The Ndjili River is a river that flows from the south through the capital city of Kinshasa in the Democratic Republic of the Congo, where it joins the Congo River. It separates the districts of Tshangu and Mont Amba. The river gives its name to the Ndjili commune and to the Ndjili International Airport. Location Kinshasa lies in a plain surrounded by hills drained by numerous local rivers, of which the Nsele and Ndjili are important tributaries of the Congo River. The climate is tropical, with a dry season and a rainy season. Kinshasa lies just downstream of the Malebo Pool, where the Congo river widens to across for a length of about . The Malebo Pool has an area of , with the Mbamu island occupying the central part. It is almost above sea level, surrounded at some distance by hills that rise to above sea level. Along the southern shore of the Pool, the land is swampy between the mouths of the Nsele and Ndjili rivers, a distance of , with the swamps covering . The swamps extend inland along the Ndjili. During the colonial era, Jesuits who settled on the Ndjili River in June 1893 at Kimbangu, in what is now Masina, were the first Catholic missionaries in the area. However, within a month they moved away from the unhealthy, swampy conditions that they found to Kimwenza, near the Petites Chutes de la Lukaya These are small falls on the Lukaya River, a tributary of the Ndjili that enters from the west, after running along the southern boundary of present-day Kinshasa. City water supply The Ndjili provides the main supply of water to Kinshasa, but tends to be polluted with human waste. Kinshasa had two water treatment stations before independence, one on the Lukunga River and one at Ngaliema bay on the Congo River. By 1985, they were both extremely dilapidated. A new station was built on the Ndikili at Kingbabwe in the Limete commune in two phases, one funded by Belgium in 1971 and the second by Germany in 1982. The French agreed to finance a second station on the Ndjili, but suspended aid to Mobutu in October 1991. A third Ndjili station funded by the Japanese was also cancelled due to the September 1991 lootings. The result was a failure to meet even minimum water supply needs. The river catchment has sandy soils and steep