Hydrologists

Hydrologists study water and how it moves across and through the Earth’s crust. They research the distribution, circulation, and physical properties of surface water and groundwater. They also study the form and intensity of precipitation and its rate of evaporation into the atmosphere, infiltration into soil, or return to the ocean.

Duties

Hydrologists typically do the following:

• Measure streamflow, volume, and other water-cycle elements of bodies of water
• Collect water and soil samples to test for specific properties, such as the pH or pollution levels
• Analyze data on the impacts of pollution, erosion, drought, and other environmental problems
• Research ways to minimize negative impacts of environmental problems on people and ecosystems
• Forecast water supplies, the spread of pollution, floods, and other events
• Evaluate the feasibility of water-related projects, such as hydroelectric power plants, irrigation systems, and wastewater treatment facilities
• Write reports and present their findings

Hydrologists study water distribution, movement, and quality above and below the Earth. Their insights and expertise help with managing resources and addressing environmental issues that involve water.

Hydrologists use a variety of equipment and techniques to collect and analyze data. For example, they may use light detection and ranging (LiDAR) or sound navigation and ranging (sonar) systems to gather data for mapping bodies of water. They also use computer modeling programs to predict water conditions and analyze complex datasets.

Working with engineers, scientists, and public officials, hydrologists help to manage the water supply in a variety of ways. For example, some groundwater hydrologists recommend locations for wells and the amount of water available for pumping; others focus on the cleanup of groundwater contaminated by spilled chemicals. Surface water hydrologists may analyze precipitation data to predict water levels of aboveground sources such as lakes, streams, and snowpacks, helping reservoir managers decide when to release or store water.

Hydrologists held about 6,300 jobs in 2024. The largest employers of hydrologists were as follows:

Hydrologists typically work in an office setting and in the field. They may need to travel to lakes, streams, and other locations, sometimes including international destinations. In addition, fieldwork may involve working outdoors in all types of weather.

Work Schedules

Most hydrologists work full time. Some work more than 40 hours a week, especially when they are in the field.

To enter the occupation, hydrologists typically need a bachelor’s degree in geology, hydrology, or a related field. Some employers prefer to hire candidates who have a master’s degree.

The median annual wage for hydrologists was $92,060 in May 2024.

Employment of hydrologists is projected to decline 0 percent from 2024 to 2034.

Despite declining employment, about 500 openings for hydrologists are projected each year, on average, over the decade. All of those openings are expected to result from the need to replace workers who transfer to other occupations or exit the labor force, such as to retire.