The Haringvliet is a large

inlet An inlet is a typically long and narrow indentation of a shoreline such as a small arm, cove, bay, sound, fjord, lagoon or marsh, that leads to an enclosed larger body of water such as a lake, estuary, gulf or marginal sea. Overview In ...

of the

North Sea The North Sea lies between Great Britain, Denmark, Norway, Germany, the Netherlands, Belgium, and France. A sea on the European continental shelf, it connects to the Atlantic Ocean through the English Channel in the south and the Norwegian Se ...

, in the province of

South Holland South Holland ( ) is a province of the Netherlands with a population of over 3.8 million as of January 2023 and a population density of about , making it the country's most populous province and one of the world's most densely populated areas. ...

in the

Netherlands , Terminology of the Low Countries, informally Holland, is a country in Northwestern Europe, with Caribbean Netherlands, overseas territories in the Caribbean. It is the largest of the four constituent countries of the Kingdom of the Nether ...

. It is an important

estuary An estuary is a partially enclosed coastal body of brackish water with one or more rivers or streams flowing into it, and with a free connection to the open sea. Estuaries form a transition zone between river environments and maritime enviro ...

of the Rhine-Meuse delta. Near

Numansdorp Numansdorp is a town and former municipality in the province South Holland in the Netherlands and is located on the island Hoeksche Waard near the Hollands Diep. On 1 January 1984, the municipalities Numansdorp and Klaaswaal were merged into one ...

, the

Hollands Diep The Hollands Diep ( pre-1947 spelling: Hollandsch Diep) is a river in the Netherlands, and an estuary of the Rhine and Meuse rivers. Through the Scheldt-Rhine Canal it connects to the Scheldt river and Antwerp. The Bergse Maas river and the N ...

splits into the Haringvliet and the

Volkerak The Volkerak is a body of water in the Netherlands. It is part of the Rhine–Meuse–Scheldt delta, and is situated between the island Goeree-Overflakkee to the north-west and the Dutch mainland to the south and east. The western part of the Volke ...

estuaries An estuary is a partially enclosed coastal body of brackish water with one or more rivers or streams flowing into it, and with a free connection to the open sea. Estuaries form a transition zone between river environments and maritime environm ...

. It is closed off near

Goedereede Goedereede () is a little city and former municipality in the western Netherlands, in the province of South Holland. The former municipality had a population of about 11,000 in 2010. It consisted of the west part of the island of Goeree-Overflak ...

from the

by the

Haringvlietdam The Haringvlietdam, incorporating the Haringvliet sluices, are hydraulic engineering structures which closed off the estuary of the Haringvliet, Netherlands, as part of the Delta Works. The structure consists of 17 sluices, several kilometres of da ...

, which provides a

road A road is a thoroughfare used primarily for movement of traffic. Roads differ from streets, whose primary use is local access. They also differ from stroads, which combine the features of streets and roads. Most modern roads are paved. Th ...

connection between the

island An island or isle is a piece of land, distinct from a continent, completely surrounded by water. There are continental islands, which were formed by being split from a continent by plate tectonics, and oceanic islands, which have never been ...

of Voorne to the north and the island of

Goeree-Overflakkee Goeree-Overflakkee () is the southernmost river delta, delta island of the Provinces of the Netherlands, province of South Holland, Netherlands. It is separated from Voorne-Putten and Hoeksche Waard by the Haringvliet, from the mainland of North ...

to the south. The dam with its sluices was built as part of the

Delta Works The Delta Works () is a series of construction projects in the southwest of the Netherlands to protect a large area of land around the Rhine–Meuse–Scheldt delta from the sea. Constructed between 1954 and 1997, the works consist of dams, slu ...

sea barrier protection works. The Haringvliet estuary contains the island of

Tiengemeten Tiengemeten is an island in the Dutch province of South Holland. It is a part of the municipality of Hoeksche Waard and lies about south of Spijkenisse. Before 1984 the island was administratively split between Goudswaard and Zuid-Beijerland, ...

, which is separated from the

river island River Island (stylised as RiverIsland and abbreviated as RI) is a London-based, multi-channel fashion brand, founded in 1948 by Bernard Lewis (entrepreneur), Bernard Lewis. The retailer has a presence in over 125 of worldwide markets, in stores ...

Hoeksche Waard The Hoekse Waard (; pre-1947 spelling: Hoeksche Waard) is an island between the Oude Maas, Dordtsche Kil, Hollands Diep, Haringvliet and Spui rivers in the province of South Holland in the Netherlands. The island, part of the namesake munici ...

by the Vuile Gat

strait A strait is a water body connecting two seas or water basins. The surface water is, for the most part, at the same elevation on both sides and flows through the strait in both directions, even though the topography generally constricts the ...

History

The Haringvliet was formed as a result of the extensive flooding event of 1216, which breached the dunes of Voorne and created a deep saltwater inlet. During a second flooding event, the St. Elizabeth floods of 1421, this inlet connected to the

Merwede The Merwede (; etymology uncertain, possibly derived from the Old Dutch ''merwe'' or ''merowe'', a word meaning "wide water") is the name of several connected stretches of river in the Netherlands, between the cities of Woudrichem, Dordrecht and ...

and became an important estuary of the

Rhine The Rhine ( ) is one of the List of rivers of Europe, major rivers in Europe. The river begins in the Swiss canton of Graubünden in the southeastern Swiss Alps. It forms part of the Swiss-Liechtenstein border, then part of the Austria–Swit ...

and

Meuse The Meuse or Maas is a major European river, rising in France and flowing through Belgium and the Netherlands before draining into the North Sea from the Rhine–Meuse–Scheldt delta. It has a total length of . History From 1301, the upper ...

rivers. It used to be ecologically rich, and its brackish waters, fed by both rivers and sea, supported a healthy population of

seals Seals may refer to: * Pinniped, a diverse group of semi-aquatic marine mammals, many of which are commonly called seals, particularly: ** Earless seal, or "true seal" ** Fur seal * Seal (emblem), a device to impress an emblem, used as a means of a ...

. It also provided an access point for migrating fish like

salmon Salmon (; : salmon) are any of several list of commercially important fish species, commercially important species of euryhaline ray-finned fish from the genera ''Salmo'' and ''Oncorhynchus'' of the family (biology), family Salmonidae, native ...

and

sturgeon Sturgeon (from Old English ultimately from Proto-Indo-European language, Proto-Indo-European *''str̥(Hx)yón''-) is the common name for the 27 species of fish belonging to the family Acipenseridae. The earliest sturgeon fossils date to the ...

. As a result of the

North Sea flood of 1953 The 1953 North Sea flood () was a major flood caused by a heavy storm surge that struck the Netherlands, north-west Belgium, England and Scotland. Most sea defences facing the surge were overwhelmed, resulting in extensive flooding. The ...

the Haringvliet was closed off by the Haringvlietdam. The Haringvliet lost its estuarine characteristics and became a freshwater lake. Because of that, the seals are gone and migrating fish can only enter the Rhine-Meuse Delta through the busy and heavy industrialised

Nieuwe Waterweg The Nieuwe Waterweg ("New Waterway") is a ship canal in the Netherlands from Scheur, het Scheur (a branch of the Rhine-Meuse-Scheldt delta) west of the town of Maassluis to the North Sea at Hook of Holland: the #Maasmon, Maasmond, where the Nieu ...

. There are plans to permanently open a few of the Haringvliet sluices, to partly restore the ecosystem.

References

{{coord, 51, 46, 18, N, 4, 12, 57, E, region:NL_type:waterbody_source:kolossus-nlwiki, display=title Rhine–Meuse–Scheldt delta Lakes of the Netherlands Natura 2000 in the Netherlands Ramsar sites in the Netherlands Goeree-Overflakkee Hoeksche Waard Voorne-Putten