Laserfiche WebLink
Northern Colorado Water Conservancy District Agenda Item 34b <br /> May 9,2014(Updated May 23,2014) <br /> Page 3 of 6 <br /> Northern Water has the authority to generate, distribute, sell, or contract to sell electric energy at <br /> wholesale rates through the operation of the facilities of Northern Water. The electric power may be <br /> used both within and outside the boundaries of Northern Water(C.R.S. 37-45-118(2)). <br /> Northern Water will own, maintain, and operate Granby power facilities through its hydropower <br /> enterprise. The enterprise was established in 2011 for the purpose of acquiring, constructing, <br /> operating, and maintaining hydropower plants; and generating, distributing, selling or contracting to <br /> sell electric energy. The governing body of the enterprise is the Northern Water Board of Directors. <br /> Water Rights <br /> Northern Water's water rights portfolio includes West Slope reservoirs: Grand Lake, Green <br /> Mountain Reservoir, Lake Granby, Shadow Mountain Reservoir, and Willow Creek Reservoir. Its <br /> East Slope reservoirs include: Boulder Reservoir, Carter Lake, Flatiron Reservoir, Horsetooth <br /> Reservoir, Lake Estes, Mary's Lake, and Pinewood Reservoir. <br /> The C-BT Project was designed to deliver 310,000 AF annually. Typically 210,000 AF are <br /> delivered depending on the quota(the amount of C-BT water established by the Northern Water <br /> Board makes available to alotees). <br /> Lake Granby has a storage right of 543,758 AF with an adjudication date of October 12, 1955 and <br /> an appropriation date of August 1, 1935. <br /> Project Description <br /> The proposed Project will utilize the existing outlet flows from Granby Dam to the Colorado River <br /> and will act as a run-of-river plant, meaning the plant operations will not change existing flows or <br /> dam releases. Alternatives were analyzed for both the powerhouse location and turbine sizing. The <br /> powerhouse locations evaluated were: <br /> Alternative No. 1 — Tunnel Outlet: This option placed the powerhouse directly at the mouth of the <br /> tunnel and was initially considered the preferred option. A single 54-inch diameter penstock would <br /> have been included. However, due to concerns by Reclamation regarding potential future work at <br /> Granby Dam and the possible impacts that work might have on the powerhouse,this alternative was <br /> removed from consideration. <br /> Alternative No. 2—Downstream: This option would place the powerhouse approximately 300 feet <br /> downstream of the tunnel. A new bifurcation would be installed within the tunnel and a 36-inch <br /> pipeline would be extended from that point. The main outlet valve would remain within the tunnel. <br /> Due to slope stability concerns with the hillside behind the powerhouse,this alternative was <br /> removed from consideration. <br /> Selected Alternative No. 3—Streamside: This option is similar to Alternative 2 except the <br /> powerhouse would be located along the bank of the outlet channel and would be approximately 200 <br /> feet from the tunnel mouth. This is the preferred alternative upon which final design is underway. <br /> An analysis was also made for turbine sizing. The goal was to cover a flow range from 20 to 75 cfs. <br /> Scenarios analyzed included a single Francis turbine, a single Turgo unit, and a two-Francis unit <br /> configuration. The optimal configuration weighing cost and revenue was the two-Francis <br /> configuration. <br />