Rivers, Floods, Flood control in the Netherlands, Delta works
The country is divided into two main parts by three large rivers, the Rhine (Rijn) and its main distributaries, the Waal and the Meuse (Maas). These rivers functioned as a natural barrier between earlier fiefdoms, and hence created traditionally a cultural divide, as is evident in some phonetic traits that are recognizable north and south of these "Large Rivers" (de Grote Rivieren).
The country is divided into two main parts by three large rivers, the Rhine (Rijn) and its main distributaries, the Waal and the Meuse (Maas). These rivers functioned as a natural barrier between earlier fiefdoms, and hence created traditionally a cultural divide, as is evident in some phonetic traits that are recognizable north and south of these "Large Rivers" (de Grote Rivieren).The south-western part of the Netherlands is actually a massive river delta and two tributaries of the Scheldt (Westerschelde and Oosterschelde). Only one significant branch of the Rhine flows northeastwards, the IJssel river, discharging into the IJsselmeer, the former Zuiderzee ('southern sea'). This river also forms a linguistic divide: people to the east of this river speak Low Saxon dialects (except for the province of Friesland, which has its own language).
Over the centuries, the Dutch coastline has changed considerably as a result of human intervention and natural disasters. Most notable in terms of land loss is the 1134 storm, which created the archipelago of Zeeland in the south west.
On 14 December 1287, St. Lucia's flood affected the Netherlands and Germany killing more than 50,000 people in one of the most destructive floods in recorded history. The St. Elizabeth flood of 1421 and the mismanagement in its aftermath destroyed a newly reclaimed polder, replacing it with the 72-square-kilometre (28 sq mi) Biesbosch tidal floodplains in the south-centre.
The disasters were partially increased in severity through human influence. People had drained relatively high lying swampland to use it as farmland. This drainage caused the fertile peat to compress and the ground level to drop, locking the land users in a vicious circle whereby they would lower the water level to compensate for the drop in ground level, causing the underlying peat to compress even more. The problem remains unsolvable to this day. Also, up until the 19th century peat was mined, dried, and used for fuel, further adding to the problem.
To guard against floods, a series of defences against the water were contrived. In the first millennium AD, villages and farmhouses were built on man-made hills called terps. Later, these terps were connected by dikes. In the 12th century, local government agencies called "waterschappen" (English "water bodies") or "hoogheemraadschappen" ("high home councils") started to appear, whose job it was to maintain the water level and to protect a region from floods. (These agencies exist to this day, performing the same function.) As the ground level dropped, the dikes by necessity grew and merged into an integrated system. By the 13th century, windmills had come into use in order to pump water out of areas below sea level. The windmills were later used to drain lakes, creating the famous polders.
In 1932, the Afsluitdijk (English "Closure Dike") was completed, blocking the former Zuiderzee (Southern Sea) from the North Sea and thus creating the IJsselmeer (IJssel Lake). It became part of the larger Zuiderzee Works in which four polders totalling 2,500 square kilometres (965 sq mi) were reclaimed from the sea.
Delta works
After the 1953 disaster, the Delta project, a vast construction effort designed to end the threat from the sea once and for all, was launched in 1958 and largely completed in 1997 with the completion of the Maeslantkering. The official goal of the Delta project was to reduce the risk of flooding in the province of Zeeland to once per 10,000 years. (For the rest of the country, the protection-level is once per 4,000 years.) This was achieved by raising 3,000 kilometers (1,864 mi) of outer sea-dykes and 10,000 kilometers (6,214 mi) of inner, canal, and river dikes to "delta" height, and by closing off the sea estuaries of the Zeeland province. New risk assessments occasionally show problems requiring additional Delta project dyke reinforcements.
Over the centuries, the Dutch coastline has changed considerably as a result of human intervention and natural disasters. Most notable in terms of land loss is the 1134 storm, which created the archipelago of Zeeland in the south west.
On 14 December 1287, St. Lucia's flood affected the Netherlands and Germany killing more than 50,000 people in one of the most destructive floods in recorded history. The St. Elizabeth flood of 1421 and the mismanagement in its aftermath destroyed a newly reclaimed polder, replacing it with the 72-square-kilometre (28 sq mi) Biesbosch tidal floodplains in the south-centre.
The disasters were partially increased in severity through human influence. People had drained relatively high lying swampland to use it as farmland. This drainage caused the fertile peat to compress and the ground level to drop, locking the land users in a vicious circle whereby they would lower the water level to compensate for the drop in ground level, causing the underlying peat to compress even more. The problem remains unsolvable to this day. Also, up until the 19th century peat was mined, dried, and used for fuel, further adding to the problem.
To guard against floods, a series of defences against the water were contrived. In the first millennium AD, villages and farmhouses were built on man-made hills called terps. Later, these terps were connected by dikes. In the 12th century, local government agencies called "waterschappen" (English "water bodies") or "hoogheemraadschappen" ("high home councils") started to appear, whose job it was to maintain the water level and to protect a region from floods. (These agencies exist to this day, performing the same function.) As the ground level dropped, the dikes by necessity grew and merged into an integrated system. By the 13th century, windmills had come into use in order to pump water out of areas below sea level. The windmills were later used to drain lakes, creating the famous polders.
In 1932, the Afsluitdijk (English "Closure Dike") was completed, blocking the former Zuiderzee (Southern Sea) from the North Sea and thus creating the IJsselmeer (IJssel Lake). It became part of the larger Zuiderzee Works in which four polders totalling 2,500 square kilometres (965 sq mi) were reclaimed from the sea.
Delta works
After the 1953 disaster, the Delta project, a vast construction effort designed to end the threat from the sea once and for all, was launched in 1958 and largely completed in 1997 with the completion of the Maeslantkering. The official goal of the Delta project was to reduce the risk of flooding in the province of Zeeland to once per 10,000 years. (For the rest of the country, the protection-level is once per 4,000 years.) This was achieved by raising 3,000 kilometers (1,864 mi) of outer sea-dykes and 10,000 kilometers (6,214 mi) of inner, canal, and river dikes to "delta" height, and by closing off the sea estuaries of the Zeeland province. New risk assessments occasionally show problems requiring additional Delta project dyke reinforcements.
