Completion Form

2023

IN STREAM STRUCTURE IMPLEMENTATION:
In winter 2023 the state of Utah awarded a contract for low-tech process-based restoration (LTPBR) on the Price River and San Rafael River for both Phase II (this project) and Phase III (an ongoing project). Per the contract conditions work needed to be completed by March 31, 2023. The contract was for the maintenance and/or construction of 50 instream structures at each of three locations (total of 150 structures): 1) Price River downstream of Woodside, UT 2) San Rafael River, near where state highway 24 crosses the San Rafael River and 3) San Rafael River near Moonshine Wash, approximately 12 miles south of the town of Green River, UT. 
Post implementation of the in-stream structures we walked the full extent of each project area, and took photos of anything that could plausibly have been built in March 2023. We looked for evidence of new posts, which were easily distinguishable from older posts, which had been in place for the past two years. We also looked for evidence of newly integrated woody material. Where used, it was easy to observe juniper needles and branches still on the banks, or swaths of cut willow, and in at least one instance tamarisk, that had been cut to provide fill material. Our survey took place during some of the lowest flows of the month. In other words, there is only a limited chance the structures would have looked any different at any other point during the month. In many instances, flows reached the top of the posts, and little or no material was visible.

We categorized the structures by the width of the channel they spanned, as either channel-spanning, or bank-attached/mid-channel (i.e., non-channel-spanning) and by size. We classified all structures into three categories: 1) No visible material 2) Limited size and material 3) Moderate size. We did not encounter any structures we would have categorized as 'large,' therefore such a category is not present. We categorized a structure as 'no visible material' when no woody material could be seen, but posts had been installed. In some instances, posts extended above the water surface, and material would have been visible if present, while in others the water surface was at the same elevation as the top of the post. In those instances, it is possible that some material was used and was simply under water. In most cases, however, there was little evidence of material below the surface which would have created altered flow paths and turbulence on the surface of the water. We categorized structures as 'limited size and material' when a structure had visible woody material but was either limited with respect to how much of the channel it spanned and/or how much material was used. We categorized a structure as 'moderate size,' when the structure appeared to have incorporated an acceptable amount of material, such that it was capable of influencing flows and forcing local geomorphic change. By contrast structures categorized as 'limited size and material,' are unlikely to force the geomorphic changes that are the goal of restoration.

In addition to field photos, we surveyed the full extent of each project site with an Unmanned Aerial Vehicle (UAV, i.e., drone) and created high-resolution (0.05 m) orthomosaics. These orthomosaics are part of longer-term monitoring efforts, but can also be used to identify and map all restoration structures. For more information, figures and tables please see the monitoring report (Price_San_Raf_as_built_monitoring_2023 on the WRI website.

In general, most structures were of limited size, and a significant amount had no visible material. Only a total of 17 structures were of moderate size across all three project locations. While it is possible that some structures incorporated more material than was easily visible, the absence of significant juniper remnants along significant portions of each stream suggests that insufficient material was collected. Along the San Rafael River at Highway 24, no evidence of juniper was found, while most structures had areas where willow had been harvested for fill material. On-site willow is insufficient for building material due to its small size (tending be less than 8 ft long and diameters rarely exceeding 1 inch), and the large size of the channel which requires significant material in order to build robust structures. Previous restoration on the Price River, for example, required multiple weeks of cutting, transporting, and staging of juniper. Of the three restoration sites, the Price River appeared to have the most juniper, the Moonshine Wash showed limited evidence of juniper, and none was observed at Highway 24. However, in all three cases, it appears insufficient material was brought to each site.

NON-NATIVE VEGETATION REMOVAL:
In a previous WRI project #4551 Tamarisk and Russian olive removal was completed on the BLM land at the Woodside site. The vegetation was removed with heavy equipment (excavator) with a thumb attachment allowing for whole tree removal. These trees were then stacked in piles and left. Those were burned by the BLM as part of this WRI proposal on March 3, 2022.

NATIVE PLANTINGS:
Container stock was planted in the fall of (October) of 2021. Plants included cottonwood trees, woods rose, chokecherry, and desert holly. All were planted in a long stem method by a youth corp. These were in areas that the nonnative vegetation had previously been removed.

BEAVER RESEARCH AND MONITORING:
Stream restoration programs are increasingly employing beaver-related restoration techniques, including beaver translocations or installation of beaver dam analogs (BDAs) to degraded streams. Both approaches can improve in-stream and riparian habitat through dam building and contributions of large woody debris. This instream structure can create complex in-stream habitat, but each has drawbacks; the survival and site fidelity of translocated beavers may be low, whereas BDAs can require long-term maintenance. Our goal was to investigate whether installation of BDAs improved the probability of translocated beavers surviving and colonizing a section of degraded desert river in east-central Utah. We translocated 39 beavers fitted with VHF and/or PIT tags to the Price River over two years, installed BDAs, and translocated another 73 tagged beavers over two years. In all four years, we monitored survival and site fidelity of VHF-tagged beavers. We also surveyed the study area for beaver dams and monitored beaver activity on the BDAs. We found similar apparent survival eight weeks post-release of pre-BDA beavers (survival = 0.50 +/- 0.08 SE) and post-BDA beavers (survival = 0.41+/- 0.06 SE). Fifteen predation-caused mortalities occurred, and 43 beavers emigrated outside of the study site. Of the 70 BDAs that were constructed, we observed signs of beaver activity on two structures. There was a decrease in the number of intact natural dams due to monsoon floods. Our results suggest BDAs may not improve survival or site fidelity of translocated beavers in desert river systems. Nonetheless, translocation remains a humane alternative to euthanasia of nuisance beavers. More research is needed on how habitat, individual behavior, and resident conspecifics influence beaver translocation success.

FISH HABITAT ASSESSMENT

Widespread hydrologic alterations have simplified in-stream habitats in rivers globally, driving population declines and extirpations of many native fishes. Here, we examine how rapid geomorphic change in a historically degraded desert river has influenced habitat diversification and ecosystem persistence. In 2010, a large reach of the dramatically degraded and simplified lower San Rafael River (SRR), Utah, was impacted by the formation of a valley plug and began to shift from a homogenous, single-thread channel to a complex, multi-threaded riverscape. We combined field measurements and drone-collected imagery to document changes in fish habitat due to the valley plug. Our results demonstrate that in 2021, the affected reach was more diverse than any other stream reach along the SRR, containing 641% more diverse habitat (e.g., pools, riffles, backwaters) than what was measured in 2015. The plug reach also retained water for periods beyond what was expected during seasonal drying, with the total extent of inundation within the riverscape increasing by over 2,800%. Since the formation of the valley plug, riparian habitat has increased by 230% and channel networks have expanded to more than 50 distinct channels throughout the zone of influence. Our results provide evidence of successful self-restoration in a formerly highly degraded reach of desert river, and encourage new methods of desert river restoration. We aim to inform the use of large-scale, disruptive restoration actions like intentional channel occlusions, with the goal of mitigating the impacts of simplification and increasing habitat persistence in the face of exacerbated aridity in the desert Southwest.

Having identified that the valley plug created complex habitat thought to be preferred by native fishes, we then monitored habitat use by nonnative species and stocked, critically endangered bonytail (Gila elegans). Utilizing electivity indices and simulations of selection, we found that four of seven nonnative species were selecting for novel and geomorphically-complex 'boundary' reaches. We also observed that stocked, endangered bonytail were selecting for newly diverse river reaches as a direct result of pool habitats found in near the wash feature. We aim to inform the conservation, management and recovery of native fishes and riparian corridors of the upper Colorado River Basin, as well as inform the use of novel restoration tools in order to mitigate the impacts of extreme habitat simplification and increase habitat diversity in over-allocated and climate-impacted desert rivers.

RESTORATION EFFECTIVENESS MONITORING: A protocol developed by Utah State University's Ecogeomorphology and Topographic Analysis Lab was used to monitor restoration effectiveness following installation of instream structures which includes ground-based structure-level observations and desktop analysis of drone imagery (see affected area polygon). 
Field observations included 1) presence versus absence; 2) structure condition; 3) geomorphic response; 4) natural beaver dams and accumulations of Large Woody Debris (LWD); 5) total number of structures through time; and 6) condition of beaver dams. For presence verses absence the restoration structures were evaluated for whether they were still there and were still as designed. Structure condition were evaluated based on whether the structure was blown out, breached, moved or buried (more than three-fourths of crest height sediment accumulation). Geomorphic response referred to the extent of erosion, deposition, and distribution of geomorphic features such as pool (scour or dam), cutbank, and uniform bed aggradation or degradation. Natural beaver dams and accumulations of LWD were evaluated by asking; Is there additional accumulation of LWD on the structure? Has the structure been taken over by beavers? Total number of structures through time included both restoration and natural structures. Lastly, condition of beaver dams included intact, breached, or blown out and active or inactive.
The drone-based data collection consisted of an FAA licensed drone pilot collecting full coverage images for each of the restoration sites at low and high flow discharge before and after restoration was implemented. With these sets of images, we assessed the geomorphic and floodplain changes associated with changes in discharge as well as to track changes over time related to restoration actions. Specifically, we assessed: valley bottom extent, changes to the surface water extent and channel width, changes to the number of high flow channels vs. low flow channels. We also assessed inundation extent and type mapping and compared their extents through time. We assessed the nature of flow overbank vs channelized flows. Assessing these changes in flow type through time is important to track changes in lateral connectivity. Active floodplain extent -- pre and post restoration was assessed. Imagery-based surveys captured large-scale changes (e.g. inundation extent and type mapping [free flowing, overflow, and ponded]) and active and inactive floodplain mapping. These are important indicators of riverscape health that are directly modified by LT-PBR structures and beaver dams. The percent and type of valley bottom inundation and/or active floodplain not only are direct measures of the quantity of aquatic habitat present within the stream corridor, but can be viewed as proxies for hydrogeomorphic and ecological characteristics and processes that are essential to riverscape health such as channel floodplain connectivity and water residence time. 
On August 15, 2022 the Price River experienced a high flow monsoon event of 1,950 CFS that was captured in a series of photos that have been uploaded onto the WRI project page. There was speculation that this flood event may have blown out the instream structures that were installed during Phase 1 and 2 of the project. In late August, 2022, after the high flows had receded, we conducted a field survey of the instream structures on the lower Price River restoration reach just downstream of Woodside to determine the fate of the structures. We identified a total of 81 structures with the following classifications: 22 blown out but still visible, 28 breached, 20 intact, and 11 natural (3 beaver dams and 8 large wood jams) (See 'After Images' on the WRI project page). All but nine of the blown out and breached structures were providing measurable geomorphic response (i.e. either aggradation or degradation of sediment). There was a mix of physical responses within the structures. Many were effective at creating in-channel habitat complexity, exposing larger particle size substrate and some even surprisingly resulted in flow onto the immediate floodplain. A majority of the structures had captured sediment to the point of needing to be added onto and/or were blown out or breached as a result of high flows, however, these structures were still providing channel complexity and improved habitat. Our overall assessment is that the vast majority of instream structures are providing their intended habitat responses and are enhancing habitat complexity by adding pool and riffle habitat for native fish.

The lower San Rafael and lower Price rivers are some of the most perturbed riverscapes in the state of Utah and are currently on the 303D list of degraded waters due to their total dissolved solids concentrations. Also, irrigation is de-watering large sections of the rivers in late summer. The physical condition of the lower San Rafael and lower Price rivers have been severely degraded over time through a combination of impacts including altered flow regimes, stream channel narrowing, instream habitat simplification and non-native vegetation encroachment. As such, these rivers are not functioning to provide sufficient habitat to support sustainable populations of native fish species and wildlife. Without restoration, the degradation of these rivers will not be reversed. 
The objective of Phase II of this project was to increase the spatial extent and local impact of previous restoration efforts on the lower Price River, to benefit imperiled native fishes and wildlife. For this phase, we increased the density of instream structures (post-assisted log structures - PALS), continued non- native vegetation removal and native plantings, and reintroduced more beavers. These restoration actions resulted in increased instream habitat heterogeneity providing important fish habitat including pools, backwaters, riffles, and labile surfaces for food. This project's tamarisk and Russian olive removal efforts likely encouraged heterogeneous native vegetation establishment and encouraged more diverse wildlife use along the riparian corridor likely benefiting numerous wildlife species including herpetofauna, birds, and mammals.

Phase 3 of this project (Lower San Rafael & Price River Riparian Corridor Habitat Improvement, Phase 3 Project 5971) is currently underway and will continue restoration on the lower San Rafael and lower Price rivers, to benefit imperiled native fish, and wildlife habitat. Habitat benefits will increase by moving onto private land adjacent to phase 2, maintain existing instream structures, add large boulders, continue non-native vegetation removal and native plantings, reintroduce beavers, and monitor the effectiveness of vegetation treatments, structures and beaver translocation. In Phase 3 we will conduct effective monitoring of the instream structures that were implemented in March of 2023 as part of Phase 2 and 3.
In terms of ensuring the long-term success of the current project, USU researchers are coordinating with stakeholders in the watershed to provide ecological flows. UDWR, TNC and TU are the leads on this component, partners have already secured several hundred thousand dollars to contribute to this effort. Providing both low flows and flood flows (after needs of water users are met) will help maintain habitat and create new habitat through natural river processes.

William Macfarlane

08/31/2023 15:24:43