Ohio State University Extension Fact Sheet

Food, Agricultural and Biological Engineering

590 Woody Hayes Dr., Columbus, Ohio 43210

Water Resources of Franklin County

AEX-480.25

Patricia L. House
Karen T. Ricker
Larry C. Brown

Water is a resource often taken for granted. In recent years, water availability and quality have become important public concerns in Franklin County. The county's population of 961,437 (1990 census data) is predominantly a mixture of urban and suburban with the fringes of the county supporting a rural population; 22 percent of households rely on ground water for their water supply. This fact sheet provides a brief overview of Franklin 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. The 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 38 inches of precipitation falls on Franklin 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 3.2 inches per month, with January, February, and October (2.2 inches each) typically being the driest months, and July (4.3 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 Franklin County, Ohio (1961-1990); data collected at Columbus Airport.

Surface-Water Resources

Franklin County's major drainage basin is the Scioto River. Many of the Scioto River's major tributaries are located in the county including the Olentangy River, Alum Creek, Big Darby Creek, and Big Walnut Creek. The Scioto River originates 50 miles northwest of Columbus and continues southward to its mouth at the Ohio River. Portions of Darby Creek and the Olentangy River are classified as State Scenic Rivers. In addition, Darby Creek located in western Franklin County is noted for being a Last Great Place as designated by The Nature Conservancy, and is a habitat for many endangered fish and mollusk species. Many private and public groups are working to improve conservation measures that will reduce erosion, surface runoff of sediment, and other pollutants in this newly recognized National Scenic River. Alum Creek drains much of the land on the eastern side of Franklin County. A generalized surface-water map of Franklin County is given in Figure 2.

Surface waters are affected by the soil type and topography of the land adjacent to them, and the way humans use the land. Land use, such as residential development, construction, and agricultural production, can increase the amount of sediment entering a body of water. The type of soils in an area also influences water runoff because of the soil's infiltration 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 344,064 land acres, of which approximately 30 percent is farmland. Thirty-five soil types have been identified in the county and vary in drainage ability from very poorly drained to well drained. Nearly half (44 percent) of the soils are somewhat poorly drained with 33 percent being moderately to well drained. The poorly drained soils limit both agricultural and non-agricultural land uses.

The county water acreage consists of two major reservoirs: Griggs located on the Scioto River and Hoover located on Walnut Creek. These two reservoirs cover 3,385 surface area acres in parts of Franklin and Delaware Counties, and are sources of the municipal water supply for Columbus. There are also two public lakes in the Metro Parks system, as well as 60 private lakes and ponds that range in size from 5 to 155 acres, plus many smaller ponds. The county contains approximately 339 linear miles of major streams and rivers [estimated from river basin maps, Ohio Department of Natural Resources (ODNR) Division of Water]. In addition, 1.5 miles of county maintained ditches and numerous miles of privately maintained ditches are used for land drainage. This availability lends itself to many uses by both communities and individuals.

Figure 2. Surface-water resources in Franklin County, Ohio (adapted from ODNR Division of Water river basin maps; illustration prepared by H. Landfried).

Ground-Water Resources

Franklin County's primary ground-water sources are the unconsolidated sand and gravel deposits and the carbonate aquifers. Unconsolidated aquifers are coarse to fine grained sand and gravel deposits interbedded with layers of clay and silt. Carbonate aquifers are constructed primarily of limestone and dolomite.

Areas in southeast Franklin County along the Scioto River and Big Walnut Creek offer the greatest potential for developing municipal and industrial ground-water supplies. Presently, the City of Columbus operates four collector wells located in the unconsolidated sand and gravel aquifers along the Scioto River and Big Walnut Creek. These wells range in depths from 68 to 109 feet and collectively produce 20 million gallons of water per day. The limestone-dolomite aquifer is the principal water supply source in the western third of the county, west of the Scioto and Olentangy rivers. Yields of 250 gallons per minute (gpm) have been developed from wells at depths of less than 300 feet; wells at greater depths produce greater yields but poorer quality water. Domestic and small industrial supplies of 15 to 25 gpm are available at depths of 65 to 175 feet. Overlying glacial deposits of sand and gravel may yield as much as 20 gpm at depths of about 90 feet.

In the northeastern part of the county a sandstone and shale bedrock is predominant, and the wells produce from 2 to 25 gpm. Wells typically are less than 100 feet deep and if properly constructed may avoid encountering hydrogen sulfide, a nuisance problem for many home wells. An overview of the ground-water resources in the county is given in Franklin County Ground-Water Resources, AEX-490.25.

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 ODNR Division of Water.

Where Does the Water Go?

Based on long-term 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 such as 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, Franklin County's 38 inches of average annual precipitation result in about 10 inches of runoff to streams and lakes, and about 6.1 inches have the potential to recharge aquifers, annually. Values for particular locations will differ according to local conditions.

Water Use

Water use for each of Franklin 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 and treatment plant capacity.

The county's largest public-water system is the City of Columbus. The City uses surface water from the Scioto River, Big Walnut Creek, Hoover and Alum Creek reservoirs for its supply, along with ground water from the south well field area in southeast Franklin County. These wells specifically serve county residents living east of High Street and south of Interstate 70, approximately 150,000 people (16% of the county population). The wells also serve Grove City, Groveport, Hamilton Meadows, the Village of Lockbourne, and the Rickenbacker Air National Guard Base.

In addition, the cities of Bexley, Gahanna and Reynoldsburg purchase water from the City of Columbus. The surrounding areas of Dublin, Hilliard, Whitehall, Worthington, Upper Arlington, Brice, Marblecliff, Minerva Park, New Rome, Riverlea, and Valley View are also served by the Columbus system. The City of Westerville has its own water treatment plant utilizing water from Alum Creek, and the villages of Canal Winchester, Lockbourne and parts of Obetz use ground water. Seventy-seven percent of Franklin county households are served by surface water supplies. Ground water is a major water source for rural households in Franklin County. Approximately 3 percent of all households obtain their water from private wells. Based on an estimated usage of 75 gallons per person per day, 1,737,000 gallons per day (gpd) from private wells are used. Additional private water uses include industry (0.51 million gpd) and livestock use (0.03 million gpd) mostly from ground-water supplies. The remaining 20 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 ODNR Division of Water.

Table 1. Water Use in Franklin County, Ohio.1
Public Water System	Population Served	Primary Water Source	Water Usage (GPD)2	Treatment Plant Capacity (GPD)
Columbus	649,585	Surface Water	116,000,000	165,000,000
Columbus	150,000	Ground Water	17,500,000	50,000,000
Bexley, Gahanna & Reynoldsburg	64,315	Surface Water3	5,001,500	N/A
Lockbourne	150	Ground Water 4	29,000	432,000
Westerville	30,000	Surface Water	3,105,000	6,000,000
Groveport	3,200	Ground Water	287,000	576,000
Obetz	3,167	Ground Water	306,500	500,000
Canal Winchester	2,617	Ground Water	252,000	720,000
Other 5	2,745	Ground Water	306,800	N/A
Other 6	22,498	Ground Water	2,425,600	5,178,000
Franklin Co. Sanitation District #4	10,000	Surface Water	200,000	N/A
1 Estimates from Ohio EPA using adjusted 1993 data; information is based on data available at time of publication.
2 GPD = gallons per day.
3 Supplied by Columbus; total treatment plant capacity figure not available.
4 Purchased from another source.
5 Includes mobile home parks, nursing homes, and subdivisions; total treatment plant capacity figure not available.
6 Includes utility companies, and water companies.

Water Quality

Natural processes and human activities 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 a water supply source (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, nutrients, acids and salts, heavy metals, toxic chemicals, and pathogens enter the state's water resources through nonpoint source pollution, affecting both ground and surface water. Examples include automobile emissions, runoff from parking lots, and runoff and drainage from agricultural fields, feedlots, home lawns and gardens, residential development, construction, mining, and logging activities.

Ground Water

As water moves through the unconsolidated sand and gravel deposits underlying Franklin County, it dissolves the minerals contained in these formations and carries them in solution. Publication AEX-490.25 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, 266 wells in the county were sampled for nitrate-nitrogen content, of which 229 (86 percent of total) contained nitrate-nitrogen concentrations in the range of 0 to 0.3 parts-per-million (ppm). This range is assumed to represent natural background levels. Twenty-eight wells (11 percent) tested in the 0.3 to 3.0 ppm range; these values may or may not indicate human influence. The nine wells (3 percent) that tested in the range of 3.0 to 10 ppm may indicate elevated concentrations resulting from human activities. None of the wells tested over 10 ppm for nitrate-nitrogen, an amount that exceeds the safe drinking-water standard. The average test value for the 266 wells sampled was 0.32 ppm. 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. Bacterial counts are another indicator of ground-water quality. The Franklin County Department of Health tests water samples for concerned citizens, and results of these tests generally indicate safe drinking water in the county. A fee for the bacterial count test as well as other water quality indicator tests is charged by the Franklin County Department of Health. For a complete list of available tests, contact the Franklin County Health Department at (614) 462-3160.

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), effluent from septic systems, 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) and ODNR have identified 13,000 stream miles in Ohio that have been affected by nonpoint source pollution. Franklin County contains portions of several streams and their tributaries that have been classified by the Assessment as being affected by nonpoint source pollution. Based on the findings of the Assessment and Inventory, the Ohio Nonpoint Source Management Plan has been implemented to help improve the quality of the state's waters. For specific information about the streams and tributaries listed in the Assessment and details of the Management Plan for the county, contact the Ohio EPA Central District Office (2305 Westbrooke Drive, Building C, P.O. Box 2198, Columbus, OH 43266-2198).

Overall, Franklin County has a safe supply of water. County citizens have a major challenge to protect water resources from pollutants that could affect the quality of the water supply. For more information about nonpoint source pollution, refer to Nonpoint Source Pollution: Water Primer, AEX 465, available from your county Extension office.

Summary

Water availability and quality are important public concerns. Water problems can be both costly and inconvenient. While the present and future availability of water is good for Franklin 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 Franklin County. For more information concerning water resources or drinking-water quality in the county, contact the Franklin County office of Ohio State University Extension (1945 Frebis Ave., Columbus, OH 43206; 614-462-6700). In addition, the following agencies may be able to provide information on other water resources topics in the county: Franklin Soil and Water Conservation District (614-443-9416); Franklin County Health Department (614-462-3160); ODNR Division of Water (Fountain Square, Columbus, OH 43224); US Geological Survey (USGS), Ohio District (975 W. Third Ave., Columbus, OH 43212); Ohio EPA (1800 WaterMark Dr., Columbus, OH 43215-1099); and Ohio Department of Health (ODH; P.O. Box 118, Columbus, OH 43226). USGS also maintains a publications list of information related to Franklin County's water resources.

Bibliography

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

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

Franklin County Ground-Water Resources. 1994. P. L. House, A. W. Jones, L. C. Brown, and K. T. Ricker. AEX-490.25. Ohio State University Extension.

Franklin County, Ohio Soil Survey. 1979. USDA-SCS.

Franklin Soil and Water Conservation District Resources Inventory. 1986. USDA-SCS.

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

Ground-Water Resources of Franklin County. 1994. P. L. House. ODNR Div. of Water. (map).

Hydrology and Water Quality Near the South Well Field, Southern Franklin County, Ohio. 1991. C. J. Childress, R. A. Sheets, and E. S. Bair. WRI Report 91-4080.

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

Monthly Station Normals of Temperature, Precipitation, and Heating and Cooling Degree Days, 1961-90, Ohio. 1992. Climatology of the United States, No. 81 (by state). NOAA.

Nitrate and Pesticides in Private Wells of Ohio: A State Atlas. 1989. Water Quality Laboratory, Heidelberg College.

Nitrate In Drinking Water. 1987. K. M. Mancl. Bulletin No. 744. Ohio State University Extension.

Nonpoint Source Pollution: Water Primer. 1993. R. Leeds and L. C. Brown. AEX 465. Ohio State University Extension.

Ohio Ground-Water Quality. USGS National Water Summary-Ohio. 1986. USGS Water-Supply Paper 2325.

Ohio Ground-Water Resources. USGS National Water Summary-Ohio. 1984. USGS Water-Supply Paper 2275.

Ohio Nonpoint Source Management Program. 1993. ODNR.

Ohio Population by Governmental Unit. 1991. Ohio Data Users Center, Ohio Department of Development.

Ohio Surface-Water Resources. USGS National Water Summary-Ohio. 1985. USGS Water-Supply Paper 2300.

Ohio Water Firsts. 1985. S. L. Frost and W. S. Nichols. Water Resources Foundation of Ohio, Inc.

Ohio Water Resource Inventory: Executive Summary and Volumes 1-4. 1992. Ohio EPA.

Ohio's Hydrologic Cycle. 1990. L. C. Brown and K. M. Coltman. AEX 461. Ohio State University Extension.

Private Water Systems Handbook. 1987. MWPS-14. Midwest Plan Service, Ames, IA.

Southwest Ohio Water Plan. 1976. ODNR Div. of Water.

State of Ohio Nonpoint Source Assessment: Volumes 1-6. 1990. Ohio EPA.

Surface and Ground Water Terminology. 1990. L. C. Brown and L. P. Black. AEX 460. Ohio State University Extension.

Water Quality of a Stream-Aquifer System, Southern Franklin County, Ohio. 1984. J. T. de Roche and A. C. Razem. WRI Report 84-4238.

Water-Ohio's Remarkable Resource. 1982. ODNR Div. of Water.

Withdrawal and Distribution of Water By Public Water Supplies in Ohio, 1985. 1989. USGS Open-File Report 89-423.

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 Karen T. Ricker. Partial financial support for this publication was provided by these cooperating agencies and programs: Franklin County office of OSU Extension; Franklin Soil and Water Conservation District; Overholt Drainage Education and Research Program; Darby Creek Hydrologic Unit Area Project (USDA Extension Service Grant No. 91-EHUA-1-0059) and the Ohio Management Systems Evaluation Area Project (USDA-ES Grant No. 90-EWQI-1-9018). The project leaders express appreciation to the following reviewers: Brady Koehler (Franklin Soil and Water Conservation District); Stephen N. Hainen (Wellfield Coordinator, City of Columbus); James M. Raab, David Cashell and Leonard Black (ODNR Division of Water); Scott Golden (Environmental Health, ODH); Steve Hindall (USGS, Ohio District); Robert Burris (USDA Soil Conservation Service, State Office, Columbus); Jay Fleming (Ohio EPA Division of Drinking and Ground Waters); and Larry Antosch (Ohio EPA Division of Surface Water). A special thanks to Michelle Roby (Agricultural Engineering Undergraduate Associate) for help in manuscript and illustration preparation, and Ted Hattemer and Kim Wintringham, Associate Editors (Section of Communications and Technology, Ohio State University Extension), for editorial and graphic production.