Water is very plentiful through the planet in general. Nevertheless, clean drinking water is not always accessible in the proper time or place for sufficient public or ecological use. The water significance is emphasized by the fact that in the past, great cultures have arisen near and along water bodies. Water quality of some purification complexes (compact units) in the Babylon Province (13 compact unit) as compared with Al-Hillah Al Mouahad Project (water treatment plant) was assessed by the Water Quality Index (WQI) methodology. WQI offers a particular number that states the overall water quality at a definite place and period based on many parameters concerning the quality of water. The water produced from the compact units was classified as "good water" according to the WQI classification with the values ranging from 85.4 in Bermana unit to 99.17 in Al-Muamera compact unit. Moreover, the research results showed that the water purification complexes work with efficiency, very close to the performance of large water purification projects and stations, and this means that it is possible to rely on them to obtain good drinking water quality, especially in small or remote areas.