GIS Mapping of the Yields of Ohio's Aquifers

The Ohio Department of Natural Resources, Division of Water, has produced statewide GIS coverages for the unconsolidated and bedrock aquifers of Ohio. These maps depict the approximate yield of the aquifers in gallons per minute. Lighter colors represent lower yields, and darker colors represent higher yields.

Well logs, drilling reports, and a variety of other geologic and hydrogeologic information were used to delineate the unconsolidated and bedrock aquifer maps. These hand drawn, 7.5-minute quadrangle maps (1:24,000) were digitized and joined to produce statewide polygon coverages. In addition to yield, attributes for the bedrock aquifer coverages include aquifer extent and bedrock unit thickness. Additional attributes for the unconsolidated aquifers include drift thickness, hydrogeologic settings, local names, and lithology.

Before the creation of the GIS coverages, the Division of Water produced countywide groundwater resource maps at a scale of 1:62,500. The county maps were produced using traditional cartographic and printing methods. This made editing and updating a difficult and expensive process. The new statewide GIS maps provide more information at a higher level of detail than the existing county maps. Consultants, engineers, planners, homeowners, and well drilling contractors who are interested in developing a groundwater supply now have current and accurate information on the groundwater resources of Ohio.

These maps were funded, in part, by a grant from the Ohio Environmental Protection Agency under provisions of Section 319 of the Clean Water Act.