GLEN LAKE - HYDROLOGIC ASSESSMENT LEELANAU COUNTY,

Prepared for Leelanau County Circuit Court - Technical Committee National Park Service Leelanau County Drain Commissioner Michigan Department of Environmental Quality Crystal River Preservation Association Association

Prepared by Hope Croskey, P.E. Gary F. Croskey, P.E., LLC Steve Miller, P.E., MTO, LLC

November 2009

ACKNOWLEDGEMENTS

We thank the following Technical Committee representatives for their support in completing this hydrologic assessment of the Glen Lake and Crystal River Hydrology. Steve Yancho, National Park Service Steve Christenson, Leelanau County Drain Commissioner Mike Stifler, Michigan Department of Environmental Quality (MDEQ) Vik Theiss, Crystal River Preservation Association Jim Dutmers, Glen Lake Association (GLA) John Kassarjin, GLA Water Level Committee

In addition, we have enjoyed and appreciated the assistance of Marlio Lesmez, MDEQ Hydrologic Studies Unit Chief for his review of the groundwater watershed delineation; Bill Klein, Michigan State University Northwest Michigan Horticulture Research Station, for his dedication to collecting pan evaporation data; and Vik Theiss for his time in providing exceedingly large volumes of documentation, records, and data needed for completion of this project.

ii TABLE OF CONTENTS

List of Figures ...... iii List of Tables ...... iv Abbreviations ...... v Acronyms ...... v Introduction ...... 1 Project Objectives ...... 2 Glen Lake and Crystal River Watersheds ...... 2 Hydrologic Related Data Maps ...... 6 System Water Balance ...... 11

Groundwater Recharge (GWI) ...... 12 Storage (ΔS) ...... 13 Precipitation (P) ...... 13 Evaporation (E) ...... 13

Groundwater Discharge (GWO) ...... 14

Crystal River Flow below Dam (DamD) ...... 15 Results ...... 16 Conclusions and Recommendations ...... 24 References ...... 26 Appendix A: MDEQ Approval of Groundwater Watershed ...... A1 Appendix B: NWS Maple City Precipitation Data ...... B1 Appendix C: Daily and Average Monthly Flows at Dam ...... C1 Appendix D: USGS Monthly Statistics for Platte River ...... D1

LIST OF FIGURES Figure 1. Glen Lake – Crystal River Groundwater Watershed ...... 3 Figure 2. Glen Lake – Crystal River Surface Drainage Watershed ...... 4 Figure 3. Platte River and Glen Lake and Crystal River Groundwater Watersheds ...... 5 Figure 4. Crystal River Watershed Hydrologic Soil Classifications ...... 7 Figure 5. Crystal River Watershed Land Use ...... 8 Figure 6. Crystal River Watershed State Quaternary Geology ...... 9 Figure 7. Distribution of Alluvium, Dune Sand, and Glacial Deposits ...... 10 Figure 8. 2005 (Dry) Water Balance Groundwater Recharge vs Platte River Recharge ...... 17 Figure 9. 2006 (Average) Water Balance Groundwater Recharge vs Platte River Recharge ...... 17 Figure 10. 2007 (Dry) Water Balance Groundwater Recharge vs Platte River Recharge ...... 18

iii Figure 11. 2008 (Wet) Water Balance Groundwater Recharge vs Platte River Recharge ...... 18 Figure 12. 2005 (Dry) Glen Lake Water Balance ...... 21 Figure 13. 2006 (Average) Glen Lake Water Balance ...... 22 Figure 14. 2007 (Dry) Glen Lake Water Balance ...... 22 Figure 15. 2008 (Wet) Glen Lake Water Balance ...... 23

LIST OF TABLES Table 1. Groundwater and Surface Drainage Watershed Areas...... 2 Table 2. Little Glen, Glen and Fisher Lakes Surface Areas ...... 2 Table 3. USGS Gaging Stations for Similar, Nearby Watersheds ...... 12 Table 4. Monthly Change in Glen Lake Water Surface Elevations (inches) ...... 13 Table 5. Maple City Annual Precipitation (inches), Rank, and Rating ...... 13 Table 6. Maple City Monthly Precipitation ...... 13 Table 7. Northwest Horticultural Research Station Monthly Pan Evaporation ...... 14 Table 8. Historical Monthly Average Low and High and Glen Lake Water Levels ...... 15 Table 9. Average Monthly Lake Michigan and Glen Lake Water Levels 2005 through 2008 ...... 15

Table 10. Average Monthly Discharges at Dam, DamD ...... 15

Table 11. 2005-2008 Calculated GWI Compared to Platte River Yield ...... 16

Table 12. Calculated GWI compared to Yield based on Platte River ...... 16 Table 13. 2005 (Dry) System Water Balance ...... 19 Table 14. 2006 (Average) System Water Balance (inches) ...... 20 Table 15. 2007 (Dry) System Water Balance (inches) ...... 20 Table 16. 2008 (Wet) System Water Balance (inches) ...... 21 Table 17. Historic Monthly Average Low and High Groundwater Outflow Estimates...... 23 Table 18. Outflow Components Discharging from Glen Lake in July and August ...... 24

iv ABBREVIATIONS cfs cubic feet per second ft feet ft2 square feet msl mean sea level mi2 square miles sec seconds

ACRONYMS

GLA Glen Lake Association DEM Digital Elevation Model MDEQ Michigan Department of Environmental Quality NREPA Natural Resources and Environmental Protection Act NWS National Weather Service USDA United States Department of Agriculture USGS United States Geological Survey

v INTRODUCTION The Crystal River Dam was purchased and repaired by lake riparians in 1937 (Hanes 1949). The “natural height” and level of Glen Lake was first established at 596.75 “above sea level” in 1944, and reaffirmed in 1945, and again in 1954 (in a decree responding to a complaint) under Act 377, Inland Lake Levels, of Public Acts of 1921 as the Glen Lake Level Control Structure. This structure controls the level of Little Glen, Glen, and Fisher Lakes and is identified by the State of Michigan as Dam ID No. 1975. For the purposes of this report the structure is referred to as the Crystal River Dam and the lake system as Glen Lake. Act 377, which was amended and replaced by Part 307, Inland Lake Levels, of the Natural Resources and Environmental Protection Act of 1994 (NREPA), authorizes the Circuit Court for the County of Leelanau (Court) to have continuing jurisdiction over the establishment and maintenance of the normal lake level of Glen Lake. The 2003 Court Order reaffirmed the normal level of “…596.75 feet above sea level with a range of up to plus two inches above and minus three inches below that level.” This corresponds to a maximum level of 596.92 feet and minimum level of 596.50 feet. The Court adopted a Management Plan that includes regulatory algorithms that “will provide a more precise mechanism for managing the lake level and sharing the environmental burden of drought.” The Order granted the GLA Water Level Committee the “…sole authority and responsibility to manipulate the dam gates in accordance with the Management Plan, the modified Lake Level Order, the terms of this Decision and the continuing supervisory jurisdiction of the Court.” The Technical Committee serves as an advisory body and information-gathering resource to the GLA Water Level Committee and includes the Leelanau County Drain Commissioner and representatives from the National Park Service, Michigan Department of Environmental Quality (MDEQ), Crystal River Preservation Association, and Glen Lake Association (GLA). The Court order requires the Management Plan to include measuring devices that are implemented, monitored, and documented to provide surface water elevations and river flow data necessary for dam operations. Responsibilities include compiling data, providing annual reports to the Court, and recommending changes or adjustments to the regulation algorithms. What is unique, and perhaps precedent setting, is the normal lake level management must include a water sharing plan with the Crystal River. To assist the GLA Water Level Committee with operating the dam in a manner to protect the water resources of both the Crystal River and Glen Lake, the Technical Committee requested this hydrologic assessment of the Glen Lake – Crystal River Watershed. Because Glen Lake is a predominately groundwater dominated flow system and direct measurements are not possible a water balance approach is used to estimate the anticipated rate of groundwater flow entering (recharging) and leaving (discharging) Glen Lake during dry, normal, and wet conditions. These estimates are then compared to monthly and seasonal flow rates observed at nearby, long term U.S. Geological Survey (USGS) gaging stations with similar watershed characteristics. The water balance uses the 10 square mile lake area of Glen Lake that is controlled by the Crystal River Dam as a storage reservoir (similar to a bathtub). The change in lake surface elevations for each month (storage) is set equal to flow entering (inflow) and flow leaving (outflow) Glen Lake. For calculation purposes measured flow rates, in cubic feet per second (cfs), are converted to inches during a given month over this 10 square mile area, which is a volume per time comparison. As part of this assessment, an exhaustive evaluation of historical information, which included discussions with professionals and a review of hydrologic, hydraulic, scientific information, lake level reports, engineering plans, survey data, and court testimony, was completed. This review resulted in the conclusion that insufficient information prior to 2005 is available for use in development of a reliable system water balance. Because reliable evaporation data is only available for the months of April through October and consistent Crystal River flow data began in 2005, the water balance is limited to the months of April through October for the years 2005 through 2008.

1

For those desiring a basic understanding of the hydrologic process prior to reading this report, please review a document entitled “Introduction to Hydrology” that is available on the State of Michigan, Hydrologic Studies Unit website (MDEQ 2009).

PROJECT OBJECTIVES The project objectives include the following. 1. Delineate the Glen Lake and Crystal River groundwater and surface drainage watersheds. 2. Provide hydrologic related data maps for the watershed including: digital elevation data, hydrologic soil classifications, land use, and geology. 3. Develop a system water balance to estimate groundwater flow that recharges Hatlems Creek and Glen and Fisher Lakes using data representative of low, medium, and high precipitation years, which correspond to dry, medium, and wet conditions, respectively.

GLEN LAKE AND CRYSTAL RIVER WATERSHEDS Contributing groundwater and surface drainage areas for the Glen Lake and Crystal River watersheds overlain on 10 meter DEM (Digital Elevation Model) data are shown in Figures 1 and 2. The work necessary to develop these watershed delineations was extensive and included consultations with the Hydrologic Studies Unit and other MDEQ staff. Public information utilized in the development included USGS topographic maps, the State of Michigan Groundwater Inventory well log database (Wellogic DB), and the Groundwater Levels (Water Level contours), all of which are available using the. ArcIMS Viewer (Michigan State University 2009), which is co-sponsored by the MDEQ and USGS. The groundwater watershed boundaries at the outlet of Glen Lake outlet, at the Crystal River Dam, and at the mouth of the Crystal River are shown in Figure 3. An 11.4 square mile area that is delineated in the statewide hydrologic drainage area layer as part of the Platte River has been determined to contribute to the Glen Lake - Crystal River groundwater watershed. This area is designated by a directional arrow in Figure 3. The groundwater and surface drainage areas are summarized in Table 1 and the lake surface areas in square miles and acres in Table 2. The Crystal River groundwater watershed, shown in Figures 1 and 3, has been reviewed and approved by the MDEQ, Hydrologic Studies Unit (Lesmez 2009). A copy of this email dated August 13, 2009, is provided in Appendix A.

Table 1. Groundwater and Surface Drainage Watershed Areas Location Groundwater (mi2) Surface Drainage (mi2) Glen Lake Outlet 54.0 29.0 Crystal River Dam 57.1 30.2 Crystal River at mouth 59.7 32.2 Platt River USGS Gage 04126740 113.9* 125.3 (118**) * Based on MDEQ delineated Platte River drainage area of 125.3 mi2, of which 11.4 mi2 contributes to the Glen Lake - Crystal River groundwater watershed. ** USGS reported drainage area, which was not revised since agreement with MDEQ statewide surface watershed delineations.

Table 2. Little Glen, Glen and Fisher Lakes Surface Areas Lake Surface Area (mi2) Surface Area (acres) Little Glen 2.2 1410 Glen 7.6 4860 Fisher 0.2 130 Total 10.0 6400

2 Fisher Lakes

Little Glen

Hatlems Creek

585

↑

Figure 1. Glen Lake – Crystal River Groundwater Watershed

3 Fisher Lakes

Little Glen

Hatlems Creek

585

Figure 2. Glen Lake – Crystal River Surface Drainage Watershed

4

Fisher Lakes

Little Glen

Hatlems Creek

11.4 mi2

Glen’s Landfill

Platte River ▲ USGS Gage 04126740

GW Drainage Area at Mouth of Crystal River GW Drainage Area at Crystal River Dam GW Drainage Area at Glen Lake Outlet GW Drainage Area of Platte River

Figure 3. Platte River and Glen Lake and Crystal River Groundwater Watersheds

5 HYDROLOGIC RELATED DATA MAPS The Hydrologic Soils Classifications are shown in Figure 4. The United States Department of Agriculture – Natural Resources Conservation Service (USDA-NRCS 2009) defines the soil groups as follows: Group A: Soils having a low runoff potential due to high infiltration rates. These soils consist primarily of deep, well-drained sands and gravels. Group B: Soils having a moderately low runoff potential due to moderate infiltration rates. These soils consist primarily of moderately deep to deep, moderately well to well- drained soils with moderately fine to moderately coarse textures. Group C: Soils having a moderately high runoff potential due to slow infiltration rates. These soils consist primarily of soils in which a layer exists near the surface that impedes the downward movement of water or soils with moderately fine to fine texture. Group D: Soils having a high runoff potential due to very slow infiltration rates. These soils consist primarily of clays with high swelling potential, soils with permanently high water tables, soils with a claypan or clay layer at or near the surface and shallow soils over nearly impervious parent material. Dual hydrologic groups: A/D, B/D, and C/D, are given for certain wet soils that can be adequately drained. The first letter applies to the drained condition, the second to the undrained. Only soils that are rated D in their natural condition are assigned to dual classes. Soils may be assigned to dual groups if drainage is feasible and practical.

The Glen Lake – Crystal River watershed is predominately hydrologic Soil Group A, which results in minimal surface runoff because of high infiltration rates. These high infiltration rates result in precipitation recharging the groundwater supply to Glen Lake.

The land use, shown in Figure 5, is predominately agriculture, forest and rangeland. Maintenance of pervious surfaces is important to retain high infiltration rates in the watershed. The State of Michigan quaternary geology is shown in Figures 6, which is a generalized statewide map with limited detail. Handy and Stark (1983) provided a more detailed representation of the Glen Lake-Crystal River watershed geology, which is shown in Figure 7. Note the dune sand and lakebed deposit between Glen Lake and Lake Michigan, both of which have high values of hydraulic conductivity that provide an avenue for groundwater to discharge to Lake Michigan.

6

Figure 4. Crystal River Watershed Hydrologic Soil Classifications

7

Figure 5. Crystal River Watershed Land Use

8

Figure 6. Crystal River Watershed State Quaternary Geology

9 Source: Handy and Stark (1983)

Figure 7. Distribution of Alluvium, Dune Sand, and Glacial Deposits

10 SYSTEM WATER BALANCE A system water balance provides the ability to estimate unknowns, from known information. In this case, a reliable estimate of groundwater inflow (GWI) supplying Glen Lake and the Crystal River watershed over a range of hydrologic weather conditions, which is needed to assist with the development of lake level and water sharing management plans. In a hydrologic water balance the change in lake elevations, or storage, ∆ is equal to inflow minus outflow. ∆ (1)

Inflow to Glen Lake includes rain and snow that infiltrates into the groundwater drainage area and supplies a constant base flow to Hatlems Creek and the springs at the edges of Glen Lake as groundwater recharge or flow (GWI) plus direct precipitation on Glen Lake (P).

(2)

Outflow includes lake surface evaporation (E), water that flows from Glen Lake to Lake Michigan as a groundwater discharge (GWO), and flow into the Crystal River over the dam (DamD). Because the water balance is on a lake surface and not the watershed drainage area evapotranspiration and interception are not a factor.

(3)

Therefore: ∆ GWI GWO (4) Where: ΔS = Change in storage, which is equal to the change in lake elevations (inches) GWI = Groundwater inflow from infiltration of rain and snow over the watershed (inches) P = Precipitation directly on Glen Lake (inches) E = Evaporation from the surface of Glen Lake (inches) GWO = Groundwater outflow (discharge) from Glen Lake to Lake Michigan (inches) DamD = Surface water discharging over the dam to the Crystal River (inches)

Calculation of the water balance requires all parameters to be converted to uniform dimensions. For this report each flow component in the water balance is converted to inches for a given month over the 10 square mile lake surface area. For example, the monthly average flow rate in cfs (volume per time) at the dam is converted to inches per month for the 10 square mile lake surface using the following conversion, where the number of days is month specific.

3600 24 __ 1 12 10 10 5280

To estimate groundwater inflow that recharges Hatlems Creek, and Glen and Fisher Lakes Equation 4 is rearranged as follows.

GWI ∆GWO (5)

The method used to validate the estimates of groundwater inflow, GWI, and a detailed description of each water balance component along with a summary of available data for each follow.

11 Groundwater Recharge (GWI) Precipitation, including snow, on the watershed infiltrates into the course glacial deposits recharging the aquifer below. Groundwater moves through the aquifer and enters Glen and Fisher Lakes and Hatlems Creek. This is evidenced by natural springs that are present along the shorelines of Little Glen and Glen Lake and the base flow observed in Hatlems Creek. Groundwater inflow (GWI) is not directly measurable and is therefore estimated using Equation 5 for the months of April through October for the four years of record 2005 through 2008. To increase the confidence of GWI estimates, the monthly values for each year (inches) are summed for a total seasonal value and compared to observations at a selected USGS long term, nearby stream flow gaging station. For comparison purposes, observed average monthly flows (cfs) for the months of April through October at the selected gage are converted to inches per month and adjusted by the drainage area ratio between Glen Lake and the selected watershed using the following formula. 57.1 3600 24 __ 1 12 __ 10 5280 Adjustments are made, within expected ranges, to the pan coefficient to estimate E, and to the aquifer hydraulic conductivity (K) and depth of groundwater flow discharging from Glen Lake to Lake Michigan for refinement of GWO. These adjustments are made to minimize the percent difference between the calculated total seasonal (April through October) GWI values (inches) using Equation 5 and those observed at a nearby stream with long term flow records for the years 2005-2008. Four nearby USGS gaging stations on streams with similar soils and land use characteristics are summarized in Table 3. The Boardman River flows are highly regulated by hydroelectric dam operations. The Crystal River below the dam is also highly regulated with the purpose being to document discharges from Glen Lake. The Jordan River is not used by the MDEQ for comparative purposes because of the uncharacteristically high base flows recorded. The Platte River Gage, which has a continuous record of unregulated flow since April 1990, is therefore selected for comparison purposes in this assessment.

Table 3. USGS Gaging Stations for Similar, Nearby Watersheds USGS Gage Stream / Location Drainage Area (mi²) Comments 04126970 Boardman River at Brown Bridge 141 Discharge highly regulated by hydroelectric Road near Mayfield, MI dam operations. 041268014 Crystal River below dam near 57.1* Discharge regulated by dam. Miscellaneous Glen Arbor, MI measurements used to develop rating curve to verify required minimum release. 04127800 Jordan River near East Jordon, MI 67.9 Uncharacteristic high base flow (2 to 3 times that expected). Not used by MDEQ for comparison purposes. 04126740 Platte River at Honor, MI 118 (USGS) Basin shape is elongated and groundwater (1990 to 2006 available period of 125.3 (MDEQ) gradients shallower than observed for Crystal record at time of analysis) 113.9 (Adjusted)# River Watershed * Includes 11.4 mi² of Platte River Basin that contributes to Crystal River groundwater recharge # MDEQ drainage area adjusted for groundwater contribution to Crystal River (125.3-11.4 mi²) (Lesmez, 2009)

A comparison of the average precipitation at Maple City of 33.94 inches for the years 1990-2006 (Platte River period of record) and 34.98 inches for the years 1959-2008 (Maple City Precipitation period of record) indicates that average flow statistics for the Platte River gage provide reasonable estimates for longer term seasonal flow volumes. Also noteworthy are the minimum monthly mean values that occurred during 1998-2001 for the period of record 1990-2006 at the Platte River gage (Appendix D), which document a regional drought during this time period.

12 Storage (ΔS) The change in lake elevation (ΔS) is regularly recorded by the GLA, Water Level Committee to a hundredth of a foot. Monthly reports with daily readings, beginning in 2005, are available on the GLA website (GLA 2009). The differences between the lake elevation on the last day of the previous month and the last day of the month of interest are summarized in Table 4. Table 4. Monthly Change in Glen Lake Water Surface Elevations (inches) Apr May Jun Jul Aug Sep Oct 2005 1.56 1.80 -1.32 -1.32 -0.60 0.24 -0.72 2006 2.52 1.80 -2.40 0.48 -1.68 -1.20 1.68 2007 1.08 -0.72 -0.96 -2.28 -2.40 -1.56 0.60 2008 2.76 -0.96 -0.36 -0.24 -3.84 -0.72 -1.56

Precipitation (P) The GLA Water Level Committee monthly reports, which began in 2005, include observations of precipitation at various locations around the lake. These observations use an array of different precipitation collection devices that may not be calibrated and use various collection time intervals. For this analysis, published National Weather Service (NWS) daily precipitation data is available for the Maple City gage located adjacent to the east side of the watershed (see Figure 3). Monthly and annual precipitation totals for the 50 years of record, ranked from dry to wet, are provided in Appendix B. Annual precipitation for the years 2005-2008 and the associated rank, and dry, average and wet ratings are summarized in Table 5.

Table 5. Maple City Annual Precipitation (inches), Rank, and Rating Annual Precipitation Rank (low to high) Rating 2007 24.82 1st Dry 2005 27.69 2nd Dry 2006 34.35 26th Average 2008 41.89 45th Wet Average 1959-2008 34.98

NWS Maple City monthly precipitation data, summarized in Table 6, are used to estimate the direct precipitation (P) on the 10 square mile surface area of Glen and Fisher Lakes in the system water balance.

Table 6. Maple City Monthly Precipitation Apr May Jun Jul Aug Sep Oct 2005 (inches) 1.42 1.90 2.68 1.70 3.12 3.85 0.85 2006 (inches) 1.59 4.25 1.76 2.78 3.27 3.62 6.04 2007 (inches) 2.43 1.20 1.84 1.24 2.48 1.92 4.00 2008 (inches) 4.91 2.8 5.29 2.61 2.03 3.36 2.13

Evaporation (E) The USDA (2009) provides monthly average evaporation estimates for Maple City, Michigan; however, documentation as to the source and reliability of the information is unavailable (Davis 2009) and is therefore discarded as a source of evaporation in the water balance. Evaporation from a lake surface is complex and varies based on water and air temperature (vapor pressure), relative humidity (water vapor content), turbulence (wind speed), and net irradiance (Linacre 1994, Calder 2002). Because of these complexities, evaporation is estimated by measuring evaporation from a US-Class A pan evaporator and multiplying by a pan coefficient. Linacre (1994) reported pan coefficients to vary widely worldwide and range between 0.60-0.82 based on 18 papers reviewed.

13 Pan evaporation data was collected between April and October at the Northwest Michigan Horticultural Research Station located between Traverse City and Suttons Bay, Michigan. This data is summarized in Table 7. This data is multiplied by a pan coefficient and used in the monthly water balance calculations. Table 7. Northwest Horticultural Research Station Monthly Pan Evaporation Apr May Jun Jul Aug Sep Oct 2005 (inches) 4.44* 4.67 7.37 7.66 6.55 4.87 2.86 2006 (inches) 4.70* 5.30 6.59 7.77 6.77 3.46 1.87 2007 (inches) 2.04* 6.63 8.32 7.66 6.71 5.26 3.35 2008 (inches) 2.89* 5.18 5.91 7.12 6.90 4.12 2.41 * estimated (Klein, 2009)

Groundwater Discharge (GWO) The water surface elevation difference, for the years 2005 and 2008, of nearly 20 ft between Lake Michigan and Glen Lake and the highly permeable lakebed and dune sand deposits, shown in Figures 6 and 7 to the north side of Glen Lake, results in groundwater discharging (GWO) to the northwest from Glen Lake to Lake Michigan. This groundwater discharge is further documented in the MDEQ Hydrologic Studies files by Croskey (1991) through the installation and observation of piezometer pairs in the early 1990s. Inconclusive data for piezometric pairs installed and monitored for the north shoreline of Little Glen Lake in the 1990s (Croskey) and the well log information for a recently installed deep well west of Alligator Hill by the National Park Service support the conclusion that groundwater does not likely discharge from Little Glen to Lake Michigan. Groundwater flow (GWO) from a high hydraulic head (high water level) to low hydraulic head (low water level) is estimated using Darcy’s Law, which is represented by Equation 6. ∆ (6) Where: 3 = Groundwater flow (ft /day) = Hydraulic conductivity of the aquifer media (ft/day) = Cross-sectional area perpendicular to flow (ft2) ∆ = Difference in up gradient and down gradient water elevations (ft) = Length of flow path (ft) ∆ The term represents the hydraulic gradient, or slope of the groundwater piezometric surface. The hydraulic conductivity (K) of this course textured formation is estimated at 300 ft/day, through a cross sectional area approximately 2 miles wide and 100-120 feet deep. The length of flow path, or distance between the inland lakes and Lake Michigan, is estimated at 1 mile. The U.S. Army Corp of Engineers website (USACE 2009) reports the monthly average Lake Michigan water levels in meters [IGLD 85] from 1918 to 2008. The following conversion provided by Menerey (2009), is used to adjust the IGLD 85 water levels to NGVD 29 or mean sea level (msl). This conversion is based on the National Geodetic Survey (2009) VERTCON software. 85 3.2808 0.37 For the months April through October, the historical monthly average low and high were 576.51 ft and 582.71 ft [msl] during April 1964 and October 1986, respectively. These values and the corresponding Glen Lake water elevations are summarized in Table 8. The average monthly Lake Michigan and Glen Lake water levels for the months April through October 2005 through 2008 are summarized in Table 9.

14 Table 8. Historical Monthly Average Low and High Lake Michigan and Glen Lake Water Levels April 1964 Historic Monthly October 1986 Historic Monthly April-October Average Low Elevation (ft) [msl] Average High Elevation (ft) [msl] Glen Lake 590.87 590.92 Lake Michigan 576.51 582.71

Table 9. Average Monthly Lake Michigan and Glen Lake Water Levels 2005 through 2008 Apr May Jun Jul Aug Sep Oct 2005 Glen Lake 596.52 596.66 596.68 596.57 596.49 596.47 596.45 2005 Lake Michigan 578.25 578.41 578.48 578.41 578.35 578.09 577.79 2006 Glen Lake 596.72 596.90 596.87 596.79 596.74 596.62 596.64 2006 Lake Michigan 577.82 578.09 578.25 578.25 578.22 577.92 577.76 2007 Glen Lake 596.87 596.88 596.81 596.68 596.48 596.32 596.28 2007 Lake Michigan 577.86 577.99 578.05 577.95 577.79 577.63 577.40 2008 Glen Lake 596.89 596.96 596.91 596.88 596.71 596.52 596.43 2008 Lake Michigan 577.53 577.92 578.32 578.58 578.51 578.38 578.09

Crystal River Flow below Dam (DamD) The USGS routinely measures flow in the Crystal River downstream of the dam and maintains a rating table for conversion of river water elevations to flow in cubic feet per second (cfs). This table is periodically revised during each year by USGS through streamflow measurements to account for seasonal shifts due to debris accumulation, movement of bottom sediment, and aquatic vegetation, all of which impact the channel’s roughness coefficient and corresponding flow and depth relationship. Since 2005, the GLA Water Level Committee has routinely recorded river elevations downstream of the dam in the Crystal River. These elevations are converted to flow estimates using the USGS rating table and are included in the monthly reports, which are available on the GLA website (GLA 2009). These recorded elevations were used to estimate daily and monthly average surface water discharges in cfs flowing over the dam to the Crystal River and are summarized in Appendix C. The average monthly discharge rates (cfs) at the dam were then converted to inches over the 10 square mile area for each month using the conversion previously provided. These discharges in cfs and inches are summarized in Table 10.

Table 10. Average Monthly Discharges at Dam, DamD Average Dam Discharge Apr May Jun Jul Aug Sep Oct 2005 (cfs) 38.9 36.1 37.6 31.7 28.5 28.1 28.6 2005 (inches) -4.48 -4.16 -4.20 -3.65 -3.29 -3.14 -3.30 2006 (cfs) 35.5 69.5 48.2 33.1 32.9 30.9 45.9 2006 (inches) -4.09 -8.01 -5.38 -3.82 -3.79 -3.45 -5.29 2007 (cfs) 56.6 44.5 35.7 32.5 27.4 24.2 24.1 2007 (inches) -6.5 -5.1 -4.0 -3.7 -3.2 -2.7 -2.8 2008 (cfs) 81.2 66.9 75.0 33.4 30.9 30.3 25.7 2008 (inches) -9.4 -7.7 -8.4 -3.9 -3.6 -3.4 -3.0

15 RESULTS In summary, monthly GLA records were used to define ΔS. The Maple City rain gage was used to estimate P. Recorded pan evaporation values at the Northwest Michigan Horticultural Research Station were adjusted with an optimized pan coefficient to estimate E. Groundwater outflow, GWo, from Glen Lake to Lake Michigan was estimated from the lake elevation records and optimized values of aquifer hydraulic conductivity (K) and depth of groundwater flow. Recorded flows at the Crystal River Dam by the GLA Water Level Committee were converted to inches over the 10 square mile area for each month and used as estimates of DamD. USGS (2009) Platte River average monthly flows (cfs) that are summarized in Appendix D were used to estimate anticipated yields for Glen Lake (inches for each month) using the following formula. 57.1 3600 24 1 12 113.9 10 5280

The optimized values of GWI using Equation 5 and the yields based on the Platte River gage are summarized in Table 11 for the years 2005-2008. When the monthly values are summed for April through October for both the calculated GWI values using Equation 5 and the yield based on the Platte River, the totals are remarkably equivalent for all four years. The seasonal totals (inches) for both methods and the differences between the estimates for each year in inches and percent are summarized in Table 12. These differences are well within what is expected for hydrologic information; for example, the USGS and other qualified individuals use the following accuracy ratings, 2% (excellent), 5% (good), fair (8%), and poor (over 8%) for river flow measurements.

Table 11. 2005-2008 Calculated GWI Compared to Platte River Yield

Calculated GWI (inches) Yield based on Platte River Gage (inches) 2005 2006 2007 2008 2005 2006 2007 2008 (Dry) (Average) (Dry) (Wet) (Dry) (Average) (Dry) (Wet) Apr 9.16 9.79 8.20 10.82 7.66 6.81 7.78 7.60 May 8.75 10.72 9.25 9.05 6.99 7.00 6.84 6.94 Jun 6.61 7.15 8.27 8.20 6.22 6.39 6.28 6.89 Jul 7.29 8.28 6.93 7.31 6.12 6.49 6.06 6.35 Aug 5.49 4.94 4.35 3.85 6.25 6.83 5.46 6.07 Sept 4.31 2.50 4.28 3.57 6.33 6.74 5.23 6.10 Oct 5.26 3.83 3.25 2.48 5.97 7.52 5.73 6.42 Total 46.86 47.21 44.54 45.28 45.55 47.78 43.38 46.36

Table 12. Calculated GWI compared to Yield based on Platte River Total (April-October)

Calculated GWI Yield based on Difference Difference (inches) Platte River Gage (inches) (%) (inches) 2005 46.86 45.55 1.32 2.8 2006 47.21 47.78 -0.57 -1.2 2007 44.54 43.38 1.16 2.6 2008 45.28 46.36 -1.09 -2.4

These values are presented graphically in Figures 8-11. For all four years, the slope of the calculated monthly GWI values for Glen Lake is much steeper than those based on the Platte River yield per square mile. The steeper slopes for Glen Lake calculated GWI values are reflective of the watershed shape and the groundwater hydraulic gradient, or slope of the piezometric surfaces, driving the recharge. The Glen Lake – Crystal River watershed is round with shorter flow distances compared with the Platte River as seen in Figure 3 and the hydraulic gradients, or slope of the piezometric surfaces that drive flow to Glen Lake are much steeper. The steeper piezometric surfaces are illustrated by the headwater lake elevations seen at Polack (Pollack) and Armstrong Lakes, for example.

16

2005 Groundwater Inflow Glen Lake & Platte River

12

10 9.16

(in) 8.75

8 7.29 Glen Lake Inflow 6.61 Platte River 5.49 6 5.26 Linear (Glen Lake ) 4.31 Linear (Platte River)

Groundwater 4

2 Apr May Jun Jul Aug Sep Oct

Figure 8. 2005 (Dry) Water Balance Groundwater Recharge vs Platte River Recharge

2006 Groundwater Inflow Glen Lake & Platte River

12 10.72 9.79 10 (in) 8.28

8 7.15 Glen Lake Inflow

Platte River 6 4.94 Linear (Glen Lake ) 3.83 Linear (Platte River)

Groundwater 4 2.50

2 Apr May Jun Jul Aug Sep Oct

Figure 9. 2006 (Average) Water Balance Groundwater Recharge vs Platte River Recharge

17

2007 Groundwater Inflow Glen Lake & Platte River

12

10 9.25 (in) 8.20 8.27

8 Glen Lake

Inflow 6.93

Platte River 6 Linear (Glen Lake ) 4.35 4.28 Linear (Platte River)

Groundwater 4 3.25

2 Apr May Jun Jul Aug Sep Oct

Figure 10. 2007 (Dry) Water Balance Groundwater Recharge vs Platte River Recharge

2008 Groundwater Inflow Glen Lake & Platte River

12 10.82

10 9.05 (in) 8.20

8 7.31 Glen Lake Inflow

Platte River 6 Linear (Glen Lake ) Linear (Platte River) 3.85 3.57

Groundwater 4 2.48

2 Apr May Jun Jul Aug Sep Oct

Figure 11. 2008 (Wet) Water Balance Groundwater Recharge vs Platte River Recharge

18 The resulting optimized values for ΔS, P, E, GWO and DamD used to calculate GWI. are summarized in Tables 13-16 in inches, cfs, and percent, and presented graphically in Figures 12-15 for the months of April through October of 2005-2008. These results are based on a pan coefficient of 0.66, which is a relatively low value in the acceptable range; however, Klein (2009) reported that the evaporation values may be high because of the proximity of the pan with an asphalt paved parking area. The groundwater outflow discharge (GWO) is estimated using Darcy’s Law (Equation 5); where the hydraulic conductivity (K) is set at 300 ft/day; the cross-sectional area perpendicular to flow (A) is 2 miles wide by 110 feet deep; and the flow length is 1 mile.

Table 13. 2005 (Dry) System Water Balance

Month GWI ΔS P E GWO DamD April (inches) 9.16 1.56 1.42 2.93 1.61 4.48 April (cfs) 79.5 13.5 12.3 25.4 14.0 38.9 April (%) 87 13 32 18 50 May (inches) 8.75 1.80 1.90 3.08 1.61 4.16 May (cfs) 75.9 15.6 16.5 26.7 13.9 36.1 May % 82 18 35 18 47 June (inches) 6.61 -1.32 2.68 4.86 1.55 4.20 June (cfs) 59.2 -11.8 24.0 43.6 13.9 37.6 June (%) 71 29 46 15 40 July (inches) 7.29 -1.32 1.70 5.06 1.60 3.65 July (cfs) 63.2 -11.4 14.7 43.9 13.9 31.7 July (%) 81 19 49 16 35 August (inches) 5.49 -0.60 3.12 4.32 1.60 3.29 August (cfs) 47.6 -5.2 27.1 37.5 13.9 28.5 August (%) 64 36 47 17 36 September (inches) 4.31 0.24 3.85 3.21 1.57 3.14 September (cfs) 38.6 2.2 34.5 28.8 14.0 28.1 September (%) 53 47 41 20 40 October (inches) 5.26 -0.72 0.85 1.89 1.64 3.30 October (cfs) 45.6 -6.2 7.4 16.4 14.3 28.6 October (%) 86 14 28 24 48 Total (inches) 46.9 -0.36 15.5 25.4 11.2 26.2 Total (cfs) 410 -3.43 137 222 97.8 230 Total (%) 75 25 40 18 42

19 Table 14. 2006 (Average) System Water Balance (inches)

Month GWI ΔS P E GWO DamD April (inches) 9.79 2.52 1.59 3.10 1.66 4.09 April (cfs) 84.9 21.9 13.8 26.9 14.4 35.5 April (%) 86 14 35 19 46 May (inches) 10.72 1.80 4.25 3.50 1.66 8.01 May (cfs) 93.0 15.6 36.9 30.3 14.4 69.5 May % 72 28 27 13 61 June (inches) 7.15 -2.40 1.76 4.35 1.59 5.38 June (cfs) 64.1 -21.5 15.8 39.0 14.2 48.2 June (%) 80 20 38 14 48 July (inches) 8.28 0.48 2.78 5.13 1.63 3.82 July (cfs) 71.8 4.2 24.1 44.5 14.2 33.1 July (%) 75 25 48 15 36 August (inches) 4.94 -1.68 3.27 4.47 1.63 3.79 August (cfs) 42.9 -14.6 28.4 38.8 14.1 32.9 August (%) 60 40 45 16 38 September (inches) 2.50 -1.20 3.62 2.28 1.59 3.45 September (cfs) 22.4 -10.8 32.4 20.5 14.3 30.9 September (%) 41 59 31 22 47 October (inches) 3.83 1.68 6.04 1.23 1.66 5.29 October (cfs) 33.2 14.6 52.4 10.7 14.4 45.9 October (%) 39 61 15 20 65 Total (inches) 47.2 1.20 23.3 24.1 11.4 33.8 Total (cfs) 412 9.37 204 211 100.0 296 Total (%) 67 33 35 16 49

Table 15. 2007 (Dry) System Water Balance (inches)

Month GWI ΔS P E GWO DamD April (inches) 8.20 1.08 2.43 1.35 1.67 6.53 April (cfs) 71.1 9.4 21.1 11.7 14.5 56.6 April (%) 77 23 14 18 68 May (inches) 9.25 -0.72 1.20 4.38 1.66 5.13 May (cfs) 80.2 -6.2 10.4 38.0 14.4 44.5 May % 89 11 39 15 46 June (inches) 8.27 -0.96 1.84 5.49 1.60 3.98 June (cfs) 74.1 -8.6 16.5 49.2 14.3 35.7 June (%) 82 18 50 14 36 July (inches) 6.93 -2.28 1.24 5.06 1.65 3.75 July (cfs) 60.1 -19.8 10.8 43.9 14.3 32.5 July (%) 85 15 48 16 36 August (inches) 4.35 -2.40 2.48 4.43 1.65 3.16 August (cfs) 37.8 -20.8 21.5 38.4 14.3 27.4 August (%) 64 36 48 18 34 September (inches) 4.28 -1.56 1.92 3.47 1.59 2.70 September (cfs) 38.4 -14.0 17.2 31.1 14.3 24.2 September (%) 69 31 45 21 35 October (inches) 3.25 0.60 4.00 2.21 1.66 2.78 October (cfs) 28.2 5.2 34.7 19.2 14.4 24.1 October (%) 45 55 33 25 42 Total (inches) 44.5 -6.24 15.1 26.4 11.5 28.0 Total (cfs) 390 -54.85 132 231 100.6 245 Total (%) 75 25 40 17 42

20 Table 16. 2008 (Wet) System Water Balance (inches)

Month GWI ΔS P E GWO DamD April (inches) 10.82 2.76 4.91 1.91 1.70 9.36 April (cfs) 93.9 23.9 42.6 16.5 14.8 81.2 April (%) 69 31 15 13 72 May (inches) 9.05 -0.96 2.80 3.42 1.68 7.71 May (cfs) 78.5 -8.3 24.3 29.7 14.5 66.9 May % 76 24 27 13 60 June (inches) 8.20 -0.36 5.29 3.90 1.58 8.37 June (cfs) 73.5 -3.2 47.4 35.0 14.2 75.0 June (%) 61 39 28 11 60 July (inches) 7.31 -0.24 2.61 4.70 1.61 3.85 July (cfs) 63.4 -2.1 22.6 40.8 14.0 33.4 July (%) 74 26 46 16 38 August (inches) 3.85 -3.84 2.03 4.55 1.60 3.56 August (cfs) 33.4 -33.3 17.6 39.5 13.9 30.9 August (%) 65 35 47 16 37 September (inches) 3.57 -0.72 3.36 2.72 1.55 3.38 September (cfs) 32.0 -6.5 30.1 24.4 13.9 30.3 September (%) 51 49 36 20 44 October (inches) 2.48 -1.56 2.13 1.59 1.62 2.96 October (cfs) 21.5 -13.5 18.5 13.8 14.0 25.7 October (%) 54 46 26 26 48 Total (inches) 45.3 -4.92 23.1 22.8 11.3 39.2 Total (cfs) 396 -42.99 203 200 99.3 343 Total (%) 66 34 31 15 53

2005 Glen Lake Water Balance

12.0 10.0 9.16 8.75 8.0 7.29 6.0 6.61 5.49 5.26 4.0 4.31 Delta S

2.0 GW In 0.0 Precipitation Inches ‐2.0 GW Out ‐4.0 Evaporation ‐6.0 Crystal River Dam ‐8.0 ‐10.0 ‐12.0 Apr Jun Aug Oct

Figure 12. 2005 (Dry) Glen Lake Water Balance

21

2006 Glen Lake Water Balance 12 10.72 10 9.79 8 8.28 7.15 6 4.94 4 3.83 Δ Storage 2.50 2 GW In 0 Precipitation Inches Inches -2 GW Out -4 Evaporation -6 Dam Discharge -8 -10 -12 Apr May Jun Jul Aug Sep Oct

Figure 13. 2006 (Average) Glen Lake Water Balance

2007 Glen Lake Water Balance 12 10 9.25 8 8.20 8.27 6.93 6 4 4.35 4.28 Δ Storage 3.25 2 GW In 0 Precipitation Inches Inches -2 GW Out -4 Evaporation -6 Dam Discharge -8 -10 -12 Apr May Jun Jul Aug Sep Oct

Figure 14. 2007 (Dry) Glen Lake Water Balance

22

2008 Glen Lake Water Balance 12 10.82 10 9.05 8 8.20 7.31 6

4 3.85 3.57 Δ Storage 2.48 2 GW In 0 Precipitation Inches Inches -2 GW Out -4 Evaporation -6 Dam Discharge -8 -10 -12 Apr May Jun Jul Aug Sep Oct

Figure 15. 2008 (Wet) Glen Lake Water Balance

Water levels ranging from a low of 577.40 feet to a high of 578.58 feet were observed on Lake Michigan for the years 2005 through 2008. The difference of only 1.18 feet resulted in a relatively constant hydraulic gradient for this time period, which resulted in estimated groundwater outflows (GWO) ranging from a low of 13.9 cfs (1.60 inches) in August 2005 to a high of 14.8 cfs (1.70 inches) in April 2008. Using the calibrated parameter values noted above for estimating groundwater outflow, GWO, and the historic monthly average low and high Lake Michigan and Glen Lake water levels provides a range of values from 10.9 to 15.5 cfs for April 1964 and October 1986, respectively.

Table 17. Historic Monthly Average Low and High Groundwater Outflow Estimates

April 1964 Historic Monthly October 1986 Historic Monthly April-October Average Low Elevation (ft) [msl] Average High Elevation (ft) [msl] Glen Lake 590.87 590.92 Lake Michigan 576.51 582.71 (cfs) 10.9 15.5 (in) 1.25 1.79

23 CONCLUSIONS AND RECOMMENDATIONS This report provides preliminary documentation that there is sufficient groundwater flow to Glen Lake to facilitate the maintenance of court ordered normal lake levels and sustain flow to the Crystal River during peak recreational times−even during the driest years of record. However, the assessment is based on four years of record and therefore should be updated in four or five years, as more data becomes available. Graphical representations of the estimated groundwater inflow, GWI, for the years 2005 through 2008, presented in Figures 8-11, show that groundwater recharge to Glen Lake is highest in the spring and declines steadily through the summer and early fall. The linear Glen Lake trend line for 2007, shown on Figure 10, provides a conservative preliminary estimate of groundwater recharge inflow (GWI) rates to the Crystal River Watershed during dry years. The use of this trend line for planning purposes should be used with caution and refined as additional data is collected and analyzed. The outflow components leaving Glen Lake during the critical summer months of July and August when evaporation is high are summarized in Table 18. During August 2007, which was the driest year of the four years evaluated, evaporation accounted for 38.4 cfs while the discharge over the dam averaged 27.4 cfs, which is 48 and 34 percent of the total outflow, respectively. During 2008, which was a wet year, August evaporation was equivalent to 39.5 cfs and the flow at the dam was 30.9 cfs, which is 47 and 37 percent of the outflow, respectively. For the four years of data, evaporation, E, accounted for nearly half of the water loss from the surface of Glen Lake and groundwater outflow, GWO, from Glen Lake to Lake Michigan ranged from 15-18 percent during the months of July and August. During the same months, dam operations, DamD, was responsible for controlling 34 to 38 percent of the water balance outflow. Table 18. Outflow Components Discharging from Glen Lake in July and August July August

E GWO DamD E GWO DamD 2005 (cfs) 43.9 13.9 31.7 37.5 13.9 28.5 2006 (cfs) 44.5 14.2 33.1 38.8 14.1 32.9 2007 (cfs) 43.9 14.3 32.5 38.4 14.3 27.4 2008 (cfs) 40.8 14.0 33.4 39.5 13.9 30.9 2005 (percent) 49 16 35 47 17 36 2006 (percent) 48 15 36 45 16 38 2007 (percent) 48 16 36 48 18 34 2008 (percent) 46 16 38 47 16 37

The following recommendations are made to assist with the continued development of this system water balance and to assist the GLA Water Level Committee with dam operations.

1. Operate the Crystal River Dam gates in response to either precipitation events (including snowmelt) that may impact court ordered lake levels or drought conditions that impact river flow. Daily operations of the Crystal River Dam are not warranted. 2. Maintain lake levels near the highest allowable levels in the spring and early summer to facilitate providing desired flow in the Crystal River in mid to late summer, while providing a desired minimum flow in the Crystal River. 3. Develop a common datum for all elevation measurement devices and measure and report using hundredths of a foot, which is consistent with USGS standards. 4. As done in the past, continue documenting river flow downstream of the dam and surface water elevations when dam adjustments are made. 5. Continue to make miscellaneous measurements and calibrate the rating table used to convert river stage to flow. 6. Consider evaluating the cost of installing pressure transducers to automatically record water levels at the USGS staff gages downstream of dam and make available on the GLA website.

24 7. The GLA Water Level Committee should estimate daily flows when daily measurements are not made, and note as such. These estimated daily flows should then be used to calculate monthly average river flow included in the monthly reports. 8. Request residents of lakes in the headwaters of the watershed, such as Armstrong and Polack (Pollack) Lakes, to document water levels between April and October each year. One water level measurement a month on a designated day over a period of years would provide a means to estimate the hydraulic gradient, or slope of the piezometric surface, of the aquifer that discharges to Glen Lake. When the water level in these lakes is at a historical low the Technical Committee should evaluate the need to reduce target river flows until the water level in these lakes is replenished. 9. Develop agreements with the National Weather Service to supply daily and monthly Maple City precipitation data and make available on the GLA website. 10. Request the Michigan State University Northwest Michigan Horticultural Research Station to supply Pan Evaporation data during the growing season and make available on the GLA website to facilitate future updates to this report.

25 REFERENCES Calder, Vince. 2002. Ask a Scientist: Temperature and Evaporation. U.S. Department of Energy. Accessed June 22, 2009 www.newton.dep.anl.gov/askasci/wea00/wea00129.htm. Croskey, H.M. 1991. Michigan Department of Environmental Quality, Hydrologic Studies Unit, Glen Lake file. Davis, Steve. 2009. State Conservation Engineer, US Department of Agriculture, Natural Resources Conservation Service (USDA-NRCS). East Lansing, MI; 517-324-5232; [email protected]; Personal Conversation. Eagleman, J.R. 1967. "Pan evaporation, potential and actual evapotranspiration." Journal of Applied Meteorology 6: 482-488. Handy, A.H., and Stark, J.R. 1984. Water resources of Sleeping Bear Dunes National Lakeshore, Michigan: U.S. Geological Survey Water-Resources Investigations Report 83-4253, 38 p. Klein, Bill. 2009 . Michigan State University Northwest Michigan Horticultural Research Station; Traverse City, MI; 231-946-1510 [email protected]. Personal Communications and Email July and August 2009. Lesmez, M.W. 2009. Hydrologic Studies Unit, Michigan Department of Environmental Quality; 517-335-3173; [email protected]. Email (Appendix A) and Personal conversations August and September 2009. Menerey, Bruce. 2009. Hydrologic Studies Unit, Michigan Department of Environmental Quality; 517-335-3181; [email protected]. Personal communication. Linacre, E.T. 1994. Estimating U.S. Class-A pan evaporation from few climate data. Water International 19, 5 - 14. Accessed June 23, 2009. www-das.uwyo.edu/~geerts/cwx/penpan.html. MDEQ (Michigan Department of Environmental Quality), Hydrologic Studies Unit. 2009. Introduction to Hydrology. Accessed September 25, 2009 http://www.mi.gov/deq/0,1607,7-135-3313_3684_3724-9352--,00.html. MSU (Michigan State University) 2009. ArcIMS Viewer. Accessed October 24, 2009. http://gwmap.rsgis.msu.edu/viewer.htm. National Geodetic Survey. 2009. Data Conversion program VERTCON. Accessed March 9, 2009. http://www.ngs.noaa.gov/TOOLS/Vertcon/vertcon.html. GLA (Glen Lake Association). Water Level Committee. 2009. Monthly Reports with Daily Readings. Accessed February 2, 2009. http://glenlakeassociation.org/standing-committees/water-level/water/. USACE (U.S. Army Corp of Engineers). 2009. Great Lakes Water Level Table for Lake Michigan/Huron 1918- 2008, Meters, IGLD 1985. Accessed June 1, 2009 http://www.lre.usace.army.mil/greatlakes/hh/greatlakeswaterlevels/historicdata/greatlakeshydrographs/. USDA (U.S. Department of Agriculture). 2009. Monthly Evaporation by County for Michigan. Accessed April 20, 2009 ftp://ftp-fc.sc.egov.usda.gov/MI/technical/engineering/MI_Monthly_Evap.pdf. USDA-NRCS (U.S. Department of Agriculture – Natural Resources Conservation Service) 2009. Hydrologic Soils Classifications. Accessed Sept 24, 2009 http://www.casscountynd.gov/Departments/Highway/documents/Hydrologic_soils.pdf. USGS (U.S. Geological Survey) 2009. USGS Surface-Water Monthly Statistics for USGS 04126740 Platte River at Honor, MI. Accessed June 23, 2009 http://waterdata.usgs.gov/nwis/monthly?referred_module= sw&site_no=04126740&por_04126740_2=891733,00060,2,1990-03,2008- 12&format=html_table&date_format=YYYY-MM- DD&rdb_compression=file&submitted_form=parameter_selection_list. Handy, A.H., and Stark, J.R. 1983. Water Resources of Sleeping Bear Dunes. U.S. Geological Survey, USGS 83-4253 13.

26 APPENDIX A: MDEQ APPROVAL OF GROUNDWATER WATERSHED

A1 A2 APPENDIX B: NWS MAPLE CITY PRECIPITATION DATA

B1 APPENDIX C: DAILY AND AVERAGE MONTHLY FLOWS AT DAM

C1 C2

C3 C4 APPENDIX D: USGS MONTHLY STATISTICS FOR PLATTE RIVER

D1

D2