Builders - Stormwater

Why do stormwater discharges from construction activities matter?

When it rains, stormwater washes over the loose soil on a construction site, along with various materials and products being stored outside. As stormwater flows over the site, it can pick up pollutants like sediment, debris, and chemicals from loose soil and transport them to nearby storm sewer systems or directly into rivers, lakes and irrigation ditches.

Builders and Contractors need to be aware that construction activities disturbing one or more acres are required to get a permit for discharging stormwater associated with construction activities from the Colorado Department of Public Health and Environment (CDPHE). In these cases, Stormwater Management Plans and Best Management Practices, i.e. water quality control measures, are necessary to ensure proper drainage and water quality.

Larimer County has an MS4 Program and regulates stormwater associated with construction activities within its MS4 boundary.  For a more detailed map, use the Flood Indicator Map (FIL).  First zoom into your area of interest and then activate the MS4 Boundary Layer by checking the MS4 Permit Area box under the Stormwater section in the layer list.

• Best Management Practices for Construction
• Best Management Practices for Small Construction Site
• Stormwater Pollution Prevention - Urban
• Stormwater Pollution Prevention - Rural

National Association of Home Builders Toolkit.  The NAHB is a trade association that helps promote the policies that make housing a national priority.