Iowa BMP Mapping Project
With the completion of the 2020 lidar flight, the question came up as to whether this data could be used to update the BMP data. After checking the 20% historical watersheds from the first run, it was determined that the lidar is showing enough differences to map the entire state again. This process is ongoing thanks to funding from the Iowa Department of Natural Resources and the Iowa Nutrient Research and Education Council.
As of May 8, 2026, 493 watersheds have been completed. If you would like access to this data, please contact Josh Obrecht. These updates will eventually be available from a new web application and updated services.
The goal of the Iowa BMP (Best Management Practices) Mapping Project is to provide a complete baseline set of BMPs dating from the 2007-2010 timeframe for use in watershed modeling, historic occurrence, and future practice tracking. The BMPs mapped are: Terraces, Water and Sediment Control Basins (WASCOB), Grassed Waterways, Pond Dams, Contour Strip Cropping and Contour Buffer Strips. We can’t guarantee that mapped practices meet NRCS standards or that they are actually the indicated practice since no ground reference analysis 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. BMPs are being collected by 12-digit HUC and finished products can be downloaded from below.
This project has been funded by the Iowa Department of Natural Resources, Iowa Department of Agriculture and Land Stewardship, Iowa Nutrient Research Center at ISU, National Laboratory for Agriculture and the Environment, the Iowa Nutrient Research and Education Council and AmericaView.
The GIS Facility, in cooperation with the Iowa DNR, has edgematched all practice features with their neighboring HUC12s within their HUC8. This has also been done across HUC 8 boundaries. The HUC 12 datasets have a column indicating presence in 2010, which is the named year of the inventory, even though data was collected from 2007-2010. For the 20% evaluated for historic and current practices, those 325 HUC 12 datasets have an additional two columns indicating presence in the 1980s and presence in 2016 as that was the first year of current imagery. There is also one statewide of all six practices with a size of 138 mb.
In Fall 2017, the GIS Facility received a mini-grant from AmericaView, a national remote sensing consortium, to develop a handbook and three tutorials to document the efforts of the Iowa BMP Mapping Project. The handbook provides an overview of the Iowa BMP (inventory) project and three companion projects. The handbook provides background on the project, information about the data structure and necessary input data, descriptions and images of the conservation practices, management considerations, and additional documents needed for project tracking for those interested in replicating the project.