MAPPING CATCHMENTS OF THINLY-SOILED KARST FEATURES

Karst topography is prevalent on the Onondaga Escarpment in western New York. Pollution of ground water can occur with karst topography due to runoff having direct access to ground water through sinkholes, exposed fractured bedrock and thinly-soiled karst features. In the study area, well contamination events have happened three times previously when unsuspecting farmers applied manure on fields which later ran off into karst features. To help address this problem we have mapped the catchments of suspected karst features in the study area using aerial photography and 1 meter contour maps. The maps were prepared using on screen digitizing techniques in a geographical Information System. Maps were printed out and taken in the field for quality control. Divide lines were checked, and ditches, ephemeral streams and culverts mapped using GPS. Field Surveys were conducted to verify the watershed, which proved to be challenging when road berms and culverts were introduced. Road berms were found to modify and occasionally reduce the size of the catchment around Karst features. The close proximity of roads to some of these features make them susceptible to stormwater inputs. This poster presentation presents statistics and representative results from a few of these features.