COLUMBUS, OH  The Ohio Department of Natural Resources (ODNR), Division of Geological Survey will conduct research that will help protect water resources and plan construction projects in the state's fastest growing county.

The ODNR Division of Geological Survey will collaborate with the Delaware County Soil and Water Conservation District and the Upper Scioto River Watershed Project to locate and map karst features throughout western Delaware County. Knowing where these geological formations exist will allow developers, landowners and officials to make sound decisions regarding construction, infrastructure and water resources.

Karst topography in Ohio forms when surface water percolates down to the water table, slowly dissolving soluble limestone or dolomite and creating voids under the earth's surface. In these areas, progressive underground erosion can lead to earthen collapses. Karst formations have high rates of permeability, reducing the opportunity for contaminant filtration, and they can also cause unusual flooding when water tables are high.

Karst features in western Delaware County are known to flank the Scioto River in a narrow band that extends from Pickaway County to the Marblehead Peninsula and the Lake Erie Islands. Sinkholes, caverns and disappearing streams can be signs of karst.

Updating karst maps will give people a more accurate resource for determining how the area's geological features can impact development. In recent years, karst features have contributed to issues during the construction of major highways such as U.S. 33 near Marysville, water contamination on Lake Erie's South Bass Island and unusual flooding in Bellevue, Ohio.

Funded by a grant through the U.S. Geological Survey, mapping these features will involve extensive computer and field work. Some potential karst areas will be located using data from previous statewide mapping efforts. Others will be located through computer-based analysis, using aerial photography and detailed computer models of the ground surface derived from Light Detection and Ranging (LiDAR). Similar to radar, LiDAR is a series of high-intensity light beams that are emitted by and bounce back to an aircraft and provide highly accurate measurements of Earth's surface features.

Once the potential karst features are identified, ODNR geologists will document their locations using Global Positioning System (GPS) units for confirmation, photo documentation and provide detailed descriptions. The new map and accompanying reports will serve as valuable tools to protect water resources and aid in planning of construction projects.

The Ohio Department of Natural Resources ensures a balance between wise use and protection of our natural resources for the benefit of all. Visit the ODNR Web site at www.ohiodnr.com.