A hydrologist studies the dynamic nature of water, the forces that cause water to move around, and what effects this movement has on the surrounding environment. Hydrologists examine issues such as precipitation pathways, the relationship between rainfall and runoff, and the effects of precipitation on soils and various landscapes. They are also involved in projects to determine and promote sustainable usage of water sources and water conservation.

At a Glance

Imagine standing in a new, exclusive residential development high on a ridge overlooking the river valley. You are a hydrologist for an environmental consulting firm that the city has hired to study the impact of residential development on the local environment.

Dozens of developers have approached the city for permits to build more houses along the ridge. Before the city approves more buildings in the area, it wants to ensure this community isn't negatively affecting the environment, including the river’s water quality.

The city has hired your firm's geologists, biologists, toxicologists, and hydrologists. As the team's lead hydrologist, you will be responsible for monitoring and evaluating water quality around the area to detect any changes that might result from this new community development.

As a hydrologist, you specialize in water's physical, biological, and chemical characteristics. One of your interests is how urbanization affects water resources, making this project very exciting.

First, you identify issues that might arise from residential development, such as surface runoff contamination. The houses along the ridge all have yards that slope toward the valley, so excess rainwater flows into the river when it rains.

As part of your study, you will collect surface runoff samples to analyze water quality. Each lot has a well-tended backyard, where lawns and flowerbeds are often treated with pesticides and chemical fertilizers. These chemicals can be picked up by rainwater and carried in runoff to the river.

Area homeowners also use the river for recreation. This means you’ll monitor the water carefully to ensure that rafters, swimmers, and sport fishers aren't negatively affecting water quality.

Your evaluation of the development's impact on the area’s water quality will be a significant part of the team's report to the city. It will help planners make wise decisions with respect to further residential development.

Job Duties

Job duties vary from one position to the next, but in general, hydrologists are involved in the following activities:

  • Monitor water supply and usage.
  • Contribute to water resource development planning by forecasting water usage and precipitation levels.
  • Use computer models to determine the most effective ways of managing available water in particular areas.
  • Analyze the effects of environmental and land-use changes on water flow.
  • Conduct research on the physical, chemical, and biological properties of bodies of water.
  • Respond to water flow situations, for example, droughts and floods, and evaluate different methods to address issues.
  • Develop integrated water and drainage management plans.
  • Prepare technical reports and studies.
  • Coordinate and supervise the work of technicians, technologists, and students.
  • Conduct climate impact studies with respect to various hydrological applications.
  • Study public and industrial water supply, water quality, wastewater, and their impacts on fish and wildlife habitats.
  • Conduct environmental impact assessments of resource projects and study the effects of natural disturbances on water quantity, quality, and aquatic ecology.
  • Conduct seismic surveys and study the formation of ocean basins.

Work Environment

Hydrologists work in a variety of locations, including:

The field:

  • Collecting samples
  • Gathering Geographic Information Systems (GIS) data
  • Performing statistical analyses
  • Setting up monitoring stations
  • Conducting field experiments

The office:

  • Analyzing data and preparing reports
  • Interpreting hydrological data
  • Creating and utilizing computer models
  • Preparing research proposals and designing experiments
  • Communicating on the phone and in meetings with clients, colleagues, government departments, and the general public

The lab:

  • Processing and analyzing samples
  • Conducting bench experiments
  • Using instruments such as spectrophotometers, gas chromatographs, and mass spectrometers to analyze water samples
  • Calibrating and maintaining lab equipment to ensure accurate and reliable measurements
  • Keeping detailed records of their work, including procedures, results, and conclusions

Where to Work

There are several places hydrologists can find employment. They include:

  • Federal, provincial/territorial, and municipal government departments
  • Colleges, universities, and research institutes
  • Natural resource companies
  • Civil engineering and forestry consulting firms
  • Environmental and engineering consulting firms
  • Not-for-profit and non-governmental organizations

Search for jobs on the ECO Canada Job Boad

Education and Skills


If you are a high school student considering a career as a hydrologist, you should have a strong interest in:

  • Biology
  • Chemistry
  • Mathematics
  • Physics

If you are a post-secondary student considering a career as a hydrologist, the following programs are most applicable:

  • Environmental Science
  • Earth Science
  • Hydrology
  • Marine Biology
  • Water Resources Engineering

In most cases, the minimum education requirement to work as a hydrologist is a university undergraduate degree.

Hydrologists who provide design input for water management infrastructure projects (e.g., dams, canals, stormwater management, pipeline, or bridge crossings) must have an engineering degree and Professional Engineer status.

Hydrologists who provide geological input must have a degree in geology and Professional Geoscientist status.

Our Environmental Professional (EP) designation can also help you progress in your chosen environmental career.


Technical Skills

  • Resource management
  • Health, safety, and environmental regulations
  • Data collection
  • Flood control and mitigating risk
  • Design hydraulic structures
  • Erosion and sedimentation control
  • Quality assurance

Personal and Professional Skills

  • Analytical and critical thinking
  • Time management
  • Attention to detail
  • Interpersonal skills
  • Physical stamina
  • Problem-solving skills
  • Oral communication skills

Environmental employers look for professionals who can combine technical knowledge with soft skills. Watch our free webinar “Essential Not Optional: Skills Needed to Succeed in Canada’s Environmental Industry” or take our Essential Skills courses.

Role Models

Kristin Hanson

I was attracted to the science of hydrology because it combines many disciplines and allows me to meet practical goals. It isn't realistic to expect I can save the entire world, however, each project I accomplish helps improve a small part of the world. The best advice I ever received was to gain experience in a variety of areas and types of projects. This allowed me to challenge myself. I started out as a research assistant and then returned to school for graduate work before progressing into more senior roles.

I have accumulated 12 years of diverse experience in planning, executing and managing environmental audits, conducting site investigations and remediating contaminated sites. My experience includes everything from collecting samples in the field to giving technical presentations and training to clients. Types of organizations that might hire hydrologists include consulting companies, municipal planning/public works departments, government regulatory agencies and industrial companies.

Jobs are most commonly found in urban centers. Things are constantly changing and I read journals and take short courses regularly. I also learn from my experiences managing diverse projects, and from interacting with the other talented professionals in my company. I am a member of the National Groundwater Association, the Association of Professional Geoscientists of Ontario and the Canadian Geotechnical Society. The industry needs talent. I predict that salaries will continue to go up as skilled professionals and the advice that they provide to the industry become more sought after.

Corporately, industries will begin to see environmental needs as something to be planned and addressed in a preventative way, rather than in a reactionary way. Air is a fast-growing area right now. Pharmaceuticals are a new contaminant being investigated. As we learn more about our environment and human health, things will continue to change rapidly. I recommend a strong background in geology and chemistry for entering this type of work. There is such diversity in this profession that you can choose the opportunity you want to match your lifestyle.

It is important to manage all aspects of your life. Don't let your personal life slip so that you work all the time. You have to achieve a balance. I have many projects on the go and typically work 40-60 hours/wk, mostly in the office. My work doesn't have typical 9-5 hours. The day isn't over until deadlines are met and reports are delivered. I never find the work boring and have different challenges each day. I manage projects, staff, schedules, clients and data, review reports and provide input to the work of others.

I am constantly juggling priorities to meet the client's expectations. I interact with clients, engineers and lawyers who have different areas of knowledge and expertise. It is important that I can communicate effectively and explain technical information in a non-technical way. My greatest work accomplishment so far has been remediation of a hazardous waste site in a residential neighborhood. This project was special because I was able to use existing laws to get the waste de-listed from hazardous to non-hazardous, which allowed my client to get the work done sooner. This ability to bridge the gap between the environment and environmental law is a unique contribution that gives me a sense of satisfaction.

Your Impact

As a hydrologist, you analyze the influence water has on its surrounding environment and how potential environmental disruptions directly impact the quantity and quality.

The two most common categories of hydrologists are groundwater and surface water hydrologists. Groundwater hydrologists study water below the earth’s surface, and surface water geologists study water above ground.

Groundwater hydrologists focus on contaminated sites or water supply. They may be consulted on where to build waste disposal sites or manufacturing sites to avoid the potential for water contamination.

Surface water hydrologists study rivers, lakes, rainfall, or runoff. The information from these sites can be used to predict future water levels or the likelihood of droughts or floods. This can then be used to develop flood management strategies or calculate where to build reservoirs to manage current water supplies.

Hydrologists play a critical role in protecting Canada’s water resources. Their most important duty is to analyze how water directly affects the surrounding environment and how environmental changes influence the quality and quantity of water. Climate change has led hydrologists to study areas where the water supply is at risk due to increased temperatures or excess water from flooding.

A hydrologist’s role is especially important in countries without reliable access to clean water. In these countries, the agrarian system may be in use, heavily relying on water management and irrigation.


Occupational Classification

Hydrologists are classified in the following occupational grouping:

NOC Code: 21102 – Geoscientists and oceanographers

What is an NOC Code?

The National Occupation Classification (NOC) provides a standardized language for describing the work performed by Canadians in the labour market. It gives statisticians, labour market analysts, career counsellors, employers, and individual job seekers a consistent way to collect data and describe and understand the nature of work within different occupations.

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