Gauge a stream's flow
Measure a stream's flow and inspect the gear installed in it, so your numbers reflect real conditions.
Career profile
Hydrologist
Hydrologists track water's path and amount, then turn data into advice on supply and flooding.
Can a town pump more groundwater without drying up the neighbors' wells? Hydrologists help answer questions like that using collected data and models.
A day in the life
Test a monitor against a sample
Compare a sample with the automatic monitor's reading, and trace any mismatch before you rely on that figure.
Model a reservoir's choices
On surface-water projects, you run computer models of a reservoir holding versus releasing water, ahead of the choice.
Map results for water managers
Turn your results into maps and a written report so water managers can weigh their options.
Quick facts
Bachelor's degree
United States
$96,600/year
United States · May 2025
1.5% growth
United States · 2025–2035
Quick orientation
Preparation, pay & outlook
Preparation
Bachelor's degreeUsually in hydrology, geology, or a related physical science.
Pay
$96,600/yearNational median for hydrologists; equivalent to $46.44 an hour.
Outlook
1.5% growthAbout 400 openings a year are projected nationally, including replacement openings.
Fit, tradeoffs & changing tools
You might like this if…
- You enjoy using math to explain something you can observe outdoors.
- You want to check an odd result before trusting it.
- You like explaining evidence to people who need to make a decision.
Things to weigh
- Field trips can mean carrying equipment, working in bad weather, and spending longer days away from the office.
- Expect substantial computer analysis between field visits.
Where AI may help
Some drought-forecasting projects use software that learns patterns from past data—machine learning—to predict low streamflow.
What people still lead
You choose the study question, check measurements, and explain what the results mean for water decisions.
What we can’t predict yet
How much forecasting these tools can take over depends on the task. Predicting drought severity and looking farther ahead remain harder than some other predictions.
Pay in context
Earnings
Your pay can vary with experience, responsibility, and location.
The national midpoint
Hydrologists had median wages of $96,600 a year, equivalent to $46.44 an hour. Half earned more and half earned less.
The national spread
The 10th-percentile wage was $64,020 and the 90th-percentile wage was $153,130 a year. These describe the wage distribution, not starting and senior salaries.
Openings with modest growth
Employment is projected to grow 1.5%, with about 400 openings annually on average. Openings include replacing workers who leave, as well as new jobs.
Getting started
Study water through a science degree
- What the route involves
- Earn a bachelor's degree in hydrology, geology, or a related physical science, with math, statistics, and science coursework.
- What it can lead to
- This is the typical educational foundation for entry-level hydrologist work.
Combine coursework with qualifying experience
- What the route involves
- For federal hydrology jobs, complete the specified science coursework and combine it with appropriate scientific water-resources experience or additional education.
- What it can lead to
- This can meet the federal Hydrology Series 1315 basic requirement through its education-and-experience option.
- What to check
- The coursework requirement includes at least 30 semester hours in listed science and related subjects, including 6 in calculus and 6 in physics. Experience alone is insufficient; check each vacancy's additional qualifications.
A relevant bachelor's degree is the usual starting point. Some employers prefer a master's degree.
After entry
Career paths
This starts where the entry routes leave off: early work, growing capability, and advancement or specialization.
Build reliable records
Get comfortable checking instruments and documenting measurements that another scientist can use.
Develop a specialty
In groundwater work, learn to connect well levels and drilling records to estimates of available water.
Lead an investigation
Progress toward designing studies and coordinating scientists and technicians through the final recommendations.
Where you can work
Public water science centers
Work alongside technicians, data scientists, and other specialists on monitoring networks and long-term watershed studies. Projects can involve several government or university partners.
- Office
- Field work
Water-supply consulting firms
Investigate groundwater for utilities, municipalities, or industrial clients. Your analysis helps connect local underground conditions to decisions about wells and long-term supplies.
- Office
- Field work
Try it
See whether the job clicks before you commit to the path.
Open Water Data for the Nation from the U.S. Geological Survey and choose a streamflow graph. Mark its largest rise and how long the flow takes to fall again. Write two possible explanations and one extra measurement you would need to distinguish them. Notice whether interpreting the pattern makes you curious.
Sources
- O*NET OnLine. Hydrologists — 19-2043.00. Accessed 2026-10-09.
- U.S. Bureau of Labor Statistics. Occupational Outlook Handbook: Hydrologists. Accessed 2026-10-09.
- U.S. Bureau of Labor Statistics. May 2025 Occupational Employment and Wage Statistics: national estimates, SOC 19-2043. Accessed 2026-09-29.
- U.S. Bureau of Labor Statistics. Employment Projections Table 1.2, 2025–2035: Hydrologists. Accessed 2026-09-29.
- U.S. Office of Personnel Management. Hydrology Series 1315: Individual Occupational Requirements. Accessed 2026-10-09.
- U.S. Geological Survey. What is Hydrology?. Accessed 2026-10-09.
- U.S. Geological Survey. Machine learning generated streamflow drought forecasts for the conterminous United States. Accessed 2026-10-09.
- U.S. Geological Survey. Work with the USGS Maryland-Delaware-DC Water Science Center. Accessed 2026-10-09.
- INTERA. Water Supply Development. Accessed 2026-10-09.
- U.S. Geological Survey. Water Data for the Nation. Accessed 2026-10-09.