Elevation Certificates in Lathrop, CA

The San Joaquin River runs through the middle of Lathrop, with Old River on the west, and the city sits at about 20 feet of elevation. The City of Lathrop states that it is protected by FEMA-certified 100-year levees maintained by three reclamation districts: RD 17 on the east bank, RD 2062 around River Islands on the west side of Interstate 5, and RD 2107, which covers Dell'Osso Farms and areas south of the Union Pacific tracks and southeast of I-5. The city notes that RD 2107 did not have 100-year protection at the time it wrote its SB 5 general plan amendment and was neither urban nor urbanizing.

Lathrop is also growing behind those levees, which puts it squarely under California's SB 5 rules. Under the city's summary, after July 2, 2016 it could not issue new discretionary permits in areas that could be flooded more than three feet deep in a 200-year event unless 200-year protection was in place or adequate progress was being made, and the city has adopted adequate progress findings for the Mossdale Tract area since then. SJAFCA's planned Mossdale Tract project covers levees along the San Joaquin River and its tributaries. For a homeowner, though, the FEMA map still controls insurance. Many Lathrop buildings sit in levee-protected zones, and owners who are in a mapped SFHA, or whose lender says so, need an elevation certificate to rate the policy or to test whether a LOMA is possible.

For a Lathrop certificate we start with a GNSS tie to a published benchmark on the FIRM's vertical datum, then use a Trimble S3 total station to measure the lowest adjacent grade, highest adjacent grade, lowest floor, garage slab, crawlspace and vent openings, and the machinery and utilities serving the building. We photograph each side of the structure and deliver a signed FEMA EC. If the lowest ground touching the house is at or above the base flood elevation, the same numbers can support a letter of map amendment, which we can submit through eLOMA when it qualifies. Lathrop work is scheduled as a mobilization from our base in Lotus. Related: the elevation certificate service, Manteca, and Tracy.