Off-Channel Reservoir Report
Aug 22, 2023
Since last month’s brief status update, the county’s project manager of the Off-Channel Reservoir (Carol Creasey) has retired. She has been temporarily replaced by Stephen Gray, the Deputy Director of Clallam County Public Works. Mr. Gray and Anchor QEA manager David Rice gave an update to the Clallam County Commissioners on Monday, August 14th. I attended the meeting in person and a good number of persons attended via Zoom. Our (Kane Lane) neighbor, Paul Moore, has followed this project for several years and contributes information to the local community at the website https://riverroadreservoir.com . He has provided what I believe to be a thorough and accurate update below. I have added a diagram that shows general proximities of our location, the preliminary plan, and what we consider the preferred option (D).
Reservoir Update August, 2023
In a work session meeting on August 14, the Clallam County Commissioners were updated on the status of the Dungeness River Off-Channel project. The contract engineers (Anchor QEA) presented four alternatives to the current 30% design for the reservoir. Three of those alternatives are located in the same area as the current 30% plan, but with wider footprints and lower embankments (dams). The fourth alternative splits the reservoir into two pools on either side of the power lines towards the south end of the site.
The reasons given for the alternatives are being responsive to public comment, and a recent geotechnical survey that suggests a fault zone may cross the proposed reservoir site. These faults were first mapped in 2007, and are currently showing on a map of faults on the United States Geological Survey website. In their presentation, Anchor QEA emphasized the uncertainty of any fault, but said that further investigation is required before any further design work can continue. Further assessment may be made in stages, with possible trenching that would cost upwards of $800,000.
The engineers said that the Washington Department of Dam Safety may request an independent peer review by a qualified third party engineer of the reservoir design since designing and constructing an embankment across an active fault is not routine.
The three designs located in the same area as the 30% design have above-ground water heights ranging from approximately 11 to 20 feet on the north end (compared to over 30 feet for the current 30% design). Water heights for the two-pool alternative would be about 20 feet above ground for one of the pools, while water would be completely below ground level for second pool. The two-pool alternative moves the reservoir south, just outside of the suspected fault, and has the advantage of being constructed in stages if full funding is not available upfront.
Addressing the fault issue means increased cost estimates for any reservoir configuration. Those costs include confirmation, analysis and modeling of any faults, additional design work, and increased consultation with the Office of Dam Safety. The cost estimate for the 30% design has increased by about $4-8 million to address the faults.
All of the alternatives require more excavation compared to the 30% design, which also increases cost. The alternatives are estimated to cost an additional $2.4-5.7 million dollars compared to the 30% design. Cost estimates have more than doubled since 2016, headed toward $50 million. At the working group meeting, Commissioner Mark Ozias said that at some point a review of the cost/benefit analysis for the reservoir may be needed.
The Department of Natural Resources has not yet transferred land ownership to Clallam County, pending partly due to the question of cleaning up an old dump site on the property, south of the actual proposed reservoir. A $39 million grant application was submitted to FEMA for construction costs. Funding remains uncertain.
Submitted by Genie Mixson and Paul Moore