Preserving biodiversity, meeting agricultural, industrial and human needs, as well as mitigating risks of flooding, drought and water pollution. Today more than ever, water is a major economic, environmental and social issue.


To ensure effective and sustainable management of this resource, which is as precious to mankind as it is to the environment, a science has been created: hydrology.

From its mechanical properties to its physical and chemical characteristics, a hydrologist is concerned with the water cycle in all its aspects. It is thanks to the studies carried out by hydrological engineers, experts in the water cycle, that we can understand its mechanisms, predict future trends, and adapt human activity to preserve this resource and life on earth.

In the form of a job description, this article explains what a hydrologist does. From the role of the hydrologist to the training and skills required, not forgetting salary and the tools needed for research work, discover a rich and essential profession.

Why hire a hydrologist?


The expertise of a hydrological engineer is crucial as it makes a major contribution to food safety, to preservation of biodiversity and to public health. By providing a better understanding of the water cycle and the way in which climate change may affect water resources, hydrologists can help to improve the quality of life.

The studies carried out by hydrologists are useful in many fields. They can be used to prevent flooding or water pollution by micropollutants, to ensure the safety of dams during their design and construction, or to integrate hydrological considerations into urban planning, for example. They can also be used to optimise irrigation in agriculture, ensure the rational use of water in industry, preserve aquatic ecosystems and biodiversity, and study the impact of climate change to propose adaptation strategies.


What is the role of a hydrologist?


Evaluating the impact of a development on water resources, studying the absorption of rainfall by the soil, calculating the flow of a river, measuring the effects of rainfall on the water regime of a region or the pollution of a river, a lake or groundwater – the tasks of a hydrological engineer are many and varied.

Working in collaboration with local players, local authorities and NGOs, but also on behalf of government bodies and water agencies, hydrologists work both as technicians in the field and in the laboratory, and as engineers in charge of modelling, planning, design and project management.

The job of a hydrological engineer involves collecting essential data (rainfall, river flow, water levels, etc.), which is then analysed and modelled to assess the quantity, quality and availability of water and, if necessary, to predict future trends.

The results of their research are generally summarised in a report, enabling them to propose models for the sustainable management of this vital resource and the protection of water and aquatic environments.

Depending on where they work and their specialty, the studies they carry out may lead them to:

  • Plan sustainable water management and propose developments that balance human, agricultural and industrial needs while preserving natural ecosystems.
  • Optimising the efficiency of infrastructures (dams, canals, irrigation systems, etc.) while minimising their environmental impact.
  • Identifying and preventing the risks associated with river flooding or drought, and avoiding the collapse of riverbanks or soil erosion.
  • Assess the impact of human activities on aquatic ecosystems and ensure sustainable and rational use for irrigation and industry.
  • Adapt buildings to climate change.
  • Reducing pollution of aquatic environments (micropollutants, pesticides, nitrates and phosphates, household products, hydrocarbons, etc.).

Tools and technologies used by hydrologists


Hydrologists can use a number of tools and technologies that vary according to the research they wish to carry out.

In the field, they may need to use a limnimeter to gauge the water level in order to study its movements, a fluviometer to measure the flow of watercourses, a pluviometer to assess the amount of rainfall, and samplers to study pollution levels, for example.

In the laboratory, chromatographs are used to analyse the chemical composition of water samples, microscopes are useful for analysing micro-organisms and spectrophotometers are used to measure the concentration of different components in water.


GPS and satellites are technologies they can also use. They enable them to draw up precise maps, measure the temperature of the water to determine its source (satellites equipped with infrared cameras) or gather information on changes in the height of the ground to assess its water content and predict possible droughts.

Finally, computer tools such as data processing, mapping and modelling software are essential to their studies.

Hydrologist engineer: the job description

What kind of training and baccalaureate do you need to become a hydrologist?


After a scientific baccalaureate, hydrologists follow five years of study, after which they obtain an engineering degree specialising in hydrology, chemistry or hydrogeology. They can also obtain a Master’s degree in “Water Sciences”, “Hydrology and Hydrogeology”, “Earth and Planetary Sciences” or “Environmental Sciences”.


How much does a hydrologist earn?

The average salary for a hydrologist varies between €33,000 and €49,400 a year, and can reach up to €80,000 for the most experienced. This variation can be explained by experience, skills (technician or engineer), training and qualifications. Hydrologists’ salaries also depend on the organisation or sector (public or private) in which they work.

What skills are required to become a hydrologist?

The job of hydrologist is multidisciplinary, requiring theoretical and technical knowledge in fields such as geology, chemistry, physics, biology, the environment and mathematics.

Hydrologists master hydrology software, which is essential for modelling, analysing and interpreting data and drawing up maps. They are capable of assessing risks and proposing appropriate developments.

Lastly, they have good communication skills, are able to summarise, and are autonomous, rigorous and good listeners, so that they can respond fully to the requests made of them.


Career prospects

Hydrological engineers have many opportunities for career development. Firstly, they can specialise in a particular field (water resource management, hydrological modelling, flood prevention, water quality, etc.). They may also move into research, where they will contribute to the development of knowledge in hydrology and publish scientific articles.

If they have good experience, hydrologists may be required to manage projects and a team. They may go on to teach and share their knowledge, or work as consultants advising companies, organisations or governments on water-related issues.


Hydrologists, an essential profession

The profession of hydrologist is necessary to ensure effective and sustainable management of our water resources. With 5 years’ study of the sciences, hydrologists are experts in the water cycle. Thanks to the research and studies they carry out, both in the field and in the laboratory, hydrologists provide essential keys to understanding human activities and construction in a sustainable and responsible way. This is essential if we are to prevent the risks associated with the vagaries of water and preserve the quantity and quality of this resource, which is vital to the environment.

Register to our newsletter

Stay up to date with industry news


Share This

Share this post with your network!