On July 6, 2021 City Council approved a construction contract with Northbank Civil and Marine, Inc. (R-2021-092) for the Nelson Dam Removal, Water Supply, Riverine Process and Fish Passage Improvements project.
This Agreement with HDR Engineering is for construction services and minor adjustments to previous tasks is necessary for the management of the construction of Nelson Dam Removal, Water Supply, Riverine Process and Fish Passage Improvements project Phase I and Phase II.
Nelson Dam is located just upstream of the twin bridges on SR 12 where the City diverts water for irrigation. It was damaged during the 1996 and 2011 floods and is nearing the end of its life expectancy. The project will replace the existing Nelson Dam and the connected fish by-pass roughened channel structure. This work will reduce flood risk and flood risk maintenance. Improve fish habitat conditions, particularly for Endangered Species Act listed Steelhead and Bull Trout, by improving the natural physical processes of the river.
The project consists of:
- Demolition of existing site floodplain and channel structures
- Demolition of the existing Nelson Dam
Construction of a new two acre Nelson Dam
roughened channel by-pass and upstream weir
- New fish screen and Piping
- Excavation of 2,500 feet of floodplain dam approach channels
- Placement of a road protection structure
HDR Engineering was previously awarded the contract to provide the engineering design, bidding, and construction services for the Nelson Dam Nelson Dam Removal, Water Supply, Riverine Process and Fish Passage Improvements project (R-2019-055). The design and permitting process took approximately 18 months.
Construction began on July 12, 2021. The design amendments and construction management is not to exceed $1,665,000 Yakima County has assigned one of their construction inspectors to the project for daily inspection. This cost was included in the Nelson Dam Nelson Dam Removal, Water Supply, Riverine Process and Fish Passage Improvements project’s financing plan.
The terms of the Agreement for Design amendments and Construction Management shall be in an amount not to exceed $1,665,000 and has been attached for City Council review.