Restoration of Puget Sound River Deltas
This page is for summarizing on-wiki resources describing the restoration of Puget Sound River Deltas.
- Among the majority of Puget Sound deltas levee or dike setback or removal is the primary method of restoration.
- In industrialized systems like the Puyallup Delta and Duwamish Delta fill removal is the primary method of restoration.
- In the Deschutes Delta dam removal is the method of restoration.
Ongoing Projects (updated 7/6/2015)
- Skokomish Delta
- Skokomish Delta Restoration - a single page describes all phases. Phase three involves breaches to a utility access causeway. Work will be substantively complete in 2015.
- Snohomish Delta - the Snohomish Sustainable Lands Strategy provides a venue for working on delta restoration issues. The Snohomish Lead Entity has a technical workgroup focused on coordination of delta restoration effort.
- Qwuloolt Restoration - setback levee construction is underway. First tides anticipated in 2016
- Smith Island Restoration - Setback levee construction anticipated in 2015, with first tides in 2016 pending resolution of a funding shortfall.
- Mid-spencer Island Restoration - additional dike removal aims to be coordinated with Smith Island mobilization.
- Diking District Six Restoration - is a potential project has some design complete.
- North Ebey Island Restoration - is a potential action that might benefit diking district maintenance.
- Stillaguamish Delta
- Skagit Delta - The Farm, Fish and Flood Initiative is a local team working on Skagit Restoration issues.
- Fir Island Farm Restoration - Setback levee construction underway, with first tide anticipated in 2016.
- Nooksack Delta
- Dungeness Delta
- Three Crabs Restoration - reconstruction of Meadowbrook Creek floodplain and nearshore anticipated in 2016.
- Nisqually Delta - Nisqually Refuge Restoration and Red Salmon Slough Restoration are being monitored. Nisqually Delta Distributary Restoration Pre-design aims to evaluate options for increasing sedimentparticles of clay, silt, sand, gravel, or cobble, transported by water, are called sediment. routing to restored delta plain.
- Quilcene Delta - a number of less well documented projects are complete, with the Removal of the South Big Quilcene Levee in feasibility.
- Skokomish Delta - Skokomish Delta Restoration describes three phases of work, with two phases restoring over 300 acres of estuarine floodplain.
- Skagit Delta - Wiley Slough Restoration, Deepwater Slough Restoration, Fisher Slough Restoration, and Milltown Island Restoration have been largely completed. Evaluating salmon rearing limitations in river deltas is looking at system scale patterns of fish use affected by restoration in the Skagit.
- Snohomish Delta - Marysville Mitigation Site, Union Slough Restoration, and Spencer Island Restoration are largely complete. Evaluating salmon rearing limitations in river deltas is looking at system scale patterns of fish use affected by restoration in the Skagit.
Planning and Analysis
- Many watershed chapters of the Puget Sound Salmon Recovery Plan identify delta restoration as a limiting factor for the recovery of populations.
- Simenstad et al 2011 describes the historical condition of Puget Sound River Deltas compared to current conditions.
- Fresh et al 2011 identifies loss of delta wetlands as a significant change in Puget Sound Ecosystems.
- Cereghino et al 2012 proposes a summary analysis of 16 Puget Sound river deltas, and how their historical potential and current degradation might affect how we think about restoraiton of ecosystem processes in those systems.
- File:Greene & Beamer 2005 skagit delta recovery plan analysis.pdf provides some evidence of chinook rearing dependance on delta wetlands, which is being extended in an effort measuring the density dependance and spatial pattern of juvenile salmon rearing in Snohomish and Skagit deltas.
- Similar work is underway associated with monitoring following the Nisqually Refuge Restoration.
- ESRP and NOAA RCNW are collaborating on a River Delta Adaptive Management Strategy to support the systematic management of risk and project development that support whole river delta ecosystem restoration and resilience through management of a sequence of river delta capital projects.
Funding and Implementation
Funding for a large Puget Sound Delta Restoration action typically requires mulitple funding sources to support feasibility, design, construction and evaluation of project work.
- Estuary and Salmon Restoration Program (ESRP) distributes state capital funds, and
- Puget Sound Aquisition and Restoration program funds projects defined by the Lead Entity system, and in addition identifies and funds large capital projects including large river delta restoration.
- Salmon Recovery Funding Board (SRFB) distributes state appropriations that match federal funds from the Pacific Coast Salmon Recovery Fund.
Objectives and Status
- Individual salmon recovery plans may have set quantitative goals for river delta restoration.
- As part of the Puget Sound Vital Signs effort, the Puget Sound Partnership has set an estuary restoration goal, both to restore a proportion of total historical delta wetlands, and to meet salmon recovery objectives.
- See the pages for individual River Delta sites to find out more information about goals and status for specific systems.