Starvation Reservoir is a popular sportfishery in northeastern Utah. Most anglers fish Starvation to catch plentiful and sometimes quite large Walleye or the very healthy Rainbow Trout that are stocked at catchable size, but allowed to grow over 2-3 years. Other species in the reservoir include Yellow Perch, Smallmouth Bass, and Black Crappie, all popular sportfish. Nongame species such as Common Carp and Flannelmouth Sucker are also common and Utah Chub is present but quite rare. Together, this species assemblage is a huge draw to anglers from hundreds of miles away, but the predators in the system, namely Walleye and Smallmouth Bass, are problematic if and when they escape the reservoir. Starvation Dam is on the Strawberry River and escapees from the reservoir can easily move the four miles down the Strawberry and into the Duchesne River where native fish such as Flannelmouth Sucker are present. We also know they can move the nearly 50 miles required down to critical habitat for the endangered fishes in the lower Duchesne and Green River. Escapement of a predacious species like the Walleye is problematic because they can move through riverine habitats, consume large quantities of other fishes including native fishes (this is well documented), and it appears that they may even have the capacity to displace the native top predator, the Colorado Pikeminnow. Walleye were increasing in the middle Green River between 2011-2014. We installed a temporary screen in the spillway channel and since then, Walleye numbers have stabilized and even declined in the Green River. Unfortunately, over the same timespan, we have also seen a decrease in Colorado Pikeminnow. We cannot say that Walleye are the one and only cause, but their presence in large numbers certainly did not help. We therefore have to do our best to minimize the impact of the sportfish species by keeping it from getting into locations managed specifically for native fish instead of sportfish. The temporary screen placed in the spillway years ago has done a great job preventing escapement, just based on anecdotal observations of declining Walleye in downstream locations such as Midview Reservoir and the Green River. However, it has been replaced once already and in its current version requires maintenance every year. We are proposing to replace the temporary screen with a permanent structure that will require less annual maintenance and last for 30-40 years. This permanent structure is a modular picket screen and will be built on a concrete pad to minimize issues with vegetation in the screen and make routine maintenance easier. The new screen will require less maintenance than the current screen and will do a great job of keeping Starvation fish out of native fish waters.

Our overall goal for this project is to protect the native fish in the Green and Duchesne rivers from predacious sportfish that escape Starvation Reservoir via the spillway. We will do this with the following objectives: 1. Hire a licensed contractor to complete the installation of the picket style screen once fabrication has been finished and delivered to the site. 2. Maintaining the screen during spills to keep water flowing through the screen and keep it from backing up water in the channel, which in higher flow years could cause a breach. 3. Monitoring the screen after spills to ensure that anything broken is repaired before the next spill. 4. Treating the spillway stilling basin with rotenone after each spill to eliminate a potential source of unwanted fish in advance of the next spill. By meeting some of these objectives with a temporary screen, we have already documented a decline in Walleye in the Green River and we are therefore already meeting our goal. We just need a more permanent structure across the spillway to ensure we can meet this goal in perpetuity.

The threats and risks of not screening the spillway channel are well documented. The Division of Wildlife Resources did a study between 2002-2005 to determine the extent of escapement over the spillway and through the dam outlet at Starvation Reservoir. They found a great deal of escapement over the spillway, and very little through the outlet. They observed all species escaping over the spillway including Walleye, Yellow Perch, Smallmouth Bass, and others, but clearly the predators were escaping and needed to be addressed. In addition, the river crews on the Green River were collecting Walleye and submitting their otoliths for isotope analysis. Through this study, researchers determined that Walleye were likely escaping Starvation, though they couldn't decipher the isotopic signatures between Lake Powell and Starvation. The more likely source though was Starvation, given the location of the Walleye that were submitted for this analysis in the middle Green River near the confluence with the Duchesne River. These fish were escaping Starvation, traveling down the Strawberry and Duchesne rivers, and entering the Green River where they were able to survive. The river crews have numerous pictures of Walleye consuming adult native fishes. In addition, they annually document the decline of native young-of-year throughout the summer season from many young-of-year natives present in backwater habitats to very few present in the fall, likely a result of nonnative predators consuming them. We will not be able to do anything with fish resident to the Green River with our screen below Starvation Reservoir; however, we can practically eliminate the threat of Starvation Reservoir as a source of nonnative predators with one very simple screen across the spillway channel.

This screen is directly mentioned in the Starvation Fishery Management Plan, finalized in November 2016. In fact, there is an entire section of the plan devoted to escapement prevention and a goal and multiple objectives addressing the need to screen the spillway channel and ensure that predatory species do not make it downstream. This plan was developed by agency representatives and anglers and approved by each of them and the Upper Colorado River Endangered Fish Recovery Program (UCREFRP).

N/A to this project

N/A to this project

Because the footprint of the screen will be contained within an already disturbed channel, no arch clearance was needed to proceed. A survey for Ute's Ladies Tresses was completed and suitable habitat was observed. The BOR will consult with the USFWS on this as they complete the CX. They estimate it will be about $580 to pay into the mitigation bank for this plant. Once the CX and consultation have been completed, we will submit an NWP 23 to the Army Corps and a stream alteration permit to the State engineer's office. All permitting will be completed by April 15, 2024 so that the Bureau of Reclamation, Force Account can lay the foundation in late spring or early summer 2024.

The process to complete this screen and get it installed has been ongoing for quite some time. The initial discussions ended up with a design that we felt was unnecessarily expensive for the task. Instead, biologists went back to the drawing board and built a temporary screen for a fraction of the cost. Although the temporary screen was adequate and worked well for keeping fish from moving downstream, it also clogged with algae quite easily and was always only meant to be temporary while we figured out what screen design/cost would be more appropriate. In 2021, the Central Utah Water Conservancy District, Bureau of Reclamation, Utah Division of Wildlife Resources, and a few other interested parties met for a week straight and completed a value engineering study. Through the value engineering process, the group decided that a Modular Picket Screen across the channel with horizontal rounded bars would be most efficient, economical, and agreeable to most of the parties involved. The screen design also included a concrete pad to aid in maintenance and access (the spillway channel is choked with bulrush). This design is relatively inexpensive, similar to the temporary screen with improvements to make it even easier to maintain, and outside the primary jurisdiction zone, which was important to our federal partners. Anything outside the PJZ would not be owned by the federal partners once built. This was very important as these agencies did not want to take on the expense or liability of owning the structure. The Utah Division of Wildlife Resources, however, will accept ownership and all expense associated with owning the structure. The Bureau of Reclamation will clear the area and pour the concrete slab sometime in late spring or early summer 2024. We plan to hire a contractor to fabricate the screen in FY24 for installation in FY25. Once the screen pieces are delivered, we will hire another contractor to install the screen on the concrete pad, assuming we receive funding on the proposed schedule. Part of the expense for FY24 will be to complete the engineering on the screen so that the contractor can fabricate it to exact specifications that the site requires. In FY25, we will continue to work with the engineer to help us worth with the contractor to install the screen.

Due to the spill schedule for Starvation, we will visit the screen multiple times each spring to clean it during the spill (once or twice weekly, depending on the spill volume that year). We will also visit the screen in the fall to complete the rotenone treatment. At these times, but especially in the fall when the spillway just has groundwater and is not actively spilling, we will inspect the screen for any needed repairs or maintenance requirements. We will also monitor the screen and spillway channel for species of fish observed so that we can ensure our effectiveness at preventing the escapement of predatory species down into the Duchesne and Green rivers. If any repairs are needed, we will schedule those for a time outside of the next likely spill. If additional funds are required, we will apply through the Division's WRI process, at the beginning of the calendar year, and make any needed repairs in the fall if funding is awarded.

We are partnering with the UCREFRP on this project, which consists of numerous water users, hydropower interests, state agencies, Native American tribes, conservation groups, and federal agencies. All in all, there are 20 partners listed on the UCREFRP website. Each of these partners reviewed or at least had a chance to review the Starvation Fishery Management Plan and provide input on the screen. Therefore, each of these partners is in support of the screen and they will also be contributing some funding through the UCREFRP as the Bureau of Reclamation (one of our federal partners) will be constructing the concrete pad with funding from the UCREFRP.

Starvation Reservoir is managed to spill in the late winter or early spring of each year. In very dry years, it does not spill, but in most others, it will spill for at least a few days if not a few weeks to months. Each spring when it does spill, we will clean the screen once or twice weekly and ensure that it is not getting clogged with debris or backing up flow, which could eventually lead to screen failure (erosion around the edges if it were allowed to continue too long). In addition, we will revisit the screen in the fall to complete the rotenone treatment on the stilling basin and at this time, we will inspect the screen for any issues or repair work needed. Otherwise, this structure should remain in place and be quite solid for many, many years.

Installation of this screen allows the Utah Division of Wildlife Resources and our partners to better conserve and sustain the endangered fishes of the Colorado River drainage and the other native species that are not as rare, but are still threatened by the escapement of these predatory fishes from reservoirs. If we can keep nonnative predators in reservoirs and keep them separate from the native fishes, the native fishes will have a much better chance of being recovered and of existing well into the future.

03/01/2025

06/30/2025

2025

Carried over into FY 2026, thank you! Unfortunately the BOR construction crew was not able to complete their portion of the concrete work in FY 2025. We are on the schedule for Fall/Winter 2025/26 and hopeful it will get done. We have moved back the contract date with our engineers and have touched base with the BOR Force Account (who had severe DOGE personnel cuts earlier this year) to see if we can remain on their FY26 schedule. They are hopefully going to work us in this fall/winter and we emphasized the importance of doing so. We are able to work with our engineers until mid-December so may have to push that back again if Purchasing will allow it. Our ACOE permit is good through March 2026 so we are still ok in that department if we can stay on the current schedule. We have put the RQS out for bid to get a installer secured and the cost secured. Bids have closed and a contractor selected and they are ready to begin as soon as we say the word.

The intent was to Install the pre-fabricated fish screen panels onto the concrete footer wall to complete the fish screen in FY25; however, due to delays (DOGE), we were unable to get that done in FY25 and all work has been pushed back to FY26. We were able to make forward progress in FY25, though, making minor adjustments to the screen design, etc. so that we are ready to move forward as soon as BOR can get their portion done.

Once installed, we will utilize the NER Aquatic operation and maintenance technician to operate and maintain the permanent fish screen below Starvation Reservoir. This work will be ongoing indefinitely. The new screen should be much easier to maintain and will be absolutely much sturdier than the current temporary screen.