Mountain View Municipal Code Div. 5 Residential Stormwater Drainage and Retention Requirements

Subsection 4.106.2 of the 2025 California Green Building Standards Code is amended to read as follows:

4.106.2 Storm water drainage and retention during construction. Projects which disturb less than one acre of soil and are not part of a larger plan of development which in total disturbs one acre or more, shall manage storm water drainage during construction. In order to manage storm water drainage during construction, one or more of the following measures shall be implemented to prevent flooding of adjacent property, prevent erosion, and retain soil runoff on the site.

1. Retention basins of sufficient size shall be utilized to retain storm water on the site.

2. Where stormwater is conveyed to a public drainage system, collection point, gutter or similar disposal method, water shall be filtered by use of a barrier system, wattle or other method approved by the enforcing agency.

3. Stormwater pollutant control measures must be installed at construction sites year round in compliance with Chapter 35 Sec. 35.33.11.1(t) of the City Code. The storm water pollutant control measures listed in the ordinance include erosion control, run-on and runoff control, sediment control, active treatment (as appropriate), good site management, and nonstormwater management through all phases of construction until the site is fully stabilized by landscaping or the installation of permanent erosion control measures.

(Ord. No. 9.2025, § 6(Exh. B), 9/9/25.)