This paper presents new data that has begun to quantify the total area of lacustrine environment loss during the past 300 years in Scotland. The aim has been to quantify historic drainage and its impact to the wetland archaeological resource in the country. Previous work analysing the Roy Military Map of Scotland (1747-55) has been expanded upon, and lochs have now been charted through all of the digitised historic mapping resource available through the National Library of Scotland. The extents and boundaries of former lochs have been established using the Canmore sites and monuments record, British Geological Survey geotechnical data, and digital terrain models. The areal dataset aims to cover all of mainland Scotland providing the clearest picture to date of where and when Improvement period loch drainage took place in Scotland. The results have shed light on the spatial dimensions of drainage that can begin to answer more clearly how historic drainage has impacted the survival, study and stability of wetland archaeology in the country. This work has fed directly into a programme of survey and excavation on Scotland’s most notable form of wetland archaeology – the crannog. Work here has sought to evaluate the crannog building tradition in north-east Scotland, which until 2015 had seen effectively no modern investigation of crannogs. The results begin to offer a counter-balance of data as previous investigation of crannogs have been focused on south-west Scotland and Perthshire. Loch drainage has negatively impacted the quantity and preservation of crannogs in north-east Scotland to a great extent, but the survey and excavation work has provided the first modern insights on the construction and chronology of crannogs in this region.