Purpose of Detailed Summary

• Organize Level I data to accommodate four study-area planning approach
• Translate/interpret data into planning considerations

Document Structure

• Introduction
• General Concepts and Basin-Wide/WRIA-Wide Findings
• Study Area 1 - Subbasins that Drain Directly to Grays Harbor
• Study Area 2 - Lower Chehalis Subbasins
• Study Area 3 - Middle Chehalis Subbasins
• Study Area 4 - Upper Chehalis Subbasins

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• Study Area 1 Grays Harbor Tributaries
• Study Area 2 Lower Chehalis Subbasins
• Study Area 3 Middle Chehalis Subbasins
• Study Area 4 Upper Chehalis Subbasins

Basin-Wide Geology Primer

• Bedrock: Usually in mountains and hills; typically poor groundwater source
• Glacial sediments: Mostly in valleys, sometimes in upland areas; can be good groundwater source; hydraulic continuity may be an issue
• Alluvial sediments: Always in valleys; usually good groundwater source; hydraulic
• continuity is issue

Basin-Wide Habitat Data

• Low LWD
• Bank erosion
• Excessive In-stream sediments
• Stream canopy reduced
• Beaver dams
• Bank rip-rap, artificial protection or dumping
• Log jams (potential fish barriers)
• Livestock access to streams
• Streamside vegetation loss
• Miscellaneous pollutant source:
• Debris torrent Inputs
• Warm summer stream temperatures
• Low DO
• Fish passage barriers at culverts
• Bank destruction by livestock

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Study Area 1 Grays Harbor Tributaries

Geology/Hydrogeology

Hydrology

• Olympic Mountain streams produce a lot of runoff
• Data gap - flow data (lack of gages and tidal influence)

Water Rights/Water Use

• Four large water rights warrant investigation:
• Wishkah River: 22.94 cfs
• Main Stem Hoquiam: 60.17 cfs
• Humptulips: 86.55 cfs (City of Ocean Shores)
• North Bay irrigation: 5.6 cfs
• Water use estimated to be much less than allocation, especially for municipal/domestic

Water Quality

• Grays Harbor Fecal Coliform TMDL: Humptulips, Hoquiam, and Wishkah Rivers identified as major sources, although data does not seem to agree with this conclusion
• Upper Humptulips Temperature TMDL: under development (technical report out)
• Water quality generally good in Olympic Mountain drainages

Habitat

• Humptulips in-stream flow apparently can't be met under natural conditions
• Rivers draining off Olympics had major channel modifications from past logging practices
• Basin-wide habitat problems

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Study Area 2 Lower Chehalis Subbasins

Geology/Hydrogeology

Hydrology

• Data Gap - No gaging station near mouth of Chehalis
• No in-stream flow control point near Montesano

Water Rights/Water Use

Satsop:

• 80 cfs (wppss)
• 570 cfs (Lake Arrowhead Community Club)
• Wynoochee;

• 1,400 cfs (noncomsumptive power)
• 110 cfs (City of Aberdeen)
• 45 cfs (City of Aberdeen)
• Use estimated to be much less than appropriation, especially for municipal/domestic

Water Quality

• Grays Harbor fecal coliform TMDL Identifies Satsop River as major source, although water quality data does not appear to support this conclusion.
• Total phosphorus yield at Montesano estimated to be highest in entire Chehalis watershed.
• Water quality generally good in Olympic Mountain rivers

Habitat

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Study Area 3 Middle Chehalis Subbasins

• 11. Black River
• 12. Cedar Creek
• 13. Chehalis River

Geology/Hydrogeology

Hydrology

• Black River drainage has been modified extensively in the past.
• Gaging station at Porter is main flow measurement and in-stream control point for Study Areas 3 and 4
• Hydraulic continuity is very high in Black River/Scatter Creek area

Water Rights/Water Use

• Water Is over-allocated between May and September
• Allocated water spread among many users
• Irrigation water rights play much larger role than in downstream study areas.
• Actual water use is estimated to be much less than allocated, especially for irrigation

Water Quality

• Black River: Temperature, dissolved oxygen, total phosphorus, ammonia-N, and fecal coliform
• Upper Chehalis and Black River TMDL developed to address problems
• Basin-wide water quality issues

Habitat

• Warm water in Black River and Scatter Creek are barriers to salmon
• Other basin-wide habitat issues

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Study Area 4 Upper Chehalis Subbasins

Subbasins:

• 1. Chehalis River Headwaters
• 2. Elk Creek
• 3. South Fork Chehalis River
• 4. Upper Chehalis River
• 5. South Fork Newaukum
• 6. North Fork Newaukum
• 7. Newaukum
• B. Salzer Creek
• 9. Skookumchuck
• 10. Chehalis River

Geology/Hydrogeology

Hydrology

Water Rights/Water Use

• Water rights distributed among many small users
• Irrigation allocation is high
• Allocated water split evenly between surface and ground water
• Large rights:
  • 140 cfs, Skookumchuck (Pacific Power and Light)
  • 80 cis, Skookumchuck (Pacific Power and Light)
  • Three groundwater rights total 40 cfs (location unknown)
  • Actual water use estimated to be much less than allocation especially for irrigation

Water Quality

• Centralia reach: Water quality characteristics more like a lake than a stream. Problems with temperature, dissolved oxygen, total phosphorus, ammonia-N.
• Upper Chehalis TMDL and Upper Chehalis Dry Season TMDL developed to address problems
• Several tributaries, including Dillenbaugh Creek, Salzer Creek, and Skookumchuck River also have documented problems
• Total suspended solids high at Dryad

Habitat

• Centralia reach water quality problems create habitat problems
• Thirteen fish passage barriers identified in Newaukum
• Other basin-wide habitat problems apply to this study area

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