Conservation Drainage: Innovative Strategies that Provide Win-Win Solutions

Abstract

Abstract. Flushing sediment and nutrients downstream causes inefficiencies in watersheds that reduce water quality and impacts agricultural economics. Increasing capacity and improving water quality throughout drainage systems is being achieved through targeted implementation of Best Management Practices (BMPs). Combinations of BMPs increase drainage effectiveness and improves water quality. These practices are provided through three types of measures: preventive, treatment, and control. These measures can include surge basins, buffer strips, two-stage ditches, rate control weirs, and culvert structures that are installed to control flow rates and allow sediment and nutrients to settle out of suspension before continuing downstream. Buffer strips provide nutrient uptake and trap sediment prior to entering the system. Weir structures slow down and dissipate the peak flow rates resulting in less sediment and nutrients traveling downstream. Minnesota‘s Blue Earth County Ditch 57 included system repairs and construction of a combination of several BMPs, resulting in significant water quality improvements and reduced flooding. Combinations of BMP‘s targeted to address specific topographic conditions are providing win-win solutions for landowners and the environment. Reductions for pollutants were as high as 50% with averages near 25%. The equivalent of over 70 dump truck loads of sediment were kept out of public waters within the first three years of construction.