The article discusses the history of a legal dispute between the city and canton of Geneva, Switzerland, with the nearby cantons of Vaud and Valais, also in Switzerland, about the water levels of Lake Geneva. Specifically it traces the history of the dispute and its final resolution by means of civil engineering designed to permanently stabilize the water levels of the lake. Among other topics addressed are how and why water levels became a political, diplomatic, and economic issue among the three cantons, the role of the Grand Council of Geneva, and the report on the situation of Swiss military officer Samuel Otth.