October 2009 - South Tahoe Public Utility District

Several options exist for efficient and flexible management of the facility. The facility needs to
receive water directly from the C-Line as well as from the Harvey Place Reservoir outlet works.
The facility should be able to be drained to Harvey Place Reservoir or the Diamond Ditch.
Figure 9.1 (at the end of Section 9) depicts a conceptual configuration of the irrigation fields
located on the northwest section of the irrigated lands in Diamond Valley. The pipeline facilities
associated with the irrigation fields are presented in Section 9.3, Project No. 3 (page 9-65). The
piping configuration shown on Figure 9.1 (at the end of Section 9) allows for the conveyance of
recycled water to the irrigation fields from both the C-Line and Harvey Place Reservoir
simultaneously, and the evacuation of the facility to either Harvey Place Reservoir or the
Diamond Ditch using a combination of new and existing pipelines and the pump back station.
The conceptual cost for the irrigation fields project, including site preparation, excavation, and
grading is approximately $3.5 million.
9.1.2 Project Considerations
Project phasing includes an initial phase of construction the irrigation fields using center pivot
equipment. The source of freshwater supply would be via a portion of the pipeline system
described in Project No. 2, page 9-63). The following phase would be the construction of the
irrigation fields using surface irrigation methods.
The irrigation fields are planned to be adjacent to portions of Diamond Valley Road. These
areas will require signage and public notification of the application of recycled water. The land
proposed for use is currently not permitted to receive recycled water. Recycled water direct land
application permits (Lahontan Regional Water Quality Control Board Reclamation
Requirements) are required prior to construction of the impoundment. Restriction on the
duration of temporary storage may be imposed by the Lahontan Regional Water Quality Control
Board for groundwater protection purposes which would affect the required pumping capacity of
the irrigation fields pump back station (Section 9.3, Project No. 3, Page 9-65).
Irrigation will be required for the areas outside of the irrigation fields (Project No. 4 - Diamond
Valley Freshwater/Recycled Water Irrigation Systems, page 9-66). The irrigation source can be
recycled water or freshwater from the West Fork of the Carson River or possibly from freshwater
stored in the Indian Creek Reservoir. Irrigation would be accomplished via flood application.
The temporary storage facility would utilize recycled water for pasture irrigation. The total
volume applied would be based on an appropriate irrigation application rate as determined by
Nutrient Management Plan (Project No. 11, page 10-77). Initially the irrigation would be
accomplished using freshwater rights, with occasional augmentation with recycled water. In the
future the proportion of recycled water used for irrigation may increase as existing application
areas are lost to development or recycled water production increases.
9.2 Project No. 2 - Harvey Place Reservoir Bypass System
Pipelines
This project addresses the purpose and need statements:
PN-5. Adequate emergency disposal facility for recycled water and options are currently
unavailable for recycled water.
PN-7. Operational control of the distribution system is insufficient.
South Tahoe Public Utility District
Recycled Water Facilities Master Plan - October 2009 Page 9-63