The first thing you should do is check your flood hazard. Flood maps and flood protection references are available at the Richmond Public Library or at the California Emergency Management's website.
You can also visit the Building Department on the first floor of City Hall to see if you are in a mapped floodplain. If so, they can give you more information, such as the depth of flooding over a building’s first floor, past flood problems in the area, and copies of elevation certificates on buildings built in the floodplain since 1991. They also have a handout on selecting an architect, engineer, or contractor. Even if you are not in a floodplain, there still may be some risk of flooding.
If requested, the Public Works Department will visit a property to review its flood problem and explain ways to stop flooding or to prevent flood damage. Call the Department at 510-307-8091 for this free service. If you are in a floodplain or have had a flood and/or a drainage or sewer backup problem, check out the assistance these sources can give you.