Switzerland

Switzerland holds 6% of Europe's clean water supplies.

An excerpt from the article 45 facts about Switzerland

Numerous rivers have their sources here, including the Rhine, Aare, Rhône, Inn, and Ticino. There are also rich reserves of groundwater and many natural and artificial lakes - lakes and other water reservoirs contain 50% of Swiss water reserves, glaciers 28%, groundwater 20%, and rivers 2%.