The Ministry of Public Security (MSP) supports the development of knowledge of flood risks. In collaboration with Laval University and the Reunification of Quebec Basin Organizations, the MSP has developed a methodical and rigorous process for documenting floods that have an impact on the safety of people and essential goods. Thus, since 2017, the Ministry of Public Security (MSP) has been acquiring in certain cases data related to the water level reached when floods with proven consequences occur in southern Quebec. Maximum water levels are indicated by flood slopes. __What is a flood disaster? __ A flood (flood) is characterized by a rise in water on land that is usually dry, the reaching of a peak, then a descent of water (decline). Waste forms at the beginning of the flood when the water, when withdrawing, deposits materials that were in suspension or floating. These materials (mud, seeds, twigs and other debris) constitute flood wastes or flood plains. __Marking and surveying floodplains and water levels__ The marking of floodwaters and water levels takes place in the field shortly after the peak of the flood. The physical indices of the maximum water level reached (abandoned by the flood) or of the current water levels are identified and marked using permanent markers (markers). Afterwards, a land surveyor will precisely record the location and the altitude of the markers. __Point data set “Water levels during a flood"__ The point data set “Water levels during a flood” contains, for each marker, the date, altitude and location (measured by a land surveyor). There are two main types of observations made in the field: the natural flood defect (line of mud, seeds or trace of water) which indicates the maximum water level reached during the flood (called MAX) and the water level observed during the field visit (called CURRENT). The list of all attributes is provided in the dataset description sheet (Additional Information section). Despite the quality of the work carried out, the Ministry of Public Security cannot guarantee the absence of errors in the data. __Related datasets__ The “Flood reference” dataset produced by the Ministry of Public Security also contains maximum water levels reached during a flood. The link to this dataset is provided in the _Documentation_ section.**This third party metadata element was translated using an automated translation tool (Amazon Translate).**