Karst, Geology & Soils of the Bonne Bonne Femme Watershed Map Femme Watershed Boone County, Missouri Which creek does your land drain to? The eastern zone (E) of the Bonne Femme Watershed was once covered by glaciers, leav- ing glacial till soils. Then, wind blown mate- Living With rials with high clay content covered the area once the glaciers receded. The topography in this area is relatively flat and karst features are absent. In the central zone (C) of the watershed, soils are mostly weathered limestone bedrock. This is the area in which caves have formed. The topography consists of steep slopes, rock outcrops, sinkholes and more deeply dissected stream valleys. The western zone (W) of the watershed is composed of wind blown soil deposits from the Missouri River flood plain. This soil is mainly silt. This zone is composed of sloping hills with few rock outcrops and no karst features. Bonne Femme Watershed Photo courtesy Tom Nagel, MoDNR Help is Available! For more information, contact the Boone County Stormwater Sinkholes, Caves, and Division at 573-886-4330, or e-mail us at Groundwater Protection in [email protected]. E Boone County, Missouri C Pierpont Sinkhole Plain The picture of the W Grassland Trail area is just south of Rock Bridge Memorial State Park and west of the Pierpont Store. The photo within the word ‘karst’ above is the Rock Bridge located in Rock Bridge Memorial State Park. Information and maps courtesy of Dr. Robert Lerch, USDA-ARS What is Karst? groundwater in non-karst areas only travel a few • Never dump Karst landscape occurs when feet per year. Therefore, pollution in a karst area anything into rainwater combines with can contaminate hundreds of gallons of ground- a sinkhole water in a very short time. carbon dioxide, dissolving or stream. In soluble bedrock such as lime- When does Boone County’s Stormwater addition to stone or dolomite, creating a Ordinance apply to me? being illegal, dumping trash, series of cracks and channels If you are disturbing 3,000 square feet or more Sinkhole dump brush, leaves, that form caves, springs, Water flowing through of land within: sinkholes and losing streams. a crack in limestone grass clippings, hazardous waste, or similar at Gans Creek. • 1,000 feet of a losing stream, Outstanding materials can contaminate well water, springs There are over 418 sinkholes of a depth of at National or State Resource Waters, or and cave streams used by people, livestock least 20 feet in Boone County; most of which wetlands; and wildlife. are located near Pierpont and south of I-70 • 100 feet of permanently flowing streams; or • Maintain a vegetative buffer (e.g. a grass near Rocheport. • When creating runoff that flows to a filter strip) around a sinkhole to filter Why does Karst need special protection? sinkhole or other direct conduit to ground- runoff. Fencing livestock out of sinkholes water such as a cave. improves water quality and protects them Sinkholes and losing streams allow pollutants to from potential harm. pass directly to cave systems and groundwater Ways You can Protect Our Groundwater • Do not locate septic systems, feedlots, without the usual filtration from soil (see • Check with Boone County before starting animal waste lagoons, or stormwater basins illustration below). In Missouri, groundwater in any grading activities or using motorized near known or suspected sinkholes or karst systems travel about one mile per day, while vehicles in or near a sinkhole. caves. How Karst Works Septic tank drain field Plugged Sinkhole • When using chemicals near karst areas, Losing Stream select the ones that bind to soil, have low Losing Stream Sinkhole used as toxicity, and degrade quickly. Always trash dump follow the directions on the label. Photo courtesy Roxie Campbell, MoDNR Ccourtesy of the Bonne Femme Watershed Project. Well Dolomite Water Groundwater table contamination from This Bonne Femme Creek swallow hole, approx. 300 septic tank drain feet from the Hwy 163 bridge, is not seen in a normal field To spring stream bed. Dye tracing indicates that up to one mile of this creek is a losing stream..