Mountain View, CA Environmental Rules: Erosion Control (2026)

Sec. 2 to require that projects disturbing less than one acre of soil, and not part of a larger development plan that in total disturbs one acre or more, manage storm water drainage throughout construction. The section lists compliance paths a builder may combine: install retention basins sized to hold storm water on site; filter any water conveyed to a public drainage system, collection point or gutter through a barrier system, wattle or other method the enforcing agency approves; or comply with the year-round stormwater pollutant control standards of Chapter 35 Sec.

1(t), which name erosion control, run-on and runoff control, sediment control, active treatment where appropriate, good site management, and nonstormwater management as required measures. Those pollutant controls must stay in place through every phase of construction until the site is fully stabilized by landscaping or permanent erosion control. Larger sites, those disturbing one acre or more either alone or as part of a bigger development, fall outside Sec. 05's residential threshold and instead trigger the state Construction General Permit and the city's separate Chapter 35 stormwater program administered under the Public Works Department.

The Building Division reviews the chosen erosion control method at plan check, and the enforcing agency inspects the installed retention basins, filters and barriers during active grading and construction to confirm the site is not discharging sediment onto adjacent property or into the public storm drain system.