Implementation of the 20-year Rural Water Supply Programme (1971-1991) whose goal was to provide safe and adequate water supply to all rural communities in Tanzania indicated an acute shortage of trained personnel of all cadres i.e. engineers, technicians, craftsmen, etc. To cater for the diverse requirements of the water sector, a Water Resources Institute (WRI) established in 1974 as a training Unit under the Ministry of Water and Energy at the time.

In 1980 the institute’s name was changed to Rwegarulila Water Resources Institute (RWRI). This change was in honor of the late Fredrick Rwegarulila, the then Principal Secretary who played an instrumental role in establishment of the Institute and development of the Water sector in general. This decision came as a resolution during the 1980 Annual Water Engineers’ Conference (AWEC) held in Tanga.

During the Public Service Reform Program in the public sector which were geared towards improving service delivery, among interventions undertaken by the government was hiving off some of government functions that were routine in nature to be performed by semi-autonomous bodies (Executive Agencies). The Rwegarulila Water Resources Institute was selected to become Agency on 22nd August, 2008 because it was one of the organizations under the Ministry of Water performing routine functions. During the process the name of the Institute was changed from RWRI to “Water Development and Management Institute” (WDMI). However, in 2016, Water Development and Management Institute changed its name again to the current name of ‘‘Water Institute’’ (WI).