Watershed/ Water Quality Management Goals

To reduce eutrophication and maintain the quality of the water in Big Bear Lake, the watershed and water quality management goals of the District shall be to: 

1.      As required under the Big Bear Lake Nutrient TMDL Implementation Plan (Phase I), prepare a revised Lake Management Plan to include the following:

·        Big Bear Lake and Watershed Model Updates

·        Big Bear Lake In-Lake Sediment Nutrient Reduction Plan 

2.      As needed, clean-out sediment basins at the mouth of Rathbun Creek. 

3.      Continue to seek funding for watershed management and lake improvement projects. 

4.      Encourage and support the implementation of watershed improvement projects by local stakeholders in the following major tributaries:

·     Rathbun Creek

·     West Summit Creek

·     Knickerbocker Creek

·     Grout Creek

·     Boulder Bay Creek  

4.      Investigate potential for removal of bottom sediment in shallow bays and at mouths of tributaries during periods of low water levels, following thorough analysis of nutrient content of sediment in area being addressed and evaluation of aquatic ecology impacts, especially relating to fish reproduction and sustenance. 

5.      Continue to maintain aeration system and destratification system in area near Bear Valley Dam and investigate potential for aeration systems in other portions of the Lake.

 6.      Expand Adopt-A-Shoreline program to further reduce amount of litter reaching the Lake. 

 7.  Cooperate with other valley agencies to provide more public information and education on the relationship between activities in the watershed and Lake water quality, enforcing District regulations as applicable and requesting stronger regulations from other jurisdictions as necessary.

8.      Work with the County of San Bernardino and the City of Big Bear Lake in concert with other regulatory agencies to control erosion caused by excavation and other construction activities.  This should include more extensive educational programs for local contractors, along with the District’s involvement in the plan review process and approval of erosion control measures for each project.  Require preparation of a Stormwater Pollution and Prevention Plan (SWPPP) on all projects with the potential for runoff into the Lake. 

9.      Cooperate with private parties to encourage removal of sediment as it relates to shorezone alterations and other development projects. 

10.  Continue to maintain the ongoing open-water lake nutrient and supporting water quality data monitoring for Big Bear Lake.  Nutrient and supporting water quality monitoring efforts will be performed at the locations shown on the attached map and include the following: 

·        Standard Water Quality Monitoring – Frequency Based on Water Temperatures

Measurements of dissolved oxygen levels, water temperature, transparency (Secchi disk) and pH levels at a frequency based on the lake water temperatures as follows:

1.  50-60 degrees F - twice per month (15 days apart)

2.  61-70 degrees F - once each week

3.  71+ degrees - twice per week 

·        TMDL-Related Nutrient and Supporting Water Quality Monitoring: 

Lake nutrient and supporting water quality samples will be collected at four of the five main lake stations from March through November of each year.  Sampling frequency will be either once or twice a month.  Water quality samples will consist of both photic zone composite samples and bottom discrete samples.   The photic zone is determined by the secchi disk depth, such that equal amounts of sample are collected from the surface, the secchi disk depth, and 2 times the secchi disk depth. Photic zone composite samples are analyzed for:  

·         Chlorophyll a (chl a)

·         Total Nitrogen

·         Total Dissolved Nitrogen

·         Ammonia-Nitrogen

·         Nitrate-Nitrite

·         Total Phosphorus

·         Total Dissolved Phosphorus

·         Orthophosphate

·         Total Suspended Solids

·         Volatile Suspended Solids

·         Hardness

·         Alkalinity

·         Total Organic Carbon (TOC) (Quarterly)

·         Biochemical Oxygen Demand (BOD₅) (Quarterly) 

All lake samples taken on the bottom (bottom = 0.5 meters above the bottom sediments) will be collected as discrete samples using the Weber sample apparatus and will be analyzed for:

      ·         Total Nitrogen

·         Total Dissolved Nitrogen

·         Ammonia-Nitrogen

·         Nitrate-Nitrite

·         Total Phosphorus

·         Total Dissolved Phosphorus

·         Orthophosphate

·         Total Suspended Solids

·         Volatile Suspended Solids 

In addition, the following parameters will be measured at open-water stations in the lake at one (1.0) meter intervals (in depth) using the YSI 6920 multi-parameter sonde, and secchi disk: 

·         pH (s.u.)

·         Water temperature (ºC)

·         Electrical conductivity (mS)

·         Dissolved oxygen (mg/L)

·         Turbidity

·         Water Clarity (secchi disk). 

  Investigative monitoring shall be conducted as conditions warrant for such things as pesticides, fecal coliform, metals and minerals. 

11.  Continue coordinating the TMDL (Total Maximum Daily Load) Work Group, working closely with the Santa Ana Regional Water Quality Control Board and seeking funding from all available sources. Ensure that adopted TMDL limits and goals are realistic and achievable, and that any final implementation schedule and monitoring programs are not over burdensome on the District’s resources. 

12.  Support the City of Big Bear Lake’s Healthy Urban Forest Initiative (HUFI) process to protect the Lake from huge sediment loads resulting from forest fires through participation in the steering committee and offering financial support as deemed reasonable. 

13.  Continue to maintain computerized data bank, evaluate success of watershed management practices, direct management actions and identify any trends which may be developing.  Any action taken as the result of water quality results shall be based on the following monitoring standards: 

·        Temperature:

I.          under 60 deg. F:        normally no management problems

II.       60 - 70 deg. F:           management problems possible and requires careful analysis

III.    over 70 deg. F:          as Lake conditions change rapidly, increase monitoring and

            be prepared for quick management response (the appearance of blue green, filamentous algae blooms may require chemical treatment)

IV.     over 74 deg. F:          trout planting ceases 

·        Dissolved Oxygen           

I.          under 2.0 ppm           fish die off possible                  

II.       under 5.0 ppm       fish will stress, need to determine reason for low oxygen and to employ corrective management      

·        Supersaturation               

      Usually denotes an abundance of photoplankton and requires careful surveillance      

·        Color                                

            Watch for significant color changes that may indicate algae blooms 

·        Transparency                  

      Maintain Secchi disc transparency over 5 feet 

·        pH                                    

      Measurements of 9.0 or greater, with water temperatures exceeding 60 deg. F may require a special assessment of fishery impacts 

·        Plankton

      The presence of blue-green algae or dinoflagellates (various strains of fresh water algae) in the plankton sample should be viewed with concern.  Using abundance criteria in association with other monitoring data, a significant increase in problem algae and a concurrent decrease in good algae may require management reaction. 

·        Nutrients                        

      Total Nitrogen:       not greater than 2.0 mg/L

      Total Phosphorus:   not greater than .20 mg/L

      (Recent tests performed at four monitoring stations during the Clean Lakes Phase I Study indicated that average nitrogen concentrations ranged from 1.25 mg/L to 1.35 mg/L and phosphorus averaged .04 mg/L to .07 mg/L.  These numbers will provide a benchmark for future evaluation of watershed management practices.) 

·        Floatables            

      There shall be no visible oil, grease, visible solids or oil slicks.  The water should be free of floating trash and debris. 

·        Microbiological Quality

      Waters shall be sampled and analyzed for microbiological contamination as conditions warrant. Careful consideration will be given to samplings in protected bays and arms where poor circulation exists and bacterial concentrations are often considerably different than open water concentrations. The fecal coliform density from any consecutive sets of samples collected within any thirty (30) days shall not exceed an arithmetic mean of two hundred (200) organisms per one hundred (100) ml.  If fecal coliform density of any sample collected exceeds one thousand (1000) per one hundred (100) ml., the District shall contact the Department of Environmental Health who shall order the closure of the water contact area.  Daily sampling shall be immediately commenced with waters analyzed for fecal coliform for at least two (2) consecutive days.  If any follow-up daily sample exceeds one thousand (1000) per one hundred (100) ml., the water contact area shall remain closed, with the appropriate signs posted and maintained by the MWD.  The area shall not reopen without prior written approval being obtained from the Department of Environmental Health.

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