C150367 Feasibility Study

• Contract/PO #: CT2015-007
• Contract/PO #: C150367
• Contractor Name: Lamar, City of
• Contract Type: Loan
• Water District: 67
• County: Prowers
• Loan Projects - Doc Type: Feasibility Study

SECTION 5 - SELECTED ALTERNATIVE
.JUSTIFICATION OF SELECTED ALTERNATIVE
Replacing the South Well Field Water Transmission line with Polyvinyl Chloride (PVC) pipe is
the most cost effective solution. Although Ductile Iron (DIP) pipe is an alternative solution that
meets the design criteria, it is not financially competitive. No action is not an alternative due to
the high rate of water loss in the existing main and the existing lack of redundancy.
PROJECT DESCRIPTION
The selected alternative is approximately 34,200 LF of PVC raw water transmission line, to be
used between the Pump Station No. 1 (PSI), south of the South well field and Pump Station No.
2 (PS2), which is adjacent to Lamar's water storage tanks and just south of the golf course. As
proposed, 14 -inch C -900 DR 25 pipe will be installed between PSI and the South well field, and
16 -inch C -905 DR 25 used between the South well field and PS2. Construction drawings for the
proposed project are attached in Appendix A.
MAP & PROJECT PLANS
Figure 1 from the previous section and the proposed construction documents, as attached in
Appendix A, depict the entire project area, with components of the existing infrastructure and
features of the proposed improvements. The 100 -year floodplain has not been studied in detail
for either hydrology (flow estimate) or hydraulics (depth of floodway) by the Federal Emergency
Management Agency (FEMA) or the tlrban Drainage and Flood Control District (UDFCD).
CONCEPTUAL DESIGN FEATURES
The pipeline has been sized for maximum hydraulic flows at build -out. The maximum flow
through the transmission line at build -out will be 2,000 gpm, or nearly double the existing
maximum raw water flow of 1,140.
Table 2 — Design Features
Pipeline
Design Flow
[gpm]
Inside
Diameter [in]
Pipe
Length [ft]
Velocity
[fps]
Friction
Loses [ft]
Elevation
Head [ft]
Existing Flows
PS1 to South Well Field
1,140
15.35
23,580
2.0
17.3
-14.29
South Well Field to PS2
1,140
12.07
10,620
3.2
24.7
20.68
Future Flows
PS1 to South Well Field
2,000
15.35
23,580
3.5
60.1
-14.29
South Well Field to PS2
2,000
12.07
10,620
5.6
85.9
20.68
City of Lamar Raw Water Feasibility Study — Colorado Water Conservation Board