The City of Oak Harbor is asking residents to reduce nonessential water use after a sewage overflow, according to a press release.

The “relatively minor” sanitary sewer discharge occurred at the Windjammer Park outfall. The city reports that the unusually heavy rain over the weekend inundated the city’s sewage treatment system, as well as other systems across Western Washington.

The city of Anacortes also had a sewage overflow event.

City officials are asking residents to reduce water usage to help slow the amount of water entering the system and to avoid any contact with harbor waters in the vicinity of the park until the overflow abates.

Oak Harbor Mayor Bob Severns said the city pumped less than 15,000 gallons of watery sewage into Puget Sound, beginning about noon Sunday and finishing before evening.

The city experienced 1.8 inches of rain in a 24-hour period.

“We anticipate that the new plant will be able to handle these loads,” he said.

The new plant in Windjammer Park is supposed to go online by the end of the year.

Island County Public Health posted beaches around Oak Harbor and the lagoon in Windjammer Park with notices Monday, according to Health Services Director Keith Higman.

The area is always closed to shellfishing because of the outfall location and the marina.

Larry Altose, spokesman for the state Department of Ecology, said the city properly reported the discharge to the department.

City officials said they needed to protect a pump station from flooding during very high flows from heavy rain, according to Altose.

Other areas on Whidbey had flooding but nothing out of the ordinary for the time of year, officials said.