Facility
Lake Windermere catchment

Windermere lies in the north-west corner of England in the English Lake District. The dominant geological structure of the Lake District is a dome of Paleozoic rocks formed by uplift in the Tertiary. This uplift produced a radial drainage pattern which was enhanced during the Pleistocene glaciation, with the major lakes occupying bedrock basins in steep-sided, flat-floored valleys. Windermere is the largest natural lake in England having a surface area of 14.8km2 at an altitude of only 40 m. The lake itself is divided by a shallow sill into two basins; the North Basin with a surface area of 8km2 and maximum depth of 64m and the South Basin with a surface area of 6.7km2 and maximum depth of 42m. The North basin of Windermere has a catchment of 180km2 which drains into the lake via two main rivers, several small tarns (lakes) and several streams. The catchment is mainly hill land, grazed by sheep throughout the year but also used intensively for recreational purposes. The villages in the valleys are also major tourist destinations with consequent increases in the sewage input to the lake. Over the past 50 years levels of dissolved reactive phosphorus in the lake have more than doubled, reaching their highest levels in the 1980s. The effluent discharged into the North Basin of Windermere from the main sewage works is now phosphate stripped in an effort to reduce the nutrient loading to the lake. The lake itself is a Site of Special Scientific Interest (SSSI), a source of potable water, a major recreational facility and a specialised fishery (for charr, Salvelinus alpinus).