Cache La Poudre River General Investigation Study

Inquires may be directed to Dave Wells @ Dave.wells@greeleygov.com

Update

We are working with the US Army Corps of Engineers to finish the Feasibility Study. Present study efforts are focused on improving flood damage reduction methods and solution economics. We are also working to develop the best plan for viable ecosystem restoration of the Cache la Poudre River. In addition, cost-shared recreational facilities may be identified.

New alternatives for flood protection and ecosystem restoration are being pursued in north Greeley. A "set back levee" alternative is being investigated.  It is located only on the south side of the river, outside of the regulatory floodway, between the west side of Island Grove Park and the UP rail road tracks. Flood protection plans will include both structural and nonstructural measures. After this set of alternatives is evaluated, the study will be completed by recommending a plan. Hopefully project design and construction will follow. 

Several significant tasks required of all Corps General Investigation Studies have been completed.  This includes the Agency Technical Review (ATR) of existing conditions, hydraulic and economic models. Study information has been compiled into a draft feasibility report with technical appendices. Information previously compiled as "deliverables" for Colorado Water Conservation Board has been recompiled and expanded to include the "future without project" description. Internal technical reviews for quality assurance and quality control have been completed on all technical work of the problem identification phase including existing conditions, future without project, as well as the plan formulation of the Decision Point 1 alternatives. The draft report has  been reviewed by the Corps Northwest Divsion in Portland and by Corp's Headquarters in Washington, DC. The draft report, released June 2010, may be downloaded below. 

* The Corps of Engineers presented a progress report to the Advisory Committee and to City Council on March 9th, 2010. City Council later confirmed the Executive Committee's recommendation to finish the study.

* The Feasibility Scoping meeting was held on March 19th, 2010. This meeting set the direction to complete plan formulation (problem solving) based on study results to date.

* Reports have been completed by OtterTail Environmental Inc.  These reports summarize existing environmental conditions of the study area. Restoration and enhancement opportunities are also discussed.

Background

The US Army Corps of Engineers and the City of Greeley are conducting a Feasibility Study of the Cache La Poudre River in and near Greeley. The study area is lower seventeen miles of the river, ending at it's confluence with the South Platte River. The primary purpose of the study is to identify buildable projects that will reduce flood damages and/or improve wildlife habitat. Work on the study began in February, 2006.  This multi-year study will cost an estimated $2,420,000.  The initial estimate when the study began was $1,560,000.  Costs are split 50/50 between the City and the Corps. The City has received $300,000 in grants from the Colorado Water Conservation Board to help with the City's share. So far, half of these grants have been spent. 

A detailed investigation of potential flood damage reduction was conducted along the urbanized reach of the Cache la Poudre in Greeley. This was performed to determine if there was a likelihood of finding a viable flood protection project before all feasibility study funds were spent. This investigation has been referred to as "Decision Point I" or "Phase I". Decision Point I was requested by the City of Greeley as a precondition for signing the Feasibility Cost Share Agreement. Work on Phase I was completed in May 2008.  It was determined that there is a likelihood of a flood protection project with a benefit to cost ratio greater than 1.0.

A public meeting, following NEPA guidance, was required before moving forward with plan formulation.  This was held Thursday evening, December 4th, 2008, at the Island Grove Event Center in Greeley.  Attendance exceeded thirty.  Numerous comments and questions were received from a roomful of interested property owners as well as various local government agencies. Five individuals from the U.S. Army Corp of Engineers from Omaha NE, presented background information in English and Spanish, and conducted an audience question, answer and discussion period followed by small group and one-on-one interaction with the attendees. The meeting focused on developing the Environmental Assessment portion of the feasibility study. It also covered hydrology, hydraulics, real estate and recreational areas.

Purpose:

The purpose of the feasibility phase is to fully define problems and opportunities, to develop and evaluate alternative plans, and to fully describe the recommended project. Since ours is a GI (general investigation) study, it can and does have multiple goals and benefits. Although we are not limited to flood control and flood damage reduction, it remains our main purpose. Other objectives include environmental restoration and enhancement, sediment management and inherently water quality improvement as well as developing recreational amenities. In addition, opportunities will be investigated for developing and accounting for attenuation of peak flows due to flooding of gravel pits and augmentation reservoirs.

Study Objectives
· Flood Control
· Environmental Restoration
· Sediment Management
· Water Quality Improvement
· Recreation
· Detention storage/augmentation

 

Feasibility Study Components

· Hydrology & Hydraulics
· Economic
· Environmental
· Real Estate
· Plan Formulation and Project Management 

Benefits of Improvements

· Reduction of property damage
· Improved public safety
· Reduce private property in floodplain
· Eliminate flood insurance needs or requirements

Downloads

Meeting Summaries:

Maps:

Links:

U.S. Army Corp of Engineers:

Omaha District: