Furu
You are correct on all counts. San Jose is located in the Central Valley. All water funnels mostly through the city, through drainage ditches, probably a radius of 7-8 miles, 11Kms.
We can get 1" for every 10-12 minutes.
Just watched the news, they are getting more, today. One spot had 31 cars towed away. Water was above bus tires, which are 36" tire diameter or more.
One taxi went into a hole in the road, probably a man hole and 3 occupants died.