BOARD01171

• Board Meeting Date: 11/19/2001
• Description: CF Section - New Loans - Larimer County - Dry Creek Flood Mitigation Project
• Board Meetings - Doc Type: Memo

City and their engineering consultants are taking into account public input derived from these
meetings to "fine tune" the selected alternative.

'. Environmental Impacts and Permittinl!
The selected alternative will apparently not involve the disturbance of the waters of the
United States, according to a preliminary determination by the Corps of Engineers regulatory
office. The project will involve the creation of new wetlands and the enhancement of existing
wetlands. The project sponsors wiIJ apply for a Corps 404 pennit for the entire project, which
will include the reservoir sites, road crossings, and open channels. Preliminary evaluation shows
that a nationwide pennit can be obtained due to the limited area of wetlands disturbed.

Surveys for the threatened species Preble's meadow jumping mouse and the Ute ladies'
tresses orchid have been conducted with the determination that no suitable habitat exists. It also
appears that no historic properties will be affected by construction; however a complete inventory
will be conducted at each of the construction sites. Any mitigation required will be consistent
with recommendations from the Colorado State Historic Preservation Office.

The Federal Emergency Management Agency (FEMA) review, comment, and acceptance
of a revision to regulatory floodplain mapping is known as a Letter of Map Revision (LOMR).
The City and County will request a Conditional Letter of Map Revision (CLOMR) prior to
construction to obtain FEMA comments on whether the overall project meets minimum
standards of the National Flood Insurance Program. The City and County will also apply for a
LOMR upon completion of the flood control improvements.

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The CWCB Flood Protection Section will review and recommend Board approval of the
revised floodplain delineation for Dry Creek, based on the completed project, in accordance with
the CWCB' s Floodplain Designation and Approval Rules, 2 CCR 408- I.

Water Ri!!hts and Water Resource Benefits
The Irrigation Company has historically made use of Douglas Reservoir water via trades
with the Water Supply & Storage Company. Douglas Reservoir water was passed into the
WS&S system, then replaced with Colorado Big Thompson water at the Larimer-Weld Canal. In
recent years, ownership of CB- T water by the Irrigation Company and WS&S has declined so
that replacement water has not been available. The Irrigation Company therefore has a need to
establish conveyance capacity between Douglas Reservoir and the Larimer-Weld Canal. The
Company estimated that construction of the pipeline as part of the flood control project would
enable it to increase annual deliveries to its irrigation customers by about 5,000 acre-feet. This
benefit is preserved and enhanced by the configuration of the preferred alternative incorporating
a pipeline to avoid ditch losses. The Irrigation Company estimated the potential annual benefit,
of improved water resource efficiency at $100,000, or $20 per acre-foot for the 5,000 acre-feet of
increased deliveries to its customers. This benefit is supported by the participation of the
Irrigation Company by partially financing the project.

Financial Summary
While the County will be the recipient of the loan and be directly responsible for its
repayment, two additional entities will take part in financing the Dry Creek Project. The 1997 .
'... IGA divided the responsibility for the project, reflecting the fact that the Lower Basin lies in both
jurisdictions. The IGA outlines each entity's cost and management responsibilities. The County

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