Persistence was mission critical for a committed team during the 12-year project to transform the 85-year old Leber Homestead in Kent into a place that protects both young salmon and people. The team worked to create a naturalized side channel that can store flood waters and let young salmon take a break from the current in the Green River.
Once prevalent in the Green River valley, off-channel wetland habitat for juvenile salmon is now extremely scarce and one of the most limiting factors for salmon survival. This type of habitat lets salmon find food and refuge away from the main stem of the river during floods. “Rest stops” are especially important during spring when young salmon are traveling to the ocean. Salmon fry that use off-channel habitat grow twice as large and have marine survival rates that are ten times higher than fry that migrate directly to Puget Sound.
Photo courtesy of City of Kent
The project benefits people as well as salmon. The new side channel provides over 16 million gallons of additional flood storage, according to Matthew Knox, Environmental Ecologist for the City of Kent.
“This storage increase helps decrease the potential impacts from floods that affect property and roadways in surrounding agricultural and urban areas,” says Knox.
Courtesy City of Kent
Knox describes the challenge faced by the City of Kent to increase safety for salmon and people.
“During the last century, the Green River has been re-plumbed, dammed and leveed, leaving the floodplain over 20 feet higher than the average water level,” says Knox. “Reconnecting this perched floodplain with the current river is difficult and expensive, but also crucial for salmon recovery.”
Accomplishing this feat meant major effort in property acquisition, design, permitting, procurement, and construction. Funding constaints meant the team couldn’t move continuously through each phase of the project. After completing each step, the team had to stop project work, roll up their sleeves and find funds for the next step.
“Over 12-years of planning, property acquisition and fund-raising got us to the place where the Leber project could be constructed,” says Knox.
Finally, on October 6, 2016, a public gathering at the former Leber Homestead celebrated a natural area that will protect young salmon and people. Kent Mayor Suzette Cook gathered sponsors, designers, and builders and around her for to memorialize their efforts in a team photo. Sue Leber, a remaining member of the original homestead family, joined them.
As part of the team, King County Wastewater Treatment Division (WTD) celebrated a milestone as well: completion of the first project to receive WaterWorks Grant Program funds. The fund comes from the Council’s appropriation of up to 1.5 percent of WTD’s operating budget for projects that demonstrate an improvement in water quality in the WTD service area and also benefit its ratepayers.
WaterWorks provided needed funding when the project team discovered arsenic-contaminated soil on the site just prior to construction.
The discovery introduced unexpected expense and potential delay. While arsenic occurs naturally in soil, high levels of arsenic are associated with emissions from metal smelters or pesticide use in orchards. Arsenic is one of the top chemicals of concern to fish, people, and Puget Sound. At the Leber Homestead site, arsenic could hurt the young salmon the project was meant to help.
WTD’s WaterWorks Grant Program filled a critical funding gap in time to let the project continue. A WaterWorks award of $100,000 supported work to address about 8,000 cubic yards of contaminated soil. Over 6,000 cubic yards were hauled away to an approved disposal facility and another 2,000 cubic yards were mixed in with cleaner soil, reducing arsenic to safe levels.
Creating a refuge for young salmon meant remvoing 90,000 cubic yards of soil, enough to fill 3600 dump trucks. Photo courtesy City of Kent
Photo courtesy of City of Kent
Says Knox, “The King County WaterWorks grant provided the City with much-needed funding to clean up the arsenic contaminated topsoil on the site. The grant guaranteed that the city could afford this essential piece of the project.”
“This project is a great example of what WaterWorks can do for water quality,” says Elizabeth Loudon, WTD’s Grant Administrator. “Removing those contaminated soils means that arsenic won’t impact salmon and other wildlife that use this site, and the cleanup prevents downriver pollution.”
Numerous partners including WRIA 9, King County, the Salmon Recovery Funding Board, the Puget Sound Acquisition and Restoration fund, King Conservation District, and the Muckleshoot Indian Tribe Fisheries Division helped meet the planning, coordinating and funding challenges of this project.
“There have been a lot of sponsors, City of Kent staff, and agency and elected officials working very hard for a very long time to make this project happen,” says Doug Osterman, King County’s Green/Duwamish (WRIA 9) Watershed Coordinator.
“The WaterWorks award made sure that this channel was ready to welcome salmon when the rivers rose this winter”.