Cal. Code Regs. tit. 23 § 3955
The goal of this TMDL is a change from eutrophic to mesotrophic conditions, which should provide adequate support for aquatic life and recreational beneficial uses. Attainment of the numeric target for total phosphorus (0.02 mg/L as an annual mean concentration in the water column) is projected to occur within approximately 21 years after final approval of the TMDL (2024). Attainment of other numeric targets and narrative water quality objectives related to protection of beneficial uses is also projected to occur by that date.
The TMDL assigns a loading capacity for phosphorus loading to Indian Creek Reservoir, as a net annual load of 82 pounds of total phosphorus in the water column. Attainment of the loading capacity and numeric target will require an 87 percent reduction in internal phosphorus loading from the sediment and a 75 percent reduction in external loading to the reservoir from the surrounding watershed and the tributary inflow.
The TMDL implementation program will use an adaptive management approach. It establishes a process and schedule for selection and implementation of specific control measures. Such measures will include best management practices to control external sources, and in-lake control methods to control phosphorus loading from the sediment. Examples of potential in-lake controls include measures to remove phosphorus-laden sediment, reduce phosphorus release from sediment, and/or increase flushing of phosphorus from the reservoir. Implementation will be the responsibility of the South Tahoe Public Utility District (STPUD), which manages the reservoir and its tributary flow; the U.S. Bureau of Land Management, which owns the watershed contributing surface runoff to the reservoir; and public and private landowners in the watershed of the tributary inflow.
The Lahontan Regional Board will use its existing authority, including the three-tier compliance approach (ranging from self-determined implementation to regulatory action) in the statewide Nonpoint Source Management Plan and Rangeland Water Quality Management Plan, to ensure implementation of the TMDL.
The TMDL implementation program includes continued monitoring of water quality in the reservoir and its tributary inflow, and periodic inspection of BMPs once they have been installed. The adaptive management approach includes flexibility for changes in the existing monitoring program over time.
If progress toward implementation and attainment of TMDL targets and indicators is not satisfactory at the conclusion of the second comprehensive review (in 2013), or if monitoring shows support of beneficial uses at phosphorus concentrations higher than mandated by the target, Regional Board staff will evaluate the need for revision of the TMDL and/or the implementation program.
Specifics of the TMDL implementation program are as follows
Summary of TMDL Implementation Program
| Implementation Process | Schedule |
| Stakeholder group is convened by Regional Board staff | By 4 months after final approval of TMDL |
| Regional Board staff and stakeholders identify specific sites needing BMPs to control external sources of phosphorus loading | By 1 year after final approval of TMDL |
| STPUD submits plan for Regional Board approval on proposed action(s) to control internal phosphorus loading | By 15 months after final approval of TMDL |
| Progress toward BMP implementation reviewed; need for Regional Board regulatory action considered | By 3 years after final approval of TMDL |
| Controls for internal and external sources phosphorus loading are fully implemented | By 2013 |
| Review of monitoring data in relation to indicators and targets | Ongoing |
| Comprehensive review of monitoring data and progress toward implementation and attainment of targets | At five-year intervals following final approval of TMDL |
| Consideration of needs for revisions in TMDL | After 2013 |
Cal. Code Regs. Tit. 23, § 3955