This paper presents new geo-archaeological perspectives on the Late Glacial and Early Holocene human occupation around a large palaeolake, the Moervaart palaeolake (∼25 km2). Intensive fieldwork, using invasive and non-invasive survey techniques, combined with modelling of the palaeotopography and palaeogroundwater and multi-proxy palaeoecological analyses have resulted in a detailed reconstruction of the landscape during the Final Palaeolithic and Early Mesolithic occupation of the area. A major shift in the occupation from the Federmesser Culture to the Early Mesolithic was contemporaneous with a sudden and drastic change in the palaeohydrology of the area between ca. 13,300 and 13,000 cal BP (end of Allerød), which coincided with a short but abrupt cooling event known as the Intra Allerød Cold Period (IACP) GI 1b. It is assumed that this event triggered the sudden drying up of the Moervaart palaeolake and surrounding ponds, which until then had provided Federmesser hunter-gatherers with extensive and fertile grounds for hunting, gathering and drinking water. The population decline which followed this hydrological event was reinforced by the prevailing cold and harsh conditions of the Younger Dryas and probably lasted until the Pre-boreal. Hunter-gatherers returned to the area in the Boreal, now settling along the proximal floodplain regions of a meandering channel which was connected with the southern Scheldt River.