Lane County is required by the federal Environmental Protection Agency (EPA) and the Oregon Department of Environmental Quality (DEQ) to maintain a stormwater management program that protects the waters of the state. In 2024 and 2025, the County adopted erosion prevention code requirements for land-disturbing activities on properties. The code applies in the following two areas:

1.  The County-administered Municipal Separate Storm Sewer Systems (MS4) Area around the Eugene and Springfield urban growth boundaries, and
2.  The Mercury Total Maximum Daily Load (TMDL) Area within the Willamette River Basin, outside of the MS4 Area
            
See the County-Administered MS4 Area map and the Mercury TMDL map, or visit the County's Zone and Plan Maps, to determine if your property is in the MS4 Area or the Mercury TMDL Area.

All land-disturbing activities within the MS4 Area and the Mercury TMDL Area, unless otherwise exempted, must use best management practices (BMPs) to meet the erosion prevention outcomes of Lane Code 9.090.030.

Erosion prevention BMPs must be used, whether an erosion prevention permit is required or not. 

For more information about the erosion prevention requirements for each area, click the link below: