PCC Meeting 7/8/10 Notes

PCC Meeting — July 08, 2010
Version: August 30, 2010
IV. Status of Identified Significant Risks
A. Dam outlet works construction
1. No change in risk rating.
B. Reservoir First Fill
1. The filling of the dam continues and the second 30 -day reservoir `hold'
period has started. Approximately 70,000 acre -feet are in storage.
Performance of the dam has been satisfactory. Releases, if necessary,
must be through the tunnel that is functional. The structure and all
associated features are being monitored 24 hours per day, seven days per
week, in accordance with the "Initial Filling Criteria" during fill periods
and `hold' periods. The 24/7 monitoring will contii ud through this second
hold period. Pumping is planned to resume in A;�gust, 2010; however,
flows in the Animas River will influence #0- amdUht of water that is
capable of being pumped. Pumping will c inue ror ;jt2 to 18 months
once pumping resumes. Risk of imp leting,reservoir ftl1ft' due to
structural performance of the dam does not appear to be it t• aatng.
2. No change in risk rating
C. Hydrological events
1. The SNOTEL sites in the Animas Rived kasin are currently at 0% of the
average Snow Water Equivalent (SWE) f6;xhis time of year. The Animas
River has been flowing - fxoughly the 90 perceibt exceedance level since
mid -June. Impacts to theirsf fill duration are impossible to predict with
certainty; however, it appears the first fl period will extend into summer
of 2011, at a minimum.
2. No change'rl rating
D. Durango P.urnping PLt
1. Redlam'abon is c0' ently in the Oracess of resolving outstanding
contractuatYssu J�y�ryer, inflation effects and the net cost of
tncbdfying the contract are.ciirirently unknown. The main unit and
auxiliary control lcstems have been installed. Functional testing of the
auxiliary systems has {been completed. Challenges in electrical and
mechamcal'equipmerii "fabrication and installation, partially resulting from
the electricaJe- design, are being addressed. These challenges resulted in
Some of the ftoat, built into the schedule for first fill, being used.
2. T lie are currently some issues with the mechanical seal water system, the
Conitfir has elected to install larger pumps in an effort to prove that the
systeri "installed meets the specification requirements There are other
minor issues involving, the cooling water system, the main pump and
motor units, the piping, the strainers, and the fish screen cleaner. The
issues are relatively minor in some instances, but may require some
additional work or redesign efforts prior to transfer to O &M status. There
are some issues with the seals on units #2, #4 and #8. The contractor is
working diligently to resolve these issues.
3. Additional studies have shown that the Obermeyer Crest Gates will not
operate properly in the conditions in the Intake Structure. The differential
required in the water surface across the gates is not available during