COUNTRY HOMES BOULEVARD RESTORATION PROJECT
Construction of Spokane County Stormwater Utility's Country Homes Boulevard Restoration Project is underway. In order to prevent future disruptions to property owners and travelers along the corridor, Spokane County Utilities Division proposed construction of the Marian Hay Pump Station to City of Spokane Force Main Project at the same time. The proposal made sense, thus there is an added dimension to the project to take onto consideration. Completion should be no later than November 2014.
The Country Homes Boulevard Restoration Project is a water-quality project that involves removal of the existing asphalt channel and replacing it with a subsurface pipe to carry flood flows, with a rain garden/bio-infiltration swale running the entire length of the nearly one mile drainage channel. The end result will allow for more natural and local infiltration of stormwater, rather than displacing it farther downstream as the existing channel does now. It will also provide an esthetically pleasing corridor for those who live and travel along the channel.
The channel was originally designed at a time when less was known about the need for treatment of stormwater that finds its way to our rivers, streams and/or the aquifer. The new facility will contain a variety of plant materials, including native grasses and trees, along with organic rich topsoil that will provide natural treatment of stormwater runoff, to reduce pollutants before the water reaches these natural resources.
The Stormwater Utility portion of the project is funded through Washington State Department of Ecology grants and matching funds from local Stormwater Fees.
The Marian Hay Pump Station to City of Spokane Force Main Project involves installation of a 24" force main on the west side of Country Homes Boulevard. That portion of the project is funded by the Division of Utilities sewer construction fund.
What does CHBRP Mean?
CHBRP is an acronym that stands for Country Homes Boulevard Restoration Project.
Throughout this County website, you will notice that references to the project will frequently involve the abbreviated form of the title, or CHBRP.
Why build the CHBRP
- Spokane County’s NPDES Phase II permit, a permit required by the EPA and administered by the Washington State Department of Ecology, states that the County must provide water quality retrofit facilities in an effort to treat polluted stormwater before it reaches a surface water body or drinking water source.
- The Country Homes Boulevard channel is the main conduit for transporting stormwater runoff within the Five Mile Watershed to the Price and Wall Regional Stormwater facility. While Price and Wall is a water quality treatment facility, it does not have the capacity to treat all of the potential stormwater pollutants that reach the facility via the channel.
- Almost all of the pollution-generating impervious surfaces (i.e., roads, sidewalks, roofs, and driveways) that stormwater runoff flows across (starting from the Prairie on down to the channel) is currently lacking any stormwater pre-treatment.
- There is a great deal of stormwater runoff that seeps through the channel’s cracks and fissures, in lieu of reaching the Price and Wall facility where it can be treated.
- By restoring the Country Homes Boulevard channel, we approach meeting the treatment requirements of today’s water quality standards.
Why can’t the Stormwater Utility just seal the cracks in the channel? Isn’t that enough to keep the weeds from growing?
No. Sealing cracks is not a solution, as it will not prevent weeds from growing. Sediment will always be transported from the Austin Draw into the channel in its existing state. Seeds will embed and grow in the sediment no matter how often the County removes the material.
In addition, leaving the channel in its existing state means the stormwater that infiltrates through the asphalt cracks remains untreated.
Who’s financing the CBBRP?
Spokane County applied for and received two Washington State Department of Ecology Stormwater Retrofit grants totaling $1.75 million.
These grants are a 75/25 match, meaning that one quarter (25%) of the project’s total cost must be covered by Spokane County, with the other three quarters (75%) provided by Ecology.
The Spokane County Stormwater Utility will fund its portion of project design and construction costs with fees collected from residents within the North Spokane Stormwater Service Area.
What are the project limits?
The Country Homes Boulevard Restoration Project will begin at the Excell Avenue intersection, and extend just north of Carolina Way to, and include a portion of, the Vern Ziegler ditch.
The CHBRP will not involve replacing or increasing the number and width of traffic lanes. The County Traffic Engineer may elect to slightly narrow existing traffic lane widths in order to re-stripe existing parking and add new bicycle lanes along the Boulevard.
What is the projected timeline for construction?
The project started on May 27, 2014. Completion should be no later than November 2014.
Will Country Homes Boulevard be closed to through traffic during construction? If so, how will it affect homeowners who live on Country Homes Boulevard?
A portion of Country Homes Boulevard will be closed as necessary to facilitate the work. Every effort will be made to provide satisfactory access to residents.
What is the County's plan for the bridge crossings?
The bridges will be demolished and replaced with new crossings in the exact same locations.
What about the project construction creating noise pollution
Yes, there will noise during demolition of the asphalt channel and subsequent grading. However, this noise will be limited to the duration of project construction.
Additionally, studies show that, on roads with speeds less than 40 mph, a 20- to 50-foot-wide vegetated centerline buffer can actually help to reduce road noise. So, post-construction, Country Homes Boulevard residents should observe a slight reduction in traffic noise levels.
People drive way too fast on Country Homes Boulevard. Will this project make it worse
Studies show that vegetated medians have a calming effect on traffic, encouraging slower speeds as the landscaping helps to visually narrow the driving lane. In other words, the plantings and trees interrupt motorists’ views further down the street, rather than being able to see an endless length of pavement a long distance ahead.
Research also indicates that the inclusion of trees and other streetscape features along boulevards may actually reduce crashes and injuries on urban roadways. In fact, accident rates on urban, tree-lined streets were reduced by 61% when compared to similar streets without landscaping and trees.
What regulatory permitting processes affect construction of the CHBRP?
- National Pollutant Discharge Elimination System Permit. The National Pollution Discharge Elimination System (NPDES) Permit was written and enacted in order to address polluted, non-point stormwater runoff. The Permit dictates that Spokane County programs and practices must be created for all new development, ensuring that stormwater runoff is being captured and treated in order to protect groundwater and surface waterbodies from further degradation.
- Conditional Letter of Map Revision (CLOMR). This conditional permit/certificate, issued by FEMA, is required due to the project being located within a designated floodplain. New hydrology for the area and hydraulic calculations for design of the system, along with resultant changes to the FIRM maps and floodplain elevations were submitted to FEMA in May 2012. The CLOMR was approved in May 2013.
- Letter of Map Revision (LOMR). Once the project is fully constructed, the CLOMR process will be repeated, and a final LOMR will be issued.
- Joint Aquatic Permit Application (JARPA). A JARPA is planned to be submitted by mid-September 2013. Multiple regulatory agencies (U.S. Army Corps of Engineers, Washington State Department of Ecology, Washington State Fish and Wildlife, etc.) joined forces to develop this application in order to streamline the environmental permitting process.
- State Environmental Policy Act (SEPA). Prior to submittal of the JARPA, a SEPA checklist was required and sent to affected property owners, the Spokane Tribes, and the Washington State Department of Archaeology and Historic Preservation. The County received a Determination of Non-Significance for the proposed project.
- Habitat Management Plan (HMP). The HMP is referred to throughout the JARPA in order to demonstrate that all aspects of potential impact to the environment have been investigated and analyzed, and will be accounted for prior to and during project construction.
How does the new bio-infiltration swale and subsurface pipe work
The new system is a combination landscaped bio-infiltration swale for treatment of stormwater runoff and a subsurface pipe to carry flow from Five Mile Prairie, flood flows, and groundwater.
Runoff from Country Homes Boulevard, and the neighboring side-streets, driveways, and sidewalks will either sheet flow into the new swale area and slowly infiltrate through the bio-engineered treatment soil or, in places where side-street runoff is currently hard-piped into the existing asphalt channel, will now be hard-piped to the swale onto an energy dissipater.
Stormwater that is carried in the subsurface pipe will still outfall at the same termination point that it does in its pre-construction condition: the Price and Wall Regional Stormwater Facility.
We’ve had occasional flash flooding problems these past few spring seasons. I’m concerned the swale won’t be able to handle heavy rainfall in the same capacity that the existing asphalt channel does.
During large storm events, when the soil is saturated and the stormwater cannot infiltrate fast enough to keep up with the rate of precipitation, water will pond up and spill over into structures in the swale that are directly connected to the subsurface pipe. The subsurface pipe is sized to carry the 100-year storm but, in most sections of the pipe, can also carry the 500-year storm.
Will standing water in the bio-infiltration swale attract mosquitoes?
No. Mosquitoes need stagnant water to breed. While the engineered topsoil is designed to infiltrate slowly for pollutant removal, stormwater runoff should not pond in the swales for longer than 72 hours.
How will the bio-infiltration swale handle snow?
Vehicle-rated pullouts will be sited alongside each overflow structure for facility cleaning, access for mowing and weeding, and for the placement of snow in winter months. There will also be a 2-foot gravel shoulder before the planting area in the channel begins, also for snowpack storage.
Additionally, plant selection will involve materials that are salt, sand, and ice tolerant.
What are your plans for the irrigation system?
Due to the height and density of the plant material, and the desire to be good stewards of the aquifer, a subsurface drip system is proposed for a high level of watering efficiency. Weather sensors will automatically make adjustments based upon on-site conditions. Other sensors can detect leaks, send alerts, and shut down the parts of the system that are leaking, all while continuing to irrigate elsewhere.
Who will be responsible for maintaining the project landscaping post-construction?
The residents within the North Spokane Stormwater Service Area are levied stormwater fees on their bi-yearly property tax bill. The Stormwater Utility will use current and future fees to maintain the CHBRP landscaping.
Weeds are currently a huge nuisance in the channel. How will the CHBRP fix this problem?
Stormwater Utility will contract landscape professionals to provide maintenance for the completed project. The first few years, extra weed abatement will be required until the closely-spaced plants grow in and around each other. At that point, the plantings will naturally block out the weeds. The facility will also have bark mulch to help prevent weed growth.
As the native grasses and trees grow, won’t that impair visibility at the intersections / crossings along Country Homes Boulevard?
Traffic studies do show that having a barricade of some kind, particularly grasses, shrubs, and trees, may decrease visibility across the median. However, the Stormwater Utility, in cooperation with the project landscape architect, will select appropriate plant material and account for overhang in order to facilitate safe vehicular sight distances at all Country Homes Boulevard intersections / crossings.
Will there be permanent signage placed at or near the project site?
No. The Stormwater Utility has decided not to build interpretive signs along the post-constructed bio-infiltration channel. There are no suitable places to put the signs that will allow passing traffic and pedestrians to safely view them.
If there are no plans for signage, how will you bring public awareness of the CHBRP to City and County residents who don’t get the newsletter or live in the Country Homes area?
The Stormwater Utility is proposing to hang banners along the existing light standards at each end of the project. These banners will meet the criteria for outreach and education, as required by the Washington State Department of Ecology.
Will the CHBRP entice wildlife to nest or live in the proposed bio-infiltration swale? Country Homes Boulevard is a very busy road and, as such, would be a dangerous place for the animals to be in addition to a vehicular hazard.
Deer, small animals, birds, coyote, moose, etc., are already frequently spotted in the area, including at the Price and Wall Regional Stormwater Facility and in the surrounding neighborhoods, due to the proximity to the vegetated hillside of the Five Mile bluff. The bluff provides important habitat for area wildlife.
It is highly unlikely that more animals will come to the project area, let alone live or nest in it permanently, as it is a very busy, noisy corridor that is simply not conducive to nesting species.
Note: Some of the statistics quoted in these FAQ’s can be found at http://depts.washington.edu/hhwb/Thm_SafeStreets.html
2013 FALL NEWSLETTER TO ADJACENT PROPERTY OWNERS
Click here for historical pictures of the channel and to see landscape renderings that will give you the concept of what the garden area will look like when construction is completed.
If you have technical questions about the project, contact Colleen Little, P.E., at 477-7241.