Water Resources Research Act Program

Details for Project ID 2002IA9B

Evaluating the effectiveness of restored wetlands for reducing nutrient losses for agricultural watersheds

Institute: Iowa
Year Established: 2002 Start Date: 2001-03-01 End Date: 2003-02-28
Total Federal Funds: $13,000 Total Non-Federal Funds: $26,093

Principal Investigators: Arnold Van der Valk, William Crumpton

Project Summary: Why restored wetlands are not consistently reducing nutrient losses from Iowa Great Lakes subwatersheds is the major focus of this study. There are three major reasons why restored wetlands may not be effective. One, the wetlands may not be properly sited. The restored wetlands may be effective nutrient traps, but most of the agricultural runoff may not pass through them. In other words, they may not be located in places where they can intercept significant amounts of agricultural runoff. Two, the wetlands may not be large enough to handle the loads of nutrients that they receive. Consequently, most nutrients simply pass through the restored wetlands. Larger or more wetlands may be needed. Three, restored wetlands may not yet have reached the nutrient removal capacity of natural wetlands.