STORMWATER MANAGEMENT STRATEGIES FOR KARST AREAS: A CASE STUDY OF SPRINGFIELD, MO

Sinkholes pose distinctive challenges to stormwater management due to their inherent geological characteristics, which can accelerate surface water infiltration and increase the risk of subsurface erosion. Springfield, Greene County, Missouri is underlain by the Burlington-Keokuk Limestone, a light gray to white, coarse- to medium crystalline, crinoidal limestone. It is a medium- to very thick-bedded limestone. The Burlington-Keokuk limestone is highly susceptible to solutional erosion, resulting in the formation of numerous karst features, such as sinkholes.

Rapid growth has created pressure for development around sensitive karst areas in Springfield and surrounding communities. Stormwater management used many standard engineering approaches, often resulting in flooding of sinkholes and adjacent areas. Having recognized the inadequacy of existing designs to control flooding and to accommodate increased runoff from future developments, the City of Springfield adopted an ordinance (effective June 19, 1989, and modified in 1990 and 1993) to address these issues. The ordinance required an approved permit for any alteration of a sinkhole or using the sinkhole for stormwater management.

Control of stormwater prior to the Sinkhole Ordinance used several approaches such as: installation of drainage pipes into the sinkhole “eye;” filling in sinkholes; elaborate drains and pumps to remove stormwater from one sinkhole and discharging into another basin or sinkhole; and enlargement of sinkhole eyes by excavation to increase the drainage capacity. In addition to reviewing these past approaches, several examples after the ordinance went into effect will be analyzed to examine the effectiveness of differing design and best management approaches to stormwater management in sinkhole prone regions.