BOARD00949

• Board Meeting Date: 5/21/2001
• Description: CWCB Director's Report
• Board Meetings - Doc Type: Memo

.

.

.

10E

The basic assumptions for the water availability study are: 1) assume additional storage volumes will
be used; 2) review the DWR current operations of the 10,000 acre-ft water supply pool; 3) review the
elevation 5432 @ 27,000 acre-ft nonnal pool and elevation 5424 @ 17,000 acre-ft operations; 4)
develop new demand curves for wet/dry year conditions; and, 5) evaluate storage pattern
opportunities based on environmental demands and controls.

The next project review meeting is scheduled for May 31 .

Cherry Dam Safety Study: A project review meeting was held on March 15. The project sponsors
welcomed the concept of a technical panel to review and comment on the study contractor's findings
and recommendations. The Board has contracted a three-member panel with technical expertise and
national recognition. The members are Nolan Doesken, CSU Colorado Climate Center; Lou
Schreiner, Chief Hydrologist, Bureau of Reclamation; and Gary Lewis, Parsons Engineering and
author of many textbooks on Dam Design Hydrology.

Greeley Flood Insurance Study: A contract with the Army Corps of Engineers has been execut~d
and work can begin on revisions to the Cache La Poudre River floodway analysis. The work is being
funded by a grant from the Federal Emergency Management Agency under its new program entitled
"Cooperating Technical Community" (CTC, now renamed CTP for "Cooperating Technical
Partnerships"). This arrangement is the first one of its kind in Colorado and staff is pleased with the
program thus far.

Rio Grande Basin Issues

Rio Grande Headwaters Restoration Project: This project, begun in 1999, is approaching its end.
On May 31 a meeting of the Technical Advisory Committee will be held where the consultant will
present recommendations that will be reviewed prior to a concluding meeting in June or July 2001.
At the concluding meeting, final technical recommendations will be presented and specific
administrative and financial recommendations for implementation will be discussed. The entities that
have been participating in the process, including local governments, will then detennine which
portions of the list of recommended actions they wish to pursue.

The 85-mile study reach, from just upstream of the Town of South Fork downstream to the Alamosa-
Conejos County line, has been divided into 7 reaches. The study reach was further divided into 30
sub-reaches, averaging approximately 2.8 miles in length. The division into sub-reaches was based
on homogeneity of characteristics related to hydrology, floodplain width, river geomorphology and
vegetative conditions. The 30 sub-reaches were then analyzed with regard to specific river issues, as
called for in the Scope of Work. The issues examined were: river hydraulics, capacity and
floodplains; geomorphology; riparian habitat; diversion structures; and local plarming issues.

A numerical scoring system was developed to combine these separate analyses to arrive at overall
sub-reach scores and rankings. Using this infonnation, the results ofthe detailed field investigations,
and a comprehensive GIS analysis, the top problems were identified.

Starting upstream, some of the problems identified include: development in the floodplain; irrigation
diversions that were rated "poor"; bank instability; an old bridge that needs to be removed; railroad
bridges with hydraulic problems; poor sediment transport; flooding outside of flood protection levee;
and diversion that impedes flow.

It is expected that the consultant and the TAC will develop recommendations for alternative projects,
on a reach-by-reach basis; a list of twelve high priority construction projects; and a list of non-
structural measures that could be applied throughout the study area.

The T AC will invite local officials, property owners and other interested parties to the May 31
meeting.

9