California save water

My words exactly . I was in New Orleans three weeks ago The first Monday we were there it rained 1 3/4 " in an hour. Somewhere in the South its flooding from October to April. if we can put a pipe line in for oil 2000 miles long why can't we make flood reservoir to collect flood water and pumping stations . California has a lot of waist land . You can dam up small valleys and fill them. Not far fetch its just not oil . A project like this would create jobs and help remedy two problems.

There has been talk about building a dam or two, in Northern California, for more water storage, but they have figured into the problem, where would the water come from?
There just isn't any more water to capture and save, other than what the winter snow pack, up in the Sierras puts into the rivers, that flows into the dams that we allready have.
And again this year, didn't get much of a snow pack up in the mountains at all.
Gonna be a real bad year for water.