The Turkana are one of the most mobile populations in the world. Traditionally, there were no permanent settlements occupied by them. Small settlements were built during the colonial period, but very few Turkana were attracted to them. Following the droughts of the 1980s, approximately one-half of the Turkana population settled in, or adjacent to, large famine-relief camps. Today it is estimated that about one-third to one-half of the Turkana population remains settled. The fastest-growing settlements are the district capital, Lodwar, and the villages located along the Turkwell River that depend upon irrigated agriculture.