Wetlands in Snake Valley and Tule Valley serve as critical habitat for two Conservation Agreement Species, least chub and Columbia spotted frog, and three spring snails currently on the U.S. Fish and Wildlife Service National Listing Workplan, bifid duct pyrg, longitudinal gland pyrg, and sub-globose snake pyrg. A key threat to habitat for these species, and spring-fed wetlands in general, is the loss or degradation of habitat and ecosystem function because of declining water table levels resulting from groundwater development and inter-basin transfer of water. These threats have come into focus from the proposed development of water supply wells and an interconnecting pipeline system in the far western portion of Snake Valley (in eastern Nevada) by the Southern Nevada Water Authority. Additional threats exist from proposed water development within the local basins. In 2009, the UGS began a 10-year project to collect hydrologic data in Snake Valley with a network of shallow (~6 ft) wells. The primary goal of this network is to provide baseline data on the depth and timing of surface water and groundwater in wetlands crucial to state sensitive species. These data are important for documenting baseline conditions and aiding with early detection of potential water declines. The data could be used to help prove impairment to the Utah Division of Water Rights in the event of future declines caused by new withdrawals in the region. The initial network consisted of 60 wells; 29 additional wells were added between 2012 and 2014 and 12 were retired in 2014. Transducers in the wells started failing in spring 2018; there are currently transducers in only 58 of the 77 non-retired wells. The UGS convened a meeting of stakeholders in December 2018 to discuss the future of the Snake Valley groundwater monitoring network. Stakeholders were interested in using the data to produce predictive models to assess how changes in water levels would affect sensitive species. Current groundwater models for the region focus on the effect of withdrawals on groundwater levels rather than surface levels. More sensitive predictive models could be used to support the proposed groundwater management plan that may be developed for Snake Valley or to protest individual water rights applications that threaten sensitive species. Stakeholders also provided the UGS with recommendations on the most important wells to maintain based on proximity to key habitat and other considerations. The UGS subsequently prioritized wells as low, medium, and high priority and ensured that active transducers were in place in all the high priority locations, with funding from the Bureau of Land Management (BLM) to replace or repair transducers that had failed in fall 2018. The UGS installed 20 wells in Tule Valley in May 2018 at the request of the BLM to start monitoring water levels in this important habitat for Columbia spotted frog. Coyote Spring, one of the springs in Tule Valley, has shown a recent decline in available surface water habitat for breeding Columbia spotted frogs and die-off of vegetation, likely associated with decreased water availability. The Tule Valley wells will provide data for the current baseline of conditions in Tule Valley.

The overall goal of this project is to ensure that adequate hydrologic data are available in critical least chub and Columbia spotted frog habitat to support protection of these species. The project has two objectives: obtaining hydrologic data in Snake Valley and Tule Valley and developing a final report for 10-year water monitoring study in Snake Valley. Objective 1: Obtain hydrologic data from Snake Valley and Tule Valley wetlands. Task 1: Download data from transducers twice per year, process data to correct for barometric pressure and anomalies, and add data to groundwater data portal. Obtain estimate on field and processing time needed to maintain network at the current size. Task 2: Maintain network by removing transducers from low priority wells and repairing or purchasing replacement transducers as needed in higher priority wells. Outcome: Additional year of data added to water level database and groundwater data portal and network with functioning transducers placed in high priority wells. Objective 2: Develop final report for 10-year water monitoring study in Snake Valley. Task 3: Summarize data, including list of wells with location, number of months of data collected, associated vegetation, trend analysis, and status as active, inactive, or removed. Task 4: Conduct literature review and review existing data and regional groundwater models to evaluate feasibility, additional data needs, and cost of linking surface water outputs to deeper groundwater levels and of linking surface water outputs to annual population data for sensitive species. Task 5: Based on results of task 4 and task 1 and feedback from stakeholders, develop a recommendation for the future of the monitoring network, including number and location of wells to maintain, estimated cost of continued maintenance, and potential funding partners. Outcome: Final report with summary of water level monitoring data, recommendations for future studies, and recommendations for future of the monitoring network.

The project area is at risk of crossing an ecological threshold from healthy spring complexes capable of supporting sensitive animal species to hydrologically altered areas not able to sustain these species. Similarly, the sensitive species themselves may be at an ecological threshold. Snake and Tule Valleys sustain the largest and most consistent populations of Columbia spotted frogs in Utah. The monitored areas also support the majority of wild least chub populations. If habitat in these areas declines, the viability of both species in Utah overall may be at risk. Major threats to these spring complexes and their associated species are lowered groundwater levels from groundwater extraction or prolonged drought.

1. Amendment to the 2005 Conservation Agreement Strategy for the Least Chub (Iotichthys phlegethontis), February 2014 -Conservation Action to address groundwater withdrawal: "UDWR agrees to coordinate with Utah Geological Survey and U.S. Geological Survey to assess current piezometer data and monitor groundwater levels at Snake Valley least chub population sites. UDWR will also coordinate with these agencies to install additional piezometers, as needed." The proposed work directly addresses this Conservation Action. -Conservation Action to address climate change/drought: "The UDWR agrees to coordinate with Utah Geological Survey and United States Geological Survey to monitor piezometers and surface flow gages at the Snake Valley wild population sites in order to evaluate the changes in groundwater levels and spring discharge rates, respectively." The proposed work directly addresses this Conservation Action. 2. Conservation Agreement and Strategy for Columbia Spotted Frog (Rana luteiventris) in the State of Utah (2009) -Conservation Element C, Restore Hydrologic Condition: "Identify water needs in current and potential Columbia spotted frog habitats" and "Maintain natural hydrologic conditions." The proposed work will provide data that will allow for identification of water needs. -Conservation Element F, Monitoring: "Monitor additional parameters (e.g., water level, precipitation), as necessary, to help interpret population fluctuations." The proposed work will provide hydrologic monitoring data that could support this type of analysis.

Not applicable.

This project has the potential to improve water quantity by providing data to document baseline hydrologic conditions and to aid with early detection of potential water declines. Predictive models of the impact of water decline on sensitive species could be used to support the proposed groundwater management plan that may be developed for Snake Valley or to protest individual water rights applications that threaten sensitive species.

Not applicable. The proposed project involves monitoring piezometers that have already been installed and thus will not cause new disturbances. All installed piezometers had clearance from the Bureau of Land Management for installation or from private landowners.

Objective 1: Obtain hydrologic data from Snake Valley and Tule Valley wetlands. Task 1: Download and process data: Surveyors will visit each well (and associated barometers) once each in the fall and the spring, measure water level, stick-up height, and electroconductivity using a handheld meter, and download pressure transducer data onto a computer tablet via an existing Solinst application. Transducer data will be corrected for barometric pressure and drift using existing processing scripts and added to the water level monitoring database and groundwater data portal. During the spring 2020 survey event, employees will estimate the total field and processing time needed to maintain the network at its current size. Task 2: Maintain network: Batteries for the Solinst Levelogger Junior Edge transducers started to fail in spring 2018 (they have a listed life span of 5 years), and we anticipate more battery failure in the year to come. We will continue to send nonresponsive transducers to Solinst to extract the remaining data and replace either the battery or whole unit, depending on Solinst's evaluation. We will redeploy transducers in all high priority wells and as many moderate priority wells as possible and remove transducers from low priority wells. Objective 2: Develop final report for 10-year water monitoring study in Snake Valley. Task 3: Data summary: We will use existing and new data analysis R and Python scripts to analyze existing water level data for each well to determine number of months of data collected and to evaluate trends after controlling for seasonal patterns. Data from existing databases will be used to list location, vegetation, and status for each well. Additional hydrologic metrics may be calculated for individual wells if identified as potentially useful under task 4. For example, it may be useful to calculate the number of days each well had surface water during the time that Columbia spotted frog lay eggs each year. Task 4: Research recommendation: Groundwater hydrogeologists at the UGS will review literature, existing data, and existing regional groundwater models to develop a proposal outlining potential approaches for linking groundwater in Snake Valley to surface water outputs. UGS wetland ecologists will work closely with Drew Dittmer from the Utah Division of Wildlife Resources to conduct a similar review of literature and existing data to evaluate approaches to modeling fish and amphibian population measures using hydrologic data. Both groups will work closely together to discuss linkages between the proposals and to develop recommendations for future studies with associated data and funding needs. Task 5: Network recommendation: We will use information on the time requirements for data download and processing from task 1, the recommendations for future studies from task 4, and stakeholder feedback to develop recommendations for the future of the network. We will address how many and which wells to keep active, based in part on data needs identified as part of task 4. We will also estimate the cost of continued maintenance of the network and discuss potential funding partners.

Data downloads, field water level measurements, and data processing on a biannual basis will be necessary for the life of the network. This project has no additional monitoring needs.

This project supports Conservation Agreements for Least Chub and Columbia Spotted Frog to better understand what hydrologic conditions occur across a range of sites with varying species populations, and over time as climate variation affects groundwater discharge and wetland hydrology - which affect habitat quality and population success. The UGS has presented results at the Conservation Team meetings for both species and continues to receive the support of the Conservation Teams. UGS convened a meeting of stakeholders, composed primarily of Conservation Team members for least chub and Columbia spotted frog, in mid-December 2018 to discuss the future of the project. The stakeholders proposed continuing to maintain the network through the end of the 10th year by replacing transducers as needed and developing recommendations for how to develop predictive models showing how changes in water levels affect sensitive species. Employees with the Utah Division of Wildlife Resources and BLM have provided feedback prioritizing wells in the network and will continue to provide that feedback in FY2020. Drew Dittmer from the Utah Division of Wildlife Resources has agreed to work with the UGS on task 4. The UGS currently has funding from the U.S. Environmental Protection Agency to quantify the relationship between climate variables and water level data in the shallow wells. This analysis is an important first step for being able to quantify the effect of groundwater withdrawal on water levels and to understand population changes related to changing water levels. Paul Inkenbrandt, who is leading this study, will be draw on his findings and be an active participant in the development of recommendations for future studies (task 4). The UGS applied for and received funds from the Endangered Species Mitigation Fund (ESMF) to support this work in fiscal year 2020 (July 1, 2019 -- June 30, 2020). The ESMF funds will support half of the field work in Snake Valley and associated data processing and the majority of office time needed for preparation of the final report, while the requested BLM funds will pay for the remainder of field work in Snake Valley, all of the field work in Tule Valley, transducer replacement or repair, and a small portion of the development of the final report.

We will develop recommendations for the future management of this project based on the recommendations of this study. We could recommend removing all the transducers and reinstalling them in 10 years to get a new baseline of hydrology to compare to our current data or we could recommend stocking all wells with a transducer for the next 10+ years if those data are necessary to complete the recommended studies. It is likely we will recommend something in between those two scenarios, with a smaller network that will continue to be monitored on a biannual basis at a reduced cost. We likely will also recommend finding funding for more comprehensive analysis of the water level data to connect groundwater levels, surface water levels, and species' parameters. We recommend that Tule Valley data continue to be collected on a biannual basis for at least five to ten years to establish a robust baseline of conditions in those wetlands.

The proposed work supports the continued maintenance of well-functioning wetlands in Snake Valley and Tule Valley, which will indirectly support current sustainable uses for these wetlands such as livestock grazing. Water level declines could decrease the availability of forage if vegetation supported by groundwater discharge was replaced to precipitation-supported vegetation.

07/01/2019

06/30/2020

2020

We uploaded and processed the 10th year of pressure transducer data for these wells and produced a report with a summary of existing data and recommendations for the future of the monitoring network. Uploading data entails visiting individuals, measuring stick-up height and water levels, and downloading transducer data using a device-specific app. Data are then processed to correct for barometric pressure and instrument drift. Methods for the report are detailed in the report.

Wetlands in Snake Valley serve as critical habitat for at least five of Utah's Species of Greatest Conservation Need, including four species threatened by groundwater withdrawal. UGS has developed a network of shallow wells to document baseline hydrologic conditions in these wetlands. Major accomplishments in FY2020 include: 1. Obtained field measurements, downloaded pressure transducer data, and replaced 18 failing transducers from wells in Snake Valley and around Mona and Mills in October 2019 and April-May 2020. 2. Processed data from all downloaded transducers by correcting for barometric pressure and drift. 3. Sent 13 transducers for battery replacement and 9 transducers for data recovery and disposal to Solinst. 4. Summarized status and trends for wetland wells, deeper wells, spring gages, and climate stations for the area as well as population trends for Least Chub and Columbia Spotted Frog. Some initial findings: a. No trend in climate data from 2000 to present when aggregated by water year; majority of climate stations showed increasing trend in minimum temperature from 2004 to present. b. Of the 55 wells with at least seven years of data, 23 each saw increasing or decreasing trends in water levels, with the remainder with no significant trend. c. Analyzing all hydrologic data together by wetland complex, Big Springs, Burbank Meadow, and Leland Harris saw significant declines in water levels over the past ten years, with declines ranging from -0.005 feet/year at Leland Harris to -0.096 feet/year at Burbank Meadows. Central Spring, Twin Spring, and South Gandy Salt Marsh had increasing trends of at least 0.017 feet/year over that time period. d. There were no trends in species parameters (egg mass and catch per unit effort) at sites with continuous data from 2009 to 2019. Least Chub catch per unit effort decline between 2007 and 2014 at Gandy and Bishop and Columbia Spotted Frog egg mass counts declined from 1997 to 2012 at Miller. 5. Conducted literature review to determine habitat needs and sensitive life periods for sensitive Snake Valley species and recommended metrics that could be studied to better understand population fluctuations and sensitivity to water levels. 6. Developed recommendations for additional studies that could be done to link hydrologic data to habitat and population dynamics for sensitive species 7. Wrote report describing numbers 4-6, above, as well as recommendations for the future of the network (currently draft undergoing review).

All data collection and data processing are complete for this project. We have a draft of the ten-year report that is currently undergoing internal revision and will be complete before the Conservation Team meetings for Least Chub and Columbia Spotted Frog in December. We estimate annual maintenance costs for this project at about $16,723, including $15,203 in direct costs and $1520 in indirect costs. Direct costs include vehicle rental and mileage, per diem, transducer repair and replacement, and personnel hours for field work, data processing, attending meetings, and project management, Costs are anticipated to rise loosely tied in inflation from cost of living raises and increases in per diem, vehicle expenses, and transducer costs. Funding for the Snake Valley work in FY21 was approximately 19% UGS, 23% BLM, and 58% Endangered Species Mitigation Fund. Each of these funders also contributed to maintenance of other wetland piezometer networks, which led to some small increases in efficiencies from shared activities. Field work in Tule Valley, funded entirely by the BLM, is particular valuable because it provides funding for a second trip to the region each season, which makes it less expensive for UGS to return to Snake Valley in the event that unforeseen circumstances prevent us from completing all downloads on the first trip to the area. In addition to project maintenance funds, this project would benefit from additional funding to allow for more detailed analysis of hydrologic, habitat, and species data. Initial funding could be as low as $6000 per year to allow for preliminary analysis of the data, but would need to be substantial higher for more detailed studies.