and from year to year. In addition, Kohala is buffeted by strong winds, which are directly correlated to soil erosion; ancient farmers utilized a series of earthen embarkments and stone walls to protect their crops. This technique has been shown to reduce wind by at least 20–30 percent. In addition to walls, there are a series of stone paths that divided the farmed area into plots of variable size. These structures are unique because although many people used such systems at the time, Kohala has some of the few to survive. The leeward slopes of Kohala were used for sugarcane plantations in the late 19th century. The trip from the fields to the mills and then boats was mechanized by steam locomotive in 1883. Several plantations on the mountain were consolidated into the Kohala Sugar Company by 1937. At the peak of its production, the company had 600 employees, of land, and a capacity of of raw sugar per year. In 1975 the company finally closed down. Kohala supports a very complex hydrological cycle. In the early part of the 20th century, this was exploited by building surface irrigational channels designed to capture water at the higher elevations and distribute it to the then-extensive sugarcane industry. In 1905, after 18 months and the loss of 17 lives, the Kohala Ditch, a vast network of flumes and ditches, measuring in length, was completed. It has since come into use by ranches, farms, and homes. A portion of the ditch became a tourist attraction until it was damaged by the 2006 Kiholo Bay earthquake, centered just southwest of the mountain. The Hawaii County Department of Water Supply relies on streams from Kohala to supply water to the population of the island. With increasing demand, the original surface channels have been supplemented by deep wells designed to channel groundwater for domestic use. In 2003 the Kohala Watershed Partnership was formed, a voluntary group of private land owners and state managers, designed to help manage the Kohala watershed and to protect it from threats, most especially invasive species. Another project to raise awareness of Kohala's ecosystem is The Kohala Center, an independent, not-for-profit, community-based organization for research and education. It was established as a response to requests by island residents to create an educational and employment opportunity related to Hawaii's natural and cultural significance. The center's mission is "to respectfully engage the Island of