This European Standard is applicable to lakes, which are water bodies occupying one or more basins with surface areas greater than 1 ha (0,01 km2) and maximum depths (at mean water level) greater than 1 m. All types of permanent lakes, including natural, modified and artificial, fresh water and brackish, except for those systems which regularly connect to the sea, are included in this European Standard, though canals are excluded. Based on these criteria it can be estimated that there are at least 500 000 natural lakes across Europe, most of which are located in the glaciated landscapes in northern and western provinces and in Scandinavia. Lakeland district