Completion Form

2024

The rebuild of two irrigation diversions that are fish barriers on the Blacksmith Fork (BSF) was the focus of this project by the Utah Division of Wildlife Resources, Trout Unlimited, Utah State University, and the local irrigation companies. The BSF-Hyrum irrigation diversion is located approximately 1.25 miles downstream from the mouth of Blacksmith Fork Canyon. It is then about 0.7 miles downstream from the Hyrum diversion to the Nibley diversion.

Construction began on the BSF-Nibley diversion during November 2022. Sunrise Engineering was the project engineer working with DWA Construction (the contractor hired by the BSF-Nibley Irrigation Company). An Obermeyer weir (hydraulically inflated) was installed as the diversion structure. The construction of the Obermeyer weir involved pouring concrete footings and installing all wiring and tubing for operation. In addition, a fishway bypass structure was poured out of concrete to be used for fish passage when the Obermeyer gate was raised.
  
DWA started construction by installing a temporary diversion structure (aka coffer dam) in the river to send water into the canal and allow dewatering of the area downstream. Most of the river's flow then was directed into the canal and then returned a couple hundred yards downstream. The coffer dam was finished in December. In late January, DWA had installed sheet piles to move water into the canal and started pumping excess water below the diversion.  They set up forms and poured concrete in February.

In late February, the DWR heavy equipment crew mobilized a track hoe and dump truck to the site. They also hauled some additional needed rock to the site. A previous contract with a private firm had already hauled 266 tons of rock to the site. The DWR crew installed three rock vanes over the course of two weeks with some delays caused by crews from DWA and a private individual (doing work on the bridge abutments) also working there at the same time. DWA continued to work on the diversion structure into March and April.

As river flows came up this spring, high sustained flows passed over the diversion and vanes without incident.  At peak flows, the water levels did rise high enough that upstream landowners were concerned about flooding. These issues are still being addressed and a new design for the Obermeyer weir and concrete footings is currently being corrected. The rock vanes performed very well. A few boulders did shift positions a little but not enough to undermine the project.  Those boulders will be repositioned this fall as the DWR crew returns to do work on a nearby project.

Upstream, the BSF-Hyrum Irrigation Company was not awarded the grant that they had submitted a proposal to the Bureau of Reclamation. The irrigation company and their project engineer (Franson Engineering) then had to regroup and extend their timelines on that project.

Clint Brunson

08/29/2024 13:57:06