MEMORANDUM TO: WEST SLOPE CAUCUS FROM: ERIC KUHN, NOVEMBER 15, 2016 SUBJECT: RISK STUDY: REPLY TO FRONT RANCH WATER COUNCIL CONSULTANT LETTER (BACK OF DOCUMENT) The West Slope is committed to proceeding with the next phase of this study. However, based on Front Range Water Council consultant Kerry Sundeen’s Nov. 9, 2016 letter that is critical of Risk Study Phase I results, I believe that before we discuss a Phase II, we need additional discussion of the Phase I draft report and its implications. We could probably benefit from some additional webinars, meetings and modelling associated with Phase I. I have a number of concerns with Kerry’s comments. I believe many of the conclusions are misleading and unfortunately, since the letter has been given broad distribution on the Front Range, unless we address them, it could undermine the cooperation we’ve seen among the West Slope, CWCB, and Denver on the water bank work group and the system conservation projects. As you are certainly aware, there is a lot of nervousness and trepidation on the West Slope over conditions in the Colorado River system and the direction of these efforts. The tone of his letter suggests that the East Slope technical participants were bystanders and only “given three briefings on the study and an opportunity to provide questions and comments.” I think their participation went beyond this. The East Slope technical members participated in an orientation, in all three progress webinars (we offered multiple webinar times for each) and two in-person meetings. The study process was open to all comments and suggestions. For example, during the initial discussion it was suggested we include climate change hydrology and, it was largely due to a suggestion by Kerry that we ended up with a demand scenario based on 90% of the D1 scenario from the Colorado River Basin Water Supply and Demand Study. On page 2, Kerry has a number of bullet points. The first bullet point states that “The hydrologic conditions of the last 25 years would be repeated and repeated to represent the long term future hydrology of the basin (i.e. stress test hydrology).” This not correct. The 1988 – 2012 stress test period was one of three different hydrologic periods (or scenarios) evaluated. Page 2 of 3 11/2/2015 SHOSHONE WATER RIGHTS: IMPLICATIONS FOR PITKIN COUNTY By using three, we were suggesting a broad range of possible future conditions might be possible. The study also looked at a long term naturalized hydrologic record (1950 -2012) and CMIP 3 based climate change hydrology from the 2012 basin study. Further we only looked at a 25 year study period out to 2040. We assumed that the recent 1988-2012 hydrology would continue into the future, but only through 2040. The long term record was picked to coincide with the Colorado Water Availability study period. One of the critical findings of the study is that the policy implications are not that much different between the three different future hydrology scenarios. Under the longer term hydrology, the need to take corrective action is less frequent, but when corrective action (drought operations of the upstream reservoirs and demand management) is needed, the shortages are similar (they are driven by the 1950s and the 2000 – 2004 droughts). For the climate change hydrology the frequency of corrective action is about the same as the 1988 -2012 period, but there are droughts that are more severe than even the 2000 – 2004 period. In the next bullet Kerry states that “existing 2007 Interim Guidelines …..would remain in place permanently. That is not true, we assumed that the existing guidelines would remain in place through 2040 (one 15 year renewal). After that we assumed it would be too speculative to go beyond 2040. I want to point out that while Kerry is correct, the stress test hydrology is about 1.5 million acre feet per year less than the long term record, it’s a million acre-feet per year more than 2000 -2016. In the Lower Basin, Arizona is actually taking a more conservative approach and evaluating the operation of their contingency plan based on a continuation of the 2000-2016 hydrology. Others (CWI) have suggested that since the 1988 – 2012 period includes 1995 -98, it may be optimistically wet. The bottom line is that we used a relatively short (25 year) study period because to go beyond that both the future hydrology and the operating conditions would be too speculative. In his third bullet Kerry notes that the “Upper Basin would experience a slow growth in demand”. Yes, but again the study looked at several different demand schedules, all from the basin study. We also used the so-called “current trends” or schedule A. What we found was that the schedules from the basin study showed a consumptive use level that was far too high for 2015, the beginning year of our study. That is why we ended up with a 90% of D1 schedule which reduces initial Upper Basin CU by 400,000 to 500,000 acre-feet per year (and which calibrates very well with the actual consumptive uses and losses report). Kerry’s 4th and 5th bullets that the study assumes that the Lower Basin drought contingency plan and that Upper Basin CRSP drought operations would be in place prior to demand management are important, I’m glad he pointed them out. My primary concern with Kerry’s letter is his characterization in the final bullet that “West Slope participants selected a Lake Powell target minimum elevation of 3525’ ….” Kerry further amplifies his comments on and questions the 3525’ target in his final bullet at the bottom of page 2 and the top of page 3. I want to make it clear that the West Slope did not select the 3525’. The 3525’ target was selected by the Bureau of Reclamation and seven basin state principals as a part of the development of the contingency plans in both the Upper and Lower Page 3 of 3 11/2/2015 SHOSHONE WATER RIGHTS: IMPLICATIONS FOR PITKIN COUNTY basins. Our study approach was to assume the Colorado plan to avoid compact problems (principle #4 of the framework) would be patterned after the Upper Basin contingency plan (for obvious reasons). I was involved in that process on behalf of the UCRC and we had Hydros conduct some modeling on the sensitivity of the 3525’ target. Reclamation conducted its own independent analysis. Jim Lochhead was also actively involved in these discussions. This is a very important matter. The Upper Division states are considering an agreement among themselves and Interior implementing drought operations of the CRSP reservoirs that uses this 3525’ target. I would hope Kerry’s letter doesn’t undermine support for this important agreement. Given the confusion and recognizing that “why 3525’?” is an important question, if the state agrees, I believe it would be appropriate to include an explanation and documentation of the 3525’ target as a part of completing the phase I report. I want to recognize Kerry’s last bullet that the phase I study does not address water availability. I agree, it was never intended to do so and it should not be used as such. I’m of the view that any future water availability study should only be undertaken once a demand management program has been agreed to by the state of Colorado, the other three Upper Division states and the Bureau of Reclamation. It is regretful that the East Slope has referred to this study in the press as a “slap-dash” water availability study to show there is no water available on the west slope. Finally, on page 2 Kerry makes several observations concerning the results of the study, including point #1 that there are “no study years in which a “compact curtailment” would be required”. I agree, but Kerry does not clearly point out that his conclusions are based on the fundamental assumption that the Lower Basin contingency plan, the Upper Basin drought operations plan, and the Upper Basin demand management plan (which under the 1950s and 2000 – 2004 could require a cut back of over a million acre-feet of consumptive use in the Upper Basin) are in place and working. The results and conclusions are very different if these plans are not in place. We need further dialogue on the future of this study. I have suggested that we have a couple of webinars in early January where we could discuss the unresolved issues related to the Phase I effort and discuss the goals of Phase II. CWCB Director James Eklund has offered to facilitate and convene these meetings. Before then, the West Slope will meet to discuss and consider our options for moving forward.