Completing a 100-mile trip, water from Canton Lake splashed Monday into Lake Hefner, boosting drinking water supplies after months of drought.
A side benefit is that some people may be able to refloat boats that have been stuck in the mud because of historically low water levels.
Officials emphasize the withdrawal of 30,000 acre-feet of water from Canton Lake is driven by the need for drinking water, not to improve boating conditions.
Utilities officials hope 20,000 acre-feet will make its way down the North Canadian River to Lake Hefner over the next two to three weeks.
The riverbed will soak up much of the rest.
That much water would raise Lake Hefner about 10 feet, said Debbie Ragan, Oklahoma City utilities spokeswoman.
Lake Hefner still would be about seven feet below its normal level.
Canton Lake water began flowing into Lake Hefner about 11 a.m. Monday, Ragan said.
Canton Lake managers began releasing the water last Wednesday.
The lake is about 100 miles northwest of Oklahoma City.
Ragan said Lake Hefner was expected to rise about a quarter-inch on Monday. The flow measured at Yukon on Monday was 400 cubic feet per second, she said.