The Blacksmith Fork (BSF) supports a Blue Ribbon Fishery in its headwaters and the canyon. However, as the river flows out of the canyon and enters Cache Valley there are six irrigation diversions in about eight miles downstream to the Logan River. The BSF-Nibley irrigation diversion is the major fish passage barrier that prevents the upstream movement of fish between the Logan River and the BSF canyon. The BSF-Nibley Irrigation Company is in the process of rebuilding their irrigation diversion and they are agreeable to making it fish passable. In addition, about 0.7 miles upstream of the Nibley diversion, the BSF-Hyrum Irrigation Company currently uses a push-up dam (a diversion structure annually constructed of earthen materials and concrete rubble). This diversion structure is located on a split channel section of the river and is destructive to stream and riparian habitat. The canal company wants to replace this structure to improve irrigation needs, fish passage, and habitat conditions.

* Restore fish passage connectivity to 25 miles of the BSF by rebuilding the Nibley diversion * Improve the structural integrity of a bridge foundation and apron immediately downstream of the Nibely diversion as part of the rebuild * Rebuild the Hyrum diversion to eliminate a push-up dam * Improve fish and riparian habitat at the Hyrum diversion * Improve the Hyrum canal irrigation water conveyance with the installation of pipe.

One of the diversion rebuild options previously being considered by the canal company for the Nibley diversion was the sole use of an inflatable dam. That diversion option would further reduce fish passage and likely eliminate any chance of improving connectivity on the BSF for several more decades. Furthermore, the bridge and apron immediately below this diversion continues to erode. If this is also not addressed, then future "fixes" for the bridge structure could also further reduce fish passage. Work at the Nibley diversion is likely the key project to making progress on improving not only fish passage, but likely the precedent needed for improving stream flows, habitat, and recreational access on the BSF in Cache Valley.

1) Utah Wildlife Action Plan (WAP 2015): Actions related to dams and diversions will focus on correcting barriers to fish movement and other mechanisms of habitat and population fragmentation. The WAP designates riverine, aquatic-forested, and aquatic scrub-shrub as key habitats for Species of Greatest Conservation Need. All these habitat types are present on and adjacent to the project footprint. Completion of this project would prevent destruction or further degradation of these key habitats. Statewide, Utah's surface area is composed of 0.22% riverine, 0.10% aquatic - scrub/shrub, and 0.01% aquatic - forested. Improvements in these very rare key habitats is probably one of the highest goals of implementing the WAP. Management recommendations in the WAP, for these particular habitats and relevant to this particular project, specifically include: maintaining or restoring sediment flow regimes. 2) UDWR Strategic Plan: this project will also help the UDWR meet its Resource Goal, which is to "Expand wildlife populations and conserve sensitive species by protecting and improving wildlife habitat. This project will specifically address objectives 2 and 3 of the UDWR Resource Goal, which are to "increase fish and game populations to meet management plan objectives, and expand quality fishing and hunting opportunities," and "conserve sensitive species to prevent them from becoming listed as threatened or endangered." 3) UDWR Logan River Drainage Management Plan (Hydrologic Unit ) identifies..... 4) Bonneville Cutthroat Trout Conservation Agreement and Strategy (signed by all states within historic range): The goal of the BCT CAS is to (1) "ensure the long-term existence of BCT within its historic range [page 2]. This project will help to address the specific objective of supporting additional BCT conservation populations in the Bear River in Utah [Table 2]. 5) The project area lies within the boundaries of Watershed Restoration Initiative Focus Areas along the BSF. 6) Little Bear-Logan Drainage (LBLD) Management Plan Native species: Bonneville Cutthroat Trout, Objective 1: Maintain known and potential conservation populations in the LBLD, Strategy c.1. Evaluate the feasibility of enhancing habitat with instream structures in high-priority sub-drainages. 7) Sportfish management for intensive yield waters, maintain a catch rate of 0.5 fish/hr. 8) Wild fish waters, General strategies, a. maintain fish populations exclusively by regulations b. Work cooperatively with land management agencies and the public to enhance or maintain aquatic habitats and aquatic wildlife.

Catastrophic wildfires and resultant floods and debris flows have eliminated isolated fish populations in many places recently in Utah. Although this project does not directly address the risk of fire and fuels, it does improve the resilience of aquatic species to handle fire effects. Reconnecting streams to allow for fish movement and migration provides for the resiliency of fish populations in the event that a fire or catastrophic flood occurs.

Rebuilding the Hyrum diversion with a permanent structure will eliminate the need for the canal company to annually construct a push-up dam and dredge the river. This will eliminate sedimentation caused by the annual use of heavy machinery and the degradation of streambanks and resultant erosion. In addition, about 1,500 feet of streambank will be stabilized with vegetative plantings and bioengineering treatments used to improve the riparian area and its sediment filtering capacity.

A stream alteration permit application would be submitted for the rebuild of each diversion. Utah Division of Wildlife Resources will complete the archeology surveys and clearance for the project.

A fish passable diversion structure is currently being designed by Sunrise Engineering for the Nibley Canal. A topographic survey has been completed that will be used for the design process. It's planned that a series of large-rock step structures (aka, cross vanes) will be used to provide the elevation needed for water diversion into the canal, as well as providing upstream fish passage. It's estimated that about 250 tons of large rock (approximately 2 to 4 feet diameter) will be need to be purchased for the Nibley cross vanes. The Utah Division of Wildlife Resources construction crew will build the cross vanes over about a 2-week period in late summer or autumn. In addition, fill material will need to be placed under the bridge abutments and apron to support their structural stability and facilitate the fish passage design. An inflatable dam structure will also be incorporated into the uppermost rock cross vane. It's envisioned that this structure would only be needed to divert water on the very lowest water years. When not in use the structure is completely deflated and will allow for the passage of streambed sediment downstream and fish passage upstream. Sunrise Engineering will provide construction oversight on the bridge and abutment stabilization and inflatable dam work. The UDWR habitat biologist will provide construction oversight of the UDWR construction crew. The Hyrum diversion will be rebuilt with a low concrete sill at the current channel split. A series of rock cross vanes will be used downstream of the sill to provide fish passage and to hold channel grade. About 1,500 of streambanks will be stabilized with vegetative plantings and bioengineering treatments used to improve the riparian area and its sediment filtering capacity. The Hyrum Canal will be put in a 36-inch diameter pipe from the new diversion structure down canal for about one mile. In addition, 1,520 feet of 24-inch diameter pipe will be installed in a canal lateral.

Observational and photo point monitoring of the cross vane structures will be completed by UDWR and TU following spring runoff in 2023. High river flows are most likely to cause any displacement or shifting of rocks in the cross vanes. Post-project surveys and hydraulic modeling of the rock cross vane structures will be completed by a doctoral student in the Department of Civil and Environmental Engineering at Utah State University. This will be done to evaluate the rate of movement and depositional patterns of bedload material (substrate that moves along the river bottom) through the cross vane structures. Stream flow measurements at the structures are need for this modeling and will be provided at USU's stream flow gages that are currently being operated between the two diversions and in the Nibley canal.

Utah Division of Wildlife Resources, Trout Unlimited, BSF-Nibley Irrigation Company, BSF-Hyrum Irrigation Company, local landowners (where in-river work will take place), Utah State University Department of Civil and Environmental Engineering, Proctor & Gamble Business for Water Stewardship Program, USDI Bureau of Reclamation

As noted, BSF in Cache Valley has been an intractable problem for decades with regards to fish passage, habitat alteration, and the dewatering of the river during dry years caused by irrigation diversions. Providing fish passage at the Nibley diversion is likely the key step to beginning to solve these issues. If these two diversions can be improved, then further potential work with these canal companies is to provide instream flows below their diversions, even during dry years. A couple different private water rights holders have expressed interest in keeping their water instream below these diversions. TU has been working with these water rights holders on potential water leases to provide instream flows for this purpose. Lastly, the BSF is a tributary to the Lower Logan River, which is currently in the midst of an Environmental Assessment to evaluate rebuild options for the Crockett Diversion. One of the major goals of this EA process is to maintain and improve river flows on this part of the Logan River, which would provide additional fisheries benefits to improving habitat and flows on the BSF n Cache Valley.

The rebuild of both diversions will support the improved operation and maintenance of canal systems that support irrigated agriculture on hundreds of acres. This project has the potential to significantly improve the recreational use of the BSF, including fishing. The BSF immediately below the Nibley diversion supported over 1,400 trout per mile in 2019. This was based upon an electrofishing survey completed by UDWR after several average or above-average water years. Improving fish passage will support the upstream movement, and survival of these fish. If future water leases can be implemented, then this also has the potential to improve fish survival and fishing conditions downstream of these diversions. Furthermore, there are opportunities to develop public access and use of the river by working with landowners downstream of the Nibley diversion.

07/01/2022

12/05/2023

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.

The immediate goals for this project were achieved at the BSF-Nibley diversion to install an Obermeyer Weir and construct three rock vanes to provide fish passage. The irrigation company now can operate and maintain their diversion without having to put boards and tarps in the river, which was a hazard to operate each year. The cross vanes installed now provide a way for fish to move upstream beyond the previous drop off the concreate apron. the BSF-Hyrum Irrigation Company is still working on design and planning for improving their diversions works as well as adjacent habitat. Because they did not receive the large federal funding, then they were anticipating to phase the work. Instream work is now proposed for 2024.

The BSF-Nibley Irrigation Company will be using the new weir to divert river flows for their water right. There is still some work that needs to happen on the concrete footings to improve sediment passage. Also, the weir will be modified to allow more water passage to lower water levels during peak runoff periods. The BSF-Hyrum Irrigation Company will be pursuing instream construction work in 2024. Piping of their canal would then take place in a subsequent outyear. There is the potential for the lower Blacksmith Fork to be a part of a Natural Resources Conservation Service funded PL-566 project, which would include an assessment of all canals and needs on this part of the river. Funding also would be provided for identified construction needs.