Issues

Water temperatures are thought to be unsuitable for salmonids in the mainstem Big River and larger tributaries;

There is concern that road related failures are contributing large amounts of sediments to stream channels during major storms;

A significant amount of fine sediment may be entering the North Fork Big River either from James Creek, or between James Creek and Chamberlain Creek based on McNeil samples collected by GMA and MRC;

High levels of fine material in streams are a concern.

Key Findings

Flow/Water Quality

There is no temperature data for the Big River Estuary; however, it is expected that the water temperatures in the mainstem Big River quickly cool once they reach the estuary due to the marine influence;

Water temperatures at sites on Donkey House, Frykman, Steam Donkey, Goddard, No Name, Water, Johnston, Wildhorse, and Arvola gulches; Chamberlain, James, West Chamberlain, North Fork Ramon, Montgomery, and Martin creeks; Russell Brook; and East Branch North Fork and North Fork Big River are suitable for salmonids;

Water temperatures at sites on the mainstem Big River, North and South Forks Big River, James, Gates, Martin, Ramon, and Daugherty creeks are unsuitable for salmonids;

Sites that appear to have strong groundwater influences based on their thermographs include Goddard, Donkey House, No Name, Water, Frykman, Steam Donkey, Goddard Wildhorse, and Johnston gulches;

Relatively large diurnal fluctuations in virtually all of the monitored sites throughout the South Fork drainage indicate that there is poor canopy and/or low flows. The only exceptions to this are the monitoring sites at Montgomery Woods Reserve, and the sites located in gulches that are apparently dominated by groundwater;

Montgomery Creek was within the fully suitable range at approximately 60°F during all three years monitored. The maximum diurnal fluctuations varied between 4-5°F. This site is in an undisturbed location in the Montgomery Woods Reserve and is probably a good example of what can be achieved with adequate canopy in the warmer interior portion of the Big River Basin. It should be noted that much of the interior watershed is naturally grasslands, and could not reasonably be expected to achieve these water temperatures;

It appears as though James Creek has a cooling effect on the North Fork Big River, Gates Creek provides some cooling effect to Daugherty Creek, Russell Brook contributes cooler water to the mainstem Big River, and Water Gulch and West Chamberlain Creek contribute some amount of cooling to Chamberlain Creek;

On February 27, 2001 a tanker truck containing approximately 7,000 gallons of used motor oil and diesel overturned on highway 20 and discharged numerous petroleum compounds into James Creek. Because of active cleanup and frequent verification monitoring, this spill is unlikely to have a sustained impact on fish and wildlife;

A water quality sampling site on the South Fork Big River below the confluence with Daugherty Creek had specific conductance and total dissolved solids measurements that were relatively high compared to Basin Plan water quality objectives;

Limited water quality data from Chamberlain Creek indicated that specific conductance was at or slightly below Basin Plan standards. Several other water quality parameters, including aluminum, copper, sodium, and zinc exceeded their respective criteria. Given the limited nature of this sampling effort and uncertainties about the method and exact location of sampling, it is suspected that this does not represent actual in-stream water quality but possibly water quality at some point in the drinking water system;

Sodium was detected at concentrations above the water quality criteria at the North Fork Big River;

Ammonia samples collected in the North Fork and South Forks Big River indicated that ammonia did not exceed the numeric criteria in either site;

The two samples of boron and sodium in the South Fork Big River exceeded their numeric criteria. In the case of boron, both samples also equaled or exceeded the DHS action level (1,000 µg/l) and agricultural use criteria (700-750 µg/l).

Fish Passage

Fish passage barriers exist on Dark Gulch, Johnson Creek, Unnamed tributary to the South Fork of the Big River, Gulch Sixteen Tributary, and Soda Gulch.

Areas of dry channel found in 31 surveyed tributaries during CDFG surveys may indicate fish passage problems;

Erosion/Sediment

McNeil core sediment samples indicated that a significant amount of fine sediment may be entering the North Fork Big River either from James Creek, or between James Creek and Chamberlain Creek. This could indicate unsuitable conditions for salmonids;

Turbidity and suspended sediment samples in ten locations across the subbasin showed values ranging from 1.6 NTU in James Creek to 811 NTU in South Fork Big River below the confluence with Daugherty Creek.

Riparian Condition

Canopy cover was suitable for salmonids on all surveyed tributary reaches within this subbasin except for James Creek.

Instream Habitat

A high incidence of shallow pools, and a lack of cover and large woody debris have contributed to a simplification of instream salmonid habitat in 21 out of 41 surveyed tributaries;

Gravel Substrate

Cobble embeddedness values in 36 out of 41 CDFG surveyed tributaries were unsuitable for salmonid spawning success. In addition, the MRC characterized spawning gravels as fair quality on 32 segments surveyed and good quality on four;

Permeability sampling indicated low to moderate amounts of fine material at East Branch North Fork Big River, and significant fine material at Daugherty and Ramon creeks. This could indicate unsuitable conditions for salmonids in Daugherty and Ramon creeks.

Refugia Areas

Salmonid habitat conditions in this subbasin on surveyed streams are generally rated as medium potential refugia;

North Fork Big River, East Branch North Fork Big River, Chamberlain Creek, Water Gulch, West Chamberlain Creek, Arvola Gulch, South Fork Big River, Daugherty Creek and Gates Creek provide the best salmonid refugia in this subbasin;

The North Fork and South forks Big River and Daugherty Creek serve as critical contributing areas.

Recommendations

Flow and Water Quality Improvement Activities

Protect instream flows in James Creek, Chamberlain Creek, East Branch North Fork Big River, Montgomery Creek, and Russell Brook to help moderate or cool the warmer North and South Forks and mainstem Big River in the summer;

Ensure that adequate streamside protection measures are used to provide shade canopy and reduce heat inputs to the North and South Forks Big River, mainstem Big River, and Daugherty Creek.

Fish Passage

Consider modifying fish passage barriers on on Dark Gulch, Johnson Creek, Unnamed tributary to the South Fork of the Big River, Gulch Sixteen Tributary, and Soda Gulch;

Erosion and Sediment Delivery Reduction Activities

Continue efforts such as road improvements, and decommissioning throughout this subbasin to reduce sediment delivery to Big River and its tributaries. CDFW stream surveys indicated that road sediment inventory and control were top tier tributary recommendations in:

● Anderson Gulch ● Arvola Gulch ● Boardman Gulch
● Dark Gulch ● Gates Creek ● Gulch Sixteen
● Gulch Sixteen Tributary ● James Creek ● Martin Creek
● Martin Creek Left Bank Tributary ● Mettick Creek ● Montgomery Creek
● North Fork James Creek ● North Fork Ramon Creek ● Park Gulch
● Rice Creek ● Russell Brook ● Soda Gulch
● South Fork Big River ● South Fork Big River Tributary #2 ● Snuffins Creek
● Valentine Creek ● Water Gulch ● and Water Gulch tributary


Sediment sources from eroding streambanks and adjacent hillslopes should be identified and treated to reduce sediment generation and delivery to creeks in the Chamberlain Creek PW, South Fork drainage, and the headwaters drainage.

Riparian and Instream Habitat Improvement Activities

Consider adding pool enhancement elements (e.g. LWD) to increase the number of pools or deepen existing pools and add shelter complexity to all surveyed tributaries in the North Fork drainage, Daugherty, Soda, Johnson (tributary to Gates Creek), and Snuffins creeks, and the right bank tributaries of Martin Creek;

Consider modifying debris accumulations in Horsethief Creek, Dark Gulch, Russell Brook, and Martin Creek to facilitate fish passage;

Ensure that this high quality habitat is protected from degradation. The highest stream reach conditions as evaluated by the stream reach EMDS and refugia analysis were found in the North Fork Big River, East Branch North Fork Big River, Chamberlain Creek, Water Gulch, West Chamberlain Creek, Arvola Gulch, South Fork Big River, Daugherty Creek and Gates Creek.

Education, Research, and Monitoring Activities

Continue water temperature monitoring at current locations where high temperatures have been detected on the mainstem Big River, North and South Forks Big River, James, Gates, Martin, Ramon, and Daugherty creeks;

Conduct a stream habitat survey of the mainstem Big River upstream from the confluence with North Fork Big River.