Steady rains during the past week have restored California reservoirs to storage levels not seen in nearly four years, but swollen river flows into the Pacific Ocean renewed concerns from water users and elected officials about lost opportunities as billions of gallons of fresh water headed out to sea.

By Monday night, Sacramento River flows were expected to exceed 100,000 cubic feet per second—equal to dumping about 750,000 gallons of water per second into San Francisco Bay.