Water transport via the lake declined due to the development of road transport, but the plan to build canals from Lake Biwa to the Sea of Japan, the Pacific Ocean and the Seto Inland Sea were conceived during a period of high economic growth.
湖上を介した水運は陸上交通の発達によって斜陽となったが、高度経済成長期には琵琶湖から運河を掘削して日本海や太平洋・瀬戸内海を結ぶ運河構想が持ち上がった。