PROJ00235

• Contract/PO #: C153633
• Contractor Name: Greeley, City of
• Contract Type: Loan
• Water District: 3
• County: Larimer
• Bill Number: HB 91-1006
• Loan Projects - Doc Type: Feasibility Study

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5.2.3 OUTLET WORKS

The outlet works were In operation at the time of our visit; therefore, the intake structure and
conduR could not be observed, Those portions of the energy dissipator which were visible
appeared to be in good condRion. No significant deterioration or cracking of the concrete were
noted. However, the lower surfaces of the energy dissipator could not be observed due to
flowing water, The outlet control gates were operated at the time of our visR, and appeared
to be functioning adequately. The discharge channel downstream of the energy dissipator
appeared to be functioning well. There were no signs of significant sloughing or undercutting
of the energy dissipator, A second visR was made on October 26, 1990 to inspect the
upstream gate and gate structure surfaces under minimum water level conditions. The gates
appears to be in good condition. (Note: The State Engineer's inspection report of July 30,
1985 indicates that the Interior of the outlet conduit had been inspected in November of the
previous year, and appeared to be in good condition.)

5,2,4 SPILLWAYS

The service spillway for Hourglass Reservoir is a side channel spillway located in the feeder
dRch which comes from Comanche Reservoir, This spillway is lined with riprap and appears
to be in good condRion, with no undercutting, movements of riprap, or erosion, The emergency
spillway for Hourglass Reservoir is an unlined earth-cut channel at the extreme right end of the
embankment. The unlined spillway does not show any significant erosion or sloughing of the
side slopes. The reservoir operational records indicate that the emergency spillway has not
been used.

5,2,5 SUMMARY OF DEFICIENCIES

Based on our reconnaissance and the review of historical information, several areas of
deficiencies have been noted. Seepage problems have been noted in both abutments of the
main embankment at the downstream toe, downstream of the dam along the discharge channel,
at the downstream toe of the dike at about Station t 14+00, and the Corps of Engineers
Inspection from 1980 reported seepage exRing the morainal ridge 300 to 400 feet downstream
of the embankment. The seepage history of the reservoir indicates that the embankment and
foundation materials are highly pervious, Continued, uncontrolled seepage could lead to material
migration and loss of embankment stability,

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