PROJ00504

• Contract/PO #: C153334
• Contractor Name: Henry Waneka Mutual Reservoir Company c/o City of
• Contract Type: Loan
• Water District: 6
• County: Boulder
• Bill Number: FSA
• Loan Projects - Doc Type: Feasibility Study

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layer was considered confined to the southeast portion of the embankment.
Based upon the soil borings. the thickness of the layer was estimated
at 3 to 5 feet and the length of the layer was estimated at 500 feet.
The seepage quantity was estimated to be from 10 to 15 AF/year. ~lereas
condition "B" results in a higher estimated seepage loss, the confidence
level of the data.is less than condition "A", due to the additional
as sumpt ions.

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C. Alternatives

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I. General Review

The value of the storage to a municipal water system and the amount

of storage needed has been previously discussed in Chapter-IV. Therefore,

the viable alternatives are those which increase the amount of storage

available to the system at the least cost. A review of the possible solu-

tions resulted in the following alternatives being selected for a more de-

tailed analysis:

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- Dam Rehabilitation

2 - Dam Enlargement

3 - Reduce Seepage Quantity

A discussion of each of the alternatives is presented below.

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2.- Rehabilitation

Due to the present storage restriction by the SED, the usable capacity

of the reservoir has been reduced by approximately 184 acre-feet (see Area

Capacity Curve on Figure-II). This restriction can be lifted if specified
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improvements are made to the dam (see Appendix-C). The required improvements

for this alternative are shown on Figures IV (page 55) and V (page 56) and

consist of reshaping the embankment (38,000 CY), adding riprap (4,600 CY),

replacing the spillway (170 CY), repairs or replacement of the outlet works,

and other miscellaneous items (refer also to Table-5, pages 43 and 44). The

required land acquisition (approximately 20 acres) is shown on Figure-IV and

is based upon obtaining the property in the flood pool as well as that land

required for the construction of the spillway and dam embankment.

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