The Middelzee (Dutch for "middle sea"; West Frisian : Middelsee), also called Bordine, was the estuary mouth of the River Boorne (West Frisian: Boarn) now in the Dutch province of Friesland. It ran from as far south as Sneek northward to the Wadden Sea and marked the border between main Frisian regions of Westergoa (Westergo) and Eastergoa (Oostergo). Other historical names for the Middelzee include Bordaa, Borndiep, Boerdiep, and Bordena. [1] The names like Bordine, mean "border". [2]
Back in the Pleistocene the Boorne was a river that had a drainage basin in Friesland, Drenthe, and Groningen. It flowed from Saalien glacial till plateau in a southwest direction, and met the sea west of Het Bildt. The Boorne passed the current location of Akkrum and Rauwerd. The connection to the Wadden Sea became blocked by sand dunes in the Weichselian time period, and the mouth of the river was forced more and more easterly, until it was heading in a north-northwest direction from Akkrum. In the Holocene, the sea rose flooding the valley to form an estuary. Before 7000 years ago, the sea was rising at a rate of 0.75 meters per century, and the rising sea was faster than the sedimentation There are still estuary sediments west of Jorwerd, that were deposited during 6400-5300 before present (Mid-Atlantic). After 5500 years ago, sea level rise slowed down to a rate of 0.15 meters per century. This allowed sedimentation to catch up and fill in the estuary. [3] Tidal inlets further to the west were blocked by sediment by 3300 years ago. However the Boorne remained open and gradually eroded further and further south and then branched west south of what is now Westergo. People started living adjacent to the channels about 600 BC. The tidal channel moved to the east to what would become the Middelzee. Before the year 900, the new tidal channel scoured deeper and deeper and flooding extended even further inland. After 900 the flooding reached its maximum extent, and it became known as the Middelzee. The southwestern extremity joined up with the Marne Estuary near Bolsward. [3]
At the beginning of the 10th century people became more organised and worked to prevent the further encroachment of the Middelzee. Levees and natural marsh bars were raised along the shore north of Steins on the western coast of Oostergo. This also happened on the north west facing coast of Westergo along the Reid. During the 10th century a dyke was established along the east coast of Westergo along the coast of the Middelzee. The mother polders were established as regions of land completely encircled by dykes. [3]
The southwestern arm of the Middelzee was progressively sectioned off by building dykes across the arm, in four stages. Around 1200 AD a dyke near Rauwerd finished the closure of the arm. This turned what was a mud flat into a salt marsh, and silt gradually collected to fill the areas in. [3]
The northern section of the Middelzee, passing Leeuwarden was dyked off in the first half of the 13th century, and by 1300 it was reclaimed up to Stiens and Beetgum. The 12th century also saw land reclamation along the north west shore of Oostergo, shrinking the funnel shaped part of the Middelzee. [3]
Leeuwarden and the trading terp villages along the coast of Middelzee lost their ability to trade with watercraft when they became isolated from the route to the Wadden Zee. [4]
Gradually the Middelzee silted up, forming the nije lannen ("new lands"). One village is called Nijlân, literally meaning "new land", and also there are several villages where the lands formerly of the Middelzee are still called it Nijlân. It can still be recognized as new land since there are only a small number of villages lying in the area of the former Middelzee. The fertile sea clay bottom is mostly used as meadow land but also Leeuwarden Air Base is situated on the new lands. The border between Eastergoa and Westergoa in the former Middelzee is now drained by the River Zwette (West Frisian: Swette), that runs from Sneek to Leeuwarden, but which once reached the southern edge of Het Bildt. [1]
By the fifteenth century the Middelzee was reduced to a funnel shape along Frisia's north coast and further silting of the remaining part rendered it unusable. From the early sixteenth century the polder of Het Bildt was formed in that funnel, and is now a Frisian municipality that fills the mouth of what once was the Middelzee.
The name Middelzee is still used as a name for an administrative coalition between the so-called Middelzee municipalities of Het Bildt, Ferwerderadiel, Leeuwarderadeel, and Menameradiel.
Friesland, historically and traditionally known as Frisia, named after the Frisians, is a province of the Netherlands located in the country's northern part. It is situated west of Groningen, northwest of Drenthe and Overijssel, north of Flevoland, northeast of North Holland, and south of the Wadden Sea. As of January 2023, the province had a population of about 660,000, and a total area of 5,753 km2 (2,221 sq mi).
The Wadden Sea is an intertidal zone in the southeastern part of the North Sea. It lies between the coast of northwestern continental Europe and the range of low-lying Frisian Islands, forming a shallow body of water with tidal flats and wetlands. It has a high biological diversity and is an important area for both breeding and migrating birds. In 2009, the Dutch and German parts of the Wadden Sea were inscribed on UNESCO's World Heritage List and the Danish part was added in June 2014.
het Bildt is a former municipality in the province of Friesland in the northern Netherlands; its capital was Sint Annaparochie. On 1 January 2018 it merged with the municipalities of Franekeradeel, Menameradiel and parts of Littenseradiel to form the new municipality Waadhoeke.
Sneek is a city southwest of Leeuwarden and the seat of the former municipality of Sneek in the province of Friesland, Netherlands. As of 2011 it is the seat of the municipality of Súdwest-Fryslân. The city had approximately 33,855 inhabitants in January 2017.
Vlieland is a municipality and island in the northern Netherlands. The municipality of Vlieland is the second most sparsely populated municipality in the Netherlands, after Schiermonnikoog.
Harlingen is a municipality and a city in the northern Netherlands, in the province of Friesland.
The Schleswig-Holstein Wadden Sea National Park is a national park in the Schleswig-Holstein area of the German Wadden Sea. It was founded by the Parliament of Schleswig-Holstein on 1 October 1985 by the National Park Act of 22 July 1985 and expanded significantly in 1999. Together with the Lower Saxon Wadden Sea National Park, the Hamburg Wadden Sea National Park and those parts of Elbe estuary which are not nature reserves, it forms the German part of the Wadden Sea.
The Frisian Islands, also known as the Wadden Islands or the Wadden Sea Islands, form an archipelago at the eastern edge of the North Sea in northwestern Europe, stretching from the northwest of the Netherlands through Germany to the west of Denmark. The islands shield the mudflat region of the Wadden Sea from the North Sea.
The Friso-Hollandic Wars, also called Frisian-Hollandic Wars, were a series of short medieval wars consisting of the attempts made by the counts of Holland to conquer the free Frisian territories, which lay to the north and east of their domain. These wars were waged off and on from 1256 to 1297, 1324 to 1348, 1396 to 1411, and from 1421 to 1422, although it could be argued that a state of war continued to exist between the County of Holland and the Frisian territories till well after the year 1500.
Sint Annaparochie is a village in the municipality of Waadhoeke in Friesland, Netherlands. It lies approximately 15 km (9 mi) northwest of Leeuwarden and had approximately 4,830 inhabitants in 2021. The village is named after Saint Anne, the mother of Mary.
Sint Jacobiparochie is a village in the municipality of Waadhoeke in Friesland, the Netherlands. It lies about 13 km north of Franeker and had approximately 1,365 inhabitants in January 2017.
The Battle of the Boarn was an 8th century battle between the Franks and the Frisians near the mouth of the river Boarn in what is now the Dutch province of Friesland.
Ygo Gales Galama was a 15th-century Frisian warlord and Galama-patriarch.
Westergoa was one of the seven sealands and one of the three that now lie within the borders of today's Dutch province of Friesland. Later it was one of the three goaen of Frisia. In the Middle Ages Westergoa most probably formed the political centre of the Frisian realm.
The Admiralty of Friesland or Frisian Admiralty was one of the five Dutch admiralties of the Dutch Republic. Set up on 6 March 1596, it was dissolved in 1795 during the reforms by the Batavian Republic.
Frisian freedom was the absence of feudalism and serfdom in Frisia, the area that was originally inhabited by the Frisians. Historical Frisia included the modern provinces of Friesland and Groningen, and the area of West Friesland, in the Netherlands, and East Friesland in Germany. During the period of Frisian freedom the area did not have a sovereign lord who owned and administered the land. The freedom of the Frisians developed in the context of ongoing disputes over the rights of local nobility.
Nijland is a village in Súdwest-Fryslân municipality in the province of Friesland, the Netherlands. It had a population of around 1,000 in January 2017.
Bildts is a conservative Hollandic dialect spoken in the largest part of the former municipality het Bildt in the Dutch province of Friesland. The dialect retains features from around 1505, when the area was reclaimed from the sea as ordered by George, Duke of Saxony. In order to achieve this task, workers from Holland, Zeeland, and Brabant moved to Friesland. The apparent similarity to present-day Frisian is due to the evolution of Frisian from the sixteenth century into the present.
The Marneslenk (Dutch), or Marneslinke (Frisian), or Marne estuary, was a former estuary in western Friesland south of Harlingen, now reclaimed to be farmland. It formed around the year 300 AD, when rising sea levels also enlarged the Almere lake to the southwest, and formed the Middelzee to the east. The Marneslenk had its mouth on the Vlie and stretched southeasterly to the area of Tirns and then headed east to the Middelzee. Between 1100 and 1300 AD the watercourse was reclaimed and turned into fields by the construction of dykes. One such dyke is the Pingjumer Gulden Halsband. The Bedelaarsvaart (Bidlersfeart) and Harnzerfeartis are what remains of this watercourse nowadays.
Sedimentation enhancing strategies are environmental management projects aiming to restore and facilitate land-building processes in deltas. Sediment availability and deposition are important because deltas naturally subside and therefore need sediment accumulation to maintain their elevation, particularly considering increasing rates of sea-level rise. Sedimentation enhancing strategies aim to increase sedimentation on the delta plain primarily by restoring the exchange of water and sediments between rivers and low-lying delta plains. Sedimentation enhancing strategies can be applied to encourage land elevation gain to offset sea-level rise. Interest in sedimentation enhancing strategies has recently increased due to their ability to raise land elevation, which is important for the long-term sustainability of deltas.