Acequia is an unincorporated community located in Douglas County, Colorado, United States. The Acequia, Colorado Territory, post office operated from January 30, 1874, until June 9, 1881, and again from April 22, 1887, until July 14, 1900. Acequia is a Spanish word meaning "canal" or "channel", so the name was likely in reference to the nearby High …Acequia is an unincorporated community located in Douglas County, Colorado, United States. The Acequia, Colorado Territory, post office operated from January 30, 1874, until June 9, 1881, and again from April 22, 1887, until July 14, 1900. Acequia is a Spanish word meaning "canal" or "channel", so the name was likely in reference to the nearby High Line Canal. Colorado became a state on August 1, 1876.