Yes, there is the same amount of water, but there are a lot more people using that water.
Locally, the southern San Joaquin Valley is drying up. It is one of the most productive agricultural areas in the world, and continues to produce, but only with deeper and deeper wells.
Historically, the five southernmost rivers all flowed into the largest lake in California, Tulare Lake. That lake is now dry, and the rivers are all completely used up, every drop. The San Joaquin, second biggest river in California that once had ocean going vessels in it, goes dry just west of Fresno. Meanwhile, wells go dry and deeper wells are drilled.
Logically, there has to be a bottom to the water table, but no one knows just how much water is left.
The 2014/15 water year was the driest in 500 years. The Sierra snow pack, source of the rivers, was almost non existent. That served to wake people up, some, but then last winter was about 75% of normal. People are now saying that the drought is over. It's not over, but now in its fifth year.
Some of the farmers in the west side of the valley have wells that go down 2,000 feet now. That's pretty expensive water.