Dungeness Off-Channel Reservoir

Dungeness Flow Restoration & Aquifer Recharge Off-channel Reservoir Project


Brief Project Description: Low flow in the Dungeness River is a significant limiting factor for four ESA-listed species of Salmon and Steelhead. Low flows are primarily a seasonal challenge, occurring in the late summer and early fall. Around mid to late August, human needs for irrigation water peak, Chinook and Pink salmon return to spawn, the snowpack feeding the river is depleted, and the river drops to its lowest flow. In all but the wettest years with ample snowpack, these low flows are insufficient to meet the needs of salmon. 

The biggest and most senior established water rights in the basin belong to the Dungeness irrigators. For more than a century the Dungeness Valley has been irrigated with water directly from the Dungeness River. In the last 20 years, Dungeness irrigators and basin partners have invested considerable resources to conserve and enhance the flow of the River. However, in low snowpack years, there is still not enough flow in the river to support salmon and also meet out-of-stream water needs. 

The solution is an off-channel reservoir to store water during winter and spring when flows are plentiful, saving this water for later in the year when river flow is low. In addition to resulting in significantly higher low-flow levels, this is a multi-benefit project that will capture stormwater and prevent flooding in the City of Sequim, provide opportunities for aquifer recharge, create a new County park with river access and recreational opportunities, and ensure the sustainability of agriculture in the Dungeness Valley - all providing climate resiliency for people, farms, and fish.

Read the Dungeness Off-Channel Reservoir Factsheet for more information. 


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Dungeness Off-Channel Reservoir

Reservoir Size

42-Acre reservoir within a new 396-Acre County Park

Storage Capacity

Roughly 1600 acre-ft of storage capacity for use during the critical low-flow period of August 15th through September 15th (the last month of irrigation season) when flows before diversions are often less than 100 cubic feet per second.

Community Benefits

The climate-resilient nature of this project provides the following benefits:

  • Stream Flow Restoration for Salmonids The project will retain up to 25 cubic feet per second of flow in the Dungeness River by avoiding diversions, allowing the target flow-restoration goal of 105 cubic feet per second to be met, benefiting ESA-listed Salmon and Steelhead.
  • Long-Term Agricultural Viability Secure access to water for irrigation is critical to maintaining agriculture in the Dungeness Valley; this project will ensure that fish can thrive, and irrigation can continue without impacting flows.
  • Aquifer Recharge In years with adequate snowpack stored winter runoff can be used for aquifer recharge that will augment flows in small streams, replenish groundwater, and possibly generate mitigation credits for the Dungeness Water Exchange.
  • Stormwater Management The project will alleviate flooding on roads and properties in the County and City of Sequim by intercepting storm flows before they reach infrastructure and pollution-generating urban areas.
  • Recreation The project site is currently owned by the Department of Natural Resources and will be eventually owned and managed by Clallam County as a new public park with hiking, biking, wildlife viewing, and river access opportunities.

Dungeness Off-Channel Reservoir Overview Map image Opens in new window
Open the Dungeness Project Overview Map (PDF)

Status

  • Funds
    • Funding to date ($15.1 million): 
      • 2019 Ecology Streamflow Restoration Grant ($4,092,854) 
      • 2020 Ecology Streamflow Restoration Grant ($3,875,699) 
      • 2022 Ecology Streamflow Restoration Grant ($1,680,000) 
      • 2021 WA Conservation Commission Grant ($54,136) 
      • 2022 WA Conservation Commission Irrigation Efficiencies grant ($250,000) 
      • Bureau of Reclamation WaterSMART Grant ($2,417,700)
      • FY2023 Congressional Funding ($2,727,870)
    • Pending funding applications
      • 2022 FEMA Hazard Mitigation Assistance Grant ($29,986,688)
    • Funding search ongoing
  • Purchase of DNR land in process
  • Since the 30% design open house in December 2022, a LiDAR investigation revealed potential fault lines (lineaments) near the planned reservoir footprint. In order to ensure feasibility of design and location, a further seismic investigation is being conducted. In addition to this seismic investigation, the County has received feedback from residents concerned about the embankment height and amount of water above ground level in the 30% design. In response to these two factors, the 30% design is currently being revised, and current alternative designs can be viewed HERE (slides 16-28) 
  • Outreach-Meetings for the Dungeness Reservoir Partners, Clallam County Commissioners, community presentations, Preliminary Design Open House (December 6, 2022)
  • Funding search ongoing

Dungeness Reservoir Partners

  • Clallam County
  • City of Sequim
  • Clallam Conservation District
  • Dungeness Valley Water Users Association 
  • Jamestown S'Klallam Tribe
  • Washington Water Trust

Supporters include Washington Department of Fish and Wildlife and Washington Department of Natural Resources.

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