/9511/17/95 639.2411/18/9511/19/95 95.8911/20/9511/21/95 11.2411/22/9511/23/95 1.6911/24/9511/25/95 1.27 166.1811/26/9511/27/95 0.19 16.8911/28/9511/29/95 134.4811/30/95 77.3612/01/95 13.60 138.6212/02/95 7.7412/03/95 14.02 158.6812/04/95 200.5912/05/95 35.35 202.77 15.87 164.6312/06/95 20.51 203.1512/07/95 20.62 8.84 192.06 16.4612/08/95 27.59 20.61 179.5612/09/95 33.57 43.64 19.47 177.5412/10/95 1.19 43.64 23.25 18.20 6.90 163.2012/11/95 5.04 43.64 18.00 147.35 4.3612/12/95 0.30 43.64 16.55 5.81 137.43 4.3612/13/95 0.94 43.64 14.97 135.45 4.36 0.8512/14/95 20.44 43.64 13.98 131.25 4.36 36.5412/15/95 0.23 0.80 11.77 45.62 13.78 126.60 4.36 0.1312/16/95 47.60 5.11 13.35 129.52 4.36 6.60 28212/17/95 0.20 17.00 47.60 2.94 12.87 135.47 28.53 4.5612/18/95 84.09 134.02 28.87 47.60 13.13 139.42 4.76 1.6512/19/95 0.70 39.07 33.45 28.2 47.60 4.25 13.73 143.88 4.76 24.06 12.61 124.96 13.59 -4012/20/95 0.41 62.31 7.22 14.12 150.01 4.76 132.8912/21/95 0.17 5.86 36.73 8.36 14.58 0.23 146.04 4.76 12.50 -9.3 128.93 15.58 -1812/22/95 0.10 0.60 23.95 132.89 -4.0 15.19 140.07 13.29 134.8812/23/95 1.03 30.60 9.18 14.80 0.06 21.13 136.05 1.16 12.89 182.08 132.89 128.83 -1.4 12/24/95 0.15 1.20 13.29 5.99 14.20 -1.8 12.17 2.25 -54.1 13.49 128.9312/25/95 0.26 20.63 7.65 13.79 45.52 133.35 32.21 419 13.29 0.17 122.9812/26/95 0.30 1.34 6.83 17.60 135.07 0.56 -42.1 12.89 -8.1 7.85 29.17 142.8112/27/95 0.88 55 13.50 29.90 5.16 139.04 12.30 1.42 148.7612/28/95 0.33 41.9 160.34 1.13 6.76 4.76 13.67 34.65 143.07 14.28 4.37 -6.3 1.9612/29/95 7.29 93 0.22 64.56 2.88 74 36.60 14.06 149.02 153.00 14.88 122.98 16.18 5.5 0.3512/30/95 0.28 30.47 14 1.69 0.75 1.19 24.03 14.47 38.06 47.3 149.00 117.02 1.0912/31/95 23 0.43 51.74 -36 15.06 24.82 15.46 9.15 148.98 0.28 0.99 12.30 9.3 132.89 7.401/01/96 0.19 4.57 188.84 133.59 65.42 111.07 41.6 15.06 31.73 6.01 150.98 0.05 11.70 -60 132.89 1.4 7.1 01/02/96 12.93 15.06 173.18 0.07 0.16 0.25 13.29 -22 124.96 -3.6 140.60 2.3 103.14 16.35 1.29 11.11 -144 38.3 33.3 15.26 -51 0.01 21.38 13.29 6.2 119.01 35 0.84 -6.0 80.93 17.44 29.7 167.23 0.04 35.15 12.50 1.79 10.31 111.07 30.15 0.32 -14.4 52.43 -2.2 24.8 27.7 8.14 5.7 11.90 2.23 86.12 5.0 105.12 -54 -5.1 20.23 0.21 15.25 16.84 1.47 147.39 0.45 11.11 103.14 4.5 22.2 3.5 13.11 4.73 10.05 -40 4.53 -0.90 21.53 133.49 37.88 0.56 10.51 3.7 4.2 -34 23 -0.5 14.86 -5.4 3.81 17.8 131.46 24.87 10.31 2.69 6.91 107.11 53.53 3.3 1.18 10.08 22 13.47 -0.23 2.51 2 131.46 1.72 -4.0 -43 -0.1 14 67.65 2.69 -3.4 31.77 13.26 133.45 -49.5 10.71 0.67 3.5 2.7 1.73 -36 123.53 0.49 48.82 99.17 145.33 13.26 2.52 -23 129.48 0.43 -0.03 -35.2 0.32 0.67 59.50 0.2 13.46 -4.3 3.3 7.94 -77 -30 125.53 -7.4 119.01 1.4 12.47 12.21 0.12 83.62 33.72 13.07 -3.6 -0.01 121.55 0.22 9.92 -40 -2.3 0.08 0.32 54.14 -5.3 31.74 12.67 -35.1 5.95 29.75 88.80 -30.1 -7.7 -249 -31.8 1.00 31.74 -4.5 12.27 127.50 0.05 3.37 15.75 -27.6 1.51 99.17 -0.93 0.08 -4.0 21.46 -31.2 31.74 -82 133.45 3.17 10.37 -5.3 -4.5 0.25 -24.9 71.52 -44.5 -4.8 81 3.72 73.39 12.87 141.20 3.17 0.38 -4.1 -63 9.92 41.62 95.21 -4.7 -27 5.37 13.46 7.12 140.19 3.17 10.40 -7 17.88 -17 -8.2 32.01 0.93 -6.7 -24.7 14.23 7.34 32.77 10.41 8.1 50.34 25.59 97.19 14.11 -6.3 9.52 31.82 -40 0.67 -4.1 23.06 -24.4 95.21 122.73 -0.7 8.00 -3 -1.7 -3.7 2.22 -39 -134 28.75 91.24 6.40 1.31 9.72 -32.1 -8.3 7.96 0.17 38.82 -127 89.26 -4.0 -3.7 5.77 0.55 9.52 -26.3 -0.3 1.02 -8.8 -13.4 7.19 -3.9 0.33 9.12 -4.8 -1.2 0.82 -12.7 9.70 22.13 1.04 -20.6 8.93 4.75 -3.9 0.25 0.75 73.74 -15.7 -1.3 12.83 -10.5 -13.1 0.21 0.94 42.93 70.94 -15.9 0.26 -3.1 135.74 1.19 -70 0.19 1.27 -2.4 3.21 -42 -1.6 33.03 -2.0 -150 17.73 0.24 26.41 33.93 -2.4 32.86 0.32 -7.0 0.15 23.81 -70 -4.2 -15.0 0.41 29.69 2.28 -85 4.33 -86 0.04 40.09 -73 -7.3 0.10 -7.0 31.7 0.57 -69 5.1 1.08 -8.5 -103 -8.6 -1.1 -7.3 4.90 13.24 33.3 4.8 73.22 140.07 0.8 -6.9 -10.3 32.7 -18.2 -28 30 -162 -3 5.0 -44 -12.1 19.2 -2.7 4.9 -16.2 -2.8 -0.3 -1.8 -4.4 4.5 2.9 -10.9 -12.3 -14.2 -9.6 -1.6 -1.8 -2.1 -1.4 Appendix B.Appendix

B–36 Hydrogeology, Hydrologic Budget, and Water Chemistry of the Medina Lake area, Texas -63.33 storage Average (acre-ft/d) 46.06 (acre-ft/d) evaporation Average total out Sw 73.39 Average (acre-ft/d) in Sw 142.30 Average (acre-ft/d) 10.60 Average (acre-ft/d) precipitation 1,044.66 sea level) Lake stage (ft above mean Average Medina 23.14 (acre-ft) (+/- error) out GW Average 96.77 (acre-ft/d) sea level) sea (ftmean above Medina Lake stage (ft above (ft BMA datum) BMA (acre-ft) total (+/- error) (+/- out system GW (acre-ft) Medina/Diversion Lakes combined hydrologic budget—Continued total storage (acre-ft) Date 11/15/9511/16/95 -60.111/17/95 -94.111/18/95 272.711/19/95 10.04 466.311/20/95 42.64 430.05 96.6 23.3411/21/95 -330.48 131.3 102.07 23.7911/22/95 107.311/23/95 47.66 50.36 43.711/24/95 21.38 1,052.59 50.711/25/95 23.53 1,052.64 22.85 1,052.58 -11.2 23.7911/26/95 1,052.74 1,044.79 62.33 -37.8 22.2711/27/95 1,044.84 1,044.78 48.5511/28/95 20.60 64.22 1.0 1,052.75 1,044.94 57.011/29/95 1,052.77 20.87 99.49 -33.2 23.7611/30/95 1,052.79 -144.5 1,044.95 19.45 64.0112/01/95 -103.5 1,044.97 1,052.79 -0.88 -71.9912/02/95 1,044.99 1,052.79 -64.0 16.45 12.5612/03/95 1,052.79 17.15 -33.1 48.05 1,044.99 78.7512/04/95 1,052.77 39.59 -17.8 1,044.99 12/05/95 62.41 21.45 1,044.99 -73.1 1,052.7712/06/95 36.17 1,044.97 -63.6 1,052.78 19.76 1,052.7612/07/95 24.26 -54.2 1,052.73 20.2312/08/95 -121.5 1,044.97 56.30 1,052.72 20.37 1,044.98 12/09/95 1,044.96 61.80 -75.2 22.8012/10/95 1,044.93 1,052.71 -2.07 -67.0 41.13 20.8912/11/95 1,044.92 -273.7 1,052.7112/12/95 24.50 -106.4 1,052.72 80.59 27.98 1,044.91 -67.9512/13/95 1,052.71 208.13 1,044.91 -95.1 21.9912/14/95 1,052.7 1,044.92 -43.3 40.03 58.4112/15/95 36.98 1,052.69 1,044.91 -60.6 1,052.6812/16/95 89.53 25.04 -18.7 1,044.9 12/17/95 1,052.67 56.99 -52.1 1,044.89 21.53 1,052.6612/18/95 1,044.88 83.47 1,052.6 -15.8 20.1912/19/95 46.20 1,044.87 1,052.58 72.7 19.9212/20/95 -142.9 1,044.86 65.19 150.69 19.0312/21/95 1,044.8 -144.5 1,052.57 20.6312/22/95 1,044.78 1,052.57 -72.00 22.51 -77.3 80.2912/23/95 1,052.56 167.08 1,044.77 -36.9 30.8312/24/95 -118.3 1,052.56 38.10 1,044.77 103.3912/25/95 27.24 1,052.55 1,044.76 -36.7 1,052.5512/26/95 37.15 173.11 19.95 1,044.76 -52.312/27/95 1,052.56 1,044.75 -43.0 1,052.54 103.40 23.56 23.3112/28/95 1,044.75 1,052.51 -49.8 127.61 -115.1 18.00 1,044.76 1,052.49 116.9312/30/95 1,044.74 18.13 1,044.71 12/31/95 1,052.48 72.26 1,052.45 101.36 16.96 -17.201/01/96 1,044.69 -40.3 1,052.43 17.9501/02/96 21.09 1,044.68 -53.6 1,044.65 1,052.41 -172.9 42.61 1,052.4 1,044.63 65.30 16.31 1,044.61 1,052.38 30.34 1,052.36 83.77 17.13 1,044.6 24.94 41.19 1,044.58 1,044.56 1,052.34 1,052.33 1,052.32 1,044.54 1,052.28 1,044.53 1,044.52 1,044.48 12/29/95 -104.2 126.16 20.48 1,052.34 1,044.54 Appendix B.

Appendix B B–37 (acre-ft) (+/- error) storage Diversion Lake (acre-ft) (acre-ft) (+/- error) storage Medina Lake (acre-ft) total ration Evapo- (acre-ft) (acre-ft) (+/- error) Evaporation Diversion Lake (acre-ft) (acre-ft) (+/- error) (+/- Evaporation Medina Lake (acre-ft) (acre-ft) (+/- error) out SW Diversion Lake (acre-ft) (acre-ft) in (+/- error) SW Medina Lake Medina (acre-ft) (acre-ft) (+/- error) Precipitation Diversion Lake Diversion (acre-ft) (acre-ft) (+/- error) Medina/Diversion Lakes combined hydrologic budget—Continued Medina Lake Precipitation (acre-ft) Date 01/03/9601/04/9601/05/9601/06/9601/07/9601/08/9601/09/9601/10/9601/11/9601/12/9601/13/9601/14/9601/15/9601/16/9601/17/9601/18/9601/19/96 118.3501/20/96 114.4101/21/96 11.92 110.4201/22/96 11.53 106.4301/23/96 11.13 104.4501/24/96 89.26 10.73 108.4001/25/96 95.21 10.53 110.3801/26/96 99.17 10.92 112.36 8.9301/27/96 95.21 11.12 110.40 9.5201/28/96 91.24 11.32 106.41 9.9201/29/96 59.98 87.27 11.13 102.45 9.5201/30/96 23.84 87.27 10.73 102.45 9.12 15.0001/31/96 46.88 93.22 10.33 104.03 8.73 119.82 119.0102/01/96 5.96 10.33 103.83 8.73 126.94 11.7202/02/96 52.45 10.48 29.96 104.07 1.92 9.32 11.90 130.9102/03/96 36.42 10.45 101.87 12.69 132.89 13.1102/04/96 0.76 19.91 10.48 100.26 0.48 1.49 13.09 132.8902/05/96 26.00 3.77 9.10 10.26 13.29 132.8902/06/96 99.07 0.19 4.98 10.11 101.06 0.37 1.66 13.29 130.9102/07/96 61.90 0.94 3.90 102.84 13.29 10.01 120.9902/08/96 1.14 10.20 24.59 105.02 0.41 13.09 119.01 -20702/09/96 0.62 48.37 123.60 10.38 105.02 12.1002/10/96 0.28 124.96 10.04 10.60 101.06 11.90 -88 128.9302/11/96 0.16 -20.7 -12.09 54.11 -103 10.60 -9 130.9102/12/96 98.88 12.50 10.20 37.56 2.51 12.89 132.89 -3.02 -25902/13/96 96.28 -10.3 -8.8 20.53 -9.5 13.09 126.9402/14/96 93.90 9.98 -0.9 -141 13.29 124.9602/15/96 91.93 -25.9 0.32 9.71 -0.39 9.71 27.08 -13 12.69 -1.4 -7602/16/96 -7.8 91.91 -19.34 9.46 -14.1 -14 12.50 132.89 -0.1002/17/96 87.97 0.08 -10.9 9.26 2.43 87.93 6.77 138.84 5.94 -4.8302/18/96 87.97 -1.2 -2.0 9.26 42.76 -7.6 13.29 144.7902/19/96 91.95 -7.1 -12.48 8.87 -2.1 31.39 -1.6 13.88 10.36 152.73 8.86 1.4802/20/96 91.91 0.31 10.69 0.88 8.87 -0.63 14.48 156.69 -5.6 -113 31.58 -1.1 9.27 7.85 -137 15.27 164.63 -0.16 89.91 0.08 0.22 52.27 144.79 9.26 15.67 0.19 1.39 156.69 93.88 -0.8 -11.3 27.35 7.89 16.46 -13.7 150.74 13.07 97.86 14.48 1.02 -19.97 9.06 10.02 103.81 0.05 15.67 27.95 0.35 152.73 -128 9.46 -97 6.84 103.81 15.07 -197 1.03 -155 0.5 0.26 9.85 -155 10.45 -136 0 103.83 15.27 1.70 144.79 -164 -12.8 44.15 43.89 10.45 6.13 101.83 174.55 -9.7 -148 0.26 0.90 -19.7 -15.5 10.45 -15.5 0.1 14.48 0.43 -13.6 32.41 188.43 186.45 10.97 89.91 -130 -16.4 -188 10.25 35.9 17.45 0 -56 186.45 81.98 0.22 -14.8 32.60 -174 13.8 18.84 18.64 0.9 196.36 82.00 53.97 -13.0 2.7 -18.8 9.06 3.4 4.9 1.47 18.64 198.35 5.4 85.96 3 8.27 -5.6 28.25 -17.4 19.64 -85 -269 2.1 89.95 -392 1 0 0.1 8.27 0.4 0.37 2.00 19.83 200.33 2.38 -0.1 0.5 0.7 80.01 0.2 8.66 -213 208.26 3.53 82.04 -26.9 -39.2 0.5 -3.3 3 9.06 -8.5 -2.95 20.03 216.20 0.50 0 0.59 87.41 45.37 0.2 0 8.07 80.50 0 -21.3 20.83 218.18 0.88 89.04 8.27 -0.5 -0.74 12.1 21.62 -6.9 228.10 -267 20.13 37.93 5.1 8.80 0.5 0.07 21.82 0.08 232.07 10.6 25.56 -3.6 8.95 22.81 0.12 -0.10 232.07 -1.0 1.8 -26.7 9.48 0.02 23.21 0.02 7.91 0.8 2.75 234.05 33.42 -0.5 1.6 6.39 -0.03 23.21 0.03 226.12 50.15 18.4 23.40 0.69 1.98 1.29 28.60 2.07 8.35 2.46 22.61 -124 12.54 0.88 -3.05 3.64 3.89 -153 2.8 0.32 83.25 14.01 -219 7.15 -177 0.27 -252 -206 -12.4 0.22 1.15 -217 -180 1.73 0.97 -15.3 -21.9 3.50 0.07 -17.7 39.22 -99 -183 -25.2 -20.6 0.29 1.00 -21.7 -18.0 26.44 0.43 -226 6.8 -444 0.14 19.3 2.2 -18.3 0.25 -9.9 0.48 -1 8.18 -253 34.57 -13.1 -184 9.3 -22.6 5.3 51.88 -2 1.0 0.03 -44.4 -195 0.12 2.9 -225 0.3 -311 -25.3 29.60 -2.0 -0.2 5.6 -18.4 -253 5.5 -15.6 1.4 0.8 -0.3 -19.5 -22.5 4.02 -295 1 -31.1 14.49 -25.3 -2.3 0.8 0.8 6.6 -5.4 -253 -294 -29.5 28.1 1.4 0.2 0.2 -0.8 1.0 4.9 -25.3 -29.4 4.2 1.4 0.2 0 0.7 -3.2 0.7 0.2 -0.5 0.1 -253 -25.3 -2 -0.3 Appendix B.Appendix

B–38 Hydrogeology, Hydrologic Budget, and Water Chemistry of the Medina Lake area, Texas storage -111.59 -154.73 -220.47 -270.93 Average (acre-ft/d) 52.91 23.95 22.00 23.79 (acre-ft/d) evaporation Average total out Sw 93.06 131.79 194.95 226.78 Average (acre-ft/d) in 97.58 84.56 Sw 119.89 100.35 Average (acre-ft/d) 2.54 0 0 0 Average (acre-ft/d) precipitation 1,044.43 1,043.77 1,043.00 1,042.61 sea level) Lake stage (ft above mean Average Medina 32.81 24.59 33.32 37.13 (acre-ft) (+/- error) out GW Average 88.05 99.34 101.10 104.93 (acre-ft/d) sea level) sea (ftmean above Medina Lake stage (ft above (ft BMA datum) BMA (acre-ft) total (+/- error) (+/- out system GW (acre-ft) Medina/Diversion Lakes combined hydrologic budget—Continued total storage (acre-ft) Date 01/03/9601/04/96 -216.501/05/96 -95.801/06/96 183.69 -23.001/07/96 -116.001/08/96 29.62 -269.9 90.41 -14.1201/09/96 -148.1 18.38 3.63 229.00 -81.6 19.10 1,052.24 131.66 34.84 32.24 21.87 1,052.22 84.18 1,044.44 1,052.22 16.83 1,052.19 1,052.13 1,044.42 1,044.42 1,052.1 1,044.39 1,044.33 1,052.08 1,044.3 1,044.28 01/21/9601/22/96 -131.101/23/96 -152.301/24/96 -53.0 75.2801/25/96 -188.1 144.2001/26/96 -177.3 22.4001/27/96 23.30 19.00 122.03 -79.901/28/96 -256.9 120.99 17.97 27.23 -202.4 1,051.67 25.00 13.28 1,051.64 160.36 123.26 20.28 34.42 1,043.87 1,051.63 1,051.58 1,043.84 28.32 1,051.54 1,043.83 1,043.78 1,051.52 1,051.46 1,043.74 1,051.41 1,043.72 1,043.66 1,043.61 02/08/9602/09/96 -178.002/10/96 -182.002/11/96 -200.7 92.9102/12/96 -93.5 95.7202/13/96 -443.0 111.22 27.76 -246.4 27.96 -86.26 30.3402/15/96 293.3602/16/96 -310.8 31.67 1,050.9 93.6702/17/96 50.45 -248.1 1,050.8602/18/96 -293.6 1,050.81 144.02 34.4102/19/96 -252.3 1,043.1 58.07 1,050.79 39.85 1,043.06 -297.2 1,050.68 111.94 1,043.01 37.42 1,050.63 98.25 39.05 1,042.99 136.07 1,042.88 1,050.5 35.33 38.76 1,042.83 1,050.44 1,050.37 1,042.7 1,050.31 1,042.64 1,050.24 1,042.57 1,042.51 1,042.44 01/10/9601/11/96 -96.101/12/96 -92.101/13/96 -183.201/14/96 -161.001/15/96 -147.001/16/96 -129.801/17/96 -137.001/18/96 -112.501/19/96 97.5801/20/96 -3.6 -398.9 98.14 -151.6 21.91 20.45 1,052.06 115.69 1,052.03 1,051.99 1,051.86 22.42 1,044.26 1,051.95 1,051.83 1,044.23 1,051.92 1,044.19 1,044.06 1,051.89 1,044.15 1,044.03 1,051.71 1,044.12 01/29/96 1,044.09 01/30/96 -117.2 1,043.91 01/31/96 -150.8 1,051.83 1,051.7402/01/96 -242.702/02/96 -248.6 1,044.03 1,043.94 02/03/96 -177.402/04/96 -241.6 134.5102/05/96 -230.102/06/96 34.13 -189.402/07/96 -166.9 -199.7 1,051.23 107.07 1,051.38 1,043.43 1,051.35 30.67 1,051.29 1,043.58 1,043.55 02/14/96 1,051.19 1,043.49 -223.6 1,050.94 1,051.13 1,051.08 1,043.39 1,043.14 1,051.04 81.22 1,043.33 1,051 1,043.28 32.34 1,043.24 02/20/96 -255.0 1,043.2 1,050.57 1,042.77 1,050.18 1,042.38 Appendix B.

Appendix B B–39 (acre-ft) (+/- error) storage Diversion Lake (acre-ft) (acre-ft) (+/- error) storage Medina Lake (acre-ft) total ration Evapo- (acre-ft) (acre-ft) (+/- error) Evaporation Diversion Lake (acre-ft) (acre-ft) (+/- error) (+/- Evaporation Medina Lake (acre-ft) (acre-ft) (+/- error) out SW Diversion Lake (acre-ft) (acre-ft) in (+/- error) SW Medina Lake Medina (acre-ft) (acre-ft) (+/- error) Precipitation Diversion Lake Diversion (acre-ft) (acre-ft) (+/- error) Medina/Diversion Lakes combined hydrologic budget—Continued Medina Lake Precipitation (acre-ft) Date 02/21/9602/22/9602/23/9602/24/9602/25/9602/26/9602/27/9602/28/9602/29/96 19.62 227.2303/01/9603/02/96 2.94 34.0803/03/9603/04/96 6.3003/05/9603/06/96 0.9503/07/9603/08/9603/09/96 89.00 101.3803/10/96 89.0003/11/96 89.00 10.20 8.9503/12/96 87.55 8.94 90.5303/13/96 82.99 8.95 238.02 220.1703/14/96 80.83 8.81 218.18 9.0903/15/96 80.77 8.34 23.80 22.02 222.1503/16/96 8.12 21.82 230.0803/17/96 243.97 8.11 101.26 22.21 236.03 50.7003/18/96 20.37 23.01 240.0003/19/96 98.84 24.40 12.85 10.18 23.60 12.67 243.9703/20/96 94.51 19.91 5.09 24.0003/21/96 90.57 45.98 9.93 3.21 24.40 96.39 178.51 -14.7303/22/96 96.48 9.49 1.81 4.98 102.43 -10.91 11.4903/23/96 0.71 9.09 24.10 106.43 17.85 138.84 -3.6803/24/96 0.45 9.68 0.45 -2.19 10.28 144.79 -2.7303/25/96 93.26 0.18 0.69 10.68 13.88 1.62 162.6403/26/96 79.38 0.11 3.43 -0.52 -0.55 22.99 14.48 166.61 52.51 164.6303/27/96 75.41 0.17 23.88 -0.39 9.38 21.08 0.41 16.26 -0.13 152.7303/28/96 77.39 63.67 0.86 32.06 7.99 13.30 5.75 16.66 -0.08 -300 16.46 -0.1003/29/96 79.38 3.58 31.07 7.59 -276 20.60 15.27 144.79 -11.4303/30/96 81.56 -15.25 47.60 9.55 7.79 -0.02 8.01 -221 99.82 144.79 -30.003/31/96 81.34 -11.29 0.81 7.99 21.51 -8.35 -225 7.77 -27.6 14.48 142.81 -2.86 151.38 -307 -34904/01/96 81.20 8.21 -22.1 -194 14.48 2.13 142.81 -2.27 -26504/02/96 79.16 1.13 0.20 -2.09 8.19 -9 -22.5 5.38 14.28 37.85 176.5304/03/96 -30.7 78.98 -34.9 1.11 -5.2 -0.41 55.80 8.17 -19.4 14.28 174.55 0.32 -24904/04/96 76.78 -26.5 0.28 -1.6 24.06 7.96 17.65 -0.30 23.79 172.56 -0.10 13.9504/05/96 74.84 0.28 0.77 -1.4 46.05 -0.8 5.44 7.94 4.6 17.45 198.13 174.55 -24.9 7.3 904/06/96 70.91 49.90 -0.2 -0.2 7.71 -0.07 6.02 73.41 33.19 -146 17.26 196.36 4.2 11.5104/07/96 65.36 -11.84 0.19 21.23 1.36 7.52 29.72 32.18 17.45 2.01 202.31 0.7 12.4804/08/96 65.65 7.13 1.1 -210 69.42 -14.6 19.64 0 3.76 208.26 7.39 1.9 -8.65 -19004/09/96 65.65 1.4 0.87 6.58 156.83 0.6 5.31 -217 0.50 20.23 1.64 22.29 8.60 8.21 216.20 65.45 6.62 -21.0 20.83 1.78 6.91 222.15 -22.7 6.99 -134 0.94 67.44 -19.0 0.22 -282 216.20 0.3 6.62 -21.7 21.62 0.41 9.43 224.13 2.15 1.23 -38 0.76 57.81 28.80 6.60 22.21 0.44 226.12 104.91 1.73 -13.4 -3.4 21.62 226.12 -28.2 6.79 9.2 0.13 24.93 22.41 226.12 2.36 -392 6.6 11.7 77.38 0.19 47.69 72.87 7.20 -3.8 0.31 26.23 22.61 73.84 226.12 79.36 51.68 22.61 38.56 -227 0.03 0.25 -4.8 22.61 47.71 228.10 1.4 -2.6 18.22 -226 80.95 -39.2 50.76 7.79 1.0 1.8 0.08 0.34 21.99 22.61 7.45 -196 80.87 1.03 -0.2 3.77 26.51 7.99 9.64 11.93 0.06 -22.7 22.81 -0.7 71.59 12.69 83.31 -22.6 -0.4 11.00 8.14 3.90 -252 0.08 2.63 -3.3 226.12 73.98 0.26 -19.6 0.94 8.12 234.05 8.90 6.63 17.90 0 4.37 245.95 66.05 1.40 1.88 -0.9 90.84 -122 8.38 7.16 2.75 -25.2 0.66 22.61 1.87 -2.8 249.92 -0.5 68.03 108.68 23.40 -174 7.46 9.77 29.83 24.60 -3.2 255.87 1.09 22.71 0.35 0.99 0.47 2.81 -0.1 -162 6.67 -12.2 24.99 0.47 255.87 -0.4 91.85 0.42 75.51 -235 -6 21.61 -232 6.87 -17.4 -231 125.55 25.59 261.82 57.34 -0.5 0.25 0.70 -16.2 0.17 39.96 49.58 -14.5 143.40 25.59 3.52 7.87 269.75 -385 0.11 52.63 -23.5 14.40 9.25 -23.2 5.40 12.62 -23.1 14.33 139.04 26.18 253.88 -0.9 -6.9 44.63 -355 14.40 -343 0.04 27.50 74.39 0.88 26.98 -2.2 1.97 -336 -3 -38.5 19.46 3.60 13.96 11.42 25.39 232.07 10.4 232.07 11.16 10 0.85 3 -1.0 44.50 2.30 -344 -35.5 -425 -34.3 232.07 -33.6 94.37 10.38 4.54 4.87 -339 0.31 23.21 23.21 -0.5 226.12 11.12 3.1 0.21 0.58 0.57 1.6 -34.4 -42.5 1.79 2.78 23.21 -235 1.5 0.5 -290 2.59 2.9 6.2 0.08 -33.9 17 22.61 0.14 0.78 56.50 22.32 0.5 22.46 0.45 1.80 59.63 0.70 17 -23.5 18 -29.0 14.17 0.4 0.9 14.13 17 0.20 0.42 12.22 8.19 -205 14.97 5.58 -132 0.45 2.6 46.43 0.11 3.54 17 17 0.11 2.6 2.7 -301 -241 -20.5 20.25 3.06 2.25 -13.2 -300 2.6 46.29 0.88 0.03 0.56 -30.1 -373 -24.1 10.80 0.56 2.6 -37.4 2.6 -351 10.6 -30.0 0.22 0.47 0.14 2.90 -306 -37.3 11.1 -5.6 15.4 -35.1 58.75 0.12 1.6 23.21 9.3 -199 -30.6 14.73 -114 1.7 2.3 6.4 -283 12.69 4.9 -19.9 1.4 -184 -11.4 -1.5 -402 -28.3 1.0 0.7 -10.5 -18.4 -0.2 -25.5 -40.2 -33.8 -1.6 -26.2 -3.8 -26 -5.1 -3.9 -3.9 Appendix B.Appendix

B–40 Hydrogeology, Hydrologic Budget, and Water Chemistry of the Medina Lake area, Texas storage -267.40 -200.03 -229.00 -257.71 -297.41 Average (acre-ft/d) 10.54 31.57 60.20 35.44 29.63 (acre-ft/d) evaporation Average total out Sw 230.08 181.91 148.76 205.29 246.15 Average (acre-ft/d) in 85.59 96.22 89.05 73.84 75.27 Sw Average (acre-ft/d)

0 0 0 8.97 36.16 Average (acre-ft/d) precipitation 1,042.12 1,041.72 1,041.41 1,040.82 1,039.89 sea level) Lake stage (ft above mean Average Medina 37.02 32.56 33.91 36.34 41.20 (acre-ft) (+/- error) out GW Average 90.82 112.37 118.93 109.09 105.88 (acre-ft/d) sea level) sea (ftmean above Medina Lake stage (ft above (ft BMA datum) BMA (acre-ft) total (+/- error) (+/- out system GW (acre-ft) Medina/Diversion Lakes combined hydrologic budget—Continued total storage (acre-ft) Date 02/21/9602/22/96 -281.202/23/96 -222.602/24/96 -220.4 128.9502/25/96 -340.0 80.1202/26/96 36.78 -299.7 66.6502/27/96 -260.8 149.87 32.48 -247.1 161.91 33.2402/29/96 44.26 1,050.11 112.9203/01/96 39.80 -309.0 1,050.06 86.1703/02/96 36.77 -168.7 1,042.31 1,050.0103/03/96 -200.8 1,049.92 353.38 35.8003/04/96 1,042.26 -205.3 1,049.85 67.65 53.8103/05/96 1,042.21 -183.4 1,049.79 127.61 1,042.12 -138.8 122.84 26.08 1,042.05 1,049.7303/07/96 28.26 123.16 1,041.99 03/08/96 28.88 -284.6 1,049.61 77.3203/09/96 26.78 1,041.93 -395.3 1,049.5703/10/96 -227.9 1,049.52 23.57 1,041.81 81.4803/11/96 -228.8 1,049.47 285.96 1,041.77 -199.2 1,049.42 137.55 50.76 1,041.72 03/13/96 45.05 113.71 1,041.67 1,049.3903/14/96 28.72 -136.5 1,041.62 82.1103/15/96 30.09 -180.9 1,049.3103/16/96 1,041.59 -165.0 1,049.22 28.37 39.6203/17/96 -221.6 1,049.16 80.7803/18/96 1,041.51 -221.0 1,049.11 22.95 1,041.42 64.5003/19/96 -232.0 25.95 1,041.36 1,049.06 94.6303/20/96 -381.9 25.24 1,041.31 67.8303/21/96 -352.1 31.55 1,048.97 -8.1703/22/96 1,041.26 -319.0 165.03 32.56 1,048.9303/23/96 -327.0 160.90 41.65 1,048.8903/24/96 48.36 1,041.17 -322.0 107.59 1,048.8303/25/96 43.56 1,041.13 -273.0 139.04 1,048.77 42.92 1,041.09 -218.0 150.12 1,048.7103/27/96 42.30 1,041.03 1,048.62 107.8003/28/96 41.45 1,040.97 -336.8 1,048.53 -37.03 37.4603/29/96 -194.4 1,040.91 1,048.44 1,040.82 03/30/96 -289.9 40.52 1,048.36 210.24 1,040.73 03/31/96 -225.6 1,048.27 1,040.64 23.2004/01/96 43.97 -290.7 1,048.2 115.12 1,040.56 04/02/96 -366.6 32.00 1,048.14 1,040.47 41.6604/03/96 39.77 -346.1 69.2704/04/96 1,040.4 -307.5 1,047.94 173.79 35.91 1,040.34 -209.5 111.97 41.80 1,047.8904/06/96 46.27 1,047.81 1,040.14 93.0004/07/96 45.80 -139.5 1,047.75 20.7504/08/96 1,040.09 -316.8 41.42 1,040.01 1,047.6704/09/96 -210.2 1,047.57 33.03 -59.46 1,039.95 -428.0 1,047.48 187.08 1,039.87 31.12 106.81 1,039.77 1,047.4 39.44 328.23 1,039.68 1,047.34 33.36 48.44 1,047.28 1,039.6 1,039.54 1,047.2 1,047.16 1,039.48 1,047.05 1,039.4 1,039.36 1,039.25 02/28/96 -194.2 -39.44 40.5503/06/96 1,049.68 -38.2 1,041.88 -46.29 20.4903/12/96 -258.0 1,049.38 138.86 32.24 1,041.58 1,049 1,041.2 03/26/96 -407.0 199.79 52.03 1,048.0304/05/96 1,040.23 -169.4 155.91 43.58 1,047.31 1,039.51 Appendix B.

Appendix B B–41 (acre-ft) (+/- error) storage Diversion Lake (acre-ft) (acre-ft) (+/- error) storage Medina Lake (acre-ft) total ration Evapo- (acre-ft) (acre-ft) (+/- error) Evaporation Diversion Lake (acre-ft) (acre-ft) (+/- error) (+/- Evaporation Medina Lake (acre-ft) (acre-ft) (+/- error) out SW Diversion Lake (acre-ft) (acre-ft) in (+/- error) SW Medina Lake Medina (acre-ft) (acre-ft) (+/- error) Precipitation Diversion Lake Diversion (acre-ft) (acre-ft) (+/- error) Medina/Diversion Lakes combined hydrologic budget—Continued Medina Lake Precipitation (acre-ft) Date 04/10/9604/11/9604/12/9604/13/9604/14/9604/15/9604/16/9604/17/9604/18/9604/19/9604/20/9604/21/9604/22/9604/23/96 29.6204/24/9604/25/96 4.4404/26/96 127.1404/27/96 115.6404/28/96 12.77 103.14 195.0504/29/96 11.6304/30/96 95.13 29.26 10.36 224.1305/01/96 92.87 230.0805/02/96 86.92 9.56 22.41 5.70 240.0005/03/96 79.20 9.33 23.0105/04/96 73.31 8.73 24.00 243.97 0.8505/05/96 65.16 7.97 28.38 55.54 247.9305/06/96 59.21 7.38 24.40 249.92 8.0005/07/96 59.15 6.56 22.51 7.10 24.79 49.43 263.80 5.6005/08/96 57.92 5.96 24.99 102.60 271.74 2.0005/09/96 32.27 5.96 5.63 26.38 275.70 4.9905/10/96 55.18 1.11 56.48 305.45 5.85 15.39 27.17 283.64 107.5505/11/96 53.22 8.07 27.57 0.31 299.50 14.1205/12/96 53.20 30.55 0.28 0.89 65.43 5.56 317.36 26.89 28.36 4.69 305.4505/13/96 53.45 38.80 5.36 29.95 0.08 16.3605/14/96 51.29 1.27 0.22 11.07 31.74 5.36 30.55 2.23 29.49 25.85 303.47 0.7005/15/96 4.27 5.39 9.70 8.56 301.4905/16/96 51.33 0.32 25.89 5.17 2.77 8.31 -102 0.56 30.35 2.62 23.40 305.45 11.14 6.4605/17/96 53.22 1.07 30.15 47.60 9.12 313.39 2.1405/18/96 55.20 1.57 5.18 6.47 -310 33.54 -243 30.55 0.66 -10.2 317.3605/19/96 2.79 53.20 0.45 58.71 111.82 46.65 5.36 1.07 31.34 2.28 4.8105/20/96 47.29 0.39 61.91 5.56 -282 -31.0 0.35 -24.3 31.74 319.34 -348 11.6605/21/96 45.26 0.11 1.05 68.05 -264 5.36 2 0.27 0.48 315.37 15.4805/22/96 45.26 58.51 4.77 307.44 0.09 -28.2 0.38 40.38 31.93 313.39 -45105/23/96 43.28 0.26 -34.8 -26.4 13.19 4.57 8.4 11.52 4.9 31.54 1.95 0.12 323.31 14.6305/24/96 43.40 26.92 30.74 4.57 -379 0.09 31.34 2.59 0.3 329.26 145.7005/25/96 -45.1 -2.2 4.37 8.91 -331 3.30 26.95 32.33 0.49 335.21 1.3 -437 0.7 3.105/26/96 52.56 11.62 2.5 53.66 4.38 -37.9 36.42 0.65 32.93 2.48 335.21 10.9105/27/96 47.90 30.43 -0.3 -220 9.50 -366 -33.1 12.4 33.52 190.10 335.21 13.42 -43.7 -32105/28/96 49.55 0.56 48.59 5.31 0.5 0.4 0.62 33.52 9.46 339.17 2.73 51.07 64.50 6.23 -367 4.82 28.51 -22.0 7.61 7.2 -36.6 33.52 2.56 1.9 -361 52.92 0.14 -32.1 5.00 4.2 13.8 33.92 2.28 196.36 2.36 -325 52.66 60.99 1.56 5.14 -36.7 0.47 6.61 210.25 1.1 0.64 15.7 52.74 -36.1 1.30 2.5 5.32 13.75 0.57 19.64 -3 214.21 0.6 2.1 -398 48.67 -32.5 151.93 5.29 0.40 21.02 0.12 7.78 214.21 12.1 0.99 44.71 0.32 5.30 2.4 -429 0.11 11.2 21.42 0.4 218.18 40.78 -39.8 55.94 -321 12.69 4.89 0.10 -0.5 10 21.42 224.13 1.95 36.85 11.38 1.8 4.50 0.03 -42.9 31.73 21.82 30.68 224.13 -320 1.7 32.93 -32.1 4.11 3.17 22.41 218.18 6 -358 32.85 3.71 9.86 -620 0.34 1.5 22.41 234.05 3.09 30.68 -32.0 -2.9 3.32 2.67 21.82 241.98 28.70 0.57 -35.8 2.9 -366 3.31 0.08 -62.0 23.40 253.88 -361 26.92 0.9 -0.4 -357 3.09 380.83 24.20 -5.7 265.78 26.98 0.14 53.72 2.89 -36.6 0.4 25.39 285.62 -36.1 26.66 8 -2 38.08 64.44 2.72 -35.7 8.12 26.58 309.42 -0.9 13.43 66.08 2.73 13.26 28.56 339.17 16.11 -1.9 30.59 68.48 -391 2.69 30.94 364.96 11.98 -0.3 8.2 16.52 -4.7 1.2 51.12 -293 33.92 2.30 366.94 17.12 -0.3 47.79 3.08 -39.1 36.50 2.83 370.91 12.78 2.99 -0.7 65.97 1.2 -29.3 36.69 0.57 2.88 11.95 56.41 37.09 0.71 2.99 376.86 -388 16.49 -0.1 59.59 0.72 2.22 0.55 -352 14.10 89 56.02 56.67 0.75 37.69 2.10 -395 -38.8 14.90 67.27 41.24 0 0.56 2.93 0.14 -35.2 14.17 -137 68.96 0.52 13.4 2.53 -39.5 10.31 -308 71.47 11.92 0.73 2.70 -1.7 -343 -13.7 53.35 12.53 0.63 2.58 -240 0 -373 -30.8 49.89 2.98 0.68 1.90 -0.3 0 -406 -462 -34.3 68.89 -21.9 -62 0.65 -277 -24.0 -236 -37.3 58.94 -29.1 0.47 -240 -339 0 -40.6 0.55 62.29 -46.2 -12 -3.3 -6.2 -240 -27.7 0 -439 -23.6 59.26 -19 -4.4 10.1 -377 -24.0 -568 0.14 -33.9 43.14 -16 13.8 -24.0 -535 -1.8 -43.9 -10 -9 23 1.5 -37.7 -600 -2.9 -56.8 12.47 23 -9 2.1 -2.4 -53.5 -26 24 -1.5 -60.0 -30 -1.4 -133 23 3.5 -1.4 3.5 -3.9 9 -13.3 16.4 3.6 -4.5 3.5 2.5 1.4 3 0.5 Appendix B.Appendix

B–42 Hydrogeology, Hydrologic Budget, and Water Chemistry of the Medina Lake area, Texas storage -227.32 -286.06 -349.77 -392.91 -333.00 -433.10 Average (acre-ft/d) 33.08 47.16 33.92 42.31 63.41 57.07 (acre-ft/d) evaporation Average total out Sw 230.08 242.38 290.03 318.59 242.78 339.50 Average (acre-ft/d) in 98.74 61.99 51.80 40.79 28.80 Sw 116.81 Average (acre-ft/d) 0 3.29 0 0 34.39 25.09 Average (acre-ft/d) precipitation 1,039.37 1,038.99 1,038.34 1,037.36 1,035.69 1,035.06 sea level) Lake stage (ft above mean Average Medina 37.43 41.58 47.83 54.31 43.24 58.80 (acre-ft) (+/- error) out GW Average 95.26 91.09 67.60 65.32 115.35 108.90 (acre-ft/d) sea level) sea (ftmean above Medina Lake stage (ft above (ft BMA datum) BMA (acre-ft) total (+/- error) (+/- out system GW (acre-ft) Medina/Diversion Lakes combined hydrologic budget—Continued total storage (acre-ft) Date 04/10/96 -100.004/12/9604/13/96 -238.1 -26.4904/14/96 -284.204/15/96 -344.9 28.63 77.84 -261.5 101.8204/17/96 131.12 36.1404/18/96 39.33 -371.8 1,047.02 -13.3204/19/96 45.96 -326.804/20/96 -217.5 46.07 133.00 1,046.87 1,039.22 04/21/96 -350.3 1,046.8 104.7404/22/96 48.21 -354.9 1,046.71 -15.84 43.6704/23/96 1,039.07 -423.2 1,046.63 83.0004/24/96 1,039 -349.8 36.45 1,038.91 97.86 -315.0 1,046.41 175.98 48.16 1,038.83 1,046.32 48.19 52.9204/27/96 54.22 1,046.26 1,038.61 04/28/96 -431.9 2.23 48.93 1,038.52 1,046.1604/29/96 -324.0 1,038.46 1,046.06 47.2904/30/96 -318.1 1,045.94 152.0905/01/96 1,038.36 -325.7 245.20 1,045.8505/02/96 53.72 1,038.26 -101.84 -622.0 1,038.14 05/03/96 54.10 -367.9 1,045.75 58.36 1,038.05 -361.7 7.60 332.08 1,045.42 1,037.95 87.93 47.21 70.11 1,045.33 77.06 1,045.24 49.19 1,037.62 48.81 1,037.53 1,045.15 1,044.98 1,037.44 1,044.87 1,037.35 1,037.18 1,044.77 1,037.07 1,036.97 05/17/9605/18/96 -337.105/19/96 -355.005/20/96 -392.0 80.49 -422.0 84.8405/22/96 103.50 42.3805/23/96 -316.0 135.80 45.3405/24/96 48.49 -415.005/25/96 50.35 -545.0 -31.63 1,043.605/26/96 -526.0 1,043.5 45.59 -583.6 49.00 1,043.39 144.6605/28/96 1,043.27 126.78 57.43 1,035.8 69.28 -130.0 196.21 1,035.7 1,035.59 66.48 1,043.1 1,035.47 71.38 -228.74 1,042.97 1,042.8 40.20 1,035.3 1,042.64 1,035.17 1,042.46 1,035 1,034.84 1,042.28 1,034.66 1,034.48 04/11/96 -301.6 178.8404/16/96 40.39 -438.6 1,046.94 185.95 55.36 1,039.14 1,046.5104/25/9604/26/96 -352.8 1,038.71 -392.0 71.07 53.0105/04/96 1,045.5405/05/96 -389.705/06/96 -352.005/07/96 1,037.74 -395.0 1,045.6505/08/96 -391.105/09/96 -350.0 1,037.85 05/10/96 -204.0 87.2005/11/96 -229.9 186.0705/12/96 51.98 -71.0 46.9305/13/96 49.96 -287.005/14/96 -249.0 38.2205/15/96 -266.0 1,044.3305/16/96 -407.0 1,044.23 1,044.66 -158.9 1,044.56 1,044.15 1,036.53 1,036.43 1,044.45 1,036.86 -66.62 1,036.76 1,036.35 1,036.65 05/21/96 29.65 -213.0 1,044.08 1,044.06 1,043.69 -89.66 1,043.98 1,036.28 1,043.91 39.23 1,036.26 1,043.84 1,035.89 1,036.18 05/27/96 1,043.73 1,036.11 -448.2 1,036.04 1,043.2 1,035.93 282.23 66.50 1,035.4 1,042.32 1,034.52 Appendix B.

Appendix B B–43 (acre-ft) (+/- error) storage Diversion Lake (acre-ft) (acre-ft) (+/- error) storage Medina Lake (acre-ft) total ration Evapo- (acre-ft) (acre-ft) (+/- error) Evaporation Diversion Lake (acre-ft) (acre-ft) (+/- error) (+/- Evaporation Medina Lake (acre-ft) (acre-ft) (+/- error) out SW Diversion Lake (acre-ft) (acre-ft) in (+/- error) SW Medina Lake Medina (acre-ft) (acre-ft) (+/- error) Precipitation Diversion Lake Diversion (acre-ft) (acre-ft) (+/- error) Medina/Diversion Lakes combined hydrologic budget—Continued Medina Lake Precipitation (acre-ft) Date 05/29/9605/30/9605/31/9606/01/96 41.8206/02/96 41.6206/03/96 6.2706/04/96 6.2406/05/9606/06/96 3.0306/07/9606/08/96 0.4606/09/9606/10/9606/11/96 38.2406/12/9606/13/96 32.29 3.8406/14/9606/15/96 30.59 3.2406/16/96 30.37 388.7606/17/96 3.0806/18/96 38.88 386.78 3.0506/19/96 46.18 376.8606/20/96 34.27 38.68 52.49 384.7906/21/96 30.31 4.63 37.6906/22/96 26.34 3.44 13.12 38.48 36.8906/23/96 22.33 3.04 392.7306/24/96 24.22 15.24 2.65 398.68 9.2206/25/96 22.08 2.46 46.08 2.25 39.27 164.55 398.6806/26/96 20.15 2.43 3.81 39.87 398.68 11.5206/27/96 19.89 53.97 0.62 2.21 24.68 1.72 39.87 398.6806/28/96 20.23 23.92 2.02 39.87 398.6806/29/96 22.14 0.71 8.10 38.60 2.00 54.95 0.43 39.87 2.15 396.6906/30/96 19.95 56.45 2.03 5.98 39.87 394.7107/01/96 20.15 0.18 64.97 2.22 9.65 -392 39.67 0.54 1.31 392.73 14.1107/02/96 18.17 38.61 86.04 2.00 39.47 392.73 16.2407/03/96 14.96 1.12 56.75 2.02 -39.2 15.95 39.27 394.71 0.20 -390 21.5107/04/96 14.52 1.83 48.22 43.72 1.82 39.27 2.68 396.69 14.1907/05/96 14.90 0.28 56.68 1.50 -495 39.47 3.09 398.68 10.93 -495 -39.007/06/96 14.10 0.46 -0.7 79.43 1.46 19.16 39.67 0.67 4.12 404.63 14.1707/07/96 15.33 54.56 1.50 -49.5 25.04 39.87 0.77 2.72 15.85 410.58 19.8607/08/96 14.76 -49.5 47.64 -0.1 1.42 40.43 1.03 40.46 2.10 -6.1 412.56 1.93 13.6407/09/96 14.64 59.13 40.60 1.54 -489 0.68 41.06 2.72 412.56 1.60 11.9107/10/96 10.23 40.45 68.06 -6.3 40.34 1.48 0.53 41.26 3.83 296.44 -9.1 131 424.46 -0.9 10.15 -48907/11/96 10.43 90.16 53.37 432.40 1.47 -48.9 41.26 0.68 2.64 426.45 10.09 -58007/12/96 59.47 6.07 52.85 -0.9 1.03 44.47 432.40 42.45 0.96 2.31 428.43 -1.4 -579 13.3407/13/96 -48.9 13.1 45.82 43.24 38.03 1.05 42.64 0.66 1.98 432.40 -355 13.21 1407/14/96 24.36 -58.0 59.40 39.72 43.24 24.27 0.58 42.84 1.97 1.31 436.36 -44607/15/96 20.39 -57.9 83.25 58.60 9.51 12 0.49 43.24 2.62 31.68 -2.3 432.40 -41307/16/96 19.80 -35.5 57.20 40.12 2.45 9.93 3.64 0.49 43.64 2.60 0.20 28.11 14.65 -733 5.3 15.99 -44.6 2.1 49.95 31.72 2.05 43.24 0.65 -1.7 -0.3 7.92 10.03 -535 14.00 -41.3 1.88 42.58 54.60 1.99 0.65 1.8 -0.5 432.40 -472 13.61 -73.3 1.97 7.03 42.31 12.30 56.43 1.61 0.8 7.93 2.93 -1.1 432.40 -0.3 8.65 -472 13.65 12.61 0.47 -53.5 55.98 1.35 45.80 1.41 1.62 43.24 2.02 -2.5 428.43 -0.1 -469 14.11 11.62 0.49 -47.2 55.44 1.37 1.29 0.73 43.24 1.43 -1.1 426.45 -0.2 11.45 -528 10.43 -47.2 1.60 0.87 0.20 1.27 0.41 39.91 0.50 42.84 2.76 -1.7 426.45 -0.4 -530 10.63 -46.9 43.45 1.17 41.68 42.64 2.86 0.36 -3.7 424.46 -0.2 370.91 0.40 -52.8 61.53 37.92 1.05 -525 9.84 42.64 0.69 2.33 436.36 -4.9 426.45 -0.3 10.86 11.48 33.30 -53.0 42.14 41.51 1.07 -493 9.24 42.45 0.72 -0.6 428.43 37.09 -0.6 -523 29.54 35.02 9.48 -52.5 33.32 43.64 0.58 42.64 0.99 430.41 -0.7 -435 -734 10.38 8.9 57.36 30.23 1.17 -49.3 42.84 2.23 0.93 432.40 -0.1 2.1 -52.3 -465 59.29 37.31 27.21 8.76 -455 43.04 -43.5 -461 10.95 -73.4 1.95 48.13 61.25 432.40 32.34 1.3 7.56 0.7 43.24 0.56 2.16 279.67 -601 11.42 -46.5 434.38 31.61 0.3 9.33 1.7 -45.5 10 6.80 15.31 -536 11.03 43.24 0.49 -46.1 1.81 47.96 1.11 8.08 27.97 -1.3 0.54 0.1 9.3 43.44 -60.1 1.57 45.68 47.37 1.15 7.90 9.64 0.3 11.99 0.45 -53.6 1.95 1.9 1.48 1.11 4.8 8.85 39.88 3.28 1.5 45.79 -0.2 261.82 11.84 -473 2.6 0.39 1.69 43.67 52.81 1.4 53.93 0.97 269.75 0.4 0.49 1.66 0.37 11.45 -499 0.3 36.84 0.82 26.18 2.53 -4.2 0.89 271.74 0.7 13.20 -472 0.42 -47.3 0.4 13.48 31.80 26.98 2.51 0.41 269.75 -578 0.1 -49.9 39.25 27.17 0.63 28.68 -0.6 64.53 -47.2 2.43 285.62 64.66 -563 34.03 2.92 0.63 -1 26.98 2.88 52.47 -447 -57.8 33.27 -113 -572 16.17 0.61 28.56 50.49 -4.1 48.78 -469 -56.3 0.73 -3.4 13.12 0.72 49.88 -557 -0.2 -44.7 -11.3 50.20 -57.2 12.20 -554 -1.6 -0.6 -46.9 48.22 3.56 75.60 -0.5 -887 55.73 -1.4 12.55 -55.7 56.81 2.83 -55.4 40.6 -0.2 -517 18.90 0 0.89 2.61 2.9 -485 -88.7 -0.2 -546 0.9 0.71 2.72 3 -51.7 6.1 0.65 5.3 -48.5 4.07 68.22 0.4 -54.6 0 0.1 0.8 0.68 55.30 -227 1.02 51.39 0.8 0 0.5 44.3 -398 -0.2 0.1 52.91 -226 -22.7 79.67 6.6 -39.8 -433 0 0 -22.6 -34.2 -440 -51.7 -43.3 -26.3 -5.1 -44.0 -7.8 -3.9 3.5 -1.5 0.5 -0.2 Appendix B.Appendix

B–44 Hydrogeology, Hydrologic Budget, and Water Chemistry of the Medina Lake area, Texas storage -406.77 -512.37 -501.52 -547.85 -533.08 Average (acre-ft/d) 29.68 63.61 46.32 50.29 40.90 (acre-ft/d) evaporation Average total out Sw 383.94 396.25 405.95 430.08 429.99 Average (acre-ft/d) in 34.13 23.08 17.11 13.25 14.82 Sw Average (acre-ft/d) 0 0 0 40.45 15.70 Average (acre-ft/d) precipitation 1,034.19 1,033.04 1,031.83 1,030.78 1,029.06 sea level) Lake stage (ft above mean Average Medina 58.50 66.84 65.62 71.27 69.84 (acre-ft) (+/- error) out GW Average 67.73 75.58 66.36 80.72 92.71 (acre-ft/d) sea level) sea (ftmean above Medina Lake stage (ft above (ft BMA datum) BMA (acre-ft) total (+/- error) (+/- out system GW (acre-ft) Medina/Diversion Lakes combined hydrologic budget—Continued total storage (acre-ft) Date 05/29/9605/30/96 -501.305/31/96 -504.106/01/96 -396.1 139.0806/02/96 -392.7 101.45 62.41 -475.0 44.83 63.84 31.8806/05/96 103.41 56.1506/06/96 -574.7 1,042.13 57.2206/07/96 63.21 -580.7 1,041.9806/08/96 -355.5 134.30 1,034.33 1,041.8606/09/96 -447.1 114.19 1,034.18 1,041.7406/10/96 72.29 -415.5 1,041.59 -78.43 73.5606/11/96 1,034.06 -734.1 26.6606/12/96 1,033.94 -536.7 55.29 -18.46 1,033.79 -475.7 1,041.3 278.01 60.7206/14/96 58.90 1,041.12 107.0006/15/96 85.52 -469.6 1,041.01 53.1806/16/96 67.79 1,033.5 -519.1 1,033.32 1,040.8706/17/96 -527.9 62.72 1,040.74 1,033.21 48.7606/18/96 -524.3 1,040.51 76.66 1,033.07 -491.3 1,040.34 62.41 1,032.94 76.8306/20/96 67.89 1,032.71 1,040.19 86.3506/21/96 -724.7 68.35 1,032.54 51.9506/22/96 -450.2 67.46 1,039.8906/23/96 1,032.39 -458.4 271.45 65.07 1,039.7206/24/96 -600.6 1,039.55 85.51 1,032.09 -540.2 3.20 -16.72 1,039.3806/26/96 1,031.92 115.18 1,039.22 63.0206/27/96 1,031.75 -436.3 64.68 70.1106/28/96 75.61 1,031.58 -474.0 1,038.8106/29/96 1,031.42 -503.1 69.83 45.0406/30/96 -475.4 1,038.66 1,038.51 1,031.01 20.2807/01/96 -579.6 1,038.31 62.40 51.2207/02/96 -564.4 65.05 1,030.86 1,038.13 1,030.71 23.1007/03/96 -447.0 132.30 66.74 1,030.51 07/04/96 -468.1 120.15 64.62 1,037.83 72.3807/05/96 1,030.33 -554.0 1,037.67 -3.1107/06/96 71.05 -548.7 1,037.51 20.2407/07/96 1,030.03 -886.2 103.93 62.36 1,037.3507/08/96 1,029.87 -517.0 1,037.15 63.92 78.24 70.73 1,029.71 -546.2 1,036.96 414.5507/10/96 1,029.55 71.19 1,029.35 46.22 1,036.81 99.3907/11/96 -72.4 1,029.16 1,036.65 64.2507/12/96 -440.7 1,036.46 68.3707/13/96 -261.2 1,029.01 71.07 1,036.2707/14/96 1,028.85 -449.7 1,035.96 118.13 1,028.66 5.8207/15/96 -252.3 -57.89 1,035.7807/16/96 57.92 1,028.47 -429.5 59.83 136.08 1,028.16 1,035.59 -441.5 38.61 -59.80 50.46 1,027.98 116.47 1,027.79 37.62 1,035.18 1,035.35 85.06 52.55 1,035.1 1,034.96 55.78 1,027.38 1,027.55 1,034.88 1,027.3 1,034.81 1,027.16 1,027.08 1,034.65 1,027.01 1,026.85 06/03/9606/04/96 143.0 -491.3 -547.83 63.80 43.24 64.73 1,041.63 1,041.4806/13/96 1,033.83 -476.9 1,033.68 57.58 62.5206/19/96 -513.0 1,040.04 41.11 1,032.24 68.9706/25/96 -463.1 1,039.05 181.57 68.51 1,031.25 1,037.98 1,030.18 07/09/96 -569.1 118.61 73.82 1,035.39 1,027.59 Appendix B.

Appendix B B–45 (acre-ft) (+/- error) storage Diversion Lake (acre-ft) (acre-ft) (+/- error) storage Medina Lake (acre-ft) total ration Evapo- (acre-ft) (acre-ft) (+/- error) Evaporation Diversion Lake (acre-ft) (acre-ft) (+/- error) (+/- Evaporation Medina Lake (acre-ft) (acre-ft) (+/- error) out SW Diversion Lake (acre-ft) (acre-ft) in (+/- error) SW Medina Lake Medina (acre-ft) (acre-ft) (+/- error) Precipitation Diversion Lake Diversion (acre-ft) (acre-ft) (+/- error) Medina/Diversion Lakes combined hydrologic budget—Continued Medina Lake Precipitation (acre-ft) Date 07/17/9607/18/9607/19/9607/20/9607/21/9607/22/9607/23/9607/24/9607/25/9607/26/9607/27/9607/28/9607/29/9607/30/9607/31/9608/01/9608/02/9608/03/96 8.2308/04/96 7.8508/05/96 7.46 0.8308/06/96 7.04 0.7908/07/96 6.43 0.7508/08/96 299.50 6.01 0.7108/09/96 295.54 6.05 0.6508/10/96 29.95 303.47 6.05 0.6108/11/96 29.55 311.40 6.17 0.6108/12/96 30.35 321.32 8.63 64.70 0.6108/13/96 31.14 327.27 9.90 65.73 0.6308/14/96 32.13 333.22 16.17 6.29 69.73 0.8808/15/96 32.73 347.11 16.43 6.49 70.31 1.0008/16/96 33.32 362.98 17.43 6.29 66.57 0.6408/17/96 34.71 3.49 376.86 17.58 6.07 55.33 0.6608/18/96 36.30 3.56 378.84 16.64 5.67 48.98 0.6408/19/96 37.69 0.87 3.79 376.86 13.83 5.49 53.55 0.6108/20/96 37.88 0.89 3.83 378.84 12.24 5.16 40.65 0.5808/21/96 0.95 37.69 3.63 89.50 4.37 386.78 13.39 5.08 68.19 0.5608/22/96 0.96 37.88 3.03 394.71 10.16 4.88 69.28 0.53 13.4308/23/96 0.91 38.68 2.67 56.68 402.64 0.66 -392 4.88 73.52 0.5208/24/96 39.47 0.76 2.93 58.92 408.59 -439 4.84 74.14 0.5008/25/96 40.26 0.67 2.23 44.65 410.58 8.50 -421 4.66 -39.2 70.21 0.5008/26/96 40.86 0.73 54.78 410.58 8.84 -510 4.44 4.62 -43.9 58.35 122.09 0.4908/27/96 0.56 41.06 410.58 6.70 -481 -42.1 4.62 51.65 3.49 -12.5 0.4708/28/96 41.06 408.59 8.22 18.31 -402 -51.0 4.44 56.48 8.28 0.45 0.4708/29/96 41.06 -7.5 408.59 -404 -48.1 42.88 172.42 0.47 0.52 -1.9 08/30/96 40.86 402.64 -426 0 5.28 -40.2 326.51 3.84 0.45 1.2408/31/96 40.86 388.76 396.69 -1.1 25.86 -576 0 5.38 -40.409/01/96 40.26 394.71 48.98 0 5.08 -42.6 0.54 0.58 6.03 38.8809/02/96 39.67 92.69 390.74 0 -57.6 4.98 0 7.74 0.55 6.6209/03/96 39.47 -7 5.08 0 0.52 5.39 13.90 39.07 -6 384.79 0.62 5.12 0 0.51 0.85 9.86 2.94 -0.5 366.94 0.68 5.16 0 0.52 0.81 -1.1 38.48 6.96 360.99 41.92 222.15 0.53 -0.9 6.55 36.69 303.47 1.01 0.44 -0.1 311.40 6.37 14.30 194.38 0.53 36.10 315.37 1.04 10.48 22.21 18.11 30.35 31.14 309.42 0.68 19.44 26.58 144.79 0.68 1.46 18.49 31.54 307.44 -538 38.48 15.43 1.93 30.94 75.43 2.49 19.07 -538 14.48 47.10 166.61 29.82 6.65 30.74 14.77 214.21 1.87 -459 -53.8 56.76 9.62 91.24 1.57 0.27 4.77 -502 8.69 -53.8 11.78 16.66 59.96 45.62 7.45 16.50 21.42 10.74 3.69 -498 -45.9 14.19 1.59 57.34 9.12 65.85 -510 7.6 -50.2 14.99 2.32 44.41 47.60 1.20 2.85 4.56 16.82 45.62 1.67 2.68 -469 3 -49.8 14.33 0.17 1.84 27.69 0.92 26.90 3.45 -444 2.1 -51.0 -281 6.59 0.25 19.69 1.1 0.13 0.31 3.64 4.76 -573 1.3 4.21 -46.9 4.56 0.20 11.59 6.92 28.18 0.10 0.66 35.33 0.38 3.49 47.60 2.78 -507 3.9 -44.4 0.5 -28.1 0.3 4.92 40.80 26.78 0.40 31.53 -555 3.7 -57.3 20.27 49.95 25.59 0.2 -403 2.90 0.07 1.04 31.66 0.38 14.73 3.72 -452 9.1 -50.7 15.68 1.73 4.76 60.21 0.6 -476 -4.1 45.62 7.88 2.75 -530 -504 4.6 -55.5 -476 63.60 1.22 0.6 -40.3 -415 6.40 0.11 -2 3.68 -193 -498 -45.2 -445 11.40 0.19 60.83 0.69 1.4 -47.6 38.53 45.62 -0.6 -480 -679 3.1 -53.0 -50.4 -445 -47.6 4.56 0.13 0.7 1.92 -41.5 -11.2 65.45 -463 0 -19.3 -49.8 -419 17.86 -44.5 0.07 1.52 -72 -0.3 29.42 0.87 9.63 0.2 -48.0 -67.9 -44.5 4.56 -9.5 0.5 0.21 20.91 -0.1 13.01 -1.7 2.1 -216 -46.3 6.9 -41.9 6.55 10.1 0.17 -55.4 -561 0.09 12.27 -7.6 -7.2 -691 0.6 0 -1.4 0 -120 2.33 -0.9 20.63 -9 3.25 33.46 7.7 -21.6 0 -8.3 0.3 1.0 -56.1 1.5 27.11 -4.4 -2.4 -1.1 -69.1 15.60 48 0.1 0.25 -12.0 -0.1 3.1 5.16 -19.3 -24 1.2 -1.4 0.76 -120 -0.7 -0.4 41 -24 -4.1 40.86 4.8 0.5 -8 -2.9 0.08 1.20 -12.0 -2.4 -0.6 -2.4 6.2 -19 -24 0.13 -27.1 13.78 -49.5 -1.2 -12 -2.4 -4.1 21.83 -2.9 -7.4 96 -1.8 -28.4 24 9.6 -4.3 2.4 -12.9 -12.6 -1.9 -1.9 -72 -7.2 -23 -3.5 Appendix B.Appendix

B–46 Hydrogeology, Hydrologic Budget, and Water Chemistry of the Medina Lake area, Texas storage -353.14 -461.93 -449.47 Average (acre-ft/d) 59.39 61.03 50.59 (acre-ft/d) evaporation Average total out Sw 304.07 329.54 327.27 Average (acre-ft/d) in 6.46 5.13 10.04 Sw Average (acre-ft/d) 0 0 36.38 Average (acre-ft/d) precipitation 1,027.12 1,025.91 1,021.12 sea level) Lake stage (ft above mean Average Medina 51.71 58.59 56.61 (acre-ft) (+/- error) out GW Average 36.11 77.81 76.73 (acre-ft/d) sea level) sea (ftmean above Medina Lake stage (ft above (ft BMA datum) BMA (acre-ft) total (+/- error) (+/- out system GW (acre-ft) Medina/Diversion Lakes combined hydrologic budget—Continued total storage (acre-ft) Date 07/17/9607/18/96 -404.5 -446.507/20/96 45.0307/21/96 -510.0 89.5407/22/96 -481.0 51.9607/23/96 -402.0 131.50 55.4407/24/96 -411.0 95.9007/25/96 62.30 -432.0 1,034.51 22.38 -576.5 60.20 1,034.36 32.18 53.66 34.47 1,026.71 1,034.02 176.81 53.80 1,026.56 56.57 1,033.85 68.84 1,026.22 1,033.71 1,033.56 1,026.05 1,033.41 1,025.91 1,033.2 1,025.76 1,025.61 1,025.4 08/15/9608/16/96 -485.508/17/96 -469.108/18/96 -452.6 88.7908/19/96 -454.0 120.66 -421.4 60.53 82.09 57.68 86.10 56.37 58.29 56.25 1,029.19 1,029 53.91 1,028.82 1,021.39 1,028.64 1,021.2 1,028.47 1,021.02 1,020.84 1,020.67 07/19/96 -421.0 51.47 54.7607/26/9607/27/96 -530.4 1,034.2107/28/96 -535.007/29/96 -456.907/30/96 1,026.41 -500.707/31/96 -494.108/01/96 -506.308/02/96 -459.908/03/96 -439.408/04/96 -575.008/05/96 -503.908/06/96 -555.008/07/96 -451.8 1,03308/08/96 -504.1 1,032.808/09/96 -497.4 1,032.6308/10/96 -671.3 1,032.4508/11/96 1,025.2 -467.4 1,025 1,032.26 1,024.83 08/12/96 -285.1 1,032.07 1,024.65 08/13/96 -480.9 1,031.9 1,024.46 08/14/96 -145.61 -695.1 1,031.73 1,024.27 -414.2 1,031.51 49.26 1,024.1 1,031.32 1,023.93 1,031.11 24.46 1,023.71 1,030.94 1,023.52 1,030 54.94 1,030.74 1,023.31 08/20/96 1,030.55 1,023.14 08/21/96 -404.9 1,030.29 1,022.94 08/22/96 -520.0 1,022.2 1,030.11 1,029.38 1,022.75 08/23/96 -527.9 159.08 1,022.49 08/24/96 -248.4 282.74 1,029.81 1,022.31 08/25/96 54.14 1,021.58 -235.3 351.68 1,029.5408/26/96 60.76 112.16 -68.9 1,022.01 08/27/96 58.30 -128.0 102.02 1,021.74 08/28/96 30.22 1,028.3 -73.5 -18.82 28.5608/29/96 1,028.07 152.24 -52.408/30/96 -147.1 1,027.85 18.3808/31/96 24.30 1,020.5 1,027.77 -4.38 1,020.27 29.0 -19.5609/01/96 1,027.68 260.23 1,020.05 83.109/02/96 13.04 -36.0 11.92 1,019.97 1,027.6509/03/96 29.92 263.11 1,027.6 1,019.88 -115.60 11.4 -95.0 49.63 149.86 1,019.85 1,027.59 11.62 1,027.58 1,019.8 -43.53 1,027.53 17.70 1,019.79 1,027.55 1,019.78 8.40 1,019.73 1,027.59 1,027.58 1,019.75 1,019.79 1,027.59 1,019.78 1,019.79 1,027.56 1,019.76 Appendix B.

Appendix B B–47 (acre-ft) (+/- error) storage -4.7 -0.7 Diversion Lake (acre-ft) (acre-ft) (+/- error) storage Medina Lake (acre-ft) total ration Evapo- (acre-ft) (acre-ft) (+/- error) Evaporation Diversion Lake (acre-ft) (acre-ft) (+/- error) (+/- Evaporation Medina Lake (acre-ft) (acre-ft) (+/- error) out SW Diversion Lake (acre-ft) (acre-ft) in (+/- error) SW Medina Lake Medina (acre-ft) (acre-ft) (+/- error) Precipitation Diversion Lake Diversion (acre-ft) (acre-ft) (+/- error) Medina/Diversion Lakes combined hydrologic budget—Continued Medina Lake Precipitation (acre-ft) Date 09/04/9609/05/96 29.81 108.5209/06/9609/07/96 4.47 16.2809/08/9609/09/96 11.9909/10/9609/11/96 1.8009/12/9609/13/9609/14/96 20.30 25.5909/15/96 151.7309/16/96 3.05 2.6009/17/96 22.76 63.3309/18/9609/19/96 93.22 8.75 6.3809/20/9609/21/96 29.71 9.32 1.3109/22/96 122.62 85.2909/23/96 4.4609/24/96 96.83 12.30 59.4009/25/96 89.45 61.70 8.53 1.0609/26/96 74.78 9.72 47.25 6.1409/27/96 62.08 9.26 9.10 73.39 170.30 0.1609/28/96 57.72 7.56 4.7709/29/96 53.20 61.49 6.27 25.55 7.34 31.7409/30/96 107.50 47.60 5.83 43.28 35.70 5.36 6.15 31.74 10.81 3.17 33.72 4.76 198.94 33.72 4.37 3.57 210.84 3.17 31.74 19.96 3.37 143.40 29.75 21.15 3.37 121.39 31.74 14.40 3.17 2.98 29.75 12.20 73.15 97.09 29.75 3.17 85.69 29.75 2.98 75.03 7.36 77.02 9.76 29.75 2.98 8.63 2.98 7.55 76.05 7.74 2.98 69.42 75.05 31.74 -120 31.74 7.70 115.04 6.94 69.06 49.59 7.55 3.17 -12.0 65.10 11.50 3.17 61.13 89.26 6.95 4.96 101.16 -48 -54.6 6.55 6.15 8.93 10.12 97.19 -8.2 -4.8 95.21 103.14 9.72 -49.6 72 9.52 10.31 -48 -7.4 71 7.2 24 -118 24 -4.8 -48 -44.3 7.1 -48 2.4 -11.8 -32.7 -47 2.4 -4.8 -6.6 -24 -24.5 -3.9 -12.6 -4.8 -4.9 -71 -17.6 -4.7 -14.5 -2.4 -24 -3.7 -0.6 -1.9 -15 -2.6 24 -7.1 -15.6 -2.2 27.8 -2.4 0 -24 -2.3 -13.6 -2.3 2.4 -10 4.2 -166 -2.4 0 -2.0 -70 -235 -13.2 -71 -16.6 -1.5 -71 24 -23.5 -7.0 -2.0 -6.4 -7.1 -142 60.6 -237 -7.1 28.1 -1.0 -1.4 3.6 -14.2 -23.7 24.2 9.1 -210 30.3 -0.2 4.2 -233 49 52 3.6 -21.0 4.5 -23.3 7.4 -8.6 7.8 -7.3 -1.3 -1.1 Appendix B.Appendix

B–48 Hydrogeology, Hydrologic Budget, and Water Chemistry of the Medina Lake area, Texas storage Average (acre-ft/d) (acre-ft/d) evaporation Average total out Sw Average (acre-ft/d) in Sw Average (acre-ft/d) Average (acre-ft/d) precipitation sea level) Lake stage (ft above mean Average Medina (acre-ft) (+/- error) out GW Average (acre-ft/d) sea level) sea (ftmean above Medina Lake stage (ft above (ft BMA datum) BMA (acre-ft) total (+/- error) (+/- out system GW (acre-ft) Medina/Diversion Lakes combined hydrologic budget—Continued total storage (acre-ft) Date 09/04/9609/05/96 -174.609/06/96 -97.609/07/96 27.709/08/96 -80.709/09/9609/10/96 -0.509/11/96 6.4 -62.509/12/96 -63.009/13/96 -62.609/14/96 -130.609/15/96 -84.609/16/96 1,027.51 67.109/17/96 -34.009/18/96 1,027.49 10.8 1,019.71 09/19/96 1,027.5209/20/96 -6.4 1,027.5 1,019.69 09/21/96 0 1,027.51 1,019.72 09/22/96 3.8 -41.9 1,027.52 1,019.7 09/23/96 1,027.5 -46.8 1,019.71 09/24/96 1,027.48 -40.709/25/96 1,027.46 1,019.72 -105.4 1,027.41 1,019.7 09/26/96 1,019.68 -93.009/27/96 1,027.38 -185.0 1,019.66 1,019.61 09/28/96 -236.4 1,027.4109/29/96 1,027.4 -218.6 1,019.58 09/30/96 -240.3 1,027.41 1,019.61 1,027.41 1,019.6 1,019.61 1,027.4 1,027.39 1,019.61 1,027.36 1,027.33 1,027.3 1,019.59 1,019.6 1,019.56 1,027.23 1,019.53 1,027.17 1,027.07 1,019.5 1,019.43 1,026.97 1,019.37 1,026.88 1,019.27 1,026.78 1,019.17 1,019.08 1,018.98 1,026.77 1,018.97 Appendix B.

Appendix B B–49 Blank Page Blank

Appendix B B–50 Appendix C

Appendix C— Water-Quality Data

Hydrogeology, Hydrologic Budget, and Water Chemistry of the Medina Lake area, Texas

Appendix C C–1 4.9 5.0 5.5 1.7 1.7 7.6 8.1 8.4 1.7 1.6 1.8 1.8 1.7 3.0 4.3 2.1 1.5 6.9 1.4 1.7 1.6 1.8 6.8 5.1 6.9 3.3 2.7 1.4 1.2 5.3 1.8 2.5 2.4 2.3 1.3 1.3 sium, Potas- (mg/L) 16 14 12 14 14 15 <1.00 <1.00 <1.00 <1.00 <1.0 <1.00 <1.00 <1.0 <1.00 <1.00 dissolved 7.7 8.4 9.8 8.0 8.6 9.0 3.4 5.0 0.27 2.9 2.1 5.3 4.1 7.2 7.1 7.8 8.5 6.9 9.2 5.9 6.9 6.2 6.5 6.2 5.5 6.5 6.3 8.7 7.9 7.2 8.6 dis- 20 20 21 26.4 25.2 21.3 21.9 17.6 24.8 12.7 10.5 13 18 11 11 16 95 36 29 42 42 (mg/L) solved Sodium, 3 3 5 6 5 8 9 68 72 76 17 17 29 61 51 80 84 17 17 35 41 42 79 39 31 97 25 34 14 16 78 55 50 15 16 10 21 17 57 54 47 19 20 17 16 17 275 238 104 168 102 114 sium, (mg/L) Magne- dissolved 56 63 92 77 73 74 69 58 80 85 81 84 62 65 81 73 67 72 91 88 78 80 71 77 72 70 58 89 92 79 136 135 154 128 137 147 121 123 151 466 491 352 387 210 359 536 498 408 359 248 126 119 dis- (mg/L) solved Calcium, g/L, per QA, micrograms less than; liter; <, µ 786 774 809 242 268 388 401 823 848 805 307 308 549 550 560 376 344 226 236 237 255 249 256 552 472 259 269 271 265 260 262 421 360 542 542 511 331 335 315 412 405 2,935 2,642 1,516 1,735 1,158 2,019 1,823 1,748 1,584 1,489 1,623 (mg/L) Dissolved constituents solids, sum of C) ° 23.5 23.3 23.7 20.5 21.8 21.3 21.4 25.0 24.2 25.1 23.0 20.9 22.8 22.5 23.3 23.9 24.9 23.7 24.5 24.7 25.5 22.8 23.9 21.8 22.0 19.0 22.4 22.1 22.5 19.4 19.8 23.5 23.5 24.6 21.5 22.9 22.7 26.3 22.5 22.8 22.7 25.1 23.0 27.2 23.2 23.8 23.8 21.8 22.1 22.1 21.0 22.9 ( per- Tem- ature pH 6.86 6.85 7.01 7.41 7.19 7.00 6.81 7.01 7.20 7.32 7.20 7.19 6.93 6.83 6.86 7.00 6.66 6.96 6.36 6.55 6.83 6.86 6.85 7.12 6.97 7.30 7.31 7.31 6.43 7.10 7.30 7.01 7.01 6.79 7.09 7.30 7.20 6.69 6.99 7.05 7.21 7.23 7.20 7.47 7.30 7.00 7.00 6.90 6.40 6.40 6.80 6.35 (units) 420 454 681 670 495 509 918 921 884 613 608 415 413 444 465 434 435 810 779 417 455 486 469 446 410 612 911 902 902 519 582 582 710 701 S/cm) ance 1,156 1,160 1,167 1,220 1,220 1,220 3,160 3,160 1,770 2,140 1,360 2,160 2,060 2,050 2,020 2,020 1,780 1,050 µ ( Specific conduct-

1 5 50 50 50 40 30 30 15 15 15 30 20 10 30 20 10 10 10 30 30 20 30 10 30 30 10 50 50 10 10 10 10 144 120 500 500 (gal/ min) 1,000 Flow 50-100 50-100 50-100 date Sample C, degrees Celsius; mg/L, milligrams per liter; milligrams mg/L, per Celsius; degrees C, ° 8/2/1995 1/22/1996 7/24/1996 1/30/1996 8/8/1996 12/15/1995 7/30/1996 8/2/1995 1/19/1996 7/24/1996 11/29/1995 8/8/1996 8/2/1995 1/22/1996 7/24/1996 2/8/1996 7/30/1996 11/28/1995 7/29/1996 11/30/1995 7/29/1996 12/5/1995 8/19/1996 1/25/1996 7/9/1996 12/5/1995 7/26/1996 3/6/1996 8/19/1996 10/30/1995 7/9/1996 3/20/1996 3/20/96 QA 7/29/96 QA 3/6/1996 7/26/1996 11/29/1995 8/21/1996 2/21/1996 8/6/1996 12/13/1995 8/21/1996 3/7/1996 8/20/1996 12/11/1995 8/6/1996 8/6/96 QA 11/30/1995 8/20/1996 8/20/96 QA 2/5/1996 8/20/1996 C; ° code Aquifer 218GLRS 218GLRS 218GLRS 218GLRS 218GLRS 218GLRS 218GLRS 218GLRS 218EDRDA 218EDRDA 218GLRSU 218GLRS 218GLRS 218EDRDA 218GLRSU 218GLRS 218EDRDA 218EDRDA 218EDRDA 218EDRDA 218CCRK 218GLRSL 218GLRSL DA); upper Trinity (GLRSU); middle Trinity (GLRSL, CCRK) (GLRSL, Trinity middle (GLRSU); Trinity upper DA); of site Type GW GW GW GW GW GW GW GW GW GW GW GW GW SPR GW GW GW GW GW GW GW GW GW 63 74 79 80 82 83 91 92 93 103 104 106 107 110 112 113 117 119 120 123 132 134 135 no. Site (pl. 2) name S/cm, microsiemens per centimeterat25 no./site State well µ AS-68-25-102 TD-68-25-402 AS-68-25-505 AS-68-25-507 TD-68-25-510 AS-68-25-511 TD-68-25-602 TD-68-25-603 TD-68-25-701 TD-68-25-806 TD-68-25-807 TD-68-25-809 TD-68-25-810 TD-68-25-901 TD-68-25-903 TD-68-25-904 TD-68-33-101 TD-68-33-103 TD-68-33-204 TD-68-33-603 AS-69-24-208 AS-69-24-602 AS-69-24-603 Water quality Water at data-collection sites, Medina area Lake Water quality Water at data-collection sites, Medina area—Continued Lake USGS site no. 293552098573001 293249098575101 293420098552601 293353098572301 293255098560401 293457098565501 293309098541901 293334098535401 293127098573701 293033098571601 293158098560401 293229098553402 293117098560301 293220098544701 293222098531201 293034098540901 292831098590201 292825098574501 292843098564601 292525098534601 294245099024701 294015099000701 294005099013201 quality-assurance sample] quality-assurance Appendix C.Appendix lake LK, water; surface SW, spring; SPR, water; ground GW, site: of Type (EDR Edwards (GLRS); undifferentiated Trinity code: Aquifer per gallons minute; [gal/min, Appendix C. Appendix

C–2 Hydrogeology, Hydrologic Budget, and Water Chemistry of the Medina Lake area, Texas g/L) µ <1 ( Arsenic, dissolved g/L) µ ortho ( Phos- phorus, (mg/L) Kjeldahl Nitrogen, ) 3 (NH (mg/L) Nitrogen, ammonia + 2 3 NO NO (mg/L) Nitrogen, ) 2 (NO nitrite (mg/L) Nitrogen, ) 3 (NO nitrate (mg/L) Nitrogen, dis- Silica, (mg/L) solved dis- (mg/L) solved Bromide, dis- (mg/L) solved Fluoride, dis- (mg/L) solved Chloride, dis- (mg/L) solved Sulfate, total Alka- linity, (mg/L) Alka- linity, (mg/L) phenol 276271 <1157 <1304 <1 271 257253 <1250 157 337 <1 352162 <1 286 58.9310 <1 252 25311 236 22 38.6 <1180 13 <1 149 412 360 0.75188 17 <1 303 1.2 295 80.8194 <1 0.2 20 0.14 170 125 20191 0.14 <1 0.18 102 15 190 1,753 14177 0.1 1.3 15 175 40 1.8 1,093185 <1 35 0.21 12 10189 0.16 <1 200 112 0.15 178 0.27 12145 16 0.10 0.46 0.10 13 171 1,328 4.2226 13 <1 6.0 0.09208 8.2 13 0.59 1,073 1.1 0.14 <1 200201 <0.005 <1 150 12 15 7.2 0.68 16188 <1 0.50 231 <0.005 15 9.9 <0.2 200 56190 <1.00 2.9 <0.010 12 187 871 1,079191 <0.005 <1 0.29 <0.50 15 14 <0.010 0.933209 12 <0.010 200 198 0.12 0.66 13 180 15 14 18273 <0.010 <1.00 <0.010 0.018 <0.20273 0.47 0.213 210 12 <0.010 35 0.17 <1 200 <0.005 24230 0.19 8.1 <0.50 0.55 0.012 3.2 <0.010230 <0.010 <0.010 0.034 12 <0.005 28 0.09 0.19 274 1.14 22 12 12 0.46 0.11 <0.005 2.64 12 0.012 <0.010 <0.010 1 0.037 <0.005 <1.0 11 149 <1.0 62 <0.010 <0.005 240 <1.00 12 12 <0.010 0.032 1.6 230 0.08 <0.005 0.666 <0.010 140 0.10 <0.50 13 <1.00 36 <0.0101.87 44 0.07 <1.00 1.7 44 0.07 12 0.026 <0.010 0.6 <1.0 <1.0 13 0.68 <0.005 33 1.3 <0.50 0.014 2.5 0.046 16 <0.001 12 <0.010 14 0.095 13 0.18 14 <0.001 0.584 0.078 <1.0 <1.0 <0.001 2.4 0.2 <0.005 <1.00 <1.0 1.1 2.4 <0.005 0.50 <0.100 <0.001 <1.0 0.037 <1.0 0.39 <0.50 11 <1.000 <1.0 <0.001 <0.005 0.17 <0.001 13 <0.005 <5.0 <1.0 10 <0.10 0.16 1.3 0.078 0.12 12 <0.005 0.6 <1.000 <0.010 0.01 <0.010 0.041 0.6 <0.10 0.7 <5.0 0.105 <0.010 <1.0 <0.001 <0.100 0.1 <0.01 <1.0 <0.100 0.449 <1.0 0.007 <0.100 <0.100 <1.000 0.06 1.7 <1.0 0.30 <1.000 <1.000 <5.0 <0.100 0.4 <5.0 0.01 <5.0 <0.100 <1.0 <1.000 <5.0 <0.01 <1 304 220 43 17 <1.00 <0.50 16 0.9 <0.100 <0.100 <1.000 <5.0 linity Alka- (field) (mg/L) Water quality Water at data-collection sites, Medina area—Continued Lake Water quality Water at data-collection sites, Medina area—ContinuedLake USGS site no. 293552098573001 278 0 283 346 27 0.99 0.15 16 <0.01 0.04 0.1 0.01 <2.0 293249098575101293420098552601 140293353098572301 311 <1293255098560401 254 <1 145293457098565501 0 163 302293309098541901 55.4 316 <1 260293334098535401 37.9 0 184 11 166293127098573701 419 209 17 <1 324293033098571601 79.0 196 <1 0.15293158098560401 22 182 197 119 <1 0.12293229098553402 14 208 0.09 2,026 182 <1293117098560301 1.5 190 0.22 183 41 <1 920293220098544701 9 0.17 194 12 186 <1 127 15 0.19293222098531201 179 157 0.51 0.09 18 7.0 179 3.7 15 5.7293034098540901 226 <1 0.22 698 <0.1 8.5 189 15 1,119292831098590201 <1 2.0 198 6.5 152 0.15 0.04292825098574501 <0.005 19 0.64 130.127 188 7.9 231 14 9.0292843098564601 <0.05 0.08 11 46 206 <1 0.06 0.017 0.037292525098534601 201 893 13 1.1 <0.05 204 14 1.6 3.0294245099024701 0.204 185 12 0.04 0.13 190 12 263 <1 12 0.11 1840.62 15 0.06 <0.01294015099000701 287 0.074 0.07 0.162 3.0 34 <0.001 191 0.0230.729 0.14 <1 <0.010 18 9.7 0.06 9.1 234 <0.010 155 0.02 0.11 0.61 12 <1.0 <0.010 <0.20 2.0 21 11 <0.010 <1 287 <0.010 10<0.010 0.75 <0.05 1.68 19 13 <0.010 0.1 10 0.045 229 149 <0.010 0.4492.55 0.003 11 0.11 12 0.05 0.08 0.0120.059 86 0.09 <1.0 0.01 <0.010 <1.0 0.687 45 <0.010 <1.0 0.081.88 11 36 <1.0 0.08 0.1 0.083 0.08 <2.0 0.014 <0.010 0.23 0.53 110.027 0.068 15 0.07 2.4 0.26 13 0.384 <0.001 <1.0 0.01 <0.010 0.34 0.083 12 0.371.52 0.19 1.14 1.1 0.002 <2.0 0.072 8.4 <0.0010.835 0.08 11<0.010 <0.010 <2.0 <2.0 0.017 0.04 <1.0 <0.010 <0.010 13 0.206 0.06 <1.0 <0.010 <1.0 0.2582.16 0.26 <0.001 0.62 0.01 0.29 <0.010 <0.001 <1.0 <0.010 1.2 <0.010 <0.001 <1.0 <0.010 <1.0 0.006 0.007 <1.0 <1.0 294005099013201 302 <1 304 56 11 0.40 0.07 14 0.879 <0.010 <0.010 <1.0 Appendix C.Appendix Appendix C.

Appendix C C–3 g/L) dis- µ Zinc, ( solved g/L) µ Vana- dium, ( dissolved g/L) µ tium, ( Stron- dissolved g/L) dis- µ ( Silver, solved g/L) dis- µ ( solved Nickel, g/L) µ ( Molyb- denum, dissolved g/L) dis- µ ( solved Mercury, g/L) µ nese, ( Manga- dissolved g/L) dis- µ ( solved Lithium, g/L) dis- µ Lead, ( solved g/L) dis- µ Iron, ( solved g/L) dis- µ ( solved Copper, g/L) dis- µ ( solved Cobalt, g/L) µ Chro- ( mium, dissolved g/L) dis- µ ( solved Cadmium, g/L) ium, µ ( Beryl- dissolved 8.4 <1.0 <1.0 6.5 1.3 <1.0 46 <1.0 7.6 5.8 0.3 1.5 27 <1.0 8,505 1.9 567 2524 <1.026 <1.032 <1.0 <1.024 <1.022 <1.0 15 <1.028 <1.0 <1.038 7.9 <1.0 <1.0 <1.035 11 <1.0 <1.0 <1.0 <1.0 <1.0 11 <1.026 <1.0 <1.0 1.4 <1.0 3934 6.2 <1.0 <1.0 <1.0 <5.0 1628 <1.0 <1.0 35 <1.0 <1.0 <1.011 423 <1.0 <1.0 <1.0 <1.0 <1.0 370 16 1.3 <1.049 <1.0 6.8 <1.0 <1.0 <1.032 1.6 <1.0 <1.0 <1.0 8.3 262 19 <5.0 2.028 <1.0 <1.0 <1.0 <5.0 26 4.8 3.9 <1.0 <1.0 <0.227 <1.0 <1.0 1.7 28 <1.023 <1.0 <1.0 <1.0 61 <1.0 <1.0 <.02 <1.025 6.6 6.9 <2.0 1.9 <1.0 33 7.0 <5.0 4.0 <1.031 2.2 <1.0 1.5 <1.0 <1.0 20.0 0.9 21 <1.0 1.2 2.938 <5.0 <1.0 <0.2 <1.0 <1.0 3.0 3.2 <1.0 <1.0 <1.0 6.9 17 <1.0 <1.0 4.837 2.1 <1.0 <0.2 3.4 21 6.9 <1.0 <1.0 <1.0 <1.0 <0.2 4.2 <1.0 5,14356 1,376 11 <1.0 5.9 4.5 <20.0 <1.0 8.0 3.331 2.0 <1.0 20 <1.0 <1.0 <1.0 <5.0 633 4.131 1.8 1.1 27 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 2.0 5.7 <1.0 <1.052 8.9 <0.2 5.0 <1.0 <0.5 3.7 <1.0 <1.046 <1.0 20 <1.0 11 293 <1.0 5,430 <0.2 7,185 8.5 <1.0 <0.2 <1.0 <1.0 5.8 <1.0 <5.044 <20.0 <5.0 <1.0 <1 2.6 <1.0 2.2 <1.0 1.0 33 <5.0 3.4 <1.0 <5.0 <1.0 2.0 2.9 65 568 7.2 1.8 <1.0 1.5 <1.0 <1.0 13 1.9 <1.0 3,426 <2.0 <1.0 19 1.8 <1 <5.0 <5 <1.0 10 <1.0 183 10 4.3 <0.2 8,016 35 <1.0 <0.2 5.3 7.1 5.5 3.2 2.9 4.6 1.3 <5.0 <1.0 <1.0 24 <5.0 <1.0 <1.0 14 3.0 <5 <3 <1.0 <1.0 156 <1.0 2.2 4,831 4.1 <1.0 <1.0 <1.0 3.2 <20.0 <5.0 6.6 <10 <1.0 2,393 2.1 <1.0 82 12 2.8 151 2.5 224 25 2.4 <3 <1.0 2,772 <1.0 <1.0 <20.0 0.2 2.6 <0.2 2.0 <10 2.5 2.7 <1.0 <1.0 <0.2 89 4.2 <1.0 22 <0.2 <5.0 <1.0 1.7 29 2.4 170 3,016 1.5 660 90 <0.2 3.1 <5.0 <10 57 <3 20 <1.0 1.0 <0.2 20 1.9 <1.0 66 2.6 <1.0 <20.0 5.2 <1.0 4.9 10 60 <1.0 2.8 10 <1.0 <0.2 70 <1.0 <1.0 300 <20.0 5.2 4,074 <1.0 11 2,605 <0.2 3,175 3.0 7,454 1.7 <1.0 7.0 <0.2 <1.0 400 2.7 <1.0 6.1 1.3 3.3 <0.1 <1 282 12 <0.2 1,741 1.9 1,218 2.8 390 <10 574 <1.0 4.6 4.5 67 <0.1 14 1.0 2.0 19 99 <1.0 <10 620 <10 <1.0 16 4.6 9,463 510 <1.0 2 1,400 <10 <1.0 3.6 1.1 160 9,400 1.9 4,800 <1 <6 3.1 1.5 1,300 21 <6 600 18 21 g/L) dis- µ ( solved Barium, Water quality Water at data-collection sites, Medina area—Continued Lake Water quality Water at data-collection sites, Medina area—Continued Lake USGS site no. 293552098573001 22293249098575101 <1293420098552601 26293353098572301 34 <1.0 <0.5 21 <1.0293255098560401 <1.0 <8 <1293457098565501 27 <1.0 33 7.3 <1.0293309098541901 <8 <0.5 7.6 <1293334098535401 <1.0 8.5 <1.0 <6 <8293127098573701 32 <2.0 2.1 1.7 <0.5 11293033098571601 33 <1.0 <1.0 <8 27 <2.0293158098560401 26 <5.0 <8 <1.0 <1.0 <1.0 <6293229098553402 571 9.9 <1.0 <5 8.5 <1.0 <1.0293117098560301 3.0 51 <8 <1.0 12 <1.0 307 <1.0293220098544701 31 <1.0 20 2.9 <1.0 <6 32 <1.0 36293222098531201 27 <2.0 <1.0 <1.0 20 5.6 1.4 <5 <1.0 27 2.0 <1.0 <1.0293034098540901 8.3 <6 2.3 <1.0 <1.0 <0.2 184 55 <1.0 <1.0 <1.0 18292831098590201 27 <0.13 0 <1.0 1.3 2.6292825098574501 3.0 <5 1.4 27 <40 <1.00 5.5 <2.0 <1.0 <1.0 1.6 <5.0 <1.0 19292843098564601 2.2 53 5.0 11 <1.0 <1.0 64 <1.0 <20 <0.02 8.4 <5.0 <1.0 24 <1.0292525098534601 33 <1.0 1.8 <1.0 41 <0.13 <1.0 <2.0 15 <2 <1.0 3.6294245099024701 <6 <0.2 77 1,817 <1.0 13 <40 6.5 13 2.5 6.4 <2.0 <1.0 3.3 31 602 <1.0 4,840 <1.0294015099000701 <1.0 <0.13 7.8 <5.0 2.4 <1.0 <1.0 <1.0 <0.2 <1.0 <20 <1.0 1.0 913 <1.0 3.2 <40 45 4.0 <8 5.2 <1.0 27 <0.2294005099013201 <1.0 <1.0 <1.0 315 5.3 <2.0 1.3 <6 8.4 6.7 <1.0 <0.2 <1.0 39 <1.0 <20 <5.0 <1.0 <2.0 11 <1.0 34 1.5 <0.2 13 2.7 1.6 <1.0 69 7,080 16 <1.0 <1.0 1.4 6.4 <1.0 12 <6 1.6 634 2.0 1.8 <1.0 22 <8 <1.0 <1.0 <1.0 <2.0 <0.2 1.3 37 <0.2 <1.0 3,050 <1.0 36 10,480 <5.0 15 <1.0 5.2 36 5.7 <1.0 2.0 <1.0 <0.2 6.1 1.1 196 <8 <1.0 11 13 <1.0 14 4,318 3.4 2.5 <1.0 <1.0 230 <1.0 <1.0 <0.2 1.5 2.4 3,277 17 30 249 4.1 12 34 3.9 <1.0 972 <1.0 <1.0 <1.0 <2.0 5.0 15 84 <0.2 8.8 <1.0 <1.0 <1.0 4.1 5.3 12 2.1 <1.0 <0.2 <5.0 4,966 <0.2 <1.0 7.2 5.6 152 1.4 3,590 82 59 <0.2 <2.0 2,395 <1.0 2.4 <5.0 1.6 <1.0 4.2 83 4.8 66 26 <1.0 <0.2 15 3.8 3.7 4.6 1 2.0 14 9.9 <1.0 86 <1.0 17 <1.0 3,219 <1.0 <1.0 0.3 <1.0 7.0 <0.2 240 3,652 <1.0 406 8.0 <0.2 <1.0 7.4 1.7 2.7 <2.0 1.8 222 4.4 1,289 <1.0 <0.2 2.1 16 6.4 3.7 412 41 98 <1.0 <1.0 <1.0 6.6 10,101 4.1 1,230 19 <1.0 3.2 3.2 1,421 364 8.9 <1.0 11.0 4,052 2.9 3.4 4.8 9.2 773 Appendix C.Appendix Appendix C. Appendix

C–4 Hydrogeology, Hydrologic Budget, and Water Chemistry of the Medina Lake area, Texas sium, Potas- (mg/L) dissolved dis- (mg/L) solved Sodium, sium, (mg/L) Magne- dissolved dis- (mg/L) solved Calcium, (mg/L) Dissolved constituents solids, sum of C) ° ( per- Tem- ature pH (units) S/cm) ance µ ( Specific conduct- (gal/ min) Flow date Sample 8/15/19968/28/1996 208/15/19968/15/96 QA 2,5708/15/1996 20 6.07 20 1,128 2,660 25.28/20/1996 2,660 6.878/21/1996 6.95 6.95 2,241 23.0 3,380 23.6 308/21/1996 23.6 1,118 10 6.80 450 2,426 346 2,269 26.6 3 415 7.13 132 216 3,319 25.0 359 7.35 455 3504/3/1996 25.05/31/1996 25 6.87 748/6/1996 235 279 190 541 22.7 261 39 14 10 17 34 28 282 262 87 3 593 543 4.2 17 76 17 30 8.10 583 8.10 9 17.1 67 23.5 7.95 22 15 30.6 330 8.5 19 348 5.4 <1.0 356 <1.00 6.1 77 79 1.1 71 22 23 26 6.0 11 15 1.5 2.4 2.1 7/30/19968/7/1996 2,950 6.51 2,950 22.6 6.85 24.1 2,598 2,400 597 472 175 218 1.7 21 8.8 15 code Aquifer of site Type no. Site (pl. 2) name no./site State well QA SW SW SW SW SW SW 11/30/1995 4/3/1996 5/31/1996 8/6/1996 29 133 210 413 DC-bottom 214 479 at 20 ft DC 412 7.82 at 30 ft DC 440 DC 8.20 18.8 8.20 at 1145 DC 4/4/1996 13.0 at 1205 DC 7.63 15.0 6/3/1996 234 8/6/1996 19.4 248 250 25 27 255 27 50 470 435 55 60 455 8.00 56 16 7.50 16.1 7.44 18 5/23/1995 19.7 19 21.9 5/23/1995 17 7.8 5/23/1995 242 262 8.3 4/2/1996 6.7 271 1.6 4/2/1996 7.0 8/29/1995 2.0 1.9 54 420 63 405 1.6 64 416 7.20 8.10 15 15.0 7.60 17 24.5 17 420 22.0 404 3.7 158 8.20 7.9 8.30 8.3 15.5 1.3 30.1 1.8 55 1.7 241 18 164 52 8.8 55 16 1.7 17 3.8 4.7 1.4 1.5 3/20/96 QA50 2,610 7.34 23.9 2,281 357 212 20 16 3/20/96 Water quality Water at data-collection sites, Medina area—Continued Lake USGS site no. 08178990 Medina R. at English Crossing SW 108179530293225098560600 SW Medina site Lake AC 293223098560000 Medina SWLake Creek blw. Koenig Medina site Lake AL-top 293426098544300293456098555500 Medina Lake siteBC-top 293324098584200 2 Medina Lake siteCC-top 12/1/1995 SW Medina site Lake DC-top AC-top AC 78 AL-bottom 5 LK LK 535293731098590300 7 Medina site Lake EC-top 8 at 1005 LK 5/18/1995 8.11 9 LK LK 17.4 10 5/22/1995 2 LK 4/2/1996 315 440 8/29/1995 EC-bottom at 1009 8/29/19951345 EC-top at 7.98 5/23/19951110 EC-top at 77 EC-bottom at 1055 21.0 5/22/1995 5/23/1995 418 4/2/1996 21 8/29/1995 163 395 8.20 397 404 8.30 15.0 2.6 8.30 8.10 29.5 403 66 29.6 419 24.5 239 1.1 420 5/23/1995 8.00 392 8.00 14 24.0 8.10 8/29/1995 146 8.30 156 25.0 4/2/1996 4/2/1996 12.0 53 29.5 155 8.0 163 417 51 241 50 16 2.5 8.00 50 422 435 53 16 17 468 24.5 4.8 54 8.20 7.20 7.70 17 30.2 1.5 7.7 18 13.9 160 8.8 16.0 16 8.6 1.7 1.7 252 8.9 269 5.2 52 1.7 1.7 1.6 58 18 60 17 8.8 17 1.6 4.3 5.0 1.5 1.4 293710099032201 TD-69-32-201293640099020001 TD-69-32-303293438099041201 AS-69-32-501292803099042601 TD-69-40-202292841099012001 TD-69-40-301292727099003201 141 TD-69-40-604 GW08179520 143 218GLRS GW 218GLRS 1/31/1996 147 MedinaLakeSW Medina GW R. blw. 12/11/1995QA30 148 218GLRS GW 218EDRDA 12/11/1995 30 149SW 3/13/1996 3 1,137 GW08180500 2,640 150 SW 218EDRDA 450 40 GW 7.23 1/24/1996 9.38 218EDRDA 30 2,910 7.20 3/13/96 12.5 12/5/1995 19.2 RiomedinaSW Medina R. nr. 23.5 450 9.16 10 2,217 755 17.1 7.20 5/18/1995 428 256 451 SW 23.5 2,665 7.21 4 369 6.87 157 136 SW 24.1 23.3 255 80 450 512 11/30/1995 175 77 248 8.07 247 10 208 35 79 15.0 8.6 5/18/1995 17 68 6.3 16 63 413 10 171 4.0 <1.0 26 7.82 19 15 18 5.5 18.8 12/1/1995 435 55 1.0 5.4 7.88 0.99 241 26 17 20.0 <1.00 <1.00 430 56 248 7.9 7.68 17.1 7.8 18 59 243 2.8 15 1.4 62 4.3 16 3.1 3.2 1.5 293856099040101 AS-69-24-803293812099031101 AS-69-24-804 137 GW 138 218GLRSL GW 1/25/1996 218GLRSL 3/20/1996 20 2,930 50 2,610 7.09 20.2 7.34 23.9 2,652 2,093 458 334 222 220 13 24 14 15 293736099034801 AS-69-24-802 136 GW 218GLRSL 1/31/1996 20 3,010 6.62 21.5 2,804 585 179 0.12 8.1 Appendix C. Appendix

Appendix C C–5 g/L) 1.0 µ ( Arsenic, dissolved g/L) µ ortho ( Phos- phorus, (mg/L) Kjeldahl Nitrogen, ) 3 (NH (mg/L) Nitrogen, ammonia + 2 3 NO NO (mg/L) Nitrogen, ) 2 (NO nitrite (mg/L) Nitrogen, ) 3 (NO nitrate (mg/L) Nitrogen, dis- Silica, (mg/L) solved dis- (mg/L) solved Bromide, dis- (mg/L) solved Fluoride, dis- (mg/L) solved Chloride, dis- (mg/L) solved Sulfate, total Alka- linity, (mg/L) 147 52 12 0.24 11 0.12 0.01 0.06 0.5 <0.01 <2.0 004.0 132 139 143 57 56 63 12 12 12 0.25 0.24 0.19 0.12 0.12 0.08 9.0 10 10 0.02 0.12 0.10 <0.01 <0.01 <0.005 <0.02 0.01 0.3 0.3 <0.010 <0.01 <0.01 0.17 <0.001 2.1 Alka- linity, (mg/L) phenol 265283 <1243 <1253 241 9.0259 256 1,630245 225 <1 1,476245 260 1,502216 9.3 270 1,420 13223 260 706 2.5 17 245207 1,590 52 4.0 230 1,500183 21 4.3 2,270 <20.00 190 0.15 25145 22 <10.00 0.20 220 1.3 15 12 22 190 9.5 5.9 15 <0.50 3.6 9.3 15 <0.005 0.22<0.010 14 7.2 35 0.67 14 50 <0.005 11 0.564 <0.005 <1.00 0.63 13 11 12 <1.00 <0.50 0.56 11 14 <0.010 <1.00 <0.50 0.20 16 <0.001 0.035 0.151 <0.50 14 <0.100 1.6 0.044 0.044 12 0.14 <0.001 0.3 <1.0 0.02 9.7 <0.100 0.5 <1.0 <0.100 0.08 0.13 <20.0 0.50 <0.100 0.78 1.5 <20.000 <0.100 <5.0 0.16 0.8 <20.000 <5.0 <0.100 0.5 0.1 <5.0 <0.100 0.1 <0.100 0.01 <0.100 30.6 <1.000 <0.100 <1.000 <1 <5.0 <1.000 <5.0 <5.0 <5.0 137130148 <1 <1167 <1169 137186 142 1.0 <1 141 <1 62146 164 62149 161 60157 136 4.0 102 <1 12 <1 100 12 140 87 13 145 12 143 0.20 15 59 0.20 60 21 0.20 60 0.08 0.24 0.09 0.28 12 0.09 12 0.38 0.06 9.1 13 10.0 0.08 12 0.32139 0.14 0.19 7.9 0.18 14.7 0.16 0.19 3.0 0.09 21.3 0.006147 0.08 <0.005 0.16140 <0.005 0.08 139 0.28 <0.005 8.8 4.0 0.23 9.8 4.0 <0.005 12 <0.005 62 152 <0.005 148 0.22 0.20 <0.010 0.16 76 12 <0.010 <0.005 65 <0.005 0.109 <0.010 0.16 <0.005 0.43 12 0.19 0.047 <0.010 12 0.19 <0.010 <0.001 0.005 0.09 0.068 0.20 <.001 0.30 <0.010 <1.0 0.006 0.19 <0.010 <1.0 0.004 9.1 <1.0 <0.010 0.08 <0.001 0.063 1.4 0.08 0.07 <1.0 0.22 <0.001 0.09 9.0 1.4 9.3 0.008 <0.005 1.1 0.003 0.10 <1.0 0.10 <1.0 <0.005 <0.005 <0.010 <0.010 <0.010 0.081 0.16 0.36 <0.001 0.005 <0.001 <1.0 <1.0 2.6 linity Alka- (field) (mg/L) Water quality Water at data-collection sites, Medina area—ContinuedLake USGS site no. 293736099034801 260 <1 255 1,847 12 3.8 0.08 14 <0.200 0.3 <0.010 <2.0 293856099040101293812099031101 281293710099032201 243 <1293640099020001 9.0 270 264293438099041201 256 226 <1 1,746292803099042601 <1 1,325 193 236 276 15292841099012001 193 <1 246 3.0 335 17292727099003201 1,434 1.0 209 173 226 4.808179520 145 180 168 <1 20 4.3 1,738 23 19 <1 <1 0.13 196 23 0.21 0.57 14 138 179 11 3.2 9.2 12 0.11 9.3 9.1 3.2 53 35 0.25 0.11<0.010 00.754 13 8.2 0.11 0.16 12 142 0.06 0.55 12 10 <0.010 0.06 0.11<0.010 12 11 0.037 54 0.53 0.16 0.13 110.128 0.06<0.010 0.67 0.008 <0.001 <0.200 0.10 0.09 21 <0.0100.755 13 0.577 0.68 <1.0 <0.010 1.2 <0.010 11 12 <0.010 0.62 0.27 <0.010 0.028 0.2 <0.010 0.0060.494 0.12 0.06 1.1 <0.010 0.01 1.3 0.177 9.0 <1.0 <0.010 <1.0 0.20 <2.0 0.003 0.19 1.02 <1.0 <0.01 <0.010 <1.0 <0.010 0.02 <1.0 0.2 <0.01 <2.0 0817899008180500 153 183 <1 <108179530293225098560600 156 0 180 0 293223098560000 46 134 133 152293426098544300 82293456098555500 134 1.0293324098584200 57 12 51 3.0 141 11 0 138 12 0.140.273 14 62 157 0.19293731098590300 3.0 62 <0.010 0 0.08 0.25 49 49 0.22 0.07 132 12 0.10 138 10.6 12 0.10 11 0.10 12 57 14 0.20 <0.001 0 58 9.0 10.0 0.190.01 0.200.167 0.08 12 1.1 0.20 138 12 0.08 0.01 0.22 0.139 0.3 0.09 9.6 59 0.25 <0.01 9.1 <0.01 0.26 0.15 10 <0.01 0.24 0.10 12<0.010 8.1 0.11 0.08 0.003 <2.0 <0.005 0.24 9.0 0.18 10 0.25 <0.005 <1.0 0.05 <0.01 0.02 0.02 0.088 0.10 <0.010 0.02 <0.01 0.4 <0.01 0.1 2.9 10 0.10 <0.01 <0.05 <0.01 <0.01 <0.02 0.02 0.007 0.02 0.1 <2.0 <2.0 0.2 <0.01 1.6 0.1 <0.01 0.04 0.22 <2.0 <0.02 0.2 <2.0 <1 <0.01 <2.0 Appendix C.

C–6 Hydrogeology, Hydrologic Budget, and Water Chemistry of the Medina Lake area, Texas g/L) dis- µ Zinc, ( solved g/L) µ Vana- dium, ( dissolved g/L) µ tium, ( Stron- dissolved g/L) dis- µ ( Silver, solved g/L) dis- µ ( solved Nickel, g/L) µ ( Molyb- denum, dissolved g/L) dis- µ ( solved Mercury, g/L) µ nese, ( Manga- dissolved g/L) dis- µ ( solved Lithium, g/L) dis- µ Lead, ( solved g/L) dis- µ Iron, ( solved g/L) dis- µ ( solved Copper, g/L) dis- µ ( solved Cobalt, g/L) µ Chro- ( mium, dissolved g/L) dis- µ ( solved Cadmium, g/L) ium, µ ( Beryl- dissolved

2.8 <1.06.3 <1.05.0 <1.05.0 <1.0 <1.0 <1.0 5.4 1.3 <1.09.0 15 <1.5 1.22.3 5.2 <1.0 <1.0 1.5 1.4 <3 <2.0 <1.0 1,354 1.8 <1.0 <15 4,000 4,152 1.4 <1.0 2.4 11,543 <9 <1.0 <1.0 <2.0 35 <30 <1.0 70 56 810 10 66 720 38 25 <1.0 <0.2 125 <0.2 110 <0.2 69 1.3 <0.2 20 <1.0 14 280 46 53 32 <1.0 54 <0.2 <0.1 12,110 41 <1.0 <1.0 <1.0 <30 11,036 13,800 1.6 <1.0 12,652 85 4.2 <1.0 <30 16 <1.0 1.4 <3 401 77 11,600 9,500 571 <1.0 <18 140 45 2812 <1.0 <1.0 <1.0 <1.038 3838 <1.0 1.630 <1.0 <1.0 <1.0 <2.0 10 <1.032 <1.029 <1.0 76030 <1.0 <0.526 170 <1.0 <1.0 <1.032 <1.0 <1.0 <1.0 <1.035 <1.0 <1.041 8.4 <1.0 <1.0 83 <1.0 <1.0 <5.0 3.1 <1.0 <20.0 <1.0 <1.029 <2.0 <1.0 <5.030 <3.0 4929 11 5.7 <1.0 <1.0 <1.0 <5.0 <10 <1.0 <5.0 2.4 1.9 <1.0 <1.0 <1.0 <0.2 <1.0 <1.00 7.8 2.5 <20.0 <1.0 <1.0 <1.0 21 <1.0 <5.0 <1.0 <1.0 3.6 <20.0 <1.0 <1.0 <1.0 <1.0 <20.0 <1.0 14 <1.0 5.5 54 <1.0 <1 17 <1.0 1.426 <0.2 4.0 <5.0 <1.0 <1.0 <1.0 <1.0 13 3.6 <1.0 <1.0 <0.2 <1.0 23 <1.0 5.0 <0.2 10,900 15,400 <1.027 <1.026 10 <1.0 <2.0 7.6 2.1 11 17 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 5.0 4.6 <1.0 <1.0 8.0 11 59 <0.2 <1.0 <8.0 <1.0 550 3.1 <1.0 69 9.0 6.1 <1.0 0.1 1.3 <1.0 <1.0 <1.0 160 <5.0 <8.0 <1.0 1.6 <0.2 19 3.7 <10 65 30 <0.2 5.2 <6.0 27 230 3.0 <1.0 2.2 560 6.6 2.8 1.6 <10 <0.2 2.8 1.2 2.5 2.0 33 <1.0 1.4 3.0 7.1 27 1.8 <1 <0.2 4.0 2,300 2.1 1.9 9.2 681 1.3 260 <0.2 4.4 <1.0 <5.0 1.7 590 <1.0 4.8 <5.0 1.5 <10 626 1.4 1,109 <5.0 <6 <1.0 6.8 <1.0 156 2.4 1.7 1,864 <1.0 <1.0 3.2 4.1 27 2.5 <1.0 <0.13 3.8 531 2.3 1.7 4.6 614 4.5 3.0 1.3 <1.0 711 2.0 <20.0 2.9 <0.2 <0.2 1,312 2.8 <6.0 1.5 1.6 1.6 681 646 1.8 45 41 <8.0 2.5 <1.0 <1.0 9.0 638 615 2.2 9.8 9.2 3.3 2.0 g/L) dis- µ ( solved Barium, Water quality Water at data-collection sites, Medina area—Continued Lake USGS site no. 293736099034801293856099040101 3.5293812099031101 <2.0 6.7 <2.0 5.0293710099032201 <2.0 <1.0293640099020001 27 <2.0 11 <1.0 7.8 <1.0293438099041201 11 <1.0292803099042601 5.2 <1.0 3.7 31 7.4 31 <1.0 <1.0 <2.0 3.0292841099012001 <1.0 12 1.6 <2.0 <1.0292727099003201 35 1,320 <1.0 11 <1.0 12,64008179520 1.2 27 <1.0 <1.0 31 1.1 10,752 <2.0 9.7 19 <1.0 1.8 12 <1.0 <2.0 <1.0 16 <1.0 20 27 2.1 <1.0 <1.008178990 47 <1.0 <1.0 5,271 8.3 <1.0 50 <1.0 <1 10 70 3.4 18 5708180500 4.1 5,013 3.5 <1.0 29 <1.0 <1.0 30 127 <2 <0.2 <5.0 <1.0 2.7 <1.0 <0.2 <1.0 <5.0 71 <1.0 <1.0 8.3 <2.008179530 1.5 <1.0 <0.2 26 <1.0 <8293225098560600 <2.0 <5.0 <1.0 82 <1.0 24 <1.0 18 56 88 54 27 <1 <1.0 15 16293223098560000 74 <8 <1.0 <1.0 <1.0 44 30 1.2 14 <2.0 28 <0.5 <0.2 <0.2 <1.0293426098544300 33 <2 39 <6 <2.0293456098555500 11,499 <1.0 <2.0 <1.0 <1.0 <1.0 <1.0 <1.0293324098584200 <1 11,480 <0.2 <1 <1.0 <1.0 <0.2 <1.0 4.1 <1.0 <1.0 3.2 <0.2 24 <1.0 <1.0 <8 <8.0 <1.0 1.9 3.8 11,954 <6 3.1 <1.0 <1.0 30 <1.0 <2 23 <5 <1.0 <1.0 <5.0 <0.2 43 15 <8.0 28 5.2 2.0 <8 <1.0 33 <5.0 926 13 <1.0 27293731098590300 <5 <6.0 <8 <2.0 13 25 11,347 <1.0 <3 <1.0 14,512 <0.2 <6 <0.2 566 24 <1.0 <1.0 <1.0 1.9 30 <10 <1.0 <1.0 11,718 <8.0 3.1 30 11 1.7 75 <8 3.2 3.5 <1.0 <1.0 243 2.1 1.4 <1.0 2.6 250 <2.0 1.0 <1.0 2.8 <8.0 <1.0 6.0 <6 150 1056 3.7 <2.0 11 7.2 <5.0 4.4 4.0 <1.0 <1.0 <6.0 3.7 6.6 <1.0 9.0 225 <8.0 290 <5 <1.0 <0.2 <0.010 8.0 <8.0 <1.0 <10 <6 <0.2 <0.13 5.9 4.9 <6.0 <2.0 4.9 <8.0 <1.0 591 3.1 6.8 11 <50 633 <8.0 <1.0 1.2 <6.0 1.4 5.0 <1.0 <5 <0.13 <5.0 310 <6.0 5.4 3.0 <1.0 <20 2.8 2.3 3.0 4.4 <1 2.0 <10 <1.0 5.7 3.0 10 19 275 <6 <6.0 <1.0 <1.0 <1.0 <0.13 <20.0 1.6 <2.0 <0.1 12 11 <5.0 574 <0.2 <5.0 <2 <6.0 <0.2 642 <2 941 <10 <0.13 <10 <10 1.8 <1.0 <8 655 1.6 <1.0 <20 4.8 1.5 <0.13 <10 5.0 <8.0 <50? <2.0 6.0 4.4 <6 41 4.0 40 2.1 <20 1.0 4.3 8.0 <0.13 <0.13 <20 <1.0 <5.0 1.7 <1.0 <6.0 538 3.6 640 <2.0 2.0 <6 596 <8 <0.2 615 684 <0.2 <6 <20.0 <20.0 8.9 <8.0 503 9.4 1.5 <6.0 1.5 9.0 7.0 <3 <8 714 <5.0 4.2 8.1 1.4 714 7.4 <8.0 <1.0 <1.0 <8.0 <5 722 <5.0 666 <5.0 1.8 1.8 2.9 4.0 Appendix C. Appendix

Appendix C C–7