A "filing fee" is $300, plus $10 per acre-foot, plus 25% penalties.
In Idaho, it takes 5 or 6 acre feet per acre to grow crops. More for long season crops like sugar beets, less for short season crops like wheat.
California has a much longer growing season than does Idaho. They often grow two crops per season, where we can only get one.
Without actual data, I might make a guess that California Ag could easily require 10 acre feet per year or more. So, a $100/acre additional tax on ag lands to pump the water under your own land.
It is just a precursor to the day the "Progressives" achieve the power to "nationalize" the farm lands of America and put them into "the collective".