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. This availability lends itself to many uses by both communities and individuals. 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.
Substantial quantities of water are available from the carbonate aquifer. 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. 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. Two inches are retained at the ground surface and evaporate back into the atmosphere in a relatively short time period.