Blue Earth County Ditch No. 57
Minnesota | Agriculture
ISG worked on this county ditch project that demonstrated to landowners methods to boost agricultural production and improve water quality.
County Ditch No. 57 was an ideal site to test water storage and drainage strategies to provide empirical evidence of the effects of Best Management Practices (BMPs).
Recognized as the first public multi-purpose drainage project in Minnesota, Blue Earth County Ditch (CD) No. 57 provided proof to landowners and agencies that conditions for agricultural production were enhanced, peak flow rates reduced, and water quality was improved by implementing a combination of BMPs on CD 57. Water storage and drainage capacity were increased, which reduced flooding and improved field conditions for crop yields, and water quality also saw marked improvements in the reduction of sediment and nutrient loading throughout the system.
A combination of BMPs included two water storage basins, buffer strips, two-stage ditch, and a rate control weir. The two storage basins significantly increased storage capacity, with the Klein Pond providing 26.3 acre-feet of storage and the City Pond providing 23 acre-feet. Peak flow rates were reduced with reductions ranging from 10% to 50% at Klein Pond and the rate control weir averaging 6% in reduction for monitored rain events. In addition to helping the system better manage rainfall events, results from the three BMPs monitored showed they removed a total of 251,000 pounds of sediment, equivalent to nearly 75 dump truck loads. The success at CD 57 serves as an example of how focused designs can benefit both landowners and the environment simultaneously.