Skip to main content
U.S. flag

An official website of the United States government

SALT LAKE CITY, Utah — A timely new website, funded by the Great Salt Lake Advisory Council and USGS, brings information about the effects of Great Salt Lake levels on different natural resources into one location with the Great Salt Lake Hydro Mapper.

Side by side satellite images of the Great Salt Lake in 1986 and 2021 showing drastic changes in surface area.
A timelapse on the Great Salt Lake Hydro Mapper site shows changes in the surface area of the lake from 1985-2021. These stills show a comparison of the lake between 1986 and 2021.

On the website, users can see how changing lake levels, which recently reached a new historic low, affect local wetlands, biology, economics, safety, recreation and land use. Both current and historical USGS data from the Saltair and Saline gaging stations automatically populate the site’s diagrams with up-to-date lake level information. Information from the Utah DNR Final Great Salt Lake Comprehensive Management Plan and Record of Decision shows whether current lake levels are beneficial or adverse for different natural resources. 

"There is significant public concern about the health and elevation of the Great Salt Lake. This new hydro mapper tool provides a single location where we can see data related to the entire Great Salt Lake watershed,” said Jamie Barnes, Utah DNR Division of Forestry, Fire and State Lands Director and State Forester. “A tool like this has really been needed for some time and now that we have it, the information it provides will help inform people about the impact the watershed has on the lake and its current condition." 

Matrix from the Great Salt Hydro Mapper webpage showing natural resource characteristics at different lake levels.
Information from the Great Salt Hydro Mapper webpage on July 27, 2022, shows resource characteristics at different lake elevation levels. Click on the image for details.

The Great Salt Lake watershed drains over 20,000 square miles of northwest Utah, southeast Idaho, southwest Wyoming and eastern Nevada. It provides a critical habitat and food for millions of migratory birds and generates approximately $1.3 billion to the Utah annual gross domestic product through aquaculture, recreation and industrial activities such as mineral extraction and processing. 

The health and success of Great Salt Lake’s natural resources depend on inflows to the lake from the watershed. Water comes into the Great Salt Lake from local streams and rivers with the largest contributors being the Bear and Weber rivers. Water exiting the lake is primarily from evaporation. The Great Salt Lake Hydro Mapper water dashboard helps scientists and users connect lake conditions to the entire watershed. Users can also view current and historic inflow measurements from different major streams on the current water data tab.  

Map from the Great Salt Lake Water Dashboard from July 27th, 2022 showing the extent of the Great Salt Lake watershed.
This map from the Great Salt Lake Water Dashboard on July 27, 2022, shows the extent of the Great Salt Lake watershed. Click on the image for details.

“The Great Salt Lake hydro mapper provides an assortment of interactive tools that allow people to easily explore USGS data collected on Great Salt Lake and within the Great Salt Lake basin,” said Christine Rumsey, a hydrologist at the USGS. “We hope it will continue to evolve in response to new ideas and stakeholder needs.”  

The Great Salt Lake Hydro Mapper isn’t just for scientists. The site can be used by policy makers and industry personnel wanting to make informative decisions, teachers and school children wanting to learn more about the lake or recreators and tourists seeking access to the lake’s wetlands, shorelines and water. 

"The Great Salt Lake Advisory Council is pleased to announce the launch of a new tool that will help people be better informed about the conditions of the lake and its watershed," said Great Salt Lake Advisory Council Chair Don Leonard. 

For more information about the Great Salt Lake please visit: 

  • The USGS Utah Water Science Center Great Salt Lake page 
  • The Utah DNR Division of Forestry, Fire & State Lands Great Salt Lake page 
  • The Utah DNR Division of Water Resources Great Salt Lake page 
  • The Utah Department of Environmental Quality Great Salt Lake Advisory Council page 
    Graph of water data recorded by the Great Salt Lake Saltair gaging station from January 2020 to July 2022.
    This graph of water data recorded by the Great Salt Lake (GSL) Saltair USGS Gaging Station 10010000 shows data from January 2020 to July 2022 from the Great Salt Lake Hydro Mapper webpage. Click on the image for details.