The water of the river N’djili is used for several facts. Indeed, due to a lack of the servicing in drinking water in several districts of the city of Kinshasa, several residents use the water of this river as water of bathing, of cooking, of washing of linens, of drink, of watering of the gardens and washing of the gardening products (vegetables and tubers), etc. There is place to underline that biggest user of the water of the river N’djili is the REGIDESO that extracts every day a nominal volume equivalent to ±550.000 m3 of raw water in order to purify it to go against at least ¾ of the population of Kinshasa in drinking water. Yet several human activities susceptible to damage the quality of the water of this river are identified in its perimeters very brought closer. The danger is that in case of pollution of the river N’djili, several score of thousands of Kinshasa’s population should be exposed directly to water illnesses with risk of the epidemiological propagation, while the REGIDESO will be obliging to use big quantities of reagents to succeed in purifying this water polluted without forgetting the risk of resistance of some badly known pollutants. It will be able to be obliged however to resort to a lot of more refined techniques and expensive. A resource of as big importance had to absolutely be protected while the activities capable to harm to its good working should be regulated restricted either.