Watershed Symposium 2022

Brenda Bowen and Kerry Case, co-chairs of the University of Utah's Climate Commitment Task Force, will share an overview of the University of Utah's first Climate Resilience Assessment and ongoing work to develop an equity-centered Climate Change Action Plan.

In 2020, the University of Utah launched its first Climate Resilience Assessment as part of the Presidents’ Climate Leadership Commitment, which President Taylor Randall re-committed to in 2021. This Climate Change Resilience assessment examined the institution’s ability to respond to climate threats in our community including risks associated with changes in temperature and seasonality (e.g., heat waves, megadroughts, dust storms, wildfires, changes in phenology) and changes in precipitation (e.g., flooding, megadroughts, reduced snowpacks). This work identified climate related vulnerabilities and strengths, developed indicators of resilience, and compiled baseline data and data gaps for key indicators. This assessment considered indicators of resilience related to social equity and governance, health and wellness, ecosystem services, infrastructure, and economics. Several the key climate change resilience indicators relate to systems that include the University and the broader watershed and ecosystem, such as water system stability and efficiency, ecosystem health and diversity, land and soil functionality, and management of campus-related ecosystems.

Now, with leadership from the Sustainability Office, the University is in the process of developing a new Climate Change Action Plan identifying how the institution will respond to changing climate. Recognizing that climate change is a threat multiplier, worsening existing problems of inequity and injustice in our society and systems, the University has chosen to center equity in this work. This new plan will outline priorities to reduce greenhouse gas emissions from operations, prepare for the current and future impacts of climate change, educate all students with skills and knowledge to work toward a sustainable future, and research effects of and solutions to climate change. In this presentation we will share an overview of this work and highlight key partnerships and opportunities for collaboration and engagement within the watershed.

Changing winter rain/snow partitioning and increased April to October evapotranspiration from warmer temperatures poses a challenge to the Salt Lake City water system. We develop a comprehensive understanding of the driving climate, hydrological, and water system dynamics influencing seasonal to decadal planning and management activities.

Changing winter rain/snow partitioning and variable winter water storage coupled with increased April to October evapotranspiration from warmer temperatures in the Western US challenges water resources management from basin to municipal domains. In Salt Lake City, Utah, population growth further compounds these hydroclimate challenges. Addressing the supply-demand challenges with a climate resilience action plan, this work highlights the benefits of a collaborative research-to-operations (R2O) partnership between the Salt Lake City Department of Public Utilities (SLCDPU), the University of Utah, and the University of Alabama. We develop a comprehensive understanding of the driving climate, hydrological, and water system dynamics influencing seasonal to decadal planning and management activities. This involved five years of extensive stakeholder engagement that led to key scientific discoveries surrounding winter precipitation anomalies, hydro-geophysical attributes improving surface water yield estimates, and key hydroclimate mechanisms influencing municipal demands.

Leveraging a systems model to replicate the SLCDPU water system and operations, we integrated the discoveries into the water systems setting to identify vulnerabilities and create preemptive (vs. reactionary) mitigation protocols at multiple forecasting horizons. This includes the development of a decision-making timeline with operational tools to prevent system deficits, characterize source vulnerabilities, and estimate conservation measures to mitigate supply deficits. The case study analyses highlight the decision-making influence the R2O workflow provides the utility, spotlighting the capacity to guide water resources decision-making over a range of hydroclimate phenomena to build water system-climate resilience.

Understanding the effect of cloud-based illumination on ET estimation is crucial for the wider application of drone based image collection. We tested the ET estimation under partial cloud and cloud free condition using the image collected by drone and found that the ET are overestimated on the pixel superimposed over cloud shadows.

Agriculture is the largest user of water in Utah and throughout most of the world but you can’t effectively manage what you don’t accurately measure. UAV based imagery are increasingly used for mapping Evapotranspiration (ET) from agricultural fields as they can produce flights on demand and provide higher resolution images. Numerous literature claims that their flexibility to fly on cloudy days and the possibility of capturing higher variability of ET is the added advantage over similar other remote sensing techniques. However, little is known about how cloud based illumination impacts on the ET mapping from agricultural field. Although drones can be flown under the cloud, the sensor's perception of ground data might be impacted by the varying weather conditions. Therefore, understating the effect of cloud on drone based ET estimation is critical for mapping ET. In this research, we estimated and compared the ET under cloudy and non cloudy condition using the images collected by Mica Sense Altum sensor mounted on DJI Matrice 210 Quadacopter on same day. ET was estimated using the Mapping EvapoTranspiration at high Resolution with Internalized Calibration (METRIC) model over three irrigated agricultural fields alfalfa, corn, and peas. Our result shows that ET values are estimated to be higher in the areas superimposed over cloud shadows compared to cloud-free areas. This information will be precious for better and more efficient water management, including precision agriculture.

The Provo River Delta Restoration Project is one of the largest river and lake restoration projects in the region and is focused on providing juvenile rearing habitat for June Sucker in the face of changing hydrology. Come visit with us to find out how to plan and implement large-scale restoration projects that benefit both wildlife and people.

The Provo River Delta Restoration Project is one of the largest river and lake restoration projects in the region. URMCC has worked with countless partners and agencies to develop the vision for reconnecting a bay of Utah Lake to the main body of the lake through this project. It has involved the development of over 22,000 linear feet of new river channel on the delta where the Provo River historically entered Utah Lake into Skipper Bay. This project took more than a decade to plan and has taken more than two years to implement. The main focus for the project is to provide rearing habitat for the threatened June Sucker, found only in Utah Lake, but the variety of water depths will also help Utah Lake adapt to a changing climate. Additional benefits will include additional recreation access to the Lower Provo River and the newly reconnected Skipper Bay and Provo River Delta. There are many opportunities to get involved with planting and stewardship starting next spring.

What are the observed trends and future projections of the climate signals? And how would the snowpack, soil moisture, and streamflow change in the future? Let's discuss results using climate and hydrologic models (i.e., VIC, and RAPID) for the Jordan river basin (i.e., Spanish Fork, Provo, Utah Lake, and Jordan River).

In the recent years, we have witnessed mega-drought events and stresses on precious water resources and the environment. The observed climate and hydrologic data show changing patterns in rain and snowpack, record high summer temperatures, variation in soil moisture contents, very low water reservoir levels, lowered groundwater, and resulting streamflow. The consequences of events have resulted in observed historical low water levels in the Great Salt Lake. For policymakers and water professionals, it is important to answer some of the key questions such as (1) what are the observed climate change signals in water basins in the state of Utah, and (2) what are the potential future projections of the climate change and hydrological responses, (3) how resilient are our water resources against changing climate and extreme events, and (4) what are potential adaptation strategies to achieve the goals of water resilience.

This presentation attempts to answer part of those questions in two parts. The first part of the presentation will include an analysis of historical data on the observed temperature, precipitation, snowpack, and streamflow in several parts of Utah. The analysis results will reveal the rate and trends in the changes of climate stressors on water resources. The second part of the presentation will cover future climate projection and impacts on water resources, including precipitation, snowpack, soil moisture, and streamflow. The analysis will be based on multiple Global Climate Model results statistically downscaled in the finer resolutions of 6.25 km, forced run the Variable Infiltration Capacity model (VIC), and Routing Application for Parallel computation of Discharge (RAPID) models.

This presentation covers the larger Jordan river basin (includes Spanish Fork, Provo, Utah Lake, Jordan River), one of the most populated basins in the state and one of the primary sources of water supply to the Great Salt Lake. The models were calibrated from 1980 to 2004 and validated for 2005 to 2020. It includes continuous daily simulations of multiple climate projection inputs until the end of the 21st century. This presentation is based on one of the ongoing and in-house modeling projects of the Utah Division of Water Resources to evaluate the impact of climate change in GSL watersheds. Water policy professionals will have an opportunity to get informed about signals and trends of climate change and its impact on water resources at the regional level. Technical water professionals will have an opportunity to learn the type and sources of data, methods, and models that can be applied to large basin-level water resources assessment.

The following are learning objectives from these presentations: 1. Basic understanding of main climate signals and trends considered in water resources assessment. 2. Become informed about climate model projections at the basin level. 3. Gain an understanding of how large-scale hydrological models are developed to simulate climate change impact at the basin level. 4. Understand how resilient our local water bodies are against the changing climate.

Granger-Hunter Improvement District, in times of extreme drought, may find it’s water supply cut. The District’s customers have responded with significant water use reductions, but in order to have a resilient supply, groundwater sources with higher levels of manganese and iron will need to be developed.

Granger-Hunter Improvement District serves West Valley City, the second largest city in Utah. Most of the District’s water comes from the Wasatch Mountains, and with Utah in a prolonged drought, surface water supplies are being impacted. District customers have conserved incredible amounts of water, mostly by reducing outdoor irrigation, but with future supplies of surface water at risk, the District has embarked on a multi-year program to develop and improve groundwater in the Salt Lake Valley. The District relies on a water wholesaler for approximately 75% of its water supply. In times of extreme drought, it is possible that supply could be cut by as much as 30%, leading to potential shortages. While District customers have reduced consumption by over 15% in the last couple of years, higher-density future growth will require a drought-resistant high-quality supply. Additional challenges include revenue shortfalls due to increased conservation, conservation-oriented rate design, and a shrinking Great Salt Lake that is directly impacted by increased outdoor water use and reduced snowfall. In order to develop groundwater for a drought-resistant supply, higher levels of iron and manganese must be removed. One treatment plant is under construction with two additional plants planned, but the cost of construction is substantial and additional funding sources, including SRF and WaterSMART grants, are being explored with some success. There is also risk of overdrawing groundwater surface water sources are also reduced to neighboring communities. The long-term plan is to encourage appropriate outdoor water use with tiered rates, and to develop reliable, clean groundwater sources if the drought continues. This session will discuss the Utah drought and the challenges that a reduced water supply will bring to residents of West Valley City, Utah, the second largest city in Utah. Future planning challenges include reduced consumption (and revenue) due to drought messaging, fixed wholesale water contracts, and higher-density growth. To plan for potential shortages, Granger-Hunter Improvement District has embarked on a long-term plan to develop and treat groundwater impacted by iron and manganese. The District has also pursued SRF loans and grants in order to reduce the cost burden on its customers.

Frequent wildfires affect streamflows which influences estimates of water budgets. It is a complex effort to accurately estimate river discharges. So, determining how well National Water Model predicts streamflow in burned areas during peak Spring and late-season low flows will help access required improvements in the model.

Research studies have found that climate change influences wildfires. Wildfires in the western United States alter the landscape and overall hydrological cycle, altering the timing and magnitude of the streamflow response to snowmelt and high intensity precipitation events. The National Water Model (NWM) is a tool to anticipate hydro-meteorological influences on streamflow and fill the gaps between coarse USGS streamflow monitoring locations, providing a decision-making tool to guide the domestic, agricultural, recreation, power generation, and flood control components of water resources management. To assess the NWM v2.1 predictive performance surrounding spring melt and supply-limiting low-flow events in recently burned catchments, we use the Cooperative Institute for Research to Operations for Hydrology (CIROH) Land Use Land Cover (LULC) Streamflow Evaluation tool. We evaluate multiple catchments in the intermountain west, and collocated with USGS monitoring stations, evaluating predictive performances using Kling Gupta Efficiency metric (KGE), coefficient of determination (R2) and Percent Bias (PBIAS). Given the observed prediction errors, determining the accuracy of streamflow predictions of NWM v2.1 in burned catchments provides a benchmark to quantify future model improvements as well as an opportunity to enhance existing predictions with new post-processing methods. As much of the drinking water for the Salt Lake area comes from these fire-vulnerable watersheds, improved modeling will help regional water prediction studies for Utah.

Salt Lake County Watershed has been collecting water quality data in streams since 2010 with an aim to learn more about the relationship between water quality and the changes happening in our valley. Over a decade later, we are still collecting data and have learned quite a few things. This presentation will give a brief overview on everything water quality-related that SLCo Watershed is currently working on, with a deeper look into how long-deploy water quality sondes can fill gaps in data and track acute stream events.

Phragmites australis, or Common Reed, is a very aggressive invasive plant that has invaded wetlands across North America. Great Salt Lake wetlands were invaded by Phragmites after the high waters of the 80's receded. In 2011, there was approximately 23,000 acres of Phragmites. Utah Lake wetlands were also invaded and had approximately 10,500 acres of Phragmites in 2012. The Jordan River is also inundated with Phragmites. Phragmites significantly negatively impacts wetland bird habitat, disrupts hydrology and sediment transport, as well as reduces plant biodiversity. A large effort by the Utah Department of Natural Resources - Divisions of Forestry, Fire and State Lands and Wildlife Resources, as well as many other entities, has made significant progress in controlling Phragmites. This presentation discusses the challenge of Phragmites control, the best practices that have been established, the current efforts taking place, and the results of these efforts.

Resilient watersheds are capable of withstanding and responding to natural disturbances, including wildfire. Collaborative, cross-boundary forest management that creates fire adapted ecosystems and communities will aid our efforts to protect vulnerable water resources and ensure long term water security.

In August of 2021, the Parleys Canyon Fire started alongside Interstate 80. Beginning with two small brush fires, by mid afternoon, the fire spread to 500 acres. Driven by winds and dry conditions, the fire forced residents of the surrounding areas to evacuate from over 5,000 homes. Multiple agencies responded to the fire and were able to fully contain the blaze after eight days. The Parleys Canyon fire presents an example of how a rapid, coordinated response to fire, and some luck, prevented a more severe fire event from destroying communities and threatening water security. Wildfire is a natural and expected occurrence in Utah’s forests, and it plays an important role in the ongoing health and resilience of Utah’s water resources. Past fire suppression practices have contributed to the increase in large, severe wildfires that cause detrimental impacts to habitats, homes, and vulnerable water resources. In the face of climate change, long-term water security is a growing concern, and the impact of catastrophic wildfires on the natural resource we depend on for drinking, irrigation, fishing, and recreation cannot be ignored. Wildfires impact air quality and may also affect available water quality and quantity, both during an active wildfire event and for years afterwards. Past fire events, including the Dollar Ridge Fire, demonstrate the disastrous impacts severe wildfires can have on Utah’s watersheds and the challenges these events present to water resource managers.

The connection between resilient, disturbance adapted forests and a sustainable supply of water is especially evident in Utah and similarly arid states. About half of the water supply in the southwestern United States comes from forests. Approximately 80% of the freshwater resources in the U.S. originate on forested land, and more than 3,400 public drinking water systems are located in watersheds on national forest lands. As we have seen an increase in the number of acres of important forested water-supply watersheds burned in the past 30 years, we have also seen an increase in flooding and erosion that can impair already vulnerable water supplies. Fire events, such as Parleys Canyon, provide homeowners and land managers with an opportunity to recognize the need for wildfire mitigation planning that protects communities and water sources along the Wasatch Front. Through shared stewardship, Utah partners with agencies, entities, and organizations to actively mitigate the impacts of catastrophic wildfire on a landscape scale, with the express purpose of protecting communities and watersheds. Central Utah Water Conservancy District (CUWCD) manages the Central Utah Project (CUP) and District network of water facilities to ensure citizens and businesses along the Wasatch Front receive clean, reliable water. Operating three water treatment facilities, two hydroelectric plants, nine reservoirs, and overseeing water supply to eight counties, CUWCD recognizes the vulnerabilities of our water infrastructure and the need for collaborative watershed management.

This presentation will highlight both the impact severe wildfires can have on water treatment facilities and the need for collaborative wildfire management to maintain Utah’s current water quality and quantity.

GSL is shrinking and the water users throughout the basin are struggling. A comprehensive supply-demand study of the entire GSL basin has never been accomplished so the Utah Division of Water Resources, USBR and water users have applied to do a basin study to provide the information necessary for sound decision-making.

This year the United States Bureau of Reclamation (USBR) has WaterSMART funding available through the Basin Study program for the first time in 5 years. In partnership with water conservancy districts, water users associations, irrigation companies, universities and environmental advocate groups throughout the basin, the Utah Division of Water Resources has applied for a basin study. Basin Studies are collaborative planning efforts cost-shared with non-Federal partners to first assess water supply and demand, then identify strategies to address imbalances. This would be an enormous task, never before undertaken but such a study must be done because only collaborative efforts can attain meaningful solutions to a sickening lake and reduced water supply. Water resource management in the GSL Basin is complex, collective effects on the lake from upstream activities are poorly understood, and upstream water users struggle to understand how best to mitigate adverse impacts to GSL while meeting the needs of water users, making it a perfect basin for this type of study. Attendees will learn what the study would entail and how it would be helpful for water management and policy in the GSL basin.

In this workshop we showcase the tools available to residents of the Great Salt Lake watershed to stabilize plummeting levels of the American West’s largest lake. The Great Salt Lake Open Toolbox is a collection of immediately implementable strategies and policies which offer us a suite of solutions to save the Lake.

Public concern about the ailing Great Salt Lake has reached new heights as the Lake dropped to a record low level for the second year in a row as a function of climate change and its shrinking of our snowpacks. News outlets around the globe reported on the crisis, garnering international attention for our capital city’s namesake. The silver lining of this unfolding environmental crisis at the Great Salt Lake is that Utahns from all walks of life are eager to learn about what can be done to save the Great Salt Lake in the face of climate change. A range of stakeholders and members of the public have used public forums, op-eds, official meetings, social media and a litany of other avenues to plead with others to solve the problem. This echo chamber has created momentum, and millions of Utahns are eager to get involved and be part of the solution to protect the American West’s largest lake from shrinking further. While nearly everybody agrees that we need to save the Lake, there isn’t much consensus on the best way to achieve that. What is the best way to keep water in the Great Salt Lake?

In this presentation, we open and unpack the tools available to save the Great Salt Lake and showcase which options have the potential to truly stabilize the water levels of the American West’s largest lake. We will explore which tools are ready to be implemented, what barriers there are to using other tools and how much water the Great Salt Lake really needs to sustain our people, our wildlife and our economy. The Great Salt Lake Open Toolbox has been assembled by studying the lessons learned from other western cities and states that have managed to protect their local aquatic landscapes. While no one tool may be a silver bullet for all the Lake’s problems, smart implementation of several tools at once could be a ‘silver buckshot’ to restore this vital aquatic ecosystem and the economy it supports.

This workshop explores what it means to save the Great Salt Lake by utilizing a collection of strategies and policies to get more water to the lake. We will unpack how each tool can contribute toward a sustainable paradigm for the Lake and its needed water budget. This workshop is jam-packed with solutions to save the Great Salt Lake and participants will leave inspired in the knowledge that there are tools to ensure we scan ustain the Lake for generations to come.

Four years into building & monitoring beaver dam analogs in the Great Salt Lake watershed and throughout Utah, we have complied several years of data. What have we learned and what opportunities do we have to improve restoration monitoring moving forward?

Streams and rivers across the American west are subject to habitat loss due in part to the extirpation of American beaver (Castor canadensis). Low-tech process-based restoration (LTPBR) has gained momentum across Utah and the region as a means to re-introduce beaver and the processes that they catalyze in river systems. We have implemented and monitored over 15 of these projects in the Great Salt Lake Watershed along with state partners and private landowners. These projects are motivated by a number of co-benefits, from riparian vegetation recruitment to floodplain reconnection, drought resilience, and extreme fire mitigation. Monitoring is a high priority, but fast and standardized protocols are often too generic to be helpful for adaptive management. The Rapid Stream-Riparian Assessment (RSRA) protocol provides metrics of overall riparian health for small to medium sized streams in this region, but not directly informative to adaptive management. In 2022, we developed a supplement to the RSRA for LTPBR projects to inform adaptive management more directly. Here, we will present the results from RSRAs on 25 restoration sites statewide before and up to 3 years post-implementation. We also share initial Amphibian Habitat Assessments from restoration sites in the elevational range of Boreal Toad (Anaxyrus boreas boreas) and an overview and initial test group feedback on the adaptive management protocol.

Groundwater levels in Utah and throughout the west continue to decline. Groundwater is an important resource providing water not only for human consumption but also for agricultural and industry needs. In order to preserve this valuable resource we need to increase our efforts to put water back into the ground.

In 2005, Utah declared Aquifer Storage and Recovery (ASR) as a critical element in most conjunctive management practices as part of their “Utah State Water Plan”. In 2017, Governor Herbert commissioned a Recommended State Water Strategy where public comments included ““Vigorously pursue … aquifer storage and recovery projects.” yet few ASR programs have been implemented since. Recently, in the 2021 Water Resource Plan ASR and other managed aquifer programs received little attention. This presentation will cover the increasing water challenges and drought situation in Utah and surrounding western states due to in large part climate change. The presentation will also discuss the successes and challenges of existing and potential ASR programs in Utah. Attendees will understand how climate change is affecting our groundwater resources and what solutions should be considered in the long term to protect this valuable resource

This presentation will feature current work of Provo and Eagle Mountain to address water scarcity through their aquifer storage and recovery efforts and include examples of mapping social, jurisdictional, and economic factors to assess infrastructure and population vulnerability from impacts of climate change.

Our climate is changing, Utah and the west are in the midst of one of the worst droughts on record, and citizens are asking about what can be done to prevent it from getting worse and how to adapt. Lake Mead and Powell are at their lowest levels on record and Utah’s reservoirs are rarely full. Some organizations and industries are being proactive on this front and preparing for extreme drought that threatens our water supplies and fuel wildfires and on the other end extreme storm events that lead to flood damage, erosion and sediment clogging our infrastructure and filling our reservoirs. Others are overwhelmed by the possible extent of impacts. Cities, counties, and watershed districts are addressing this difficult issue in many ways. From dealing with unprecedented drought and water scarcity to flood events to developing adaptation plans, Utah cities and watershed districts along with others across the nation are being proactive through planning for the future of their water supplies, while also addressing the challenges of extreme damaging and erosive flood events.

This presentation will feature current work of Provo and Eagle Mountain to address water scarcity, and contrast this with what several watershed districts in other parts of the country are doing to address volatility in precipitation events. Examples include increasing efficiency in the management of groundwater and surface water sources, rethinking how we store water by using aquifer storage and recovery (ASR) instead of surface water reservoirs, aquifer sustainability planning, facilitating climate resilience workshops with local communities for them to plan for upcoming changes from storms, floods, heat, and warming winters. The results of these workshops have been incorporated into City Comprehensive Plans and resulted in multimillion dollar ASR projects. Other examples include mapping social, jurisdictional, and economic factors to assess population impacts of climate change, infrastructure vulnerability studies, and designing plant community restorations prepared for invasive species encroachment. This presentation will provide several examples of climate adaptation projects initiated by cities in Utah and watershed districts from other parts of the country.

Utah Lake is such an important part of Utah and should be well managed. Part of that management is studying the fish within and determining if those fish could adversely effect those who fish at the lake. In our study we are looking at trace metal content specifically since many trace metals like Arsenic can severely effect human beings.

Utah Lake (Central Utah, USA) is a shallow, hypereutrophic lake, and the third largest freshwater body west of the Mississippi River. It serves as the main irrigation source for the surrounding area which contains more than 600,000 people. Utah Lake is surrounded by multiple anthropogenic and natural sources of trace metal pollution that affect the fish which are consumed by residents. The purpose of the study is to analyze the content of selected trace metals in four popular sport fish: White Bass (Morone chrysops), Black Bullhead (Ameiurus melas), Northern Pike (Esox lucius), and Common Carp (Cyprinus carpio). One hundred fifty-nine fish were collected from the Provo Bay area of Utah Lake, divided into male and female, dissected, and separated into two sets of tissues (offal and filet). The samples were weighed (0.0005g) in replicates of three, digested in the MARS using EPA method 3015, and analyzed in the ICP-OES for trace metal (As, Cd, Cr, and Pb) content. Statistical analysis was performed using the R programming language. Results reveal that trace metal levels present in the fish tested exceeded standards set by the European Union; As was detected at 0.295 ppm (p<0.0001), Cd at 0.040 ppm (p<0.100), and Pb at 0.415 ppm (p<0.001). For the most part trace metal levels were higher in the offal tissues compared to the filets. For example, Pb, Cd, and Cr levels were moderate to highly significant (p<0.01 to p<0.0001) and found in concentrations of 0.360 ppm, 0.020 ppm, and 0.280 ppm in the filets and 0.63 ppm, 0.105 ppm, and 0.82 ppm in the offals, respectively. In contrast with the overall trend, Arsenic in the filets of White Bass, Common Carp, and Northern Pike are 2.27, 1.45, and 1.44 times higher than in the offal tissues. Northern Pike also broke the trend in Lead levels where the filets had a concentration of 0.340 ppm versus 0.240 ppm in the offal tissues. These results, while preliminary, show that people who eat certain fish from Utah Lake may be at risk of exposure to toxic levels of trace metals. Furthermore, this study could help regulatory agencies manage trace metal release into Utah Lake.

Linking how annual variability in climate drives 2-3 year changes in streamflow, resulting in a multi-year response of GSL volume.

When in drought, it is especially pertinent to understand how much water is available, where it is available, and when it will be available for down-stream water users and for ecological impacts on large scale ecosystems such as Great Salt Lake (GSL). Headwater catchments are the primary water suppliers and storage regions for Great Salt Lake water supplying tributaries. These catchments hold snow at high elevations and release that snowmelt as seasonal providers to seasonally recharge Great Salt Lake. Along with seasonal controls from snowmelt, headwater catchments hold water within the catchment subsurface and slowly release water throughout the dry season and into the following subsequent years, buffering lake levels even during low snow years, or exacerbating reductions in streamflow input when catchment storage is below average. This project addresses the challenge of predicting Great Salt Lake levels, and begins to address the upstream processes that lead to high or low GSL levels. Using over 118 years of historical streamflow and climate data in 10 headwater tributaries to the Jordan River and Weber River (both terminating in GSL), we identify a surprising multi-year periodicity in headwater catchment storage. This multi-year periodicity of high and low storage in the headwaters is positively related to 3-4 years of antecedent precipitation, and 2-3 years of antecedent seasonal melt rate. The previous year’s temperature is negatively related to catchment storage, suggesting that in in warmer years, headwater storage is depleted. We also find that catchment storage is directly related to GSL elevation, where high storage results in high GSL lake level, and low storage results in low GSL elevation, there seems to be a 2–3 year lag time in this relationship, suggesting that headwater catchments storage may respond at a faster time scale (1-4 years) to snowpack and temperature variability, but GSL may respond to climate patterns over a longer timescale. These findings suggest that GSL is controlled by multi-year climatic patterns that first control streamflow totals in headwater catchments and subsequently control how much water is available for runoff into GSL.

With Great Salt Lake dessication, Northern Utahns have expressed worry about the effects of dust storms on air quality and health. We present dust flux and geochemistry data for the Salt Lake Valley, and investigate possible sources of specific metals within dust, as well as the current limitations of environmental health evaluations of dust.

The Salt Lake Valley, UT, USA, home to more than 2 million people, is situated proximal to the drying Great Salt Lake and to the east of other dry playas. Prior work has found that these playas contribute dust to snowpack in the Wasatch and Uinta Mountains to the east of the cities, and that dust contain high relative abundances of trace metals like Pb and Cu. However, no prior study has characterized the contributions of geogenic dust and industrial particulate pollution to communities along the Wasatch Front. In this study, we analyzed the dust deposited in 18 passive samplers positioned near the Great Salt Lake, Ogden, Bountiful, the Salt Lake Valley, and Lehi for total dust flux, the < 63 μm dust fraction, 87Sr/86Sr, and trace element geochemistry. We observed the highest dust fluxes at wealthy exurban sites near the western boundary of the urban area. Within the urban corridor, strontium isotope ratios and the spatial distribution of trace elements suggested that Great Salt Lake playa dust contributes only a small amount of material to dust in urban areas. Instead, based on the < 63 μm dust fraction, our results suggest the contributions of local soil disturbance. In our data, many trace metals exceed EPA Regional Screening Levels for soil (As, Co, Cu, La, Li, Mn, Ni, Tl, and U) and exhibited enrichments relative to both upper continental crust and playa dust collections. This suggested the direct contribution of particulate pollution via industries like Cu mining, concentrating and smelting, and oil refining, as well as historical pesticide and herbicide applications. Bulk ‘priority pollutant’ relative abundances did not track income, race or ethnicity demographics. However, certain elements (As, V) indicated a statistically significant positive correlation with income, whereas Pb, Tl and Ni indicate enrichment in the least wealthy and least white neighborhoods. Findings from this study suggest the importance of understanding constituent-specific loadings from particulate matter and dust in urban areas influenced by industry.