Water  is  an  irreplaceable  resource  for  all  forms  of  life,  which  varies  in  quality in different categories such as polluted, little polluted, good, regular  and  excellent  due  to  the  interaction  with  sources  of  pollution,  in 2018 Peru adopted the Canadian model " ICA-PE ”instrument with which the variation in the quality of surface waters can be evaluated. The objective  of  this  study  was  to  evaluate  the  variation  in  the  water  quality  of the Coata River in the Maravillas Bridge - Coata Bridge section due to  the  existence  of  polluting  sources.  To  establish  the  variation  in  water  quality between the sampling points ACFC-01 and DCFC-03, the source of contamination FC-02 was located, and FC-04 between the points of DCFC-03 and DCFC-05, from from which water samples were obtained from which 18 para...