© 2021 KALW
KALW Public Media / 91.7 FM Bay Area
Play Live Radio
Next Up:
Available On Air Stations

Earthquake Flood Risk Prompts Order To Drain California Dam

Flickr / Creative Commons
Lake Anderson Dam, Morgan Hill, CA


It’s been an unusually dry February in the Bay Area, causing concern about a potential drought. Now, federal regulators have added to those worries with the announcement that Santa Clara County’s largest water supply needs to be drained.

Federal officials say that the Anderson Dam, near Morgan Hill, is unsafe to hold water. They’re concerned that an earthquake could be enough to collapse it and cause flooding.


This isn’t the first sign of trouble with the dam. Local regulators are already working on a project to make it more earthquake safe. And the reservoir is currently limited to being kept about half full, at the most, to reduce flood risk.


The Federal Energy Regulatory Commission has ordered the reservoir to be completely emptied by October.


Local officials say they agree there are safety issues that need to be addressed. But draining the reservoir entirely may not be safe, either. They’re worried it could cause lasting damage to the structure, and harm nearby wildlife.