Elevation Certificates in Gilroy, CA

Gilroy's flood map is built around two creek systems, Uvas Creek and Llagas Creek. FEMA's flood data for the city shows mapped flood zones along Uvas Creek, Llagas Creek, West Branch Llagas Creek, Lions Creek, Miller Slough and the Princevalle Drain, plus overbank and overflow areas off Uvas Creek. The mix is wide: AE zones with base flood elevations, AO and AH shallow-flooding zones, approximate Zone A, and some Zone D. Most panels covering the city are dated May 18, 2009. The city also adopted the Uvas Creek Overflows Floodplain Management Study, prepared in 1995, as a basis for applying its floodplain rules in affected areas.

Gilroy's floodplain ordinance, Chapter 27E of the City Code, was rewritten in 2016 after a Department of Water Resources visit and uses the state model ordinance as its base. It keeps the city's long-standing higher standard: in AE, AH and A1-30 zones, the lowest floor of new or substantially improved homes must be at least one foot above the base flood elevation, and in AO zones one foot above the depth number. The ordinance tracks improvements cumulatively, so a series of smaller remodels can add up to a substantial improvement. It treats a building without its required elevation certificate as out of compliance until the documentation is provided, and in areas without a published BFE new development has to propose one. Fill placed above the BFE has to be certified by a civil engineer or licensed land surveyor for a LOMR-F. At the time of the 2016 update the city held a Community Rating System Class 8 rating.

An elevation certificate in Gilroy begins with a benchmark tie on the FIRM's vertical datum using GNSS, then a Trimble S3 total station survey of lowest adjacent grade, the lowest floor, garage and crawlspace, flood vents, and machinery and utilities, with photos of each side of the building. We process in Trimble Business Center and sign the EC. If the structure sits at or above the BFE on natural ground, we can prepare a letter of map amendment or file through eLOMA; if fill raised the site, a LOMR-F is the route. Gilroy work is scheduled as a mobilization. See our elevation certificate service and the Morgan Hill and Hollister pages.