Watershed Symposium 2024

Summary:
Learn what steps has the state of Utah taken and plans to take for the long term health of the Great Salt Lake.

Full Abstract:
Commissioner Brian Steed and Deputy Commissioner Tim Davis will provide an update on the implementation of the Great Salt Lake Strategic Plan, current conditions of the lake, and the next steps for the long term health of the lake.

Summary:
This study aims to identify major phosphorus origins in Utah Lake’s watershed, quantify phosphorus influx from each source to Utah Lake, visualize HAB occurrences, and assess the correlation between phosphorus levels and HAB distribution.

Full Abstract:
This study aims to identify major phosphorus origins in Utah Lake’s watershed, quantify phosphorus influx from each source to Utah Lake, visualize HAB occurrences, and assess the correlation between phosphorus levels and HAB distribution. To accomplish this goal, our research team conducted in-situ water sampling and nutrient concentration measurements. We utilized geographic information systems (GIS) and remote sensing geospatial techniques to categorize key phosphorus sources to Utah Lake, employed empirical models to quantify nutrient runoff, and leveraged Google Earth Engine (GEE) and ArcGIS Pro to automate the processing of Landsat images for visualizing HAB distribution in Utah Lake. The identified key nutrient sources include urban lawns, golf courses, parks, herbaceous, deciduous forest, evergreen forest, mixed forest, hay/pasture, and cultivated crops. Their respective total areas ranged from 9.5 km² to 1,775.7 km², with golf courses being the smallest and deciduous forests being the largest. Notably, urban lawns and cultivated crops, covering 337 km² and 344.41 km2, emerged as two significant phosphorus sources to Utah Lake, despite constituting only 7.5% and 7.6% of the total Utah Lake Watershed area, respectively. Furthermore, our analysis revealed a close correlation between HAB distribution and phosphorus levels in the lake. Prior studies on Utah Lake have focused primarily on phosphorus loading from wastewater treatment plants (WWTPs) and atmospheric deposition. While WWTPs are still the major phosphorus contributors to the occurrence of HABs, our findings suggest that land-derived non-point nutrient sources play a substantial role in triggering HABs in Utah Lake.

Summary:
Development of the Great Salt Lake Basin Plan is underway and the Utah Division of Water Resources is excited to update you on the progress of the first-ever basin-wide water management tool. Implementation of the tool will ensure a resilient water supply for Great Salt Lake and all water uses, including people and the environment, in the basin.

Full Abstract:
The Utah Division of Water Resources is excited to share an update on the first-ever Great Salt Lake Basin Integrated Plan (GSLBIP). Since we presented at the 2023 Watershed Symposium, we’ve made significant progress, completing several key foundational tasks and paving the way for more impactful milestones ahead. These tasks will culminate in the creation of an important decision-making tool for improved water resource management. When the tools and research findings from the project are complete, decision makers will be equipped to make informed decisions about water planning in the Great Salt Lake Basin. Once implemented, the goal of the Great Salt Lake Basin Integrated Plan is to ensure a resilient water supply for Great Salt Lake and all water uses — including people and the environment — throughout the watershed. As part of the 2024 GSLBIP update, the Division of Water Resources team will dive into how we’re actively bringing the recommendations in the GSLBIP Work Plan (completed in April 2024) to life. We will bring attendees up to speed on the planning and modeling approaches, discuss near-term milestones and begin exploring possible watershed management alternatives to be considered in the scenario-planning process. Alongside the development of an innovative water resource modeling tool, the GSLBIP is conducting important research that will shape and guide future water planning decisions. The Gap Analysis in the GSLBIP Work Plan identified over 150 potential projects that could enhance understanding of water flows in the Great Salt Lake Basin. Project partners honed in on eight key projects, and all are now officially underway, marking an exciting step forward in the plan’s progress. We will provide an update on those projects and explain how we envision them playing a pivotal role in future watershed planning.

Summary:
A native walk of the Bear River with the ancestors of the Bear River and the life ways it provided and must still provide.

Full Abstract:
The Northwestern Band of the Shoshone Nation has lived in the Bear River Watershed for over 13,000 years. The Bear River was the most important resources to our ancestors. It gave life. It was abundant with game, wetlands, drinking water, fish, and was a trail system for our people, and it always flowed into the Great Salt Lake. We would like to discuss our Tribal History of the Bear River and how we used it historically, how we used the Great Salt Lake, and how the depletion of these resources would be catastrophic to every in the Wasatch Front. We want to discuss food we used, grounds we farmed, and all the native plants that existed and how losing them is causing us to lose the river and a depletion in the Great Salt Lake. It'll be a native walking experience of the Bear River.

The poster session is a forum for presenters from around the world to highlight programs and to share successful ideas with colleagues by presenting a research study, a practical problem-solving effort, an innovative program, and more. Poster presentations provide other conference participants an opportunity to quickly and easily become acquainted with a variety of topics.

Summary:
Great Salt Lake Stormwater Study: Basin-Wide Analysis of Stormwater Flows, Low-Impact Development and Groundwater Contributions developed a water-balance model to explore the impacts of Low-Impact Development (LID) on the Great Salt Lake watershed.

Full Abstract:
This study , completed in 2023, entitled Great Salt Lake Stormwater Study: Basin-Wide Analysis of Stormwater Flows, Low-Impact Development and Groundwater Contributions developed a water-balance model to explore the impacts of Low-Impact Development (LID) on the Great Salt Lake watershed. LID refers to, “engineered systems, either structural or natural, that use or mimic natural processes to promote infiltration, evapo-transpiration, and/or reuse of storm water as close to its source as possible to protect water quality and aquatic habitat.” LID mimics the undeveloped water flows within a watershed which reduces the volume of runoff and the flows through conveyances thereby improving water quality of stormwater. The team performed an integrated water assessment, including quantification of the influence of low impact development practices associated with post-construction retention stormwater permit requirements on runoff to the Great Salt Lake. The project consisted of a literature review, data compilation, and methodology development and implementation that led to development and application of a SWMM model to estimate how future development with and without LID impacts surface water runoff and groundwater recharge in the context of the Great Salt Lake watershed. SWMM model results were used in MODFLOW groundwater models to elucidate both the surface and groundwater paths to Great Salt Lake. This talk will highlight the potential impacts of LID on the Great Salt Lake watershed including surface water and groundwater systems.

Summary:
Dust blowing from dry lakebeds annually darkens the snowpack of the Great Salt Lake Basin. The darkened snow absorbs more sunlight, resulting in earlier snowmelt. Here, we have used a combination of fieldwork, satellite observations, and modeling to quantify the impact of dust snowmelt, in hopes of improving water supply forecasts in the region.

Full Abstract:
Seasonal snow in the Great Salt Lake Basin (GSLB) provides critical water resources for human infrastructure and local ecosystems alike. The GSLB snowpack has a first order influence on water availability to 2.7 million Utahns and provides the main surface inflows to the Great Salt Lake. Snowmelt rates are primarily controlled by snow albedo, which is impacted by surface darkening from light absorbing particles (LAPs). In the Wasatch Mountains, the primary LAP constituent is dust originating from dry lakebeds across the eastern Great Basin. Dust accelerates snowmelt, adding uncertainty to streamflow forecasts. Despite this, the impact of dust on snowmelt timing is not well known in the GSLB and is not directly accounted for in operational models. Here we present three years of research targeted at quantifying the spatial and temporal distribution of dust on snow and its impacts on snowmelt rates and timing across the GSLB. Our work includes a time series of point-based field observations, analysis of 23 years of satellite remote sensing retrievals, and basin distributed process-based snowmelt modeling. Results reveal that dust impacts snowmelt annually, but with high variability year-to-year, and with no strong temporal trends in the last two decades. The annual impact of dust on snowmelt was quantified over two distinctly different water years (2022 and 2023) by running two model implementations with different albedo representations: 1) A standard time decay relationship representing clean snow albedo evolution, and 2) daily remotely sensed observed snow albedo from MODIS. Differences between model runs, evaluated by melt rates, surface water inputs, and snow depletion timing, reflect the influence of snow darkening on snowmelt across the basin. This approach has allowed us to parse out physical drivers of snowmelt and is the first study to quantify snowmelt acceleration due to dust over the GSLB.

Summary:
In the Western US, irrigation companies play a key role in water conservation, navigating diverse challenges and strategies. Interviews with 18 companies in the Great Salt Lake Basin reveal varied conservation practices and highlight themes like motivations, techniques, and barriers. These insights can support effective water management policies.

Full Abstract:
In the Western US, water conservation efforts are currently top of mind and a rising priority for many individuals and entities. Irrigation companies are an example of an entity whose priorities are focusing on water conservation. Irrigation companies are on-the-ground, day-to-day water managers that are faced with decisions and challenges when it comes to water conservation. There is empirical evidence that emphasizes the importance of multi-scalar, multi-dimensional water conservation efforts. The wide array of efforts and practices related to water conservation are all important when looking at the big picture of conservation. Therefore, viewing a diverse set of conservation efforts to be available to irrigation companies can allow for individuals and entities of all sizes and capacities to participate in conservation efforts in accessible ways. Therefore, the steps and efforts that entities like irrigation companies are able to take toward conservation are critical within the larger picture of water conservation. In the Great Salt Lake Basin, 18 irrigation companies participated in semi-structured interviews where topics around water conservation efforts were discussed. Within the realm of irrigation companies, water conservation efforts look quite different even within the same basin. Examples of some of these efforts include reducing general water usage, work towards making more efficient systems, and participation in water leasing and banking. Conservation themes that arose in the qualitative analysis of the interviews include conservation motivations, conservation decisions, and specific conservation techniques and applications of these irrigation companies. Discussions of the enabling and constraining factors around conservation such as funding and collaborative relationships also arose. These enabling and constraining factors give insights into how to better support the work of these companies at larger policy levels. The themes and findings here are being shared not as a way to dictate what other irrigation companies should be doing, but rather what other irrigation companies could be doing in terms of water conservation. These insights also recognize the work and efforts that these companies are currently participating in and highlight how water conservation is an important component to these irrigation companies. In order to build off these qualitative findings, future efforts of this project will potentially include a paired survey of irrigation companies in the basin to capture more generalizable, quantifiable perspectives. Co-Author: Courtney Flint, Professor, Utah State University, https://courtneyflint.wordpress.com