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, kokanee, 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 sportfish species by keeping them 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 intensive repair nearly 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. Preparing the location for the permanent screen in the Starvation spillway channel, laying a 10 foot wide concrete pad across the channel in that location, and installing a specially fabricated modular screen (fabricated to specific design specifications) across the channel and attaching it to the concrete pad. 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. In order to get this whole project going, however, we need a properly designed structure, which we are working towards with the engineering firm Hansen, Allen, and Luce. This phase of the project solely works with HAL and other partners to finalize the basics for a 30% design that can be used as we move forward.

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).

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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. Engineering and design work will be paid in FY23 to get the design to 30% and work with partners to ensure everyone approves of the design, in FY24 to take the design to 100% 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 work 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. In addition, due to the multiple agencies managing various aspects of Starvation Reservoir, we are also working with Utah State Parks, BOR, CUPCA, USFWS, and CUWCD to finalize the design for the screen and complete the permitting.

Starvation Reservoir is managed to spill in the late winter or 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.

07/01/2022

06/30/2023

2023

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 and allowed to grow over 2-3 years. Other species in the reservoir include Yellow Perch, Smallmouth Bass, kokanee, and Black Crappie, all popular sportfish. 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 middle 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 does not help. We therefore have to do our best to minimize the impact of sportfish species by keeping them from getting into locations managed specifically for native fish. We also owe it to our partners in the Upper Colorado River Endangered Recovery Program to do our best to minimize impacts of our sportfisheries on downstream native fish resources. 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 regular, intensive repair after spills. 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, which was identified by all partners (U.S. Bureau of Reclamation, Central Utah Water Conservancy District, the Central Utah Project, and Utah State Parks) as the ideal structure and location to meet everyone's needs and goals for the project. The screen will be fabricated and installed on a concrete pad to minimize issues with vegetation around 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. ESMF funds were used in FY23 to help complete the 30% design work for the screen. All funding was provided as payment to Hansen, Allen, and Luce, the engineering firm we have been working with on the 30% screen design. HAL provided all requested deliverables and on time, before the end of the fiscal year and we have been pleased with their work thus far. The 30% design will be taken to 100% in FY24. Once that is complete, we'll send the design for fabrication and we'll also work with our partners on permitting for the structure. Installation of the screen is anticipated for Sept 2024.

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 through the following objectives: 1. Preparing the location for the permanent screen in the Starvation spillway channel, laying a 10 foot wide concrete pad across the channel in that location, and installing a modular screen (fabricated to specific design specifications) across the channel and attaching it to the concrete pad. 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. In order to proceed, we need a properly designed structure, which we are working towards with the engineering firm Hansen, Allen, and Luce. This current phase of the project solely works with HAL and other partners to finalize the basics for a 30% design that can be used as we move forward. To this end, we met with HAL a number of times to discuss the screen in FY22 and FY23. They have visited the site multiple times for surveying purposes. In addition, we have met online numerous times to discuss the design, add features to aid in cleaning and maintaining the screen. HAL has responded to all of our concerns and concerns from the CUWCD and BOR (our partners in this effort and owners/operators of the dam) and have thought extensively about how the screen could impact the spillway channel, in an effort to minimize damage to infrastructure.

In FY24, we are working through Purchasing to select an engineer to take this 30% design to 100%. There will be a quick turnaround time on this as we also need to put the screen fabrication out to bid this fall/early winter so that a contractor would have time to fabricate it and deliver it to the site before June 20, 2024. We will also be working towards the permitting on the screen. BOR is currently working on the NEPA and consultation with the USFWS on ULT mitigation. Once that is completed, DWR and BOR will apply for an ACOE permit. We anticipate that being completed overwinter, leaving the construction portion only. BOR Force Account will be prepping the site after the 2024 spill and will pour the concrete pad (Recovery Program will cover this). The selected engineering firm will work with BOR on that effort. In addition they will work with the screen fabricator, responding to questions about the design as needed. And finally, we anticipate hiring a contractor to install the screen in FY25, as funding is available. The engineering firm will assist with that portion as well, as needed. The screen should be fully functional in the 2025 spill!