In an unprecedented move, sewage has been released into Kohlman Creek in Maplewood to keep the E. coli-tainted water from backing into homes, prompting the closure of the swimming beach at Lake Gervais County Park.

"It's a highly unusual situation," said Cliff Aichinger, administrator with the Ramsey-Washington Metro Watershed District.

The decision, made in consultation with officials from St. Paul, Ramsey County and the Metropolitan Council, was forced by waves of record-setting rainfall. It was one of several sewage-bypass situations that developed Thursday afternoon across the Twin Cities.

An estimated 450,000 gallons of sewage was released into the creek late Thursday. That sounds like a lot, Aichinger said, but the sewage will become quite diluted as it makes its way downstream.

Kohlman Creek flows first into Kohlman Lake, then into Lake Gervais. The chain of lakes also includes Keller and Round lakes, ending with Lake Phalen, the centerpiece of Phalen Park, one of the most popular parks in St. Paul.

Aichinger said there is no reason at this point to be concerned about Lake Phalen, where the Capitol City Triathlon will take place as planned on Sunday.

The situation is similar to what happened several weeks ago, when three public beaches in the western Lake Minnetonka community of Mound were closed and about 20 Minnesota cities and industries were forced to bypass their sewage-treatment operations and channel untreated waste into lakes and streams because of heavy rain.

The release into Kohlman Creek was not the only sewage bypass that came in the wake of Thursday's storm. Similar bypasses also resulted into sewage spilling into the Mississippi River at Wabasha Street and Humboldt Avenue in St. Paul, Maxwell and Carmen bays in Lake Minnetonka, and into Medicine Lake and Bassett Creek in Plymouth, according to the Metropolitan Council.

"The sanitary sewer system interceptor was overtaxed," Aichinger said of the Kohlman Creek situation. "People are trying to keep their basements dry and their sump pumps are running — and they're running them into their drains, which they shouldn't do."

The decision, he said, came down to letting sewage back up into 15 to 20 nearby homes, which would have posed a health risk to many people, or release it into the creek and close the unguarded beach at Lake Gervais.

The beach will likely stay closed into early next week, Aichinger said. Test results take 24 to 36 hours to be returned and, starting on Friday morning, the water will be tested several times before the all-clear is given to reopen.