Gilroy, CA Invasive Plant Rules: Prohibited Species (2026)

Chapter 27A's Article II stream protection rules apply to all properties within a streamside review area, defined in Section 27A.2 as land within 50 feet of the top of bank of a stream. Under the riparian corridor protection standard at Section 27A.5(a)(1), removal of native vegetation is flatly not permitted, no non-native species may be planted between the top of banks at all, and invasive species specifically are barred from a wider 150-foot buffer measured from the top of bank. Any new landscaping in the area must also comply with the City of Gilroy's adopted Consolidated Landscape Policy.

These riparian rules apply on top of the chapter's broader building and site requirements, which also govern bank stability setbacks, erosion control, grading, and floodplain conveyance near streams. Section 27A.4 exempts narrow categories of work from full chapter review, including remodels of existing single-family homes on lots of 10,000 square feet or less, under three cubic yards of earthwork, interior alterations, small storage buildings of 120 square feet or less, sewer or water lateral replacement, re-roofing, low wood fences set back from the bank, and any modification 50 feet or more from the top of bank or riparian corridor edge, whichever is greater; none of those exemptions apply if the activity occurs directly in the stream channel.

Non-exempt property owners must submit development plans under Section 27A.6 showing bank stabilization and revegetation efforts before work proceeds, reviewed alongside any other required city permits.