Water from Canton Lake today will start flowing about a hundred miles southeast to replenish one of Oklahoma City's main supplies of drinking water. It's expected to reach Lake Hefner within three to five days. Unseasonably warm and dry weather has caused Lake Hefner's water level to drop significantly and Oklahoma City officials say 16,000 acre-feet of water will be drawn from Canton Lake and down the North Canadian River to reach Hefner. Canton's water levels are expected to drop about three feet.