Water Body Name: | Stevens Creek |
Water Body ID: | CAR2055002019990218134341 |
Water Body Type: | River & Stream |
Lines of Evidence (LOEs) for Decision ID 9434 |
LOE ID: | 8678 |
Pollutant: | Low Dissolved Oxygen |
LOE Subgroup: | Pollutant-Water |
Matrix: | Water |
Fraction: | None |
Beneficial Use: | Warm Freshwater Habitat |
Aquatic Life Use: | Wildlife Habitat |
Number of Samples: | 11 |
Number of Exceedances: | 1 |
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING |
Data Used to Assess Water Quality: | Data used to evaluate dissolved oxygen was collected by SWAMP in 2002-2003. In 1 out of 11 seasonal deployments, minimum dissolved oxygen levels fell below the objective of 5 mg/L. The deployment where this occurred was a lower watershed deployment during the dry season. |
Data 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 |
Water Quality Objective/Criterion: | The numeric water quality objective for dissolved oxygen is 5.0 mg/L minimum for waters designated as warm freshwater 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 spanning lower to upper watershed locations on this creek. |
Temporal Representation: | The SWAMP Program performed continuous monitoring of dissolved oxygen at 15 minute intervals for periods of 1-2 weeks in two dry seasons and one wet season in 2002-2003. |
Environmental Conditions: | The Stevens Creek watershed is in the western Santa Clara Basin. The watershed of Stevens Creek is a 38 square mile drainage basin, with its headwaters high in the densely forested Santa Cruz Mountains. The upper portions of the watershed drains upland, mountainous or hilly landscapes where human development is largely absent. The lower portions of the streams flow through western Santa Clara Valley, a large flat alluvial valley draining into South San Francisco Bay. Land uses in the watershed include mining, urbanization, forests, and parks. |
QAPP Information: | All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB 2002). |
QAPP Information Reference(s): |
Lines of Evidence (LOEs) for Decision ID 9162 |
LOE ID: | 8543 |
Pollutant: | Temperature, water |
LOE Subgroup: | Pollutant-Water |
Matrix: | Water |
Fraction: | None |
Beneficial Use: | Cold Freshwater Habitat |
Number of Samples: | 11 |
Number of Exceedances: | 6 |
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING |
Data Used to Assess Water Quality: | Comprehensive water quality assessment was conducted at the Stevens Creek watershed as part of SWAMP assessment. 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 five locations throughout the watershed.
The measured temperatures ranged from 9.3°C to 25.5 °C and varied with season and location. The 17 °C criterion for steelhead was exceeded in 6 out of 11 deployments. Five exceedances were recorded in the dry season and 1 was measured in the wet season. High water temperature exceeding 24 °C, that is a maximum short exposure temperature for survival of salmonids (EPA 1977) was also measured at one monitoring location at lower reach of the Creek during summer dry season. At this monitoring site the leathal temperature for salmonids (< 24°C) persisted for 4.25 hours. |
Data 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 |
Temperature criteria for freshwater fish: protocol and procedures. Ecological Research Series. EPA-600/3-77-061 (NTIS PB270032). Prepared by W.A. Brungs and B.R. Jones. U.S. Environmental Protection Agency, Washington, D.C | |
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 fish 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 located on the mainstem of Stevens Creek. The highest temperatures were recorded at the most downstream location in July 2003. High temperatures exceeding the threshold for steelhead were measured in most parts of the creek with the exception of the upper reach. |
Temporal Representation: | In 2002 and 2003 the SWAMP Program performed continuous monitoring of temperature at 15 minute intervals for periods of 1-2 weeks in each of three different seasons: winter wet season (3 sites), spring runoff season (1 site), and summer dry season (7 sites). |
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): | Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version) |
Lines of Evidence (LOEs) for Decision ID 7669 |
LOE ID: | 5540 |
Pollutant: | Trash |
LOE Subgroup: | Pollutant-Nuisance |
Matrix: | Not Specified |
Fraction: | None |
Beneficial Use: | Wildlife Habitat |
Number of Samples: | 11 |
Number of Exceedances: | 4 |
Data and Information Type: | Occurrence of conditions judged to cause impairment |
Data Used to Assess Water Quality: | Data results were obtained through application of the Urban Rapid Trash Assessment (URTA) methodology, developed by the Santa Clara Valley Urban Runoff Pollution Prevention Program. The URTA is a modification of the Rapid Trash Assessment (RTA) developed by the Surface Water Ambient Monitoring Program (SWAMP). The URTA method documents the total number and characteristics of pieces of trash per one hundred feet of stream or shoreline. The trash assessment protocol involves picking up and tallying all of the trash items found within the defined boundaries of a site. The tally results for level of trash (relating to REC2) and transportable, persistent, buoyant litter (relating to WILD) assessment parameters were considered for the listing determination. These results are available for field visits/trash surveys conducted in 2004 through 2007 according to the Urban Rapid Trash Assessment (URTA) methodology. This waterbody had transportable, Persistent, Buoyant Litter parameter scores in the marginal urban and poor category (indicating threat to Wildlife Habitat beneficial uses) at three locations on three different dates in 2004, 2006 and 2007. |
Data Reference: | Memo: Development of Urban Rapid Trash Assessment Protocol. March 13, 2006 |
Spreadsheet of Urban Rapid Trash Assessment (URTA) data collected by the Santa Clara Valley Urban Runoff Pollution Prevention Program, 2004-2007 | |
Water Quality Objective/Criterion: | The Basin Plan prohibits discharge of Rubbish, refuse, bark, sawdust, or other solid wastes into surface waters or at any place where they would contact or where they would be eventually transported to surface waters, including flood plain areas.
The Basin Plan has a narrative objective for floating material, Waters shall not contain floating material, including solids, liquids, foams, and scum, in concentrations that cause nuisance or adversely affect beneficial uses. The Basin Plan has a narrative objective for settleable material, Waters shall not contain substances in concentrations that result in the deposition of material that cause nuisance or adversely affect beneficial uses. |
Objective/Criterion Reference: | San Francisco Bay Basin (Region 2) Water Quality Control Plan (Basin Plan) |
Evaluation Guideline: | If the URTA Parameter 3 (Transportable, Persistent, Buoyant Litter) is in the marginal urban or poor condition category (scores 0-10), then WILD is not supported. The URTA defines marginal urban or poor condition for this parameter as follows. this level of trash is a medium prevalence (76-200 pieces) or large amount (>200 pieces) of transportable, persistent, buoyant litter such as: hard or soft plastics, styrofoam, balloons, cigarette butts. These types of items are all detrimental to aquatic life. |
Guideline Reference: | Memo: Development of Urban Rapid Trash Assessment Protocol. March 13, 2006 |
Spatial Representation: | URTA data were collected for this waterbody in six locations in 2004 through 2007. |
Temporal Representation: | URTA data were collected for this waterbody on seven dates in 2004 through 2007. |
Environmental Conditions: | |
QAPP Information: | Data were collected by trained staff in accordance with URTA methodology developed by SCVURPPP and are deemed reliable and of sufficient quality on which to base listing determinations. |
QAPP Information Reference(s): |