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Living on Karst

A Reference Guide for Landowners in Limestone Regions

Produced by the Cave Conservancy of the Virginias, June 1997

The Problem with Stormwater Runoff

Runoff: The water from rain or melted snow that does not infiltrate the soil but flows over the land surface; precipitation drainage.

Everything that goes into a storm drain, flows out into the groundwater, streams, lakes, or river. In karst areas, sinkholes are nature's storm drains, and the dissolved caves beneath are like nature's piping system. As groundwater moves through the earth, wide open spaces such as caves can carry thousands of gallons of water at a time. This groundwater reemerges on the surface as springs or through wells.

Each time trash, motor oil, anti-freeze, litter, pet waste, fertilizer, yard and garden debris, household chemicals, and road sand and salt are dumped on the ground or washed into storm drains, drinking water, groundwater, and aquatic life are endangered. With every rain or snow these pollutants can be carried into the groundwater/surface water system.

What You Can Do at Home

  • Never dump anything into a storm drain or sinkhole.
  • Recycle motor oil at a local gas station.
  • Use fertilizers wisely. Have soil tested to determine proper amounts.
  • Keep pesticide use to a minimum. Use least toxic alternatives.
  • Maintain vegetation on steep slopes to keep soil in place.
  • Compost yard and garden debris.
  • Do not overfill car radiators and fix leaks.

Pollution from Rooftops

Roof runoff contains water pollutants such as bird droppings, chemicals from roofing materials, and heavy metals leached from gutter. In an EPA study, roof runoff was one of the most toxic samples collected.

  • Move down spouts from roof gutters so water discharges onto grassy areas away from foundations and septic systems. This will allow runoff to filter into the soil, where harmful pollutants are broken down by soil organisms.

in karstlands, uncrontrolled or altered runoff can cause structures to be undermined, resulting in subsidence or damage