October 2009 - South Tahoe Public Utility District

Pressure required to allow full functionality of the pipeline at each outlet is a consideration in the
design. The necessary pressure will be generated by the hydraulic head differential in the
Waterfall Pipeline. Therefore, the projects will require facility planning including a determination
of the demand locations, integrated design and construction schedules. A determination of the
water pressure at delivery for each alignment should be made.
9.8.2 Project Requirements for Implementation
The three alignment alternatives have been developed, it is important to examine the properties
that can be served from each alignment, and to determine the delivery water pressure that each
alignment is capable of producing. Figure 9.3 (at the end of Section 9) shows the three possible
alignment alternatives and the Waterfall pipeline used to pressurize the West Fork Pipeline.
9.8.3 Alignment 1 – Fredericksburg Road
The Fredericksburg Road alignment runs from the Paynesville Bridge on the North side of the
Diamond Valley Road, across Highway 88 to Fredericksburg Road. To minimize road
disturbance the alignment is planned to be located along the east edge of Fredericksburg Road,
a distance of approximately 11,000 feet, to the southern corner of the Gansberg Property.
The capability of delivering 20-30 psi to each of the three contract irrigators on the up gradient
side of their irrigated lands is a major advantage to the Fredericksburg Road alignment.
The conceptual cost for this alignment alternative is $4.6 million.
9.8.4 Alignment 2 – Highway 88
The starting point of the proposed Highway 88 alignment is also at the Paynesville Bridge.
Starting on the north side of the bridge, the alignment would head west along Diamond Valley
Road to Highway 88. The alignment would then follow north along the highway for
approximately 11,800 linear feet. The end of this alignment lies at a lower elevation than the
Fredericksburg Road alignment. Approximately 20-30 psi will be available to the California
irrigators at the points of delivery. The pressure provided by the pipeline can be harnessed to
move water through the irrigators‟ piped distribution system, thereby eliminating the need for
pumps. Pressure relief valves should be installed at each irrigator‟s connection point.
The construction of this alignment would be less cumbersome, as the available right-of-way
along Highway 88 is much wider and flatter than that of the proposed alignment along the
Fredericksburg Road. The Highway 88 alignment also has the added advantage of delivering
recycled water to permitted lands on both sides of the highway. This alignment benefits those
irrigators with ranches split by the highway.
The conceptual cost for this alignment alternative is $5.0 million.
9.8.5 Alignment 3 – Chambers Lane
The Chambers Lane alignment alternative is similar to alignment 2 except the first leg of the
alignment runs 4,000 feet north along Chambers Lane from the Paynesville Bridge before
turning west to Highway 88. The alignment then runs north to the same terminus location as
alignment 2. The total length of alignment 3 is approximately 13,000 linear feet and would also
generate 20-30 psi flowing at 25 cfs.
South Tahoe Public Utility District
Recycled Water Facilities Master Plan - October 2009 Page 9-73