The Sand Creek dam could not be put into place instantly. There were eight aspects which had to be taken into account, to ensure the construction would be a success.
1. The closure of the dam had to take place during low water levels, and preferably during the period of neap tide, which occurs twice a month.
2. The caissons could not be sunk down during rates of flow higher than 0.8 metres per second.
3. The caissons had to be sunk by means of a crane, which ensured that the caissons would be placed in a straight line.
5. On the day of the placement of the caissons, the sand and the stones should be dumped at both sides of the dam, since the water could flow under the caissons.
6. The joints between the caissons needed to be filled.
The flow danger
The Sand Creek dam has a length of 830 metres and connects South-Beveland to North-Beveland, between Goes and Kortgene. The Sand Creek dam separates the (salty) Oosterschelde from the (fresh) Lake of Veere. The dam which closes the Lake of Veere on the side of the North Sea is called the ‘Veerse Gat’ dam. The construction of the Sand Creek dam was necessary because otherwise the ‘Veerse Gat’ dam could not have been built. If the Sand Creek dam was built after the ‘Veerse Gat’ dam, there would have been serious problems as a result of the tidal movements. To understand this, we have to return to the caissons. These concrete blocks were placed one by one in the closing gap. The smaller the remaining gap, the stronger the flow. The flow would become so strong that the last caissons would not be able to be placed. If the ‘Veerse Gat’ dam would have been placed without the Sand Creek dam, the seawater could also have caused problems via the back side.
Like many other dams, caissons played an important part during the construction of the Sand Creek dam. The caissons which were used for the Sand Creek dam were 11 metres long, 7.5 metres wide and 6 metres high. This is about as large as a semi-detached house. The caissons were built near the village Kats on the island North-Beveland. However, the manufacture process turned out to be harder than originally expected.
A special crane was used to ensure that the caissons were placed at right angles to the plunging stones. After the caissons were placed, they were filled with large amounts of gravel and sand. Extra top-pieces were attached to make them higher. Consequently, sand was dumped at the caissons for nine days, and as a result they stood very firmly. Following that, an asphalt layer and a road were built.