Floodplain Management Information

Adobe Creek

There are four creeks that run through Los Altos, one of which you probably live near. These creeks are Adobe Creek, Hale Creek, Permanente Creek and Stevens Creek. In addition, there is the by-pass near Blach School which carries overflow from Permanente Creek to Stevens Creek.

During rain storms, stormwater naturally flows to the creeks, which is eventually conveyed to the San Francisco Bay; however, during periods of heavy storms the amount of water flowing to the creeks can be too much to be contained within the creek banks and cause flooding.  Flooding is likely to be limited to properties closer to creek areas; however shallow flooding could occur in areas throughout the city including city streets. 

Floodplains along creeks are a natural component of the city of Los Altos environment.  Understanding and protecting the natural functions of floodplains helps reduce flood damage and protect resources. When flooding spreads out across the floodplain, its energy is dissipated, which results in lower flood flows downstream, reduced erosion of the stream bank and channel, deposition of sediments higher in the watershed and improved groundwater recharge. 

Understand flooding risks.  Six inches of fast-moving flood water can knock over an adult and it takes only two feet of rushing water to float most vehicles.

Building in Special Flood Hazard Areas

Various design and construction methods may be used to minimize, mitigate and protect against flooding.  Property owners can consult with building design, engineering, and construction professionals to determine which methods are the most effective and comply with local regulations.  Special Flood Hazard Areas (SFHA) are those areas designated by the Federal Emergency Management Agency where floodplain management regulations must be enforced and the area where the mandatory purchase of flood insurance applies.  These areas are also known as the 100-year flood zones.  Specific regulations that apply to the SFHA can be found in Los Altos Municipal Code Chapter 12.60 Floodplain Management.    For more information regarding flood zone management and development regulations in Los Altos, please call the Planning Division at (650) 947-2750.

Flood Insurance

Flooding is generally not covered by a standard homeowner’s insurance policy. A separate flood insurance policy is required to cover damages to buildings incurred by flooding.  The city of Los Altos participates in the National Flood Insurance Program (NFIP) that makes available federally backed flood insurance for all eligible buildings, whether or not they are located within the floodplain.  Note that there is a 30-day waiting period before coverage goes into effect. 

Elevation Certificates

Elevation Certificates (EC) provides elevation information necessary to ensure compliance with community floodplain management ordinances; to inform mitigation actions that will lower flood risk; and/or support a request to remove a building from a high-risk flood area. The EC lists a building’s location, lowest point of elevation, flood zone, and other characteristics. 

Record of Properties with Elevation Certificates  - this list includes those properties which the city has record of an EC.  To request an EC, please submit a public information request.

City of Los Altos Emergency Preparedness Information

Plan for emergencies. Prepare a family disaster plan. Make an emergency kit with emergency supplies such as a flashlight, batteries, water, and non-perishable food. Sign up for AlertSCC, the Santa Clara County emergency alert system.

Valley Water Information

Federal Emergency Management Agency (FEMA) Information 

Get Flood Ready