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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5.6

the liner against uplift from pore pressures in the embankment during rapid drawdown
of the reservoir, a buttress of natural on-site materials should be constructed on the
upstream face. This option will also require the removal and replacement of the existing
riprap on the upstream face.

6. Partial RCC Uner. A partial upstream liner couid be constructed of roller-compacted
concrete (RCC). The areal extent of such a liner would be similar to that of a partial
clay liner, discussed above. The RCC liner should be placed in a three-foot thickness
over the reservoir area, and on twelve-foot-wide horizontal benches on the upstream
face. The RCC would also serve as slope protection, and wOOd not require the
placement of riprap. Exlsllng riprap on the upstream face could be reused in other
areas of the project.

It should be noted that the reservoir has not been operated at maximum storage levels in
recorded history, and probably never has been. Due to the nature of the foundation materials,
it would be difficult or impossible to predict the effects on seepage of lifting the current gage
height restriction for any of the proposed alternatives.

LIMITATIONS

This study was performed to evaluate conceptual level design alternatives. Test holes drilled
for this study were spaced to oblain a reasonable picture of subsurface conditions for
conceptual design purposes. Variations from the conditions portrayed which were not indicated
by test holes frequently occur. When preliminary designs are selected, additional work should
be performed to conflrm the conditions to be used in final designs. The purpose of this study
was limited to selecting a general direction for rehabilitation designs. The information in this
report should not be used for construction or bidding purposes.

Woodward-Clyde Consultants represents that our services are performed within the limits
prescribed by the client, in a manner consistent with the level of care and skill ordinarily
exercised by other professional consultants under similar circumstances. No other representation
to client, expressed or implied, and no warranty or guarantee is included or intended.

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