With the recent promulgation of the Chesapeake Bay TMDL (Total Maximum Daily Load), inputs of sediment, nitrogen (N), and phosphorus (P) to the Bay must be reduced throughout the entire Bay watershed. Agriculture, urban, and wastewater treatment discharges are all included in the TMDL requirement. Although advances have been made, agricultural land use remains the overall largest source of N and P to Bay waters. As rain falls on agricultural land, becoming runoff, nutrients and sediment from field and other areas, especially from row crops, are mobilized and transported to the Bay and its tributaries.
Processes to reduce and/or treat stormwater runoff continue to be developed, refined, and implemented in agricultural areas. These processes are commonly known as Best Management Practices (BMPs) and include technologies such as swales and buffer strips. While these practices can be effective when implemented and maintained, they commonly result in taking valuable cropland out of production. Additional tools are needed to address the agricultural runoff challenge.
High Impact Environmental (HIE) of Chestertown, MD, has developed a swale/basin technology (herein titled: “Cascading System” of Floodway Stormwater Containment Basins) to address runoff from field crop areas. A prototype practice installed at HIE anecdotally has shown significant potential in runoff control, with runoff discharge only occurring during large rain events (maybe greater than 5 or more inches). Smaller rainfall events are fully captured and attenuated by the practice. The net result is reduced runoff and nutrient loads to the local Chesapeake Bay tributary.
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