PROJ00444

• Contract/PO #: C150012
• Contractor Name: Model Land and Irrigation Company, The
• Contract Type: Loan
• Water District: 19
• County: Las Animas
• Bill Number: EIA
• Loan Projects - Doc Type: Feasibility Study

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SECTIONSIX

InvestigaUon and RehabllltaUon Measures

6.2.1.2 Outlet Pipe and Cradle

The outlet pipe will be a 4'0" diameter RCP with a reinforced concrete cradle. The pipe will be
a Class IV, Wall B pipe, designed for a loading of30 feet offill. The cradle will provide a
uniform foundation for the pipe and will limit deflection of the RCP. The excavation below the
cradle will extend to bedrock; with compacted structural fill placed from bedrock to the bottom
of the cradle to provide a firm foundation. The RCP will be embedded into the intake structure
upstream and the headwall downstream.

6.2.1.3 Stilling Basin and Heaclwal/

The stilling basin is designed as a plunge pool and will contain grouted riprap for the initial 50
feet downstream ofthe headwall, with ungrouted riprap for a minimum of75 feet downstream of
the grouted riprap. This basin with provide stilling action for flows up to 250 cfs and will reduce
velocities entering the canal to minimize erosion.

6.2.1.4 Hydraulics

The outlet works was designed to accommodate the maximum flow requirement of250 cfs at
normal reservoir level, El. 5750.2 (gage height 20). The pipe was designed hydraulically to
function with inlet control so that open channel flow exists in the pipe through the dam. An air
vent will be provided just downstream of the gate to provide an air supply so that open channel
flow is maintained. The calculated outlet works discharge rating is shown on Table 6-1.

Table 6-1
OUTLET WORKS DISCHARGE RATING

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5733.2 3 88
5734.2 4 102
5735.2 5 115
5736.2 6 129
5737.2 7 142
57382 8 153
57392 9 164
5740.2 10 174
5741.2 11 185
5742.2 12 195
5743.2 13 204
5744.2 14 213
5745.2 15 222
5746.2 16 230
5747.2 17 238
5748.2 18 246
5749.2 19 254
5750.2 20 262

URS Breiner Woodward Clyde

68ClOO44333.00IR2.doc 1131100(3:18 PM)/PROJECTS 6-3