PROJ00318

• Contract/PO #: C153618
• Contractor Name: Greeley, City of
• Contract Type: Loan
• Water District: 3
• County: Larimer
• Bill Number: SB 87-15
• Loan Projects - Doc Type: Feasibility Study

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repaired several times in the past by patching existing defects. Most of the
repair work has been done to the inlet drop structure. The latest repair in
1982 embedded an l8-inch diameter PVC pipe and elbow in concrete within the
lower porti on of the 36-i nch diameter CMP condui t, and through the
intersection of the drop section and the upstream end of the original arch
out1 et condui t. Fi gure V. 1 is a sketch of that modi fi cati on; Thi s
modification greatly reduced the discharge capacity of the outlet works.
Flows through the conduit are controlled from the crest by a manually operated
sl i de gate located at the downstream si de of the wet well. Hi gh flows are
controlled by the 18-inch diameter conduit section.

Inspection of the outlet conduit and wet well showed them to be in fair
condi ti on. A log of the i nspecti on is i ncl uded in Appendi x A. A few inches
of sand and gravel covered the conduit invert downstream of the slide gate.
Some erosion of the invert concrete could be detected upstream of the wet well
but is not serious. Waste mortar from the various patching efforts is evident
in several locations at the base of the side walls. Several minor cracks and
pin-hole seeps were noted in the c.onduit. Minor erosion has occurred at
several horizontal construction joints associated with the method in which the
condui twas ori gi nally constructed, whi ch produced feather edges of concrete
separated by tar paper. Patchi ng of defects over the years wi th mortar and
epoxy seems to be performi ng we 11 with no evi dence of spall i ng or
deterioration. The wet well was in good shape with the exception of a cold
joint about 15 feet above the bottom of the well. Seepage was evident through
the segregated, unconsolidated aggregate at the joint around the perimeter of
the wet well. There is also evidence that some differential movement may have
occurred. Sand and gravel have been collecting at the bottom of the wet well
with several cobbles, about four inches in diameter, have been deposited in
the recess formed by the steel gui des of the sl I de gate. Un1 ess increased
flow velocity, that would occur when the gate is closed, washed these cobbles
away, it would be impossible to close the gate. The gate and operating stem,
although rusty, appeared to be in satisfactory operating condition.

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