National Weather Service has issued a Flood Watch from 7 PM PST this evening through 10 PM tonight. 
FLOOD Watch from the National Weather Service
National Weather Service San Francisco CA
1200 PM PST Mon Dec 13 2021
San Francisco-San Francisco Bay Shoreline-San Francisco Peninsula Coast-East Bay Interior Valleys-East Bay Hills and the Diablo Range-
Santa Cruz Mountains-Santa Clara Valley Including San Jose-Northern Monterey Bay- Including the cities of Livermore, Scotts Valley, Pacifica, San Francisco, Hayward, Watsonville, Fremont, Live Oak, Santa Cruz, San Ramon, Antioch, Berkeley, San Jose, Blackhawk, Walnut Creek, Daly
City, Boulder Creek, Concord, Day Valley, Pittsburg, Pleasanton, and Oakland
1200 PM PST Mon Dec 13 2021
...FLOOD WATCH IN EFFECT FROM 4 PM THIS AFTERNOON TO 10 PM PST THIS EVENING...
* WHAT...Flooding caused by excessive rainfall is possible.
* WHERE...A portion of northern California, including the following areas, East Bay Hills and the Diablo Range, East Bay Interior Valleys, Northern Monterey Bay, San Francisco, San Francisco Bay Shoreline, San Francisco Peninsula Coast, Santa Clara Valley Including San Jose and Santa Cruz Mountains.
* WHEN...From 4 PM this afternoon to 10 PM PST this evening.
* IMPACTS...Excessive runoff may result in flooding of rivers, creeks, streams, and other low-lying and flood-prone locations. Creeks and streams may rise out of their banks. Flooding may occur in poor drainage and urban areas. Low-water crossings may be flooded. Storm drains and ditches may become clogged with debris. Extensive street flooding and flooding of creeks and rivers are possible.
* ADDITIONAL DETAILS...
- High resolution models are showing a line of heavy rain moving through the region with the potential of producing periods of heavy rain late this afternoon and through this evening.
http://www.weather.gov/safety/flood
Address/Location
East Bay Regional Park District Police Department
17930 Lake Chabot Rd
Castro Valley, CA 94546
Contact
Emergency: 9-1-1
Non-emergencies: 510-881-1833