16600 Sinks Rd, Florissant, MO 63034

Karst Preservation District

An approximately four square mile area of north St. Louis County located in the community of Old Jamestown is characterized by a unique karst topography. It has been scientifically identified as the Florissant Karst region by the geologic/scientific community as being one of the finest examples of deep funnel-shaped sinkholes in the central United States. Sinkholes, springs, and caves are among the common features in karst areas. This type of topography presents serious constraints to urban development in particular soil creep near sinkhole depressions, localized flooding near sinkholes, and potential groundwater contamination from stormwater runoff and sewage effluent. A primary characteristic of this karst area is the existence of surface sinkholes into which all surface runoff flows. The area is considered to be internally drained, and as a result has no surface channels that convey surface runoff to larger surface streams. This section is therefore necessary to protect this significant natural environmental geologic area. It is the purpose of this section to preserve the Florissant Karst area in its natural state, while allowing development at an intensity that can be accommodated within the constraints of the geological features of this unique area.