Ohio State University Extension

Food, Agricultural and Biological Engineering

590 Woody Hayes Dr., Columbus, Ohio 43210

Water Resources of Montgomery County

AEX-480.57-98

Herbert M. Lane
Extension Agent
Agriculture and Natural Resources
Montgomery County

Larry C. Brown
Associate Professor
Extension Agricultural Engineer
Food, Agric. and Biol. Engineering

Water is a resource often taken for granted. In recent years, water availability and quality have become important public concerns in Montgomery County. The county's population of 572,137 is predominantly urban, and 100 percent of the households rely on ground water for their water supply. This fact sheet provides a brief overview of Montgomery County's water resources, and is intended to help increase public awareness and understanding about this vital resource. By understanding where water is obtained and how it is used in the county, residents can gain a better appreciation for their water supply. Water resources terminology used in this publication is included in Surface and Ground Water Terminology, Fact Sheet AEX 460, which provides a listing of generally accepted water resource definitions. Ohio State University Extension publications are available through all Ohio county Extension offices.

Precipitation

An average of approximately 39 inches of precipitation falls on Montgomery County annually. Figure 1 illustrates the average monthly precipitation for the county for the period 1961 to 1990. Based on this 30-year record, the average precipitation is 3.3 inches per month, with January (2.3 inches) typically being the driest month, and May (4.2 inches) the wettest. However, there can be extreme variations in some years and in certain months within a year. Such seasonal and yearly extremes may have serious consequences and are not always apparent from the long-term precipitation information.

Figure 1. Average monthly precipitation (in inches) in Montgomery
County, Ohio (1961-1990); data collected at Dayton.

Surface-Water Resources

Approximately 90 percent of the county lies in the Great Miami River basin, which flows south to the Ohio River. A narrow strip along the southern half of the eastern county line lies in the Little Miami River basin, which also drains to the Ohio. A generalized surface-water map of Montgomery County is given in Figure 2.

Figure 2. Surface-water resources in Montgomery County, Ohio (adapted
from ODNR Division of Water river basin maps; illustration prepared by
K. A. Weber).

Surface water quantity and quality are affected by the soil type, geology, the topography of adjacent land, and the way people use the land. Changes in land use, such as residential development and agricultural production, may increase the amount of sediment and other pollutants entering a body of water. The soils and terrain also influence the amount of runoff because of infiltration, percolation, and water holding characteristics. With some soils, rainfall is more likely to run off, while other soils allow water to infiltrate more readily.

The county contains approximately 297,000 land acres, of which 40 percent is farmland. Forty-three soil types have been identified in the county and vary in drainage quality from very poorly-drained to well-drained. A large portion of the soils are moderately well-drained.

The county water acreage consists of about 612 acres of lakes of five or more acres, the largest being 170-acre Eastwood Lake. Smaller ponds number more than 100. The county contains approximately 255 linear miles of major streams and rivers (estimated from river basin maps, Ohio Department of Natural Resources [ODNR] Division of Water). In addition, 16.5 miles of county-maintained ditches and numerous miles of privately-maintained ditches are used for land drainage.

Ground-Water Resources

Montgomery County's primary ground-water source is the Great Miami Buried Valley aquifer, consisting of sand and gravel glacial outwash deposits. The aquifers below the Great Miami and Mad River Valleys can produce well yields of 2,500 gallons per minute (gpm) or more, and those under Twin, Little Twin, Wolf, and Bear Creeks as well as the Stillwater River, may yield over 500 gpm. Upland aquifers of clay till over non-water-bearing shaly limestone bedrock underlie as much of the county as the high-yielding aquifers, producing extreme variations in local ground water yields. A 115-foot deep municipal well drilled into the buried valley aquifer produces 2,500 gpm, while a 180-foot deep well one mile away can only draw 2 gpm from the shaly limestone bedrock. Concentrations of 300 to 500 parts-per-million (ppm) of calcium carbonate are common, making the local ground water extremely "hard." Softening is recommended for water containing over 150 ppm of CaCO3, and iron is also often found at levels sufficient to be a nuisance. An overview of the ground-water resources in the county is given in Montgomery County Ground-Water Resources, AEX-490.57.

The yield of a well will vary considerably depending on the age and depth of the well, well construction, the diameter of the casing, pump capacity and age, and more importantly, properties of the geologic formation. Specific information on ground-water availability and wells can be obtained by contacting the ODNR Division of Water.

Where Does the Water Go?

Based on long-term statewide weather records, Ohio receives an average of 38 inches of precipitation per year. These 38 inches move through a complex path called the hydrologic cycle. Of these 38 inches, about 10 inches (26 percent) become runoff, which moves immediately to surface-water bodies like streams and lakes. Two inches are retained at the ground surface and evaporate back into the atmosphere in a relatively short period of time. Twenty-six of the 38 total inches enter the soil surface through infiltration. Twenty of these 26 inches go into soil storage and later are returned to the atmosphere by the combination of evaporation and transpiration (evapotranspiration). The remaining 6 inches of precipitation (16 percent of the total) have the potential to recharge the ground-water supply. Two of these 6 inches eventually move to springs, lakes, or streams as ground-water discharge. The remaining 4 inches either return to the atmosphere by evapotranspiration or are withdrawn to supply water needs. For further reading, refer to Ohio's Hydrologic Cycle, AEX 461.

Statewide averages applied to the county's average annual precipitation provide a rough estimate of how many inches will result in runoff and how many inches have the potential to reach aquifers. Based on statewide averages of runoff and ground-water recharge, Montgomery County's 39 inches of average annual precipitation result in the same 10 inches of runoff to streams and lakes, and about 6 inches with the potential to recharge aquifers annually. Values for particular locations will differ according to local conditions.

Water Use

Water use for each of Montgomery County's public water-supply systems is given in Table 1. For each water system, this table presents an estimate of the population served, water source, estimated daily usage, service connections, and treatment plant capacity. The county's largest public-water system is the Dayton system, which uses 91 wells for its supply. All of the other public-water systems also use ground water as their source.

Ground water is a major water source for rural households in Montgomery County. Approximately three percent of all households obtain their water from private wells. Based on an estimated usage of 75 gallons per person per day, 1.6 million gallons per day (gpd) from private wells are used. Additional private water uses include industry (6 million gpd), quarrying (1.9 million gpd), and livestock use (11 million gpd), mostly from ground-water supplies. The remaining 97 percent of households use public-water supplies with ground water as the source, as identified in Table 1.

Some water users in Ohio must register their withdrawals with the ODNR Division of Water. Through the Water Withdrawal Facility Registration Program, owners of facilities capable of withdrawing 100,000 gpd (70 gpm) or more must register those facilities. Information collected through this program includes withdrawal capacity, ground- or surface-water sources, location and type of water use, and location of discharge points. The program is for registration only, and not for allocation or permission. Registered withdrawers file annual reports of their water use. This information helps planners at ODNR to determine the availability of water for projected needs and to better manage and protect Ohio's water resources. Documenting water use also provides official records for individual uses. For more information, contact the ODNR Division of Water.

Water Quality

Human activities and natural processes affect the quality of our water supplies. Throughout Ohio, human activities contribute to both point and nonpoint source pollution. Point source pollution is the introduction of impurities into water (ground water or surface water) from an identifiable, known location. Examples of point sources can include industrial plants, power plants, commercial businesses, and wastewater treatment facilities.

Nonpoint source pollution also involves the introduction of impurities into a surface-water body or an aquifer, except the route is usually non-direct and the sources are diffuse in nature. A major portion of the sediment and nutrients enter the state's water resources through nonpoint source pollution, affecting both ground and surface water. Examples include automobile emissions, runoff and drainage from agricultural fields, home lawns and gardens, residential development, construction, mining, and logging activities.

Natural processes such as precipitation also have an impact on surface water and, to a lesser extent, ground water. For example, rainfall that is acidic ("acid rain") may alter the quality of a stream, lake, or other water resource that receives the rainfall.

Ground Water

As water moves through the glacial outwash, deposits or the bedrock formations underlying Montgomery County, it dissolves the minerals contained in these formations and carries them in solution. Publication AEX 490.57 summarizes some of the county's natural ground-water quality aspects.

Human activities, such as agricultural production, domestic waste disposal, and lawn and turf care, may have some influence on the county's ground-water quality. In a 1987 study by Heidelberg College, 249 wells in the county were sampled for nitrate-nitrogen content, an indicator of water quality. Results showed that 167 wells (67 percent of total) contained nitrate-nitrogen concentrations in the range of 0 to 0.3 ppm. This range is assumed to represent natural background levels. Thirty-seven wells (15 percent) tested in the range of 0.3 to 3.0 ppm, values that may or may not indicate human influence. The 34 wells (14 percent) that tested in the range of 3.0 to 10 ppm, may indicate elevated concentrations resulting from human activities. Only 10 wells (4 percent) tested at over 10 ppm nitrate-nitrogen, which exceeds the safe drinking-water standard. The average nitrate-nitrogen concentration for the 249 wells tested was 1.8 ppm. The design, location, and condition of a well, combined with the characteristics of the soils and geologic formations in which the well is constructed, influence the potential for pollutants to enter the well. The Montgomery County Combined Health District provides bacteriological water sampling for local citizens. For more information contact the health district at 614-225-4362.

Surface Water

Runoff and sediment from residential development, construction sites, and agricultural lands may enter the county's streams and lakes. Also, runoff may carry other pollutants, such as lawn and agricultural chemicals (pesticides and fertilizers), oil and gas from spills, and industrial wastes.

Through the Ohio Nonpoint Source Assessment and Water Resources Inventory, the Ohio Environmental Protection Agency (Ohio EPA) has identified 13,000 stream miles in Ohio that have been affected by nonpoint source pollution. Based on the findings of the Assessment and Inventory, the Ohio Nonpoint Source Management Program has been implemented to help improve the quality of the state's waters.

Water quality monitoring indicates that all or parts of the following Montgomery County streams are impaired by nonpoint source (NPS) pollution: Stillwater River, Little Beaver Creek, Little Twin Creek, Wolf Creek, Great Miami River, and Mad River. These streams are impaired by one or more of the following NPS pollution categories: agriculture, storm sewers, on-site wastewater treatment, or habitat alteration. Other county streams are impaired by point source pollution (municipal and/or industrial wastewater). Point source impaired streams include the Great Miami River, Stillwater River, Wolf Creek, and Bear Creek. Montgomery County also contains streams that have good water quality and are attaining chemical and biological water quality standards. Monitoring has shown that all or parts of the following streams have good water quality: Twin Creek and Opossum Creek. For specific information about the streams listed in the Assessment and Inventory documents, and details about the Nonpoint Source Management Program for the county, contact the Ohio EPA Southwest District Office, 401 East Fifth St., Dayton, OH 45402; Phone: 419-285-6357. Information about nonpoint source pollution is also discussed in Nonpoint Source Pollution: Water Primer, AEX 465, available from your county Extension office.

It is important to note that as of June 1998 less than half of Ohio's streams have been evaluated by the Assessment. As water quality monitoring continues statewide, the list of Montgomery County affected streams and streams with good water quality will change. Residents have a major challenge to protect water resources from pollutants that could affect the quality of the water supply.

Summary

Water availability and quality are important public concerns. Water problems can be both costly and inconvenient. While the present availability of water is good for Montgomery County, water is a precious resource that must be conserved and protected. We must all work together to maintain an adequate supply of good quality water.

This fact sheet provides information about the water resources in Montgomery County. For more information concerning water resources and drinking-water quality in the county, contact the Montgomery County office of Ohio State University Extension (1001 S. Main St., Dayton, OH 45409). In addition, the following agencies may be able to provide information on other water resources topics for the county: Montgomery Soil and Water Conservation District; Montgomery County combined Health District; ODNR Division of Water (Fountain Square, Columbus, OH 43224); U.S. Geological Survey (USGS), Ohio District (975 W. Third Ave., Columbus, OH 43212); Ohio EPA (P.O. Box 1049, Columbus, OH 43216-1049); and Ohio Department of Health (ODH; P.O. Box 118, Columbus, OH 43226).

Bibliography

1990 Census and 1992 Estimates of Ohio's Population: State, Counties, Cities, and Villages. 1994. Ohio Department of Development.

Doane's Agricultural Report. 1992. Farm Water Systems.

Estimated Water Use in Ohio, 1990, Public Supply Data. 1993. USGS. Open-File Report 93-72.

Gazetteer of Ohio Streams. 1960. Ohio Water Inventory Report No. 12. ODNR Div. of Water.

Ground-Water Resources of Montgomery County. 1986. James J. Schmidt. ODNR Div. of Water. (map).

Hydrologic Atlas for Ohio: Average Annual Precipitation, Temperature, Streamflow, and Water Loss for the 50-Year Period 1931-1980. 1991.

L. J. Harstine. Water Inventory Report No. 28. ODNR Div. of Water.

Inventory of Municipal Water-Supply Systems by County, Ohio. 1977. Ohio Water Inventory Report No. 24. ODNR Div. of Water.

Inventory of Ohio's Lakes. 1980. Ohio Water Inventory Report No. 26. ODNR Div. of Water.

Montgomery County Ground-Water Resources. 1998. H. M. Lane, L. C. Brown, J. Raab, and N. M. N'Jie. AEX 490.57. Ohio State University Extension.

Montgomery County, Ohio Soil Survey. 1976. USDA-SCS.

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Acknowledgments

This publication was produced through the Ohio Water Resources Education Project, in cooperation with: ODNR Division of Water; Ohio EPA; USGS, Ohio District; and ODH. Project leaders are Larry C. Brown and N'Deye-Marie N'Jie. Partial financial support for this publication was provided by these cooperating agencies and programs: Montgomery County office of OSU Extension; Overholt Drainage Education and Research Program; and the Ohio Management Systems Evaluation Area Project (USDA Extension Service Grant No. 90-EWQI-1-9018).

The project leaders express appreciation to the following reviewers: Jim Dillon (Program Administrator, Montgomery SWCD); Hugh Trimble (Environmental Specialist, Ohio EPA, Southwest District); Wayne Jones, Jim Raab, David Cashell, and Leonard Black (ODNR Division of Water); Scott Golden (Local Services, ODH); Steve Hindall (USGS, Ohio District); Deba Mohler and John Armentano (USDA Natural Resources Conservation Service, State Office, Columbus); Julie Gillenwater (Ohio EPA Division of Drinking and Ground Waters); and Larry Antosch (Ohio EPA Division of Surface Water). A special thanks to Kim Wintringham, Technical Editor (Section of Communications and Technology, Ohio State University Extension), for editorial and graphic production.