Soil erosion is the movement of soil particles down and from sloping land. These moving soil particles decrease soil productivity and degrade water quality. Soil erosion thins and can completely remove topsoil, the soil layer richest in organic matter and plant nutrients. It reduces agricultural productivity and causes significant downstream water-quality issues. Sediment loss from eroded cropland is one of the nation’s biggest water quality impairments, costing the United States billions of dollars each year in both on-site productivity losses and off-site environmental damage. Beyond economic impacts, soil erosion diminishes the soil’s capacity to store water and nutrients, directly threatening sustained food production and ecosystem health in agricultural regions.

The WEPP Model (Water Erosion Prediction Project) is a process-based computer simulation tool developed by the USDA since 1985 to predict runoff, soil loss, and sediment delivery by using fundamental physical processes of water erosion. It operates on a daily step to simulate rainfall, infiltration, soil detachment, sediment transport, and deposition across hillslopes and small watersheds. The WEPP Model serves as the core engine of the DEP, enabling it to generate realistic hillslope erosion estimates that reflect how soil, topography, weather, and management practices interact daily.

How can I use the DEP data for my farm, watershed or project?

The DEP supports farm and watershed planning by identifying erosion hotspots where conservation efforts are most needed. You can access free daily erosion maps and downloadable estimates through the DEP interactive map to evaluate erosion risk, assess the effectiveness of strategies such as cover crops and reduced tillage, and prioritize conservation investments. The data also helps conservation professionals and planners meet water quality goals. For instance, by focusing on sediment reduction efforts and measuring how specific practices influence runoff and soil loss at watershed levels.

How does the DEP help protect water quality and communities?

The DEP promotes water quality and community resilience by providing early warnings and targeted information about erosion-related sediment and nutrient pollution. This data helps prioritize conservation efforts where erosion risk is greatest, allowing conservation districts, local planners, and watershed groups to intercept sediment and nutrients before they reach streams, lakes, and drinking water sources. By converting complex geospatial erosion estimates into easy-to-understand daily maps and watershed-level risk assessments, DEP enables communities to develop smarter riparian buffers, wetlands, and stormwater practices that reduce flood risks, enhance aquatic habitats, and lower water treatment costs, ultimately strengthening environmental and public health downstream.