California laws determining ownership of groundwater are a convoluted tangle rooted in England's common law. With the drought and other supply constrictors as a backdrop, a dynamic panel of experts illuminates who owns this necessity, why, and the ramifications. Buzz Thompson, founding director of Stanford Law School's Environmental and Natural Resources Program; Linda Sheehan, executive director of the Earth Law Center; and Eric L. Garner, the first American to chair the International Bar Association's Water Law Committee, discuss potential solutions to this Gordian knot of legal constraints. Mark Gold, UCLA associate vice chancellor for environment and sustainability, moderates.