WATER RESOURCES RESEARCH GRANT PROPOSAL
Project ID: IA1681
Title: Evaluating the Effectivenss of Restored Wetlands for Reducing Nutrient Losses from Agricultural Watersheds
Focus Categories: Wetlands, None
Keywords: Wetlands, Watersheds, Nutrient loss
Start Date: 03/01/2001
End Date: 02/28/2002
Federal Funds: $3,000
Non-Federal Matching Funds: $5,784
Congressional District: Iowa 3rd
Arnold G Van der Valk
Professor, Iowa State University
William G. Crumpton
Associate Professor, Iowa State University
What is proposed is the first quantitative analysis at the watershed level of the effectiveness of actual wetland restorations for reducing non-point pollution resulting from agricultural activities. Specifically, one major goal of this project is to determine why restored wetlands in the IGLW seem not be effective nutrient traps. Three possible reasons will be investigated. One, the restored wetlands may not be located in a given subwatershed where they can intercept significant amounts of agricultural runoff. Two, the restored wetlands in a given subwatershed may not be large enough to handle the loads of nutrients that they receive and most nutrients simply pass through the restored wetlands. Three, recently restored wetlands may not have the same capacity to remove nutrients as natural wetlands.
The other major goal of this project is to improve the effectiveness of future wetland restorations as nutrient traps. This will be done by using the data about restored wetlands and their physical characteristics to model nutrients movement and retention in subwatershed and restored wetlands to determine if nutrient exports from particular subwatersheds could be further reduced by altering the location and/or size of restored wetlands. The major product of this study will be a set of workable guidelines for siting, sizing, establishing, and managing restored wetlands within agricultural watersheds to minimize nutrient losses from them and to maximize the amount of land that can be kept in production.