In ancient times, Oahu was split into socio-economic units, known as ahupua’as, to ensure that life was efficient. In 1905, to bring water from one side of the island to the other, the Oahu Sugar Company built a water system consisting of 27 miles of ditches and tunnels, and that system was purchased by the State of Hawaii in the late 1990s after the Oahu Sugar Company closed. Because of this, the rights to the system's water were contested, and eventually, the Hawaii Water Commission set guidelines for water usage. The water usage was set because there were so many groups, especially between the Windward and Leeward sides of the island, who needed the water, using reasons ranging from cultural to economic.