Estonia has long-lasting traditions and experience in hydrometrical observations. First observations were visual and their descriptions can be found in old publications. It is believed that the water-energy of the Narva waterfall has been used since the 15th century. Special systematic hydrological investigations started in the 18th century.

Research papers by Andres Tarand provide an insight into Estonian hydrology. According to him the first measurements of water level in Estonia were carried out by the 7th class(rate) astronomer Ivanov in the port of Tallinn between 1805 and 1813. In Narva-Jõesuu the sea level measurements were arranged by the pilot-captain Larsen according to the order of the Narva town council in 1829.

The oldest series of coastal observations preserved in the archives of the Estonian Meteorological and Hydrological Institute date back to 1842 when water-level observations were carried out in the port of Tallinn. Regular measurements of water temperature started on Estonian coast between 1887-1889 (Sõrve 1887, Tallinna sadam, Tahkuna, Vaindloo, Vilsandi, Osmussaar, Ruhnu 1898, Virtsu, Narva- Jõesuu 1899).

In 1865 Professor of Tartu University Arthur von Oettingen founded Tartu Meteorological Observatory and, according to Anto Juske, the post of water measurements was opened by the Emajõgi river near the stone bridge in 1866 or 1867. In 1879 the post of water measurements was opened on Lake Ülemiste near Tallinn. By 1902 10 such posts were active in Estonia. Their aim was to study possibilities for navigation and storage of water energy.

An engineer and technical scientist August Velner participated actively in the development of hydrological network, later also meteorologist Kaarel Kirde, hydrologists E. Oldekop, K. Hommik, T. Eipre, A. Kask, K. Arukaevu, Harald-Adam Velner and others contributed to the task.

• In 1922 15 posts of water measurements were at work
• by the end of 1937 their number had already reached 89.
• The number of hydrometric posts reached the climax in 1940 with 103 active posts.
• The Mustvee lake post opened in 1920 served as a basis for the Tiirikoja Lake Station, established in 1949.
• In 1950 a special station for marshland studies was opened at Tooma.

The founder of Estonian hydrology August Velner graduated from the Institute of Road Construction Engineers in 1911. He participated in the studies of Russian rivers and designing of the Volga-Don Canal. In 1920 he returned to Estonia, was a lecturer in Tartu University and Tallinn Technical College , the head of the Bureau of Inland Waters, the head of the hydrological department of the Estonian Hydrometeorological Service, in 1944-1946 the head of the Chair and Professor of the Road and Water-Construction Department at Tallinn Technical University and was a leading figure in large projects concerning water constructions, water supply and sewer systems.

Evald Oldekop (1885-1952) graduated from Tartu University in 1911, worked in Tashkent from 1912-1921, was one of the founders of the Turkestan Meteorological Institute and lecturer at Tashkent University. Later in his life he was a teacher in Tartu, in 1940-1947 a co-worker of the Estonian Hydrometeorological Service and in 1947-1951 he worked in the Institute of Scientific Construction Research where he dealt with the questions of hydrological prognoses and river classification. His formula for calculation of evaporation is well known and widely used up to now.

The development of hydrology in independent Estonia is a great extent related to the name of Professor Kaarel Kirde(1892-1953), the director of the Tartu Meteorological Observatory. He organized and supervised meteorological and hydrological observation work in Estonia, was the head of the Department of Hydrography in the Commission of Waterbodies Research and one of the founders of the Estonian network of meteorological and hydrological stations.

After WW II the development of hydrology was associated with the hydrological department of the Estonian Meteorological and Hydrological Institute (EMHI).

The department of hydrology at the EMHI was headed for a long time by an outstanding hydrologist, Doctor of Technical Sciences Tiit Eipre(1904-1986). Under his supervision huge work was carried out in assessment of runoff , water supply and surface water hydrology of Estonian rivers. He was one of the founders of Endla Nature Reserve. T. Eipre is also the author of several monographs.

Topical problems were the pollution of rivers, Lake Peipsi and sea water, their oxygen content and pH level. Streams(currents) and hydrography of the Gulf of Finland were studied jointly with Finnish researchers. The obtained results were of great use for hydrometeorological service of the Olympic regatta in Tallinn in 1980 ( l. Alekseyeva, I. Saaremäe and others).

Extensive work on the dynamics of hydrological and chemical regime of Lake Peipsi was carried out by L. Merila- Toomsalu, A. Jaani, S. Kaputerko, Academician H. Simm from the Institute of Zoology and Botany of the Estonian Academy of Sceinces and others.
Ago Jaani studied the dependence of the condition of Lake Peipsi on solar activity. A hydrologist and polar explorer August Loopmann (1927-2001) who studied Antarctic lakes and water regime of Estonian marshes worked in the EMHI and other institutes.

Svetlana Yevreyeva worked in EMHI and other institutes, dealing with the problems of the climatic variability of ice cover of the Baltic Sea and the water level of Estonian water bodies and their modelling.

Harald-Adam Velner is one of the best known hydrologists in Estonia. He is the son of the founding father of Estonian hydrology August Velner , Doctor of Technical Sciences, Professor of Tallinn Technical University and several foreign universities. His research deals with the problems of water protection, exhaust waters, prognosis of water quality in water bodies, complex exploitation of water and hydroenergetics. He has been the secretary general and chairman of the Baltic Sea Water Protection Commission in Helsinki for a long time.

Karl Hommik (1904-1983), a hydrologist, Doctor of Technical Sciences worked in several posts with agricultural profile, among others for an extended period in the Estonian Institute of Land Cultivation and Amelioration where he studied the regulation of soil water regime and created a suitable land drainage method. His co-workers E. Soovik, H. Tomson, U. Tomberg and others are well known.