MI staffers provide update on water supply situation

City currently sits in the advisory stage of water shortage contingency plan.

In an update on Mercer Island’s water supply situation, the city’s sustainability program analyst Alanna DeRogatis noted that the Island presently sits in the advisory stage of its water shortage contingency plan.

DeRogatis joined Public Works chief of operations Jason Kintner at city council’s June 4 meeting for a presentation focused on the Island’s water shortage consumption reduction actions. The four stages of the plan are advisory, voluntary, mandatory and emergency, and the advisory juncture recognizes serious potential for a water shortage and implementation of supply management actions, according to city documents.

A recent Reporter article noted that the city issued a May 29 social media notice that the public is encouraged to take small water conservation steps while crews work to mend the out-of-service Seattle Public Utilities (SPU) 24-inch main water supply pipeline that serves the Island as the city utilizes a 16-inch backup line for the time being. The city learned of the mainline leak on April 3 near the hillside below 40th Avenue Southeast near 95th Court Southeast.

According to city documents, the backup line can reliably supply the Island with about 2.73 million gallons of water per day; the water demand regularly exceeds three million gallons per day during the summer months.

“July is our highest demand month on Mercer Island and so we are looking at implementing voluntary stage reductions starting this month in anticipation of July,” DeRogatis said. “We are hoping that those voluntary actions are well-received by the community and well-participated in because we are hoping to avoid mandatory and emergency stages.”

Kintner said that city officials are concerned that if the Island continues to draw down its two reservoir tanks, the city could have a critical situation on its hands.

“We are asking the community to step up and help with our conservation efforts to just slightly bring down our consumption levels so that we can maintain sort of status quo with our reservoir tanks operationally each and every day,” he said. “It’s extremely important that our community help us with this task of water conservation until that main pipeline is repaired.”

Present conservation efforts are necessary to ensure the city has sufficient water supply to sustain water quality, safety and firefighting requirements in the high-demand summer months, the May 29 notice explained. Some suggested alterations in residents’ water use are running full loads of dishes and laundry, taking shorter showers, and adjusting lawn mowers to 2-3 inches.

On the repair front, Kintner said that SPU is proposing to reline the existing main pipeline by pulling 1,100 feet of flexible liner through the pipe from two excavation pits. With limited public access and its location on a steep slope, Kintner noted that the pipe is immensely challenging to reach.

Kintner added that the city hopes the pipe will be fully operational by the close of July.

Councilmember Lisa Anderl commented on the water conservation efforts at the June 4 meeting: “I’m so confident in this community, that we will not have to move past the voluntary stage. We unfortunately have experiences with water emergencies, but fortunately we know that the community steps up like champs during that time.”

DeRogatis said the city’s communications plan of water conservation actions and impacts consists of apprising residents, businesses, community groups and more, and maintaining a Let’s Talk page as a primary resource for information along with regular social media postings, through its MI Weekly email newsletter and more.

For more information, visit the city’s Let’s Talk page at: https://letstalk.mercergov.org/water-conservation-guidance