Low-flow spring spared Community Covenant Church
Editor’s note: Article updated on 7/31/19 to reflect Allan Bisnett’s correct position with Community Covenant Church. He is not the pastor, he is council treasurer.
Twisp leaders asked the federal government to help them protect the town from erosion along the Methow River, which is threatening buildings and a sewer line on the north end of town.
The extent of the threat was spelled out in a June 26 letter Mayor Soo Ing-Moody sent to the U.S. Army Corps of Engineers’ Seattle office. The west bank of the river had eroded 83 feet over the past 10 years and was within 40 feet of a structure on the Community Covenant Church property.
“Other homes are also within 200 feet of the eroded riverbank,” the letter said.
The letter emphasized a sewer line, near the church and about 300 feet west of the bank. “If the riverbank erosion were to be allowed to expose the sewer main, a catastrophic release of untreated raw sewage would be discharged into the Methow River,” the letter said.
Mentioning the sewer line to the Army Corps was essential. The agency is authorized to protect public infrastructure but cannot directly assist with protecting private properties.
Corps spokesman William Dowell acknowledged on Monday (July 22) that the agency had received Ing-Moody’s letter. Before the corps can help Twisp with its erosion problem, the project will need to get approval and funding first, Dowell said in an email.
“At this point, it is too early to provide any status,” he wrote.
The corps is already helping Twisp develop a flood contingency plan that would include possible responses to erosion at the north end of town and other river-related problems, Dowell wrote.
If the corps does agree to work directly on the erosion problem, the first step will be a study: What can be done to prevent the river from migrating to the west? The study would need to consider impacts to salmon that any construction in the river would bring. The cost of the study would be shared evenly by the town and the federal government.
Channel migration occurs naturally in rivers that flow along a flat valley floor and experience relatively high peak flows during spring snowmelt. The Methow’s migration was especially severe in 2017 and 2018. Unusually high flows those two springs caused nearly half of the 83 feet of erosion since 2009.
Scientists say an Okanogan County levee may be accelerating the erosion at the north end of town. The levee was built in the 1940s, about 2 miles north of Twisp, to protect Highway 20.
Last year, Community Covenant Church council treasurer Allan Bisnett had been concerned that one more spring of significant erosion would destroy a gazebo on church grounds that sat about 25 feet from the river’s edge.
However, the church got a reprieve. Runoff this past spring was only half of the average flow for that time of year, and the bank didn’t move at all, Bisnett said.
The town’s Parks and Recreation Commission is working under new deadline pressure. Twisp received word in April from the state Recreation and Conservation Office (RCO) that the town must update its Trail and Recreation Plan by March 1, 2020, to remain eligible for RCO grants.
The RCO has funded the Twisp Trail along the Methow River, connecting Twisp Park to Methow Street, and the sports complex planned for the ballfield south of Twisp Airport.
The Twisp Trail and Recreation Plan was on the agenda for the Parks and Recreation Commission’s June meeting. When available, the commission’s agendas are posted at townoftwisp.com under “Town Notices and Agendas.”
If Old Schoolhouse’s new brewery at TwispWorks hadn’t installed expensive pretreatment equipment for its wastewater, the discharge would have been more than the town’s treatment plant could handle. Clearly, it wouldn’t take much growth in town — particularly industrial growth — for the wastewater plant to be over capacity.
The state Department of Ecology is helping Twisp improve and expand its wastewater treatment facilities. The agency announced on June 28 that the town will receive a $112,810 low-interest loan that will be spent on an engineering report for plant upgrades. The town will not need to repay half this principal amount.
The report will account for both industrial and residential growth, Denham said.
The treatment plant and its staff have proven themselves to be up to the task of handling whatever has come its way in recent years. Ecology also announced on June 28 that Twisp received its third consecutive Wastewater Treatment Plant Outstanding Performance award, for 2018. The town’s treatment plant was one out of 109 to earn this distinction, among some 300 statewide.
Twisp met all the requirements of the plant’s National Pollutant Discharge Elimination System (NPDES) permit, including effluent limits, monitoring and reporting requirements, and spill prevention planning.