A plan to build two 35-mile long water tunnels is now in the hands of state regulators.
The tunnels would carry water from northern California to central and southern California.
Opponents and supporters were at a California Water Resources Control Board meeting Thursday.
Supporters say the tunnels will guarantee an earthquake-resistant water supply for millions of Californians. Opponents say the tunnels jeopardize the environments of the San Francisco Bay and the ecologically sensitive Sacramento-San Joaquin Delta.
The state board is one of several state and federal agencies scheduled decisions regarding the $17 billion project.
The board is considering whether to slow their decision-making process until key design and environmental reports are completed.
-Capital Public Radio Staff, AP contributed to this story