October 2009 - South Tahoe Public Utility District

elatively minor in comparison to operational difficulties compounded by inadequate pipeline
capacities to convey the necessary flows.
9.10 Project No. 10 - Wade Valley Pipeline
This project addresses the purpose and need statement:
PN-7. Operational control of the distribution system is insufficient.
The Wade Valley pipeline project (see Figure 9.3, at the end of Section 9) is a series of
infrastructure improvements along the Diamond Ditch in Wade Valley. Currently portions of the
ditch are lined or piped while other portions are not lined. Implementation of this project is
contingent upon the severity of continued erosion in the Diamond Ditch.
9.10.1 Project Description
Erosion of the Diamond Ditch has occurred in areas of steep gradient and sections lacking
energy dissipation structures. The solution to this problem may be a series of phased piping
projects designed to target the problem sections first. The end result of the phased construction
plan is a continuous pipeline from Diamond Valley to the Waterfall Pipeline forebay located in
Wade Valley.
A conceptual piping configuration is required to determine the final configuration of this section
to the Diamond Ditch. An alternative alignment across the irrigated pasture of the Ace Hereford
would minimize the piped distance from Diamond Valley to the Waterfall Pipeline and the Onfarm
Pipeline. The 20-inch diameter pipeline would be approximately 7,500 feet in length. This
optional alignment would also benefit sprinkler irrigation in Wade Valley by providing enough
pressure to operate an efficient pivot irrigation system.
The initial phases of this project focus on addressing the existing stability and erosion problem
in the Diamond Ditch, and future considerations should evaluate the feasibility of a parallel
pipeline through Wade Valley.
The conceptual cost for the Wade Valley Diamond Ditch improvements is $3.1 million.
9.10.2 Project Considerations
While the Diamond Ditch is the primary conveyance mechanism of the District‟s recycled water
system, the District must consider the issue of capital investment for improvements to the
Diamond Ditch that is owned by others.
9.11 Project Variations
The recycled water infrastructure projects listed previously require capital investment and
construction. Included among these projects are three potential revenue generating
alternatives; however, the majority of the recycled water infrastructure projects intend to improve
the District‟s Alpine County operations. The potential revenue generating recycled water
infrastructure projects include the following:
(1) Grow Biomass Crops for Pulp Production Using Recycled Water
Under this variation recycled water would be used for growing biomass crops (such as
poplar and willow) for use in pulp wood production. The crops would be harvested every
South Tahoe Public Utility District
Recycled Water Facilities Master Plan - October 2009 Page 9-75