FLOOD07306

• County: Weld
• Community: Greeley
• Stream Name: Cache La Poudre River
• Basin: South Platte
• Title: Cache La Poudre River General Investigation Study, Greeley, CO
• Date: 5/1/2005
• Prepared For: Greeley
• Prepared By: USACE, Omaha, NE
• Floodplain - Doc Type: Project

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the Federal funding and local funding must be available at the same time and in
proportional amounts, Without this timing, the schedule will slip and require
adjustments, resulting in cost escalation and interruption of product delivery. The
Federal share is dependent upon annual Congressional appropriations, The Sponsor's
share is dependent on local budgetary constraints. Additionally, the State of Colorado
Water Conservation Board has agreed to provide funding contingent upon the Corps and
the city of Greeley negotiating an FCSA during FY 2005, It is also assumed that both
parties will be able to maintain stable staffing levels and continuity in their employee
work efforts during the feasibility study.

In an effort to reduce study costs, the Sponsor has requested that existing data and
information be used to define project feasibility, instead of initiating large scale new data
collection and modeling efforts. In some cases, this may lead to less accurate definitions
of both the problem and potential solutions, If discrepancies are encountered that require
additional study or data collection, it could become necessary to modify the Cost Share
Agreement at that time and resolve the technical issue,

Some of the specific technical assumptions and constraints that were noted in preparation
of the current cost estimate include:

I, Of the 17 mile reach of the Cache la Poudre River noted in the Reconnaissance
Report, the primary focus of this study will be on the area between Birch Avenue
upstream to N 47th Street. The economic analysis for determining the feasibility
of flood damage reduction measures will be heavily weighted towards thc roughly
2 miles of high damage potential near Highway 85,
2. It is assumed that 2 or 3 viable flood damage reduction alternatives will emerge
from the first phase of this Feasibility Study that will be carried forward for
detailed hydraulic and economic analysis.
3, Existing data will be used where ever possible. Sufficient analysis should be
performed to verify that the existing data is reasonable and sensitivity analysis
performed on computations used in evaluating alternatives where applicable,
4, Each member of the PDT will log items of concern where they feel that additional
analysis are needed before Plans and Specifications can be developed, relative to
their area of expertise, These items will be presented to all members of the team,
(Federal and local) when limitations in the scope of this feasibility study result in
uncertainty that additional study would alleviate,
5, The city of Greeley will provide existing survey data needed for hydraulic
modeling.
6. Stable channel analysis of the Cache la Poudre River will not be included in this
scope of work.
7, Evaluation of the off,channel storage will be performed by Hydrology utilizing
rating curves to be furnished by Hydraulics, Two off,channel storage sites are
assumed for the purpose of estimating the cost of this feasibility study,
8, No tributary evaluation will be performed under the reduced scope of work.
9, Existing survey information will be used to create a TIN or DTM model. The
GIS work will be performed as a creditable in-kind service and it is assumed that

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