Philipsdam
The Philipsdam was not part of the original Delta Plan. The dam is located between the Krammer and the Eastern Scheldt, connecting Sint-Philipsland via the Grevelingendam with Goeree-Overflakkee and Schouwen-Duiveland.
The Philipsdam contains the Krammer sluices for both commercial shipping and recreational boating.
The Philipsdam in statistics
- Built between 1976 and 1987
- 7 kilometers long
- 11 small caissons, each 6 meters high, 7.5 meters wide, and 11 meters long
- 2 sluices for commercial shipping, each 280 meters long and 24 meters wide
- 2 yacht sluices for recreational boating, each 75 meters long and 9 meters wide
Origin
In the original Delta Plan, the Philipsdam was not included. This is because the plan was to fully close off the Eastern Scheldt, which would eliminate tides and turn the estuary into freshwater. This freshwater could be used for drinking water and agriculture. Additionally, the shipping route from the Port of Rotterdam to Antwerp would no longer be affected by tides. However, closing off the Eastern Scheldt would come at the cost of nature.
When it was decided to protect the nature in the Eastern Scheldt, the goal was to retain as many benefits as possible from the planned freshwater reservoir. To achieve this, the "compartmentalization works" were built: the Philipsdam, Oesterdam, Markiezaatskade, and Bathse Spuisluis. The water basins behind these Delta Works were "compartmentalized," meaning they were separated from the Eastern Scheldt and its tidal movements.
These Delta Works were not constructed for protection against the sea, but to shield the water behind the compartmentalization works from the salty Eastern Scheldt. The Philipsdam, together with the Oesterdam, reduced the surface area of the Eastern Scheldt, thereby increasing the tidal effect and preserving the natural area. To allow for continued shipping, a large sluice complex, the Krammersluizen, was built.
Construction
The Philipsdam was constructed between Sint Philipsland and the already built Grevelingendam. It was positioned as far "back" as possible within the Eastern Scheldt estuary to maximize the size of the natural area of the Eastern Scheldt. Additionally, this allowed for the possibility of an open connection between the Grevelingenmeer and the Krammer, should the Grevelingenmeer ever become fresh water in the future. The connection to the Grevelingendam also provided an easy link to the existing road infrastructure.
For the construction of the Philipsdam, no concrete caissons were used. Instead, the Krammer was filled with sand, which is unique given the depth of this sea arm.
Krammersluizen
The Krammersluizen form an immense complex: it is one of the largest projects ever designed and executed by Rijkswaterstaat. This complex includes the lock chambers, the freshwater basin, the saltwater basin, and the control buildings. A bridge with a movable section has been built over the sluice complex, spanning the northern sluice chamber. Since 2017, 34 wind turbines have also been installed on the complex.
Because the sluices are located at the boundary between saltwater and freshwater, they use a clever system to keep the waters separate. When the sluice opens and a ship enters, freshwater and saltwater mix. However, freshwater is lighter than saltwater, so once the sluice is closed, the saltwater is pumped out from below, or the freshwater is pumped out from above (depending on the direction of travel). Afterward, the sluice can be reopened, and the ship can depart in a single type of water. In maritime circles, the Krammersluizen are known as the "snail sluice" because this process takes quite a bit of time!
In 2014, an experiment was conducted to test a new method of separating freshwater and saltwater. A bubble screen blows air bubbles from the bottom upwards. Ships can pass through this screen, but saltwater is blocked, while freshwater is used for flushing. Starting in 2025, the Krammersluizen will be renovated with this new system, which will also make it easier for fish to swim from the Eastern Scheldt to the rivers.
