WSP05756

• File Number: 8443.200
• Description: Narrows Unit - Mailing Lists Correspondence
• State: CO
• Basin: South Platte
• Water Division: 1
• Date: 3/6/1984
• Title: Proposed Conceptual Mitigation-Management Plan And Compensation Analysis
• Water Supply Pro - Doc Type: Report/Study

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2470

the
the
the

target species.
near future. In
21,000 acre area

The reanalysis ~ill be provided to you in
the meantime, a draft management plan for
is provided for your information.

In the po~tion of the management area in the conservation pool
waterfowl would receive major consideration for development. A
system of waterfowl islands, dikes and feeding areas would be
constructed in the upper end of the conservation pool. As the
reservoir is drawn down, these areas would be supplied water by a
direct diversion out of the South Platte River and lateral
ditches leading to the individual dikes. It is proposed that
about 39 dikes would be required. Waterfowl islands will be
constructed within selected dikes. The number of islands may
vary depending on the size and configuration of the island. In
addition it is proposed to develop some dikes for waterfowl
feeding areas in the conservation pool. Waterfowl nesting
structures would be constructed on the islands and dikes. The
estimated cost for the waterfowl developments including materials
and labor is shown below.

TYpe of Development

# of Units

Cost

Waterfowl islands and l/
dikes (3 islands/dike) and
feeding area dikes

39 dikes

$ 2,000,000

Main diversion structure

1 500,000
II miles l,084,000
3 miles l09,000
39 l07,000
Unknown 20,000
l05l acres crop-sharing
$ 3,820,000

Delivery Ditch

Lateral Ditch

Head Gates

Nesting structures

Waterfowl feeding fields

Total for Waterfowl Development

l/Water needs are calculated to be 6,276 acre feet of ~ater to
~aintain the l,046 surface acres created by the island dikes, and
540 acre feet of water to maintain the l20 surface acres created
by the feeding area dikes. This is based on estimated
evaporation rates of 3 acre-feet per surface acre, and doesn't
address seepage losses as these will accrue to the reservoir's
pool. Evaporation was not included during the times that the
conservation pool is up to the extent that the various dikes
~ere not creating additional evaporative surface. Losses from the
ditch system ~ere considered to be neglible, and seepage losses
would accrue to the reservoir regardless of whether the ~aterfo~l
developments were constructed.

The upland game and big game habitat developments would be planned

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