■ Water level control 　 ● Target water levels for Lake Biwa □ Maintenance and Management of Facilities 　 ● Weeding of lake levees 　 ● Patrols of lake levees 　 ● Inspection of sluice gates 　 ● PInspection of drainage facilities 　 ● Dredge ship route □ Operation of Facilities 　 ● In drought conditions:internal drainage facilities 　 ● In flood conditions:water supply facilities and gates for water level and bypass aqueducts □ Gathering Environmental Data in the Lake Biwa Basin 　 ● Hydrologic and meteorological data 　 ● Lake Biwa information provided by comprehensive automatic observation stations 　 ● Lake Biwa water environment survey including submerged plant observation ■Water level control Lake Biwa's water level is controlled by the Ministry of Land, Infrastructure and Transport by regulating the discharge rate (flow) from the Seta River Weir. The bypass aqueducts are owned by the Incorporated Administrative Agency Japan Water Agency but they need to be controlled together with the existing Seta River Weir. Thus control is a commission of the Ministry of Land, Infrastructure and Transport. Target water levels for Lake Biwa The Lake Biwa Development Project has specified target water levels for the Lake Biwa in order to maintain effective flood control and water utilization. For example in the non-flooding season, water level is maintained consistently 0.3m higher than the high water level. During flooding season, it is pre-lowered by 0.2m to 0.3m to reduce its high water level. A Lake levee crest 　 B Design high water level The basic level for mapping out a flood control plan that is determined according to a simulated flood having the potential of occurring 'once in a century' C Normal water level The maximum reservoir level under normal conditions D Limited water level in flooding season A level lowered beforehand as a precaution to prevent flood damage in the lake area during the rainy season and as a result of typhoon E Usable low water level The minimum level of water utilization F Compensation water level The level at which damage caused by a lowering of the water level. All flood control and water use facilities for Lake Biwa should be worked out in compliance with the above standard water levels. Top▲ 　   ■Contact us Copyright(c) 2003 Incorporated Administrative Agency Japan Water Agency Lake Biwa Development Integrated Operation & Maintenance Office All Rights Reserved.