A $13.4 million proposal to address storm-water issues in three unincorporated areas of Spokane County is expected to come before the county commissioners soon for consideration.


The proposal is included in the countys first Comprehensive Storm Water Management Plan, a proposed six-year strategy drafted by county engineers to begin addressing storm-water issues for about 212 square miles of unincorporated land.


The county planning commission has recommended approval of the plan, but a date hasnt been set for the board of commissioners to take action on the proposal, says Brenda Sims, storm-water manager for the county.


If they approve it, storm-water projects called for in the plan likely would begin next year, she says.


The improvements would include development of eight- to-30-acre sites for sediment basins and infiltration ground for storm-water runoff projects in targeted Glenrose, West Plains, and North Spokane areas. Sims adds the countys storm-water engineering section has selected those three priority areas as the county begins to look at potential storm-water problems over the next 20 years, knowing the sediment basins and infiltration sites might have to be used for up to 50 years.


A sediment basin is a lined pond where water sits, allowing particles of dirt and other sediment to settle to the bottom, says Sims. After the sediment settles, the water from such a basin goes into an infiltration site where the earths geology allows the water to soak into the ground.


Sims says the estimated costs of the projects planned over the next six years at the three targeted areas, including the purchase price of the land, totals $13.4 million, with $5.9 million for the West Plains, $4.1 million for Glenrose, and $3.4 million for North Spokane. Included in those costs are water and groundwater studies, and the construction of grass-lined ditches.


An environmental analysis will be performed before the county buys land for the facilities, she says.


Although the county assessed an annual storm-water fee of $10 for single-family homes from 1993 through 2004, and spent about $2 million on capital improvements over that period of time, this is the first detailed plan to address storm-water problems outside the cities of Spokane County, says Sims.


In anticipation of the planned storm-water projects, the county commissioners raised storm-water fees and service charges effective Jan. 1, 2005, and those fees and charges, coupled with accumulated revenue since 1993, leave the countys storm-water utility section with about $5 million to begin such work.


To finance storm-water improvements beyond that initial $5 million, the proposal calls for the county to issue a series of revenue bonds that wouldnt require a vote of the people, Sims says. Those bonds would be repaid with money from the household fees, she says.


Because much of the storm water in the Spokane area, primarily caused by heavy rain and the melting of snow over frozen ground, doesnt run off in permanent streams but instead trickles away in seasonal drainages, the infiltration facilities Sims speaks of wouldnt involve treatment of water, but instead would be selected sites with sediment basins and areas where water overflows would percolate into the ground.


I think drainage can become a community amenity, she says, stressing the idea that the selected sites wouldnt have standing water most of the time, but instead would be covered with green foliage. She even suggests the possibility of a soccer field at a site.


The sites


Only the North Spokane site has been selected thus far, says Sims. She says the county owns eight acres of land with good infiltration capability at the northwest corner of Price Road and Wall Street, just north of the Spokane city limits. She suggests that site can be used to meet the North Spokane areas storm-water drainage needs.


Much of the storm water that would drain to that site would come off of Five Mile Prairie, Sims says.


Finding a 20- to 30-acre parcel of land with good infiltration potential on the West Plains, though, is more of a challenge because bedrock in many places there is so close to the surface, limiting the absorption of standing water into the ground, she says. Yet, she says, the county is looking at a potential site northwest of Spokane International Airport.


An initial proposed site for Glenrose, near the Palouse Highway and 57th Avenue on the South Hill, was bought by a private individual before the county could acquire it, and the new property owner has other plans for its use, says Sims. Therefore, the county is still looking for 20 to 30 acres of land with good infiltration characteristics there, she says.


Geologic and ground-water studies are key in deciding where to place infiltration sites, since an extensive series of grass-lined ditches also will have to be developed to divert storm water to those sites. The ditches will follow drainage patterns and be dug to utilize gravity flow, Sims says.