Skokomish Valley Updates
Seth Book, Skokomish Tribe environmental biologist – Water Quality
Overview of the Tribe’s projects:
We do work all over the Hood Canal region.
This year, we had a few fish kills this summer, plus a dead zone in lower Hood Canal, near Lynch Cove. Finding zero dissolved oxygen in this area. We’ve seen this before, in 2007, where there is nothing able to live in that area for a period of time. Our fish kills haven’t been as big as in the past but it’s a big concern for us.
Shellfish bed harvest closures because of water quality issues.
Skokomish is legendary for flooding in the fall. But the past few years have not had floods reach the tribal center, so that’s a good thing.
Water quality assessments – look at more than 21 freshwater sites and assess, plus 9 well sites. Expanded lab to include organics analysis, as well as nutrients analysis as before.
The program has been monitoring water quality since 1995. Main constituents are water quality parameters. We work under EPA guidelines.
Surface monitoring locations include at gages on South Fork and North Fork of the Skokomish River, at the tribe’s hatchery on Enitai Creek, as well as out in the estuary.
Groundwater monitoring at nine wells, mostly accessed from Skokomish River Road.
There is a potential model with USGS PUD1 MCD, Skok and Squaxin island tribes and stakeholders to figure out how much water there is in these aquifers so we can better understand how much water we have in the future and how it would impact groundwater and the local hatchery operations.
Work funded by EPA grants: General Assistance Program, the 106 Clean Water Act and the 319 non point source pollution.
Bacteria dominated because of shellfish impacts. Fecal coliform and ecoli are causing closures. Nutrients can be an issue. We had large macro algae blooms in estuary; sea lettuce species that grew in big thick mats smothered shellfish beds. Plus the dead zones.
Flooding – the septic systems aren’t working and so when flooding, don’t touch the water.
We are doing additional studies, but we need to pinpoint the places to correct them. Cattle, septic, recreational, all the different impacts – we have to keep up on. it shows we need to continue to work together.
Florian Lesichner, Tacoma Power: Skok River Channel Monitoring
Skok valley is most frequently flooded valley in West Washington.
Why does it flood? When water exceeds bank channel, and out of flood plain, that’s when flooding happens.
Rivers should only flood about 1-1.5 years. For the Skok, it needs to be at 14,000 cfs to flood.
Army Corps of Engineers is studying the history of the river’s flooding, figuring out what could have contributed to this increase over the decades.
Part of new dam re-licensing agreement for Lake Cushman – large pulses of water are released to help push sediment down river, as dams have prevented natural flow of sediment in river system. Monitoring 11 sites for this effort.
North Fork – so far – not much happening. very stable.
South Fork – very dynamic.
Mainstem – has been somewhat stable.
Flows above about 4,000 CFS starts to flood landowners in the valley.
Flood damage reduction and mitigation plan is due early 2017.
Rich Geiger – Mason County Conservation District: What projects are ongoing and what projects are slated for the near future
In 1930s, state and county started working on flooding projects in the area. Historically the focus has been on flooding and restoration, but they were seen as band-aid projects – the problem was not being corrected.
In 2003 – there was a dike breach and channel change in a single flood event. At this point, Army Corps of Engineers (ACOE) was brought in to (re) start the General Investigation process.
Recon Phase was from 1999-2000
Feasiblity Phase 2006-2015 – wrapping up now.
ACOE is now recommending to Congress several projects to take place, including setting back a levy and reconnect an old channel that was the mainstem one time.
Army Corps – not doing all the projects needed, as there has been a lot of local agencies doing work already. Floodplain reconnecting, new channel creation, channel and riparian restoration, etc.
For the Corps restoration projects, pending funding – design phase 2017-19; construction 2019-2021
Recommended plan features: engineered logjams (creating better habitat for salmon and help with sediment transport issues in this year); removal of levee at confluence of mainstream and north fork; work with landowners to move back an existing levee (will expand flood plain, lower flood levels, create side channels); wetland restoration at the valley’s Grange property (creating side channel)
There is so much sediment in the river channel that water actually goes underground during fish migration season.
Local restoration projects:
- Skokomish Estuary restoration –
- 2007 – removed a mile of dike west of Nalley Island, built elevated boardwalk
- phase 2 – removed more dikes around Nalley Island
- phase 3 – cut more channels, replacing undersized culverts with bridges on Tacoma Access and Skok Flats roads, reconnecting the tidal channels from estuary to the fresh water sources
- South Fork LWD – Holman Flats
- 2015 – harvesting wood to stockpile at Holman Flats (was a potential dam site in the 1950s for Tacoma but abandoned because of earthquake fault)
- in 2010, completed a LWD phase in SF. Natural, no anchoring, no cable connection, just interlinked.
- Results – all structures have remained in tact and gathered additional wood. Helped with channel reformation.
- on average, gravel bar heights increased 2.4 feet though project reach; max accumulation height on structure was 6.6 feet.
- South Fork Canyon Fish Passage Assessment
- just upstream from Holman Flats
- Location of High Steel Bridge
- Good news – some passages are pretty good.
- Collecting data to model flow through these falls and determine what fish can do, then figure out what could be done to help with fish passage
- Mainstem LWD – Design only (SRFB funding)
- Weaver Creek Realignment 2015 construction
- similar to a type of project you’ll see on the Skok
- located between Mainstem and purdy Creek.
- Creek is great shape up the valley – historically had a severe s-shape to it
- in the mid 1900s, oxbow was cut off and slightly straightened the river
- now river bed is so high, sediment has built up and in fact flows backwards into old channel; thus blocking off Weaver Creek
- Goal is to realign it to old channel shape.
- West Skok Valley Road
- also known as the Dips
- goal is to realign the road, reconnect river into an old channel, possibly move road toward the valley wall or above the valley
- Upper South Fork Assessment 2015 SRFB
- eight miles in length, from Church Creek to Brown Creek