Wyoming State Water Plan
Wyoming State Water Plan
Wyoming Water Development Office
6920 Yellowtail Rd
Cheyenne, WY 82002
Facilitator Joe Lord welcomed the group and the meeting was opened at 5:00 pm. The overall meeting agenda was reviewed, followed by an introduction of all attendees. There were no Planning Team issues on the agenda. A sign-in sheet was passed around to record attendance.
Pat Tyrrell of States West introduced Mr. Gary Watts of Watts & Associates, who was present to discuss preliminary population projections. Mr. Watts is a consulting economist who is on the consulting team for the Green River Basin Water Planning Study.
Mr. Watts' presentation began with a discussion of current population estimates for the basin in comparison to the estimates given in the earlier Framework Water Plan. Actual growth in the basin by year 2000 will have been more than the earlier plan had estimated. Mr. Watts then went on to show four different projections to the year 2030 he has made to date, including data from:
- State of Wyoming DAI growth estimates;
- Federal Bureau of Census estimates based on tax return address changes;
- Federal Bureau of Census estimates based on job growth; and
- Actual 1960-1990 regional growth rates, extended into the future.
Mr. Watts proposed that the DAI numbers be used as a "low" growth scenario, the Census projections (which were similar) be used as a "moderate" growth scenario, and the 1960-1990 rate used as a "high" growth scenario. Mr. Watts noted that the "high" scenario proposed may actually be too high, in that the base population (+/- 30,000) in 1960 is not the same base population as exists today (+/- 60,000). He indicated that maybe the absolute growth amount, in terms of number of people, might be a better "high" scenario estimate than the percentage approach.
Comments and questions posed after Mr. Watts' presentation follow:An industry representative noted that the "high" scenario might be too high because he is not aware of any industry expansion plans in the works (such as the expansion that fueled growth in the 70s and 80s). Mr. Watts noted the comment and said he would be contacting industries in the basin to discuss future plans.
A questioner wondered whether the projections included consideration for population movement due to "baby boomers." Mr. Watts said he was unaware of objective data on this demographic, but to the extent this group would move away from Wyoming as well as move into the state, the overall effect is likely small.
A questioner asked about the time frame for counting seasonal employees, and whether they were included in census figures. Mr. Watts said that census numbers typically use the "permanent" address when counting people, so whether seasonal employees are included or not depends on if, and where, they claim that address. The overall effect of the counting of these workers is probably small because some are probably included that are not residents of Wyoming and vice versa.
A questioner wondered whether, and how, the agricultural community is counted. The answer was yes, agricultural residents (farmers and ranchers) are included in the rural sector count.
One questioner wondered if the projections Mr. Watts was making were made the same way that a commercial venture, such as Wal-Mart, might make them before deciding to build in a certain location. Mr. Watts was unsure what data such commercial decisions were based upon, but suggested state projections were available and very possibly used in that way.
A questioner asked if projections for future power generation needs had been looked into as a way of forecasting population growth. Mr. Watts said no, but that it was something he could look into.
One questioner asked whether the 1980-1990 (or 1980-2000) period, specifically, had been looked at as an actual growth period for future projection because that period would not be unduly influenced by the industrial growth spurt of the 70s and early 80s. Mr. Watts said no, but it could be.
The final questioner asked whether Mr. Watts had a feeling for which economic sector would see the most growth in the study period. Gary said he did not have that information at hand, but could review the assumptions in the econometric models used and could have that information, as well as the current makeup (population as a function of economic or industrial sector) presented at a future BAG meeting.
Mr. Bill Klippert made a presentation on the operation of Viva Naughton (VN) Reservoir, which is owned and operated by Naughton Powerplant. Highlights of his presentation follow:
- VN dam is roughly 70 feet high and 3,200 feet in length with a storage capacity of 45,184 AF. The High Water Line elevation is 7242 feet msl.
- The dam was built in 1960, with subsequent enlargement and the addition of hydropower capacity. Hydropower generators (2) are capable of supplying 567 and 173 kiloWatts of power. The primary purpose of the reservoir is to provide a continuous supply of cooling water at 25 cfs to the Naughton Powerplant under a 2-year drought scenario. No agricultural water is specifically included in the reservoir storage permit.
- Penstock (2) capacities are 740 cfs (54-inch Howell-Bunger valve) and 100 cfs (18-inch Howell-Bunger valve).
- The service spillway uses 2 16-ft wide by 11-ft high slide gates with a combined capacity of 12,000 cfs. Ultimate dam protection from overtopping is provided by an earthen fuse plug.
- The inflow to the reservoir is not measured because of the number of tributaries entering the various arms (in addition to the main stem Hams Fork). Outflow is measured below the dam. Inflow is calculated based on outflow and reservoir storage values.
- The size of the powerplant generators at the Naughton plant are: Unit No. 1: 160 Net MW Unit No. 2: 210 Net MW Unit No. 1: 330 Net MW
- Reservoir operations can be simply described as follows:
- Permit allows storage of runoff in excess of prior rights (160 cfs)
- Not constructed for flood storage (no flood pool) but can be operated to assist is reducing flooding levels below the dam.
- Historic inflows have ranged from 0 to 2,500 cfs; historic outflows from 30 to 2,250 cfs.
- Goal is to fill by June 20, snowpack data are used to help plan storage schedule.
Questions and comments:One questioner asked why it doesn't make sense to enter into an agreement with the State of Wyoming and other users to enlarge the reservoir and include flood control and irrigation purposes. Mr. Klippert responded that they have not been approached with a serious offer (economically speaking) to do that.
A comment was made that one reason there is no agricultural dam in the basin is that one of the favorable sites had been overfiled by industry before the irrigators could file.
One questioner asked what Naughton had done to benefit the downstream irrigators. Mr. Klippert responded that they have over-released in non-drought years for agriculture benefits. However, they have been careful not to establish a predictable pattern of over- releases. A predictable pattern could result in the irrigators coming to rely on releases that may or not materialize in years the water is needed for the power plant.
A question was asked about where the power from the hydropower plants was used. Mr. Klippert responded that it generally offset the power use at the Kemmerer substation. Another questioner asked Mr. Klippert's reaction to the filing of instream flow water rights on the Hams Fork below the reservoir. Mr. Klippert believes instream flows are not tied to storage and therefore the filing is of no effect to the reservoir operation.
In response to other comments, Mr. Klippert indicated that the reservoir has an Emergency Action Plan on file with the State of Wyoming. This plan contains detailed information on the inflow design flood magnitude, downstream flooding effects and other safety-related data. Also, Mr. Klippert said that while the plant was designed for a 30- year life, the availability of spare parts should keep them running for the foreseeable future.
Discussion of Issues Meeting Held on November 6, 1999
Mr. Lord walked the group through the results of the issues meeting held in Rock Springs the previous Saturday. One question was whether tonight's attendees should consider the presentation, and any follow-up, as adoption of the issues document by consensus. The answer was yes, although the document would be "cleaned up" grammatically and organizationally following the meeting. Additional comments on the issues included:
- Under Water Quality, address the use of wetlands to improve water quality.
- Address the anecdotal comment that declining glaciers in the Wind River Range may have a measurable impact in water supply in the Green River.
- Note that the issue of access under the heading of Recreation is intended to mean: "does access (or lack thereof) have an effect on the use or economic value of water resources in the basin."
These and other comments will be included in the final issues statement and posted on the Water Planning website.
The meeting was adjourned at 8:20 pm.