Long-awaited water from the Central Utah Project may still be another 10 years in reaching the Sevier River Basin, consultants told water users and water organization officials at recent meetings in Richfield, Delta Santaquin and Nephi.
A preliminary plan for construction of the irrigation and drainage system that will lead to approval of a final plan was outlined by Luther P. Hintz, manager of Brookman-Edmonston Engineering Inc. of Orem, a consultant to the Central Utah Water Conservancy District.Public meetings to identify alternatives for the irrigation and drainage system Environmental Impact Statement will be held in May, Hintz reported. An EIS draft is expected to be completed by late 1994, followed by public reviews and hearings.
Target date for the water conservancy district to approve the final EIS is the summer of 1995. Late that year, final decisions and presentation of the plan to the Secretary of Interior are scheduled.
Hintz and other consultants estimated costs of the drainage and irrigation phase of the project at $230 million, $150 million to be provided by the federal government and the balance by area residents. Also commenting at the meetings were consultants Jay Franscon, Rick Lind, Jim Riley and Allen Crabtree.
If and when the Sevier River Basin receives CUP water, it will be through an exchange of water rights and pumping Strawberry Reservoir water from the Diamond Fork drainage across the geographical divide north of Nephi.
The water could then be delivered by gravity flow into the Lower Sevier River Basin. Water users on that end of the system would transfer some existing water rights to those in the Upper Sevier River Basin.
Consultants said the water would be conveyed through a gravity pipeline for a distance of some 70 miles. Several tunnels would be needed to get the water to its destination at the Sevier Bridge Reservoir, commonly referred to as Yuba Dam.
Plans call for locating the main pipeline in Diamond Fork and Spanish Fork canyons, along Salem Bench above Spanish Fork and Payson, near the mountains east of I-15 between Santaquin and Nephi, and then west of U-28 from Nephi to the reservoir.
Water could be delivered throughout the year to Utah and Juab counties directly from the conveyance pipeline or through exchange with agricultural groundwater supplies, Hintze said.
Water would be delivered to the Sevier Bridge Reservoir only during winter months for use during the irrigation season. This would maximize use of the main conveyance pipeline and optimize its sizing, consultants agree.
Hintze reported that preliminary studies indicate an average annual water supply of about 100,000 acre feet of CUP water could be delivered through the irrigation and drainage system. This would include about 36,000 acre feet that would be delivered to the Sevier Bridge Reservoir.
The CUP project will benefit 176,000 acres in southern Utah County, eastern Juab County and the Sevier River Basin. The Basin extends from Hatch, Garfield County, northerly through Piute, Sevier, Sanpete and Millard counties.
Construction of a reservoir near Hatch and another near Clear Creek in Sevier County are being considered for storing water in the Upper Sevier Basin.
Most of the CUP water will be used to irrigate agricultural land in meeting crop water deficiencies that often occur during the late summer and fall months, particularly during dry years. Some might be used for industrial purposes.
The amount of available water is expected to vary from year to year, depending on water demand during dry and wet years and water exchange capabilities on the Sevier River system.
Water quality was also addressed by the consultants, who noted the Sevier River is affected by return flows from agricultural use and by natural intrusion of minerals. Quality degradation is most evident in waters within and below the Sevier Bridge Reservoir, it was reported.
Water in the Strawberry Reservoir is apparently of higher quality than that in the Lower Sevier Basin. Hintze believes that water quality would be improved in the Sevier Bridge Reservoir when comingled with that from the Strawberry. Degradation of water quality in the Sevier and possible measures to improve it are being studied.
Consultants also noted that water efficiency measures could be developed within the irrigation and drainage system. These could include lining and combining existing canals, on-farm irrigation improvements, and conjunctive use of surface and groundwater in Utah and Juab counties.
Fisheries in the upper portions of the Sevier River system as well as water quality in the Sevier Bridge Reservoir would be benefactors of such measures, consultants said.