In this thesis two dams excavated in the Merovingian settlement Oegstgeest-Rijnfrontare discussed. This settlement is located along a former river branch of the Old Rhine river at the place where...Show moreIn this thesis two dams excavated in the Merovingian settlement Oegstgeest-Rijnfrontare discussed. This settlement is located along a former river branch of the Old Rhine river at the place where tributaries enter the river. Water management which is crucial for the continuity of the habitation is discussed. Dam A is located at the mouth of a side creek that flowed out into the Old Rhine river. This dam measured about 45x10 meters and was constructed of about 1000 wooden poles and about 900 cubic meters of sods. The dam could be dated to the first half of the sixth century. Dam B was located 100 meters further to the east and measured about 25x5 meters. It was constructed of about 500 wooden poles and contained at least 125 cubic meters of sods. Both dams were probably constructed in the early Autumn. The construction of the dams implies that it was not an ad hoc construction, some planning had to be involved, because it would have taken some time to fell all trees necessary and to gather all sods needed for the dam body. In addition to the dams more structures related to water management that were dug up in this settlement. Some of them like a bridge are also discussed in this thesis. All these structures show that the people inhabiting the settlement were capable to deal with problems caused by water. The construction of these structures implies that there would have been some sort of communal cooperation within the settlement, since it is impossible for a single family or household to construct, for example, dam A. It is likely that the settlement was divided in ‘districts’ that all put in some effort. Also the future research is discussed, since it is likely that more dams will be discovered in the future.Show less