Investigation of the Geology and Hydrology of the Mogollon Highlands of Central Arizona: a Project of the Arizona Rural Watershed Initiative

Prepared in cooperation with the ARIZONA DEPARTMENT OF WATER RESOURCES Investigation of the Geology and Hydrology of the Mogollon Highlands of Central Arizona: A Project of the Arizona Rural Watershed Initiative

The Mogollon Highlands of east developing an understanding of the central Arizona is a region of forested hydrogeologic framework, which is the plateau and mountains, deep, sheer- relation between geologic and hydrologic walled canyons, and desert valleys. properties, that can be used for water-- Known for its scenic beauty and resources management purposes and that ARIZONA characterized by a generally mild climate, will support the development of an the area, though still sparsely populated, interpretive and predictive model to Mogollon attracts an increasing number of tourists estimate the effects of climate and water Highlands and summer residents. Furthermore, the use on the sustainability of regional water study area permanent population is expected to resources. nearly double over the next 50 years. Although the three continguous areas Consequently, there is increased pressure in north-central Arizona are being studied on the water resources of this area for separately, a single data base is being several sometimes conflicting uses. constructed from which Rational management of water resources data on each area can is necessary to meet increased domestic be extracted separately. requirements while ensuring an adequate supply of water for commercial and 111û30' 111û00' agricultural use, for Indian lands, and for preservation of valued environmental elements, including surface waters, COLORADO riparian woodlands, forest and grassland M 34û30' OG PLATEAU OLL areas, and wildlife and aquatic habitat. ON k ee R Such management requires an under- r IM l C Strawberry si standing of the relations among different s Overgaard o Pine components of the hydrologic F Kohls Ranch Tonto system—recharge areas, surface flows, E Village as er shallow aquifers, deep aquifers, discharge t V iv erde R Payson areas, and the regional ground-water flow 110û30' system—and how each is affected by k

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The U.S. Geological Survey (USGS) h n

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is conducting an assessment of the I

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d T A e in cooperation with the Arizona Z A R A i N v L C Department of Water Resources. The e H r M A study, funded through the State’s Rural O U

N Watershed Initiative program, is one of T A I three assessments being conducted by the N S USGS. Assessments also are underway er iv R in the Upper-Middle Verde River S watershed and on the Coconino Plateau. alt Theodore 0 10 MILES Each study has as its objectives: (1) the Roosevelt collection, compilation, and e valuation of Lake 0 10 KILOMETERS all existing geologic, hydrologic, and related data pertaining to the study area Figure 1. Location of Mogollon Highlands study area. The dark brown line delineates and the creation of a data base that is the primary study area; the more extensive area of light-brown tones delineates the proposed readily accessible to the public and (2) boundaries for regional ground-water flow modeling.

U.S. Department of the Interior USGS Fact Sheet 159-00 U.S. Geological Survey December 2000 Physical Setting (Wilson and others, 1959; Feth and Hem, within fractured parts of the Payson 1963; Mayer, 1978; Richards, 1987; granite, and alluvial aquifers in the basin The extended study area encompasses Weisman and Weir, 1990; Weir and fill of the Tonto Creek Basin and along about 4,855 mi2 (fig. 1), and the main Beard, 1997). some streams. Some springs discharge area of focus includes the Fossil Creek, The most significant structural from the Precambrian rocks of the Sierra East Verde River, and Tonto Creek characteristics include the shallow Ancha and Mazatzal Mountains, but the Basins below the Mogollon Rim. The northeastward dip of the Paleozoic hydrologic characteristics of those rocks Mogollon Rim is the eroded and rocks;» the extensive fracturing of are not well known. The aquifers within dissected southwestern edge of the sedimentary and granitic rocks; solution the sedimentary rocks are recharged from Colorado Plateau and is one of the most features, such as caverns, in carbonate precipitation falling on the southern edge striking physical features in the study rocks; and northwest-southeast trending of the Colorado Plateau. Permeability area; it trends mainly east-west for about extensional faults associated with Basin within the sedimentary rocks generally is 80 miles, forming a steep escarpment and Range deformation. The Diamond Rim the result of fracturing, jointing, and about 2,000 ft above a lower, stepped Fault, which forms a secondary escarpment faulting of rocks of otherwise low plateau. South of the Mogollon Rim, the generally less than 1,000 ft high below the permeability. Within carbonate rocks, Transition Zone, an area of mountain main escarpment of the Mogollon Rim east permeability can be increased by the ranges and valleys, separates the of Payson, is the largest and most formation of solution features, such as Colorado Plateau from the Basin and continuous of the northwest-southeast conduits and caverns, by widening of Range province. Altitudes within the trending extensional faults. joints and fractures, and by dissolution of study area range from more than 7,500 ft beds. The cap rocks of the Mogollon Rim, at the top of the Mogollon Rim to about Hydrology which can be Tertiary basalt, and 1,500 ft at the mouth of the Verde limestone or sandstone of the Kaibab River.»ÊPrecipitation ranges from more Perennial surface-water flows are the Formation and Coconino Sandstone, than 30 in. at the higher elevations to result of ground-water discharge and are generally are highly fractured and permit about 15 in. annually at the lowest desert restricted mainly to the major streams of rapid infiltration of surface waters to lower locations. Above about 5,000 ft,» Fossil Creek, the East Verde River, and layers. Waters infiltrating the sedimentary vegetation is primarily Ponderosa pine Tonto Creek plus a few of their larger rocks frequently discharge at springs on forest with piñon pine and juniper tributaries. Other streams are intermittent the face of the Mogollon Rim and along woodland, oak woodland, and Sonoran or ephemeral. canyon walls and stream channels desert vegetation at successively lower The ground-water system consists of particularly where permeable rocks overlie altitudes. Population of the study area is several components including multiple less permeable rocks or where fractures or approximately 21,000, about two thirds aquifers within the sedimentary rocks of faults force ground-water flow to the of which live in the town of Payson. the Mogollon Rim, water-bearing zones surface (Feth and Hem, 1963). According to the Arizona State Land Department, about 80 percent of the land NORTH EXPLANATION is owned by the Federal government, VOLCANIC ROCKS TERTIARY primarily within the Tonto National KAIBAB FORMATION Forest, and about 15 percent of the land COCONINO SANDSTONE is included within five Indian PERMIAN reservations. Only 2.4 percent of the land UPPER SUPAI FORMATION within the study area is privately owned. LOWER SUPAI FORMATION PENNSYLVANIAN NACO FORMATION Geology REDWALL LIMESTONE MISSISSIPPIAN The edge of the Mogollon Rim MARTIN FORMATION DEVONIAN exposes a sequence, nearly 3,000 ft TAPEATS SANDSTONE CAMBRIAN thick,»of Paleozoic sedimentary rocks MAZATZAL QUARTZITE PRECAMBRIAN that are capped by Tertiary volcanic PAYSON GRANITE rocks in the western part of the study area DIRECTION OF WATER MOVEMENT (fig. 2). The Paleozoic section is FAULT underlain by Precambrian rocks including the Mazatzal Quartzite and the Payson AREA OF FRACTURES granite. The Payson granite forms a SIGNIFICANT DISCONFORMITY topographic bench along the base of the rim that extends for about 10 miles west SOUTH to east. The town of Payson sits upon this exposure of granite. South of Payson, the Mazatzal Mountains and Sierra Ancha ? ? ? ? consist largely of Precambrian sedi- mentary, volcanic, and metamorphic rocks. The two mountain ranges flank the Figure 2. Schematic diagram of geology of the study area showing a generalized north valley of Tonto Creek, which is filled to south cross section from the crest of the Mogollon Rim to the granitic terrain around with alluvium of Quaternary and Tertiary the town of Payson. Springs may be fed directly from recharge areas on top of the Mogollon age to a depth of about 5,000 ft Rim or may be fed from deeper ground-water systems. from an average of 900 gal/min in the southern part of the study area to 52 gal/min on the Mogollon Rim and 48 EXPLANATION 111û30' 111û00' gal/min on the Colorado Plateau. The WELL NWIS contains about 123 springs that SPRING are within the study area, mainly on the face of the Mogollon Rim and in the canyons of major tributaries (fig. 3). 34û30' Discharges range from 0.05 to 18,620 gal/min (fig. 4).

Strawberry Pine Water Use

Ground water is the source of almost Payson 110û30' all water for human uses except

recreation in the study area. Surface

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e water generally cannot be used because r d

e water rights to surface flows are owned by users downstream. About 30 water companies deliver almost 3,500 acre feet 34û00' of water per year to commercial and R domestic customers in the area. There iv e are few irrigated lands in the study area. r The town of Payson accounts for about half of the region’s water use. On the basis of population projections, water er use by the year 2050 could range from iv R about 6,500 to more than 7,600 acre-feet Sa lt per year. None of the communities 0 10 MILES within the study area, however, have an 0 10 KILOMETERS adequate 100-year water supply, according to the Arizona Department of Figure 3. Locations of wells and springs in the study area. Water Resources. Some wells within the study area go dry during periods of Although the Coconino Sandstone is water is about 65 ft south of Payson, drought. Restrictions on domestic water an important aquifer elsewhere on the about 86 ft in the mainly bedrock use are frequently imposed in several Colorado Plateau, most communities aquifers on or at the base of the Mogollon communities during dry spells. Some within the study area obtain water for Rim, and about 105 ft on the Colorado wells have shown a decline in water domestic use from lower-lying formations, Plateau above the rim. Wells south of levels in recent years but it is not known particularly the Supai and Naco Payson are considerably more productive if this reflects a regional trend or is Formations. The lower Paleozoic than those on the rim and on the instead related to climatic variability and formations, including the Redwall Colorado Plateau. Well discharges range local hydrologic factors. Limestone and Martin Formation, are productive aquifers elsewhere as indicated by spring discharge in several streams, but they have not been developed significantly in the study area. The town of Payson obtains its water from wells in the Payson granite. The location of water within granitic rocks of the study area is dependent on the degree of weathering, fracturing, jointing, and faulting in the rocks because unweathered, unfractured granitic rocks have extremely low primary porosity (Southwest Ground- water Consultants, Inc., 1998). A survey of the USGS National Water Information System (NWIS) ground-water data base shows approximately 1,200 wells in the study area (fig. 3). Most wells in the northern half of the study area are in bedrock aquifers; in the southern part of the Tonto Creek Basin, most wells are in valley fill alluvium. Average depth to Figure 4. A spring discharging into Fossil Creek. Table 1. Values for selected water chemistry properties in Mogollon Highlands 4. Analysis of temporal relations [m S/cm, microsiemens per centimeter; mg/L, milligrams per liter; N, number of analyses; R, range; Mn, mean; Md, median] among various components of the Specific Dissolved Fluoride, Arsenic, hydrologic system including precipitation, Water conductance solids dissolved dissolved source pH (m S/cm) (mg/L) (mg/L) (mg/L) streamflow, spring discharge, and ground- N R Mn/Md N R Mn/Md N R Mn/Md N R Mn/Md N R Mn/Md water levels using new and available data. Wells 383 6.7Ð 7.40/ 472 55Ð 1,165/ 197 63Ð 1,241/ 339 0Ð4 0.57/ 138 .001Ð .023/ 5. Hydrochemical analyses to deter- 8.9 7.40 25,000 750 97,700 482 0.35 .22 0.11 Springs 89 6.34Ð 7.34/ 110 25Ð 782/ 97 14Ð 517/ 87 0Ð 0.40/ 9 .001Ð 0.18/ mine ground-water flow paths and 8.20 7.36 4,660 695 3,230 400 6.8 0.20 1.4 .008 residence times of ground-water within Streamflow 397 5.58Ð 8.08/ 406 17Ð 319/ 349 40Ð 349/ 323 0Ð 0.92/ 89 .001Ð .022/ 12.00 8.20 800 351 440 197 3.3 0.50 .17 0.13 different parts of the hydrogeologic system. 6. Integration of geologic and Water Quality where are the flow paths, and what is the hydrologic information to develop availability of water from that system? conceptual and predictive models of the Water quality within the study area is 8. Is the Payson granite recharged regional hydrogeologic system. variable. Well water tends to have high significantly from overlying or adjacent 7. Sensitivity analysis to identify those concentrations of dissolved solids, and aquifers or is it recharged only from components of the hydrogeologic system individual water samples from wells and precipitation? What constitutes sus- that exert the greatest control over springs have high concentrations of tainable use within the Payson granite? regional ground-water flow to aid in arsenic and fluoride (table 1). U.S. 9. What are the flow paths south of optimizing the collection of new data. Environmental Protection Agency Payson into the alluvial valley of the 8. Development of a predictive model (USEPA) Primary and Secondary Tonto Basin? of regional ground-water flow to Drinking-Water Regulations include a 10. What are the hydrogeologic examine the effects of different water- range of 6.5 to 8.5 for pH and a characteristics of the Precambrian rocks resources development scenarios on the maximum of 500 milligrams per liter that form the Mazatzal Mountains and the hydrologic system. (mg/L) for dissolved solids. Concen- Sierra Ancha south of Payson? trations of fluoride greater than 4.0 11. How is human use affecting the —John T.C. Parker and Marilyn E. Flynn mg/L and of arsenic greater than 0.05 surface- and ground-water systems at mg/L exceed USEPA Maximum present, and how will future use affect References Contaminant Levels. these systems in terms of water availability and quality? Feth, J.H., and Hem, J.D., 1963, Reconnaissance of Remaining Questions 12. How are precipitation, surface- headwater springs in the Gila River drainage basin, Arizona, U.S. Geological Survey water flows, and ground-water flows WaterÐSupply Paper, 1619ÐH, p. H1ÐH54. A number of questions are linked or partitioned throughout the Mayer, L., 1978, Evolution of the Mogollon Rim fundamental to understanding the hydrogeologic system? in central Arizona: Tectonophysics, v. 61, hydrogeologic system of the Mogollon p. 49Ð62. Rim area. These include: Possible Approaches Richards, A.M., 1987, Gravity analysis of the Tonto 1. What is the recharge area for and Payson basins, central Arizona: Flagstaff, springs and wells in the Paleozoic The first year of the USGS study Arizona, Northern Arizona University, sedimentary rocks? mainly involved the collection and Master’s thesis, 162 p. 2. Where is the ground-water divide compilation of existing data and the Southwest Ground-water Consultants, Inc. (SGC), 1998, Long-term management program of separating flow toward the rim from flow development of a hydrogeologic data base. the town of Payson’s water resources: moving toward the Little Colorado River? These aspects of the study are expected to Phoenix, Arizona, Southwest Ground-water 3. What are the hydrogeologic charac- continue throughout the life of the project, Consultants, Inc., Report for Town of Payson, teristics of the Tertiary volcanic rocks however; the identification of data needs, 61 p. + appendices. that cap some areas of the rim? collection of new data, and evaluation, Weir, G.W., and Beard, L.S., 1997, Preliminary 4. What are the rates of ground-water synthesis, and analysis of data will geologic map of the Strawberry quadrangle, Yavapai, Gila, and Coconino Counties, flow from the recharge areas to springs become increasingly important as the Arizona: U.S. Geological Survey OpenÐFile and wells in the upper Paleozoic aquifers project continues. Some of the approaches Report, 94Ð0265, 1 sheet. such as the Coconino Sandstone and that may be used to answer the questions Weisman, M.K., and Weir, G.W., 1990, Geologic Upper Supai Formation? above and to develop conceptual and map of the Pine 7.5-minute quadrangle, 5. Is there significant leakage from the interpretive models of the hydrogeologic Coconino and Gila Counties, Arizona: U.S. upper Paleozoic aquifers into underlying system in the study area include: Geological Survey Miscellaneous Field Studies Map, MFÐ2123, 1 sheet. sedimentary rocks and granite? 1. Synthesis and interpretation of Wilson, E.D., Moore, R.T, and Peirce, H.W., 1959, 6. How sensitive are the water-bearing existing geologic mapping to develop a Geologic map of Gila County, Arizona, zones within the Lower Supai Formation preliminary three-dimensional geologic Tucson, Arizona Bureau of Mines, 1 sheet. and the Naco Formation to variability in framework of the study area. recharge? What are the hydrologic 2. Analysis of the spatial relations For further information, contact: characteristics of these formation? What among streams, springs, wells, and John Parker constitutes sustainable use in aquifers geologic features, including unit U.S. Geological Survey, WRD within the Lower Supai and Naco thickness, lithology, and dip, and 520 North Park Avenue, Suite 221 Formations? structural characteristics including faults, Tucson, Arizona 85719-5035 7. What are the characteristics of the fractures, and joints. regional ground-water flow system? Which 3. Analysis of the spatial variability in E-mail: [email protected] or visit geologic formations are components of the aquifer characteristics and the relation of home page http://az.water.usgs.gov regional ground-water flow system, such characteristics to geologic features.