Does anyone where I can drive to a river in the San Francisco / Bay Area?

There is a Polish tradition that when Winter ends, you make little figurines out of sticks that symbolize Winter and any other bad things you like, and throw them into a river. I wanted to take my girlfriend to do this, but I suddenly realized that I know of no moving rivers in the Bay Area that we could drive to. Any ideas? Preferably something within 10-15 minutes of the Penninsula.Does anyone where I can drive to a river in the San Francisco / Bay Area?
There is a river in Niles Canyon (the Niles district of Fremont)..its called Alameda Creek and runs from Fremont to Sunol, I found a website that has a map, etc:



http://www.riverfacts.com/rivers/10399.h鈥?/a>



I'm sure there are lots of others, I'm just real familiar with that one!



Here is another web site that lives rivers in San Francisco County:



http://en.wikipedia.org/wiki/Category:Ri鈥?/a>Does anyone where I can drive to a river in the San Francisco / Bay Area?
The map shows Alameda Creek between Union City and Fremont on the east side of the Bay. I have not actually been there, so I don't know what kind of water flow there is in reality.