Wasilla reservoir tank shut down

WASILLA -- Half of the city of Wasilla's reservoir system is shut down and empty due to structural problems in a one million gallon tank, according to city director of public works Don Shiesl, who delivered the bad news to the city council at its meeting Monday.

"We consider this a very serious issue, and we may have to come back to the council for supplemental funding," Shiesl told the council. "This is an indication of how important the new Bumpus reservoir project is to the city," he said.

The city has funded and designed wells and a reservoir at the Bumpus Ballfields property. Test wells have been drilled at the site, and the reservoir tank itself will be built and ready to be filled with water in the fall of 2003.

Currently, Wasilla's water works uses two reservoir tanks that hold one million gallons each. One is north of Iditarod Elementary school, the other is off Spruce Avenue. The Iditarod tank recently failed a routine inspection and was emptied. The tanks provide storage capacity and pressure for the system. High water pressure is particularly important at fire hydrants, but Shiesl said the system is designed to deliver enough water pressure even with one tank.

"There won't be any pressure problems, there will just be reserve capacity problems," Shiesl said. "We over-build water supplies for this reason."

Shiesl who said the inspection showed that structural steel beams holding up the roof of the tank were twisted. The tank isn't in danger of leaking or collapsing, but its roof might be.

"It's an uninsulated tank so the ice builds up, and apparently that's what caused the problem," Shiesl said.

Public works currently has a consultant working out a plan to repair the Iditarod tank, according to Shiesl. Although he doesn't know what the repair job will cost yet, Shiesl said the administration will likely use emergency procurement procedures to fund the repairs and then go to the council for approval.

The Iditarod and Spruce Avenue tanks were both built in 1980. Shiesl said the tanks are plumbed in series and water travels from the Spruce Avenue tank to the Iditarod tank. Even the pumps that fill the system are over-built, according to information from Shiesl and public works engineer Archie Giddings. The Spruce Avenue tank is normally filled at about 975 gallons per minute, but a second back-up well has a pumping capacity of 250 gallons per minute, according to Giddings. The two wells can be pumped simultaneously in an emergency, according to Giddings who also said a third well at Iditapark can add another 250 gallons of per minute.

The plan for a reservoir at Bumpus Ballfields includes a 2 million gallon tank which will double the city's capacity when it is filled next year. The Bumpus Ballfields are located on a 120-acre city-owned parcel. That gives the city room to drill more wells and build more reservoir tanks at the site in the future.

"Eventually, there could be as many as three or four there," Shiesl said.