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 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. 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.

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. 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.

07/03/2023

06/30/2024

2024

We started the fiscal year going through Purchasing to work with an engineering firm on the final design of the screen and the specifications for fabrication. We had two requests to complete the work and selected the most qualified based on what was submitted for our review. That firm was too expensive, however, and we selected the next firm in line. We have had a great deal of experience with this firm, however, so we were happy to be able to work with them. Once we selected the engineering firm, finally, we set them to work on the final plans and the fabrication specifications as these documents were required to be sent to all cooperators and to Purchasing to select a contractor for fabrication. We received these much later than anticipated (end of January). We got them approved by all the partners within just a few weeks though. Once the plans and specs were received and approved, we set about trying to find a contractor that was within our price range. That proved to be quite difficult. Initially we wanted to work with a general contractor, but the price increase was intense. We had to instead put the work out to Purchasing to minimize the markup on the work. This yielded an affordable contractor with great references and experience working on fish infrastructure. We selected them and after discussing the design and working out a few issues there, they got to work on the initial screens immediately. Our engineer went to their shop, approved the quality of that initial screen and gave the go-ahead to proceed with fabrication of the remaining screens. We had written that contract so that they only had to complete the screen fabrication by June 30th, they had until July 31st for delivering screens to the site. They made both of the deadlines and the screens are now sitting onsite on CUWCD property below Starvation dam, waiting to be installed.

This project has been ongoing for about 10 years now. The overall goal is to minimize escapement of nonnative predators from Starvation Reservoir and eliminate them from being able to get to critical habitat for the endangered fishes in the Green River. We started with an initial engineered design for the screen, but trashed that design due to cost. We then waited a few years and then undertook a value engineering exercise with all partners to assess all options and choose the best one as a group, one that suited all partners and considered effectiveness of the screen and cost. We started working towards the option that was identified during that exercise and have been working on that for about the last 4 years. This project has been pretty tedious to work through, between having to spend so much time work with partners to ensure all 6 were/are on board with the design, etc, working with them on the permitting process (NEPA, arch clearance, ULT, 404, leasing, etc), working through Purchasing that it significantly delays our forward progress, to having to push push push to get the product, only to receive it late, to wrong turns and having to double back, to permitting delays and unresponsive partners when we need signatures and permitting assistance. HOWEVER, we worked through it. We were able to get the final plan set and specifications, select a fabricator and get all of the screens fabricated, completed NEPA and a Pre-Construction Notice for the NWP 23. Most funds were expended (we ended up not needing all of the funds identified for screen fabrication) and all partners were happy with the product and the progress. The screens were delivered on July 9, 2024 so not in FY24, but they are in our possession and ready to be installed once the BOR can pour the concrete foundation. The final pieces of the project are just an MOU that all the partners sign, discussing how we will all work together to operate and maintain the structure into the future, and the installation of the structure itself.

The DWR NER natives, sportfish, and aquatics habitat folks will continue to monitor this structure, clean it regularly during reservoir spills and 1-2 times throughout the year as needed. They will also (in association with CUWCD) keep the spillway channel mostly free of bullrush to minimize channel roughness and keep the screen functional in higher flows. If any major repairs are needed and additional funding is required, NER DWR staff will work with DWR SLO staff and the Upper Colorado River Endangered Fish Recovery Program to determine the best means for acquiring the funds and will work as quickly as possible to make the repairs and keep the screen functional in perpetuity. CUWCD are the main folks "on-the-ground" and their assistance will be essential for monitoring the state of the structure in years when Starvation doesn't spill and we wouldn't visit the site as often. Overall, we have developed a good partnership and this structure should be much easier to maintain and be much more effective than the temporary screen we currently have.