Morocco's Atlantic coast, faces significant anthropogenic disturbances, leading to pollution in its waters used for various purposes. The primary objective of this study is to shed light on how the depollution project, a crucial part of the Bouregreg Valley development plan, has influenced the coastal area of the city. This has been achieved through a comprehensive analysis of the water quality, focusing on both physico-chemical characteristics and bacteriological aspects. Thirteen specific physicochemical parameters and fecal pollution indicators were meticulously monitored along the coastline. The goal was to gain insights into how water quality has changed over time and across different locations. The results of this investigation have revealed the substantial impact of the Wastewater Treatment Plant (WWTP) on the area, with varying degrees of efficiency observed, such as 63.04% for turbidity, 52.21% for BOD5, and 40% for organic matter.