City of Spokane adds stormwater work to Havana Street project
Permeable bike lanes, swales part of projectJanuary 15th, 2015
The city of Spokane is using its project to replace a water main under Havana Street in the Southgate neighborhood as part of a pilot program to test new stormwater mitigation techniques, including installing porous asphalt bike lanes, says city spokeswoman Marlene Feist.
The city currently is handling the design on the project, which is estimated at $3.7 million, Feist says. It hasn’t been sent out to bid yet, but Feist says construction could begin in the spring and should be completed in the fall.
The project, which will replace a 36-inch water main running under the street from 37th Avenue to Glenrose Road and from Glenrose Road to the reservoirs at 57th Avenue, also will include some trees and landscaping, in addition to the bike lanes and side swales, says Feist.
“The South Hill is where we have those combined sewers, so we’re trying to find ways to deal with the water on-site, instead of sending it to combined sewers,” she says. “There have been a number of projects where we’ve used bio-swale type stuff. This time, we’re going to try the porous asphalt (bike lanes) so we don’t have to keep widening the street to get all these components in.”
Porous asphalt, Feist says, will allow rainwater and snowmelt to soak through to the ground, which will help eliminate runoff.
“We’ll put certain kinds of gravels and soils underneath, so it acts as a treatment system,” she says. “We also are going to put some swales in as well because we haven’t tried the porous bike lanes before.”
The design for the project includes sidewalks, but has less curbing than usual so that water can run into the swales if it doesn’t get soaked through the porous asphalt, Feist says. The project also will include some pavement rehabilitation, she says.
Part of the project will extend into Spokane County, Feist says.
“We’re going to work with the county to complete the road,” she says.
The project is part of the Spokane Streets levy, which turned the city’s former street rehabilitation bond into a 20-year property tax levy, which voters passed last November. The work will be paid for by a combination of levy funds, city water funds, and some Drinking Water State Revolving Fund dollars.
Julie Happy, another city spokeswoman, says that coinciding with the Havana Street project will be a new 12-foot-wide paved bike trail along 44th Avenue, from Freya Street to Havana Street. Along with the trail, a redundant water main will be placed, which will provide water for the area while the water main under Havana Street is being replaced.