Press Release

Drained and detained Sunday, April1,2001 Everett Station underground vaults to tame storm water -by Kate Reardon Herald Writer

EVERETT- Construction crews lowered two large concrete vaults into a monstrous pit this week east of Broadway.

The water-collection vaults are so large they will be able to hold 341,110 gallons of water - or about 7,580 average size bathtub's full

It's probably the largest detention vault facility in Everett, said Dan Mathias, utilities engineer for the city.

The vaults will eventually be paved over for a parking lot at everett Station, a new $44 million transportation center on Pacific Avenue expected to open late this year.

Detention ponds and vaults store storm water to prevent flooding or erosion downstream. A number of detention ponds are a combination of flow control and treatment.

The Everett Station vaults, however, will control water flow through a 25-inch pipe to the city's storm-water and sewage collection system, which goes to the treatment plant on Smith Island north of Everett.

Storm water from a 17-acre area around the transportation center will drain into the vaults. Storm water flows in that part of town put stress on the city's system, Mathias said. So the new detention vaults should relieve some pressure.

The larger of the two vaults will hold 198,980 gallons of water and the smaller will hold 142,130 gallons. Average stay of water in the vault will be about half a day, Mathias said. But water could stay there longer if heavy rains hit, he said

The price tag to buy and install the larger vault is $239,500. The cost for the smaller vault is $170,000. There are about 200 storm-water detention facilities but only 10 are underground, Mathias said. The underground vaults are more expensive, but can be a better choice when land for a project is in demand.

The Boeing Co. in Everett has the largest storm-water detention facility, a three-acre pond that holds 15 million gallons of water. Boening's pond was built more than 30 years ago and was the first in the area, Mathias said.

The city started requiring detention facilities in 1978.

copyright 2001 The Daily Herald Co., Everett, Wa.

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