With Belfast's rapid growth, there was a fast-growing demand for more and more water. The two existing upload water catchments were becoming increasingly insufficient. In 1891, local civil engineer, Luke Livingston Macassey was appointed the task of finding a source of water large enough to sustain Belfast. Five potential sites were surveyed in County Down, and County Antrim. Macassey ultimately decided on the Mourne Mountains in Down. The reason the Mournes proved so popular with Macassey was the cleanliness of the water and the high amount of rainfall - both paramount factors in water sources. Upon deciding on the site, water commissioners agreed on securing a catchment area. Private Acts of Parliament (in 1893, 1897 and 1899) allowed the Belfast City and District Water Commissioners to purchase the Mournes land and related access permits and water rights. At the time the catchment was capable of providing some of water per day, but this was too much. A scheme was developed and divided into three phases: