Issues

High sediment levels in streams create problems for fish habitat;

There is an ongoing potential seasonal fish passage barrier at the mouth of the Van Duzen River;

Fish access to habitat is potentially blocked at various points in the subbasin;

Urban wastewater disposal poses a problem to aquatic ecosystems in the subbasin;

Water temperatures are stressful to salmonids in mainstem Van Duzen and Eel rivers as well as in Howe and Price creeks.

Findings

High sediment levels in streams create problems for fish habitat.

Filling of pools by sediment is an issue in every creek surveyed in this subbasin. The majority of streams were of the lowest suitability in terms of pool depth and frequency;

Pool shelter is a widespread issue in the subbasin. Every stream surveyed in this subbasin with the exception of Oil Creek has pool shelter values that were below suitable and none met target values;

Substrate embeddedness is very high on Wolverton Gulch, Wilson Creek, Dean Creek, Nanning Creek and Westfork Howe Creek. With the exception of Oil Creek, all streams surveyed were poorly suited for spawning;

The two most common geologic units in this subbasin are the Wildcat Group, which is largely comprised of fine sediment and is highly erodible, and the Coastal Belt melange, which is even more erodible but contains a wide range of sediment sizes from boulders to silt;

Extensive soil disturbance associated with historic and current timber harvest and road construction has occurred throughout the subbasin as well as continued grazing operations in riparian areas;

Bank erosion due to unfenced grazing operations, large debris accumulations, and other factors was found to be an issue on several streams surveyed in this subbasin;

The 1964 flood contributed massive amounts of sediment to the Van Duzen and Eel Rivers and tributaries thereto (Kelsey 1977).

There is an ongoing potential seasonal fish passage barrier at the mouth of the Van Duzen River.

Bar skimming had been the preferred method of gravel extraction on the Lower Van Duzen River up until 1996. This method has been shown to widen channels thus creating a shallow, braided reach (Humboldt County 1992);

Stranding and mortality of early run fall Chinook on the shallow riffles at the mouth of the Van Duzen River occurred frequently before 2001 due to aggradation and the widening of the low flow channel from gravel mining -in 2001 alone, 136 Chinook perished;

Agency and gravel mining cooperation has built a single thread channel in the Lower mile of the Van Duzen River since 2001;

Since 2001, the lower four miles of the Van Duzen River have been purposefully blocked to salmonids by three temporary culverts. These culverts are in place from the time the first adults arrive at the mouth until a flow of 150cfs is surpassed to ensure safe upstream passage for adult Chinook.

Fish access to habitat is potentially blocked at various points in the subbasin.

Log debris accumulations occur on Cummings, Dean, Atwell, West Fork Howe, Adams, and Nanning creeks, and Wolverton Gulch which may affect fish passage;

Culverts on Wolverton Gulch and Adams, Slater, Nanning, Fiedler, Cummings, Barber and Oil creeks may be barriers to fish passage (Taylor 2000);

The mouth of Dean Creek is a perched bedrock and sediment delta and potentially acts as a barrier to fish passage;

Connectivity at the mouths of Fiedler and Cummings creeks and Wolverton Gulch may be an issue due to sedimentation and subsurface flow.

Urban wastewater disposal poses a problem to aquatic ecosystems in the subbasin.

In 2003, Rio Dell’s wastewater treatment facility received a ‘cease and desist’ order from the Regional Water Quality Control Board for problems arising from sludge removal and summer discharge into the Eel River through gravel bar percolation. These problems are ongoing, and the city has until 2009 to correct them (NCWQCB).

Water temperatures are stressful to salmonids in Mainstem Van Duzen and Eel rivers as well as in Howe and Price creeks.

Maximum weekly temperatures above 68º Fahrenheit were recorded in the Eel River at the confluence with the Van Duzen River from July 1st through mid September, 1996, as well as in the Van Duzen River at the 101 bridge during that same timeframe (HCRCD 1998);

Sites monitored in Howe and Price creeks were found to be moderately unsuitable for salmonids, recording maximum weekly temperatures above 66º Fahrenheit in June through October over several years.

Recommendations


What watershed and habitat improvement activities would most likely lead toward more desirable conditions in a timely, cost effective manner?


Upper Subbasin Issues Recommendation Activities
XXX: Highest Priority
Streams Barriers to Fish Passage. Continue efforts to identify and alleviate fish passage impediments at culverts or other road crossings. Improve fish passage by modifying debris accumulations. Improve fish passage by building fishways at sediment deltas that may impair anadromous fish migrations.    
Adams Creek   X X      
Oil Creek   X        
Atwell Creek     X      
West Fork Howe Creek     X      
Dean Creek     X X    
Slater Creek   X        
Barber Creek   X        
Nanning Creek   X X      
Van Duzen River       XXX (ongoing)    
Wolverton Gulch   XX X X    
Fiedler Creek   XX   X    
Cummings Creek   XX X X    
  Flow and Water Quality. Ensure that water diversions used for domestic or irrigation purposes bypass sufficient flows to maintain all needs of fishery resources. Identify, protect, and enhance thermal refugia where water temperatures regularly exceed 68ºF. Plant willows, redwoods, alder or fir trees to help reduce water temperature in areas with insufficient shade. Remove excessive contributions of wastewater to aquatic ecosystems.  
Eel River     XX   XX  
Price Creek   XX X XX    
Howe Creek     X XX    
Van Duzen River   X XX      
Cummings Creek   X   X    
  Erosion and Sediment Reduction Continue to identify and reduce sources of sediment delivery to stream channels from road systems. Re-vegetate exposed stream banks and/or install structures to increase bank stability Modify debris accumulations to prevent further erosion of stream banks. Build livestock exclusionary fencing along creeks and create offsite watering areas. Install instream structures that enhance natural sorting of spawning gravels.
Price Creek   XX X   XX  
Adams Creek   XX   X   X
Sweet Creek   XX X      
Muddy Creek   XX        
Howe Creek   XX X   X  
West Fork Howe Creek   XX   X   X
Atwell Creek   XX X X    
Crystal Creek   XX        
Dean Creek   XX   X    
Nanning Creek   XX   X    
Van Duzen River     XX      
Wilson Creek   XX        
Wolverton Gulch   XXX X X X  
Cuddeback Creek   XX XX      
Fiedler Creek   XX XX      
Cummings Creek   XX X X    
  Riparian and Instream Habitat. Increase depth, area or shelter complexity in pools, by adding LWD or combinations of boulders and LWD. To increase the number of pools, design and install pool forming structures. Consider planting barren nearstream areas with alder, willow, redwood, or fir trees to increase streamside shade canopy and cover and to allow for LWD recruitment.    
Price Creek   X X X    
Adams Creek   XX        
Sweet Creek   X XX X    
Muddy Creek   XX X X    
Howe Creek   XX XX X    
West Fork Howe Creek   XX XX X    
Atwell Creek   XX X      
Crystal Creek   X XX X    
Dean Creek   XX X      
Nanning Creek   X        
Van Duzen River   X   X    
Wolverton Gulch   XX X XX    
Wilson Creek   XX XX      
Cummings Creek   XX XX X    
  Education, Research, and Monitoring Conduct retrospective surveys of habitat improvement structure effectiveness to assess need for project maintenance. Water quality and temperature monitoring should be conducted over several years to characterize conditions in streams. Conduct water quality monitoring to assess impacts from wastewater treatment facilities and livestock. Conduct habitat inventories.  
Eel River     XX X    
Price Creek   X XX      
Barber Creek         X  
Slater Creek         X  
Howe Creek   X XX      
Van Duzen River     XX X    
Cuddeback Creek     XX   X  
Fiedler Creek     XX   X  
Cummings Creek   XX