Ridgetop stormwater project keeps flowing
January 8, 2010 · 4:25 PM
Before Silverdale began its rapid development, the hill between Ridgetop Boulevard NW and Silverdale Way NW consisted of a towering forest and a wetland at its base to absorb the constant Pacific Northwest rainfall.
But as new homes were built along the ridge, and farmers at the bottom of the hill dumped new sediment into the wetland, stormwater began rushing down the slope in larger volumes, polluting the water in Clear Creek and eroding the stream bank.
With a new $900,000 project, set to begin in summer and finish in October, Kitsap County hopes to recreate the original wetland, located along Silverdale Way, which once kept the stormwater in check.
Heavy equipment will be used to dig out the fill in an effort to return the area to its original state.
“We are trying to restore the natural flow,” said David Tucker, associate director for Kitsap County Public Works.
A stormwater pond was originally built up the hill in the mid-1980s, Tucker said. Over time, it became clear the pond was not large enough to retain all the stormwater that flowed down the hill, as evident by major flood damage to the creek and along Silverdale Way from a snow storm in 1997.
Though the county expanded the pond by about 50 percent, it was clear more wetland area was needed, Tucker said.
The project is essentially an excavation project, he said. The county plans to remove the dirt and other ingredients in the soil around the wetland, which was actively farmed until the 1980s.
Jon Brand, an engineer with the county, said new vegetation will also be planted around the wetland to held suck up the water, filter pollutants and slow the flow.
A stormwater facility already exists higher up on the hill to reduce potential pollutants from residential septic systems.
The dirt road that goes through the property will also be replaced by a pervious surface, which will allow water to flow naturally through the road into the soils and will reduce the amount of sediment.
It will also create an extension of the Clear Creek Trail from Silverdale Way to Ridge top.
Tex Lewis, chairman for the Clear Creek Task Force, said the project has been on his radar for more than five years.
“There is quite the population center there on Ridgetop and we figure people would love to take a bike path all the way to Bangor,” he said.
The county received a $318,000 grant for the project from the state Department of Ecology. It also bought two acres at the bottom of hill around the wetland area in December 2004 with funds from the county’s surface and stormwater management funds and real estate excise tax.
The $900,000 must be spent by July 2011.