Great Salt Lake Water Conservation Toolkit

The Great Salt Lake Watershed is witnessing rapid population growth in several of its regions, leading to a surge in demand for residential and other urban water uses. There is a pressing need to divert more water from the system to meet these demands. However, such diversions could exacerbate ongoing water scarcity issues in the region. It is imperative to prioritize and maximize water efficiencies in all water use sectors. By doing so, we can reduce the demand for water and minimize the need for additional diversions from the Great Salt Lake watershed, ultimately contributing to sustainable water management in the region.

In arid climates characterized by prolonged droughts and irregular precipitation patterns. Climate change exacerbates these water issues by further stressing the hydrological system. In this context, the entire hydrological system faces a heightened risk of failure, jeopardizing the welfare and livelihoods of those who depend on it. Therefore, it is critical to adopt proactive measures that promote sustainable water management across water users and mitigate the impacts of climate change. By adopting water conservation practices, we can ensure the long-term viability of the hydrological system and safeguard the well-being of both present and future generations.

Acknowledging the shared responsibility of all water use is central to creating equitable solutions and meaningful, achievable conservation efforts. The greatest users of water: Irrigation, and Residential/Domestic use also represent the greatest opportunity for impactful water savings and can be leaders in the charge of preserving the Great Salt Lake and it's supporting systems.

To address the complex water management challenges facing the Great Salt Lake, it is essential to gain a comprehensive understanding of the path that water takes as it is diverted and used to support human activities. By mapping out the entire water supply chain, from diversion points to end-users, we can identify potential points of conflict and pinpoint opportunities for water conservation. With this information, we can develop effective strategies and policies that promote sustainable water management practices, reduce water loss, and enhance efficiency. Furthermore, by understanding the complexities of the water system, we can develop a more informed and collaborative decision-making process that involves all stakeholders. Ultimately, such an approach can help to safeguard the Great Salt Lake and its associated ecosystems, while ensuring a reliable and equitable water supply for all.

Water management is a highly complex and multifaceted issue, complicated by centuries-old legal frameworks such as English Common Law that govern water diversion and use. This complexity is further compounded by challenges in accurately tracking down water users and quantifying their usage, leading to significant gaps in our understanding of how water is being utilized. Additionally, once water is diverted, tracing its journey and ultimate destination can present an intricate and challenging task.

It is crucial to overcome these challenges and obtain a clear picture of the water supply chain. This information informs decision makers by identifying areas for improvement and aiding in the implementation of effective policies and practices to promote sustainable water management. As water scarcity continues to pose a significant threat to our ecosystems and communities, it is essential to prioritize and invest in developing a comprehensive and reliable understanding of our water systems. Ultimately, this will enable us to make informed decisions, safeguard our water resources, and ensure a reliable and equitable water supply for all.

We used data collected from the United States Geological Survey (USGS) National Water Use Information Program. In summary this dataset collects an approximation of water used in millions of gallons per day (Mg/d) every 5 years by county for the entire nation. You can check out the National Water Use Information Program  here .

Our first step was determining what counties were most relevant to our study of the Great Salt Lake Watershed.

There are 30 counties contributing land area to the Great Salt Lake watershed. It's unreasonable to assume that rain falling on each distant corner of the watershed truly has the potential to reach the Great Salt Lake. In selecting the counties to analyze we wanted to keep our focus on meaningful contributions to the lake. Everyone living in the watershed has the opportunity to make a difference, but we focused our study on counties with at least 25% of their land area within the watershed boundary. We made sure to include any county touched by one of the three contributing rivers: Bear, Weber, and Jordan.

After selecting counties and retrieving data for each we began making connections within the USGS dataset, tracking water as it traveled through pipes (transport of water) into buckets (destinations/water uses). We categorized water use buckets into the following 7 categories:

• Irrigation 
• Livestock 
• General Public use
• Energy 
• Industry 
• Commercial
• Domestic

After organizing the data by water user, our next task was to aggregate data and measure the 30 year average amount of water flowing through each county and in turn each basin. Take the Weber Basin for example.

Using the water and land use datasets we are able to integrate this information into a comprehensive tool representing the current water use situation, and allowing water managers to set goals and generate scenarios for the future.

The first portion of our tool takes information specific to the area, shown here the Weber Basin to demonstrate current water use. The far-left column shows the amount of water from each source (Millions/gallons/day diverted), then water users (M/g/d used in each category) and finally the destination of water after being used (M/g/d returned or lost to the system).

This information is compared with land use inputs. In the row of irrigation users there are sections for total irrigated land acres, and irrigated acres per irrigation system as well as average irrigation system efficiency. With these inputs the tool is able to calculate use per surface and use per irrigation system.

Similar calculations happen in the domestic category. Population use per capita is calculated. In the Weber Basin each person uses 152 gallons of water every day.

After developing an understanding of current water use in the area, the tool asks water managers to set savings goals using sliders to represent percent savings.

With percent savings goals defined the tool generates a target scenario. This scenario includes a water use target, or the amount of water used after savings, and the amount of water saved, or the difference between use before and after the tool is applied.

Once a scenario is generated for each water user, water managers can interact with irrigation use and domestic use to generate scenarios to meet their defined goals.

It's no secret that irrigation is the biggest consumer of water in the Great Salt Lake Watershed. Water used for irrigation fuels the economy through agricultural export and provides essential food to people throughout the watershed. Irrigation technology is rapidly improving; increasing the efficiency of water use and helping agriculturists grow more crops with less water. With 60% of irrigation water being allocated to the Bear River Basin, there is enormous potential for savings in this region.

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With the most agricultural acres, and thereby the most irrigation water use -- the Bear River Basin has the most potential to positively benefit the lake by increasing irrigation efficiency.

Let's set a hypothetical goal of 15% water savings for irrigation water use in Cache County, assuming 0% savings in all other categories.

One possible scenario to meet this savings goal is to first subsidize improvements to flood and sprinkler irrigation systems, bringing the average efficiencies of each to 75%. Second in making this scenario reach target savings is reallocating 1,000 acres of flood irrigation and 2,000 acres of sprinkler irrigation to a new drip system. These changes are visible in the tool when comparing the current situation (top row) with the interactive scenario building row below.

A plausible location for this irrigation system change is on irrigated lands surrounding the small 6 acre drip farm currently existing creating a large drip irrigation system over land currently irrigated using flood methods and sprinklers.

The interactive portion of the tool uses updated efficiencies and acreage to calculate a new water use metric representing the proposed settings. We can see that this scenario meets the 15% savings goal by comparing proposed water use (194 M/g/d) with the water use target (196 M/g/d).

The last portion of the tool uses savings goals and situations to demonstrate the impact of proposed changes. By saving 15% in the irrigation category, making no other changes, Cache County has the potential to save 34.6 M/g/d, using only 88% of their original water use.

As population continues to grow in the Great Salt Lake watershed, the potential for water savings in the urban sector also grows. Specifically, domestic use can contribute meaningful water to the lake by increasing residential efficiencies.

The Jordan River Basin is home to 67% of people in the Great Salt Lake Watershed and the largest urban centers: Salt Lake City and Provo. It's no secret that these, and other urban centers of the watershed are only growing. The large population of the Jordan River Basin has the potential for tremendous water savings in the Domestic, and other urban water use categories.

When we look at a map of Urban Footprint, we can see that most of this population likely lives in Salt Lake County.

Population is only continuing to grow in the county, meaning that increasing domestic efficiency is the only option for water savings. With a current per capita water use of 187 gallons per person per day, the potential contributions to the lake from the domestic water users in this region are huge.

Let's imagine water managers in Salt Lake County set a water savings goal of 15% for domestic use, and 0% savings in other categories.

If we assume population will continue to follow growth trends, and plan for a future population of 1,300,000 we must reduce per capita water use by at least 29 gallons per person per day. This is the minimum efficiency required to meet 15% savings goals, using only 117 M/g/d across the county. Plausible methods for improving per capita water use include education campaigns and encouraging waterwise planting on residential properties.

By saving 15% in the domestic water use category and making no other changes Salt Lake County has the potential to reduce their overall water usage by 6%.

It's easy to get caught up in the complexity of water issues facing the Great Salt Lake Watershed. It's even easier to ignore--thinking that the problem is so big there is no way to truly make a difference. If there is one thing demonstrated in our findings and savings calculations it's that every water user, no matter how insignificant their use has an opportunity to make meaningful contributions to the lake.

The West Desert Watershed is frequently ignored in discussions about water and the Great Salt Lake, there are no significant rivers, and little water to be found. Even with the small amount of precipitation arriving in the West Desert, there is opportunity for efficiency improvements and significant water savings across users.

What will you do with this greater understanding of Great Salt Lake water issues? Will you commit to water your lawn less? Taking shorter showers? Vote to subsidize water efficient irrigation? Be the change!

If you are interested in how our tool works, or want to apply this methodlogy to an area of your jurisdiction we encourage you to download it!

Check back for county specific water savings tool(s) soon.