Iowa Best Management Practice (BMP) Mapping Project
The Iowa Best Management Practice (BMP) Mapping Project was completed by Iowa State University and funded by Iowa DNR, IDALS, Iowa Nutrient Research Center at ISU, National Laboratory for Agriculture and the Environment and Iowa Nutrient Research and Education Council. The BMP Project provides an inventory of already existing conservation practices in watersheds across Iowa. BMPs were identified using different types of aerial imagery. Analysis of BMPs in the Upper Iowa River Watershed used LiDAR, infrared, and natural color imagery, from 2007 to 2010. Researchers from the project visually scanned the different imagery types to identify a variety of practices including, grass waterways, ponds, terraces, WASCOBs, contour strip cropping, and contour buffer strips. The results from the analysis were not ground truthed to identify which practices are currently on the ground. Iowa State University recognizes that the identified practices may or may not have been constructed to any state or federal standard and that differences in actual practices on the ground may differ from those identified in the 2007 to 2010 LiDAR imagery, noting,
“We can’t guarantee that mapped practices meet NRCS standards or that they are actually the indicated practice since no ground truthing is being performed. Data being utilized to digitize the BMPs include LiDAR derived products such as DEM, Hillshade and Slope grids; CIR aerial photography from the 2007-2010 timeframe, NAIP aerial photography and historic aerial photography.”
The goal of the BMP project is to provide an relative baseline of data for conservation practices that are on the ground between the 2007 to 2010 time frame. This data can be used for extensive watershed modeling, documenting historic occurrences, and future practice tracking. To supplement data from the Iowa BMP Mapping Project, the ISU GIS Facility has developed an online web page where results are available for download by each subwatershed in Iowa. Results can be used by WMAs, County SWCDs, NRCS, Cities, and County Engineer/Secondary Road offices and others to evaluate the existing BMPs in their watersheds.