Figure 1. Average monthly precipitation (in inches) in Marion County, Ohio (1961-1990).
Donald J. Breece
Kristina M. Boone
Larry C. Brown
Water is a resource often taken for granted. In recent years, water availability and quality have become important public concerns in Marion County. The county is predominantly rural with a population of 67,974 (1980 census data), of which 37,040 live in the city of Marion. There are also eight incorporated villages. About 21 percent of the water used in the county comes from ground-water sources. By understanding where water is obtained and how it is used in the county, residents can gain a better appreciation for water as a most important resource. Providing a brief overview of Marion County's water resources, such as rivers, streams, ponds, reservoirs and ground water, this fact sheet is intended to help increase public awareness and understanding of water resources. 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. OSU Extension publications are available from all county Extension offices.
An average of approximately 34 inches of precipitation falls on Marion County annually. Figure 1 illustrates the average monthly precipitation for the county for the period 1951 to 1980. Based on this 30-year record, the average precipitation is about 2.8 inches per month, with February (1.8 inches) typically being the driest month, and March and April (3.6 inches) the wettest. There can be, however, extreme variations in some years and in certain months within a year. Such seasonal and yearly extremes, which may have serious consequences, often are not apparent from long-term precipitation information.
Figure 1. Average monthly precipitation (in inches) in Marion
County, Ohio (1961-1990).
Marion County has two major drainage basins whose waters eventually reach the Ohio River: Scioto River, including Little Scioto River; and Olentangy River. Major streams that drain into these rivers include: QuQua Ditch (or Cauquaw Run), Flat Run, McDonald Creek, Mud Run, Rock Fork and Rush Creek. Tymochtee Creek, Pawpaw Run, Thompson Ditch and Prairie Run feed the Sandusky River drainage basin, which empties into Lake Erie. About 20 percent of the county drains into Lake Erie, with the Walbash moraine being the drainage basin divide. A generalized surface-water map of the county is given in Figure 2.
The Scioto River basin is approximately 6,510 square miles in size, and includes more than 4,000 miles of rivers and streams. It stretches from just inside Auglaize County to the Ohio River at Portsmouth in Scioto County. The Little Scioto River begins in Crawford County and flows into the Scioto River at Green Camp, draining 113 square miles. The Olentangy River basin is approximately 536 square miles in area, and stretches from southern Crawford County to Franklin County, were it empties into the Scioto River.
Marion County contains approximately 259,072 land acres, of which approximately 83 percent is farmland. Most of the soils in the county were formed from glacial till, and are generally unstratified, compact silty clay loams, or clay loams. The subsoil is fine-textured, slowly or moderately slowly permeable. Since the county is generally level, characterized by only 235 feet of relief, drainage is a major management concern for cropland and homesites. The highest elevation is 1,105 feet above sea level in Tully Township; the lowest is 870 feet in Grand Township.
The county's surface-water supply consists of about 535 acres of lakes, and approximately 270 linear miles of streams and rivers (estimated from river basin maps, ODNR Division of Water). This availability lends itself to many uses by both communities and individuals.
figure 2. Surface water resources in Marion County, Ohio (adpated
from ODNR Division of Water river basin maps).
The primary ground-water source is the carbonate aquifer of limestone and dolomite, which serves as an adequate water supply for both individual wells and public-water systems. Limestone mainly consists of calcium carbonate; dolomite is very similar, but contains some magnesium carbonate, in addition to calcium carbonate. Both are commonly referred to as limestone, which is familiar to most Ohioans as a construction material.
Residents of eastern Marion county, roughly east of State Route 98, try to obtain ground water from either the shale bedrock or shallow sand and gravel deposits above non-water bearing shale. Dry wells are common in the shale bedrock. The majority of the county, west of State Route 98, receives water from the limestone bedrock (carbonate aquifer). Substantial quantities of water are available from the carbonate aquifer. An overview of the ground-water resources in the county is given in Marion County Ground-Water Resources, AEX-490.51.
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 Ohio Department of Natural Resources (ODNR), Division of Water.
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 like streams and lakes. Two inches are retained at the ground surface and evaporate back into the atmosphere in a relatively short time period. 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 may result in runoff and how many inches have the potential to reach aquifers. Based on statewide averages of runoff and ground-water recharge, Marion County's 34 inches of annual precipitation results in about 9 inches of runoff to streams and lakes, and about 5 inches have the potential to recharge aquifers, annually. Values for particular locations will differ according to local conditions.
Approximately 15 percent of Marion County's population receives water from private wells. The remaining 85 percent uses public-water supplies. Nearly 86 percent of this public-water supply comes from surface sources; the remainder is supplied by ground water. There are 4,250 registered wells in the county.
The county has a number of villages, but only the City of Marion and two villages have public water systems. Table 1 lists these public water-supply systems along with the population served, primary water source, estimated daily water usage and treatment plant capacity. These systems provide water for domestic, commercial and industrial uses, which should be considered when using the data in Table 1.
| Table 1. Water Use in Marion County, Ohio.1 | ||||
|---|---|---|---|---|
| Public Water System | Population Served | Primary Water Source | Water Usage (GPD)2 | Treatment Plant Capacity (GPD) |
| Caledonia | 800 | Surface Water | 68,000 | 218,000 |
| LaRue | 860 | Ground Water | 100,000 | 144,000 |
| Marion3 | 45,500 | Surface Water4 | 9,100,000 | 900,000 |
| 1 Abstracted from Inventory of Municipal Water-Supply Systems by County, Ohio (1977), and updated with data from: 1991 Public Water System Inventory Report, Jean E. Whitson, Ohio EPA, Northwest District Office, Division of Water, Bowling Green, OH; and Ohio-American Water Company. | ||||
| 2 GPD = gallons per day. | ||||
| 3 Ohio-American Water Company also serves surrounding suburban areas. | ||||
| 4 Surface water from the Scioto and Little Scioto rivers normally supplies 75 to 80 percent of supply needs according to the Ohio-American Water Company. | ||||
In both surface and ground waters in the county, the presence of certain minerals and agricultural chemicals has caused some concern about water quality. Most of the minerals are naturally occurring, such as iron, sulfates and dissolved solids. Water hardness is a problem in many areas.
Human activities, such as agricultural production, domestic waste disposal and lawn and turf care may have some influence on ground-water quality in Marion County. However, in 1987, 68 county wells were sampled for nitrate content, of which 65 (96 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. One well (<1 percent) tested in the range of 0.3 to 3.0 ppm; these values may or may not indicate human influence. One well (<1 percent) that tested in the range of 3.0 to 10 ppm may indicate elevated concentrations resulting from human activities. Only 1 well (<1 percent) tested at more than 10 ppm nitrate-nitrogen, which exceeds the safe drinking-water standard. The average test value of the 68 wells tested was 0.2 ppm. The state average in 1987, based upon 16,166 wells tested, was 1.3 ppm.
Northern Marion county has 40,600 acres of farmland that lies within the boundaries of the Lake Erie drainage basin. Agriculture in the area has been identified as a nonpoint source of phosphorus pollution in the lake. As part of the 1978 Water Quality Agreement (revised 1987) between the U.S. and Canada, Ohio became responsible for reducing nonpoint source phosphorus loading, and Marion County's share of the reduction goal is 8.7 tons per year. To achieve this goal, county farmers are implementing improved fertility management strategies and sound erosion control methods. Marion County citizens have a major challenge to reduce soil erosion and to protect water resources from pollutants that could affect the quality of the water supply.
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 excellent for Marion 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 was intended to provide information to the public on water facts for Marion County. For more information on water resources and drinking-water quality in the county, contact the Marion County Extension office. In addition, the following agencies may be able to provide information on other water resources topics in the county: Marion Soil and Water Conservation District; USDA Soil Conservation Service; Marion County Health Department; ODNR Division of Water (Fountain Square, Columbus, OH 43224); U.S. Geological Survey, Ohio District (975 W. Third Ave., Columbus, OH 43212); Ohio Environmental Protection Agency (1800 WaterMark Drive, Columbus, OH 43266); and Ohio Department of Health (PO Box 118, Columbus, OH 43226).
If you have other factual county water-resources information that might be of interest to the public, please send copies to the author of this publication at the Marion County Extension Office.
Central Ohio Water Plan. 1977. ODNR Division of Water.
Gazetteer of Ohio Streams. 1960. Ohio Water Inventory Report No. 12. ODNR Division of Water.
Ground-Water Resources of Marion County. 1979. K.S. Crowell. ODNR Division of Water. (map).
Growing Season Rainfall (May-Sept.) 1972-91. D.J. Breece, Ohio Cooperative Extension Service, The Ohio State University, Marion County.
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 Division of Water.
Inventory of Ohio's Lakes. 1980. Ohio Water Inventory Report No. 26. ODNR Division of Water.
Marion County Ground-Water Resources. 1992. D.J. Breece, J.M. Raab, K.M. Boone and L.C. Brown. AEX-490.51. Ohio Cooperative Extension Service, The Ohio State University.
Monthly Normals of Temperature, Precipitation, and Heating and Cooling Degree Days, 1951-80, Ohio. 1982. Climatography of the United States No. 81 (by state). National Oceanic and Atmospheric Administration.
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 Cooperative Extension Service, The Ohio State University.
Ohio Ground-Water Quality. USGS National Water Summary - Ohio. 1986. U.S. Geological Survey Water-Supply Paper 2325.
Ohio Ground-Water Resources. USGS National Water Summary - Ohio. 1984. U.S. Geological Survey Water-Supply Paper 2275.
Ohio Surface-Water Resources. USGS National Water Summary - Ohio. 1985. U.S. Geological Survey Water-Supply Paper 2300.
Ohio's Hydrologic Cycle. 1990. L.C. Brown and K.M. Coltman. AEX-461. Ohio Cooperative Extension Service, The Ohio State University.
Phosphorus Reduction Goals and Strategies. 1991. Dennis DeWeese, SCS Water Quality Coordinator. Fact Sheet No. 1. Ohio Cooperative Extension Service, The Ohio State University.
Private Water Systems Handbook. 1987. MWPS-14. Midwest Plan Service, Ames, IA. (Available through your county Extension office).
Public Water System Report. 1991. Ohio EPA, NW. District Office, Bowling Green, OH.
Soil and Water Conservation District Resource Inventory. 1985. USDA-Soil Conservation Service.
Soil Survey of Marion County, Ohio. USDA-Soil Conservation Service.
Surface and Ground Water Terminology. 1990. L.C. Brown and L.P. Black., AEX-460. Ohio Cooperative Extension Service, The Ohio State University.
Water - Ohio's Remarkable Resource. 1982. ODNR Division of Water.
This publication was produced through the Ohio Water Resources Education Project, in cooperation with: ODNR Division of Water; Ohio EPA; U.S. Geological Survey (USGS), Ohio District; and Ohio Department of Health (ODH). Project leaders are Larry C. Brown and Kristina M. Boone. Support was provided, in part, by: the cooperating agencies; Marion County Extension Office; Marion County Phosphorus Reduction Committee, grant from Ohio EPA under provisions of Section 319 of the Clean Water Act as amended in 1987; Overholt Drainage Education and Research Program; and USDA Extension Service Grant No. 90-EWQI-1-9018.
The project leaders express appreciation to the following reviewers: James M. Raab, David Cashell and Leonard Black (ODNR Division of Water); John. H. Brown (USDA-Soil Conservation Service); Scott Golden (Environmental Health, ODH); John V. Fark and K. Troy Putnam (OSU Extension); Tim Lawrence (Agricultural Engineering, OSU); Larry Antosch (Ohio EPA Division of Water Quality Planning and Assessment); and Tim Fishbaugh (Ohio EPA Division of Drinking and Ground Water).
A special thanks to Michelle Roby and Ross A. Roberts (Agricultural Engineering Undergraduate Assistants) for help in manuscript and graphics preparation, and Judy Kauffeld and Tonya Ewing (Section of Communications & Technology, OSU Extension) for editorial and graphic production.
All educational programs conducted by Ohio State University Extension are available to clientele on a nondiscriminatory basis without regard to race, color, creed, religion, sexual orientation, national origin, gender, age, disability or Vietnam-era veteran status.
Keith L. Smith, Associate Vice President for Ag. Adm. and Director, OSU Extension.
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