BOARD02349

• Board Meeting Date: 5/11/1998
• Description: Flood Section - Floodplain Management Program - Status Report on the Colorado Extreme Precipitation Investigation Project
• Board Meetings - Doc Type: Memo

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. Increased head available for power generation.

. A more representative procedure for estimating PMP values for selected basins in
Colorado.

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B. 1998 Project Proposal

The original Phases II and III tasks are combined into Phase II Parts A and B. This change was
made to complete the project in its' initial time frame. The original targeted completion date for
the project, under the provisions of the SEO proposal to the CWCB, was June 30, 200 I.
To keep the Project on its initial project schedule, the State is combining Phases II and III into
Phase II part A and B. In general, Phase II-Part A is the development ofa STATE EXTREME
PRECIPITATION MODEL and seek endorsement from other user agencies, and Phase II-Part B
will develop a procedure and methodology for the computation of the extreme precipitation
values for a basin and estimating the probable frequency for a project design. The project
"Scope of Wark" for the contract will be completed for the contracted tasks under the specific
provisions of a 30- month Performance Schedule as outlined for the project.

5. PROJECT OBJECTIVES

The objectives for the project remain unchanged from the I 994 project authorization and funding
by the Colorado General Assembly. These objectives are:

. Modernization of the procedure and methodology for the determination of the precipitation I'
. values for an extreme storm and resulting flood event;
. Development a "State Model" for the determination of precipitation values for the
mountainous areas of Colorado which are more representative of the region rather than the
national values as presently presented by the National Weather Service;
. Formulation of a procedure/methodology for the computation of extreme precipitation
values; and
. Determination if the standards, which govern the safe passage of large floods through a
spillway, are reasonable for Colorado basins.

6. PROJECT TASKS

The 1998 project tasks for the E P investigation project are defined in the following sections
reference as Phase II parts A and B including any more recent major storm events.

A. PHASE 11- Part A
I. The contractor shall research and evaluate the climatologic and meteorologic characteristics
of the 20 selected storms as determined in the Phase I contract.
2. The Phase I findings and results are presented in a report entitled "Colorado Extreme Storm
Precipitation Data Study-Climatology Report #97-1 dated May 1997.
3. If a storm event that occurred in 1997 or during the contract period the contractor may add
the event's data into the data population as discovery during Phase I.

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