Abstract
At Lake Kasumigaura, water levels have been maintained at 1.3 m in winter and 1.1 m in all other seasons to meet the national government's plan for The Kasumigaura Development Project since 1996. Although the winter increase was tentatively discontinued in 2000, it resumed in 2003 as an "Experimental water level management" program that was run by the government. The stated aim of this management program is "to harmonize the water usage and conservation of lake nature". However, recent scientific knowledge suggests that reductions in water levels may also achieve this goal and should, therefore, be tested.
