Renton, WA Environmental Rules: Erosion Control (2026)

D1, requires anyone who clears, grades, or otherwise disturbs a site to control erosion 'to the maximum extent practicable' so sediment doesn't reach drainage facilities, water resources, or adjacent properties, applying the performance criteria in the City's Surface Water Design Manual. During the seasonal limitation period, October 1 through April 30, D2 tightens that further: clearing and grading is only allowed if the applicant demonstrates to the Director's satisfaction that runoff will comply, based on site conditions, the extent of disturbed area, and the specific erosion and sedimentation control measures proposed.

D4 requires an erosion and sedimentation control plan approved by the Development Services Division before any clearing or grading proceeds during that window. If silt-laden runoff violating the Design Manual leaves the site, or the approved control measures aren't maintained, D5 gives the department inspector authority to issue a partial or total stop-work order on the spot. Under D6, if that erosion problem isn't adequately repaired within 24 hours of the stop-work order, the City can issue a notice and order requiring adequate controls and can bar further clearing or grading, beyond maintenance and repair work, until the following April 30.

C6 requires hydroseeding or another approved ground cover within 30 days of completing grading work on any portion left unworked for 90 days, reinforcing the same erosion goal on the general development-standards side of the code.