The water line at Campbell Lake in South Anchorage is creeping down this week as crews drain it to fix a sewer line there that became unmoored after the Nov. 30 earthquake.
Crews opened the gates to start draining the body of water on Sunday, and it will take a couple of days to completely empty, said Sandy Baker, spokeswoman for Anchorage Water and Wastewater Utility. The goal is to have the gates back in place by May 10, so the lake will start to fill up again.
During the 7.1 earthquake last year, part of the ground under the human-made lake “near as we can tell, liquefied,” Baker said.
Anchors on a sewer line buried under the 125-acre lake came undone. The pipe floated up at some point, Baker said, but it wasn’t noticed until mid-March, because it was covered by ice.
“There was no indication that there was any problem. ... Until all of the sudden, you could see part of the sewer line popping up through the ice," Baker said.
The utility put divers in the water to make sure there weren’t any other problems with the sewer line, and verified that there weren’t any leaks, Baker said.
“There was no sewage coming out,” she said. “Thank heaven.”
But the utility — working with a contractor — still needs to drain the water into Turnagain Arm via Campbell Creek in order to replace the pipe and anchor it beneath the lake once again, this time with “better, bigger anchors that hopefully an earthquake can’t undo,” Baker said.
Crews couldn’t do that work while there was still ice, she said, because the ice would have crushed the fish there, which include chinook, sockeye, and pink salmon. A temporary fix was put in place earlier this year.
“We don’t want to disrupt any of the fish cycle,” Baker said. “That’s an important part.” The fish will go into the creek while the lake is drained, she said.
Campbell Lake was constructed in 1959, when resident David Alm created a dam at Campbell Creek, according to a research paper on the Anchorage Waterways Council website. The land under the lake is now owned by Campbell Lake Owners Inc., a homeowners association for the area.
The massive 1964 Alaska earthquake caused the lake’s dam to fail, draining the lake, according to that research paper. Heavy rains in 1989 then washed out the dam and it was replaced that same year.