| Water Body Name: | Redwood Creek (Marin County) |
| Water Body ID: | CAR2013001320080714110732 |
| Water Body Type: | River & Stream |
Lines of Evidence (LOEs) for Decision ID 7746 |
| LOE ID: | 5854 |
| Pollutant: | Benthic-Macroinvertebrate Bioassessments |
| LOE Subgroup: | Population/Community Degradation |
| Matrix: | Not Specified |
| Fraction: | None |
| Beneficial Use: | Cold Freshwater Habitat |
| Number of Samples: | 4 |
| Number of Exceedances: | 0 |
| Data and Information Type: | Benthic macroinvertebrate surveys |
| Data Used to Assess Water Quality: | Benthic macroinvertebrates were sampled from four sites in the Redwood Creek watershed in April 2005 by the SWAMP program. Benthic macroinvertebrate assemblage metrics were similar to values observed at reference sites in perennial creeks and indicated excellent to good conditions. Taxa richness score ranged from 32 to 36 and % sensitive EPT were 30 to 33. |
| Data Reference: | Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment |
| Water Quality Objective/Criterion: | All waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce significant alterations in population or community ecology or receiving water biota. In addition, the health and life history characteristics of aquatic organisms in waters affected by controllable water quality factors shall not differ significantly from those for the same waters in areas unaffected by controllable water quality factors. |
| Objective/Criterion Reference: | San Francisco Bay Basin (Region 2) Water Quality Control Plan (Basin Plan) |
| Evaluation Guideline: | Benthic macroinvertebrate assemblage metric scores that are within the range of scores for minimally disturbed reference sites indicate no substantial alterations in community ecology. Taxa richness values at reference sites sampled by the SWAMP program between 2001 and 2003 ranged from 28 to 59. Reference conditions determined for perennial streams such as Redwood Creek, usually exhibit taxa richness > 38 and % sensitive EPT > 44. A perennial stream could be described as in - excellent condition - if there is no difference between the metrics measured at the site and those established for reference sites. A perennial stream will be described as in - good condition - if the site metrics indicate minor loss of bio-integrity but still a good structure and function, and sensitive species are present in abundance. |
| Guideline Reference: | Water Quality Monitoring and Bioassessment in Nine San Francisco Bay Region Watersheds: Walker Creek, Lagunitas Creek, San Leandro Creek, Wildcat Creek/San Pablo Creek, Suisun Creek, Arroyo Las Positas, Pescadero Creek/Butano Creek, San Gregorio Creek, and Stevens Creek/Permanente Creek. Oakland, CA: Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board |
| Spatial Representation: | Benthic macroinvertebrates were sampled from four sites. Three of these sites were located on the mainstem of Redwood Creek, with the remaining site located on Green Gulch - a small tributary. |
| Temporal Representation: | All four sites were sampled for benthic macroinvertebrates in April 2005. |
| Environmental Conditions: | |
| QAPP Information: | All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB 2002). |
| QAPP Information Reference(s): | |
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| LOE ID: | 5755 |
| Pollutant: | Oxygen, Dissolved |
| LOE Subgroup: | Pollutant-Water |
| Matrix: | Water |
| Fraction: | None |
| Beneficial Use: | Cold Freshwater Habitat |
| Number of Samples: | 12 |
| Number of Exceedances: | 1 |
| Data and Information Type: | PHYSICAL/CHEMICAL MONITORING |
| Data Used to Assess Water Quality: | Comprehensive water quality assessment was conducted at the Redwood Creek watershed as part of SWAMP assessment in 2005. Continuous field monitoring of temperature, dissolved oxygen, pH and specific conductance was conducted to determine temporal variability in basic water quality at four locations. The 7 day average minimum concentrations of dissolved oxygen were between 6.74 and 9.81 mg/L during dry season, 9.03 -10.72 during spring season, and 10.38 11.8 during winter wet season.
Minimum dissolved oxygen levels fell below the objective of 7 mg/L only once during the dry season in August 2005. The below objective concentrations were detected in Green Gulch, one out of 4 monitoring points in the Redwood Creek watershed, located just upstream from the confluence with Redwood Creek. During that period minimum values of DO ranged from 4.74 to 7.95 mg/L. |
| Data Reference: | Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment |
| Water Quality Objective/Criterion: | The numeric water quality objective for dissolved oxygen is 7.0 mg/L minimum for waters designated as cold water habitat. The median dissolved oxygen concentration for any three consecutive months shall not be less than 80 percent of the dissolved oxygen content at saturation. |
| Objective/Criterion Reference: | San Francisco Bay Basin (Region 2) Water Quality Control Plan (Basin Plan) |
| Evaluation Guideline: | |
| Guideline Reference: | |
| Spatial Representation: | Dissolved oxygen was measured at four sites. Three of these sites were located on the mainstem of Redwood Creek, with the remaining site located on Green Gulch -a small tributary. |
| Temporal Representation: | At all monitoring locations the SWAMP Program performed concurrent continuous measurements of dissolved oxygen at 15 minute intervals lasting 6 to 12 days. The measurements were conducted during late spring (May 2005), summer dry season (August 2005), and winter wet season (February 2006). |
| Environmental Conditions: | |
| QAPP Information: | All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB 2002). |
| QAPP Information Reference(s): | |
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| LOE ID: | 5752 |
| Pollutant: | Temperature, water |
| LOE Subgroup: | Pollutant-Water |
| Matrix: | Water |
| Fraction: | None |
| Beneficial Use: | Cold Freshwater Habitat |
| Number of Samples: | 12 |
| Number of Exceedances: | 1 |
| Data and Information Type: | PHYSICAL/CHEMICAL MONITORING |
| Data Used to Assess Water Quality: | Comprehensive water quality assessment was conducted at the Redwood Creek watershed as part of SWAMP assessment in 2005. Continuous field monitoring at 15 minute increments of temperature, dissolved oxygen, pH and specific conductance was conducted to determine temporal variability in basic water quality at four locations.
The estimated 7-day mean temperatures ranged from 12.08°C to 15.47 °C and varied with season and location. The 14.8 °C criterion for coho salmon was exceeded in 1 out of 12 continuous temperature deployments during the dry summer season at the downstream reach of the creek. The 17 °C criterion for steelhead was never exceeded. |
| Data Reference: | Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment |
| Water Quality Objective/Criterion: | Temperature objectives for enclosed bays and estuaries are specified in the "Water Quality Control Plan for Control of Temperature in the Coastal and Interstate Waters and Enclosed Bays of California" including any revisions to the plan. In addition, the following temperature objectives apply to surface waters: The natural receiving water temperature of intrastate waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Water Board that such alteration in temperature does not adversely affect beneficial uses.
The temperature of any cold or warm freshwater habitat shall not be increased by more than 5°F (2.8°C) above natural receiving water temperature. |
| Objective/Criterion Reference: | San Francisco Bay Basin (Region 2) Water Quality Control Plan (Basin Plan) |
| Evaluation Guideline: | Sullivan et al. (2000) reviewed a wide range of studies incorporating information from laboratory-based research, field observations, and risk assessment approaches and developed criteria for assessing temperature risk to aquatic life. The 7-day mean temperature (maximum value of the 7-day moving average of the daily mean temperature) of 14.8°C was established as the upper threshold criterion for coho salmon and 17.0°C for steelhead trout. The risk assessment approach used by Sullivan et al. (2000) suggests that temperatures exceeding the above thresholds will cause 10% reduction in average growth compared to optimal conditions. |
| Guideline Reference: | An Analysis of the Effects of Temperature on Salmonids of the Pacific Northwest with Implications for Selecting Temperature Criteria |
| Spatial Representation: | Temperature was measured at four sites. Three of these sites were located on the mainstem of Redwood Creek, with the remaining site located on Green Gulch - a small tributary. |
| Temporal Representation: | Concurrent continuous measurements were conducted at both monitoring locations. Temperature was recorded at 15 minute intervals over 6 to 12 days during late spring (May 2005), summer dry season (August 2005), and winter wet season (January/February 2006). |
| Environmental Conditions: | |
| QAPP Information: | All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB 2002). |
| QAPP Information Reference(s): | |