As California copes with the persistent drought, dwindling groundwater is a big issues. 

Last year, Gov. Jerry Brown signed off on a package of laws to help the state better regulate groundwater use, called the Sustainable Groundwater Management Act.

But as the Center for Investigative Reporting has found, there is a provision that could make it hard to track the biggest water wasters.

Lance Williams wrote about it in CIR's Reveal and he joined the show with more.