Assessment of Water Quality of El Oulfa Wetland (Morocco) Using the Water Quality Index and the Trophic State IndeX

Water quality degradation is one of the most pressing environmental challenges in reservoirs around the world, making the trophic status assessment essential for restoration and sustainable use. This study aimed to evaluate the surface water quality of El Oulfa pond through the calculation of two critical indices: the Water Quality Index (WQI) and the Trophic State Index (TSI). Water samples were collected from July 2021 to July 2023 at three sampling stations.Twelve physico-chemical parameters, including temperature, pH, electrical conductivity, dissolved oxygen, Secchi disk depth, total suspended solids, total phosphorus, soluble reactive phosphorus, ammonium, nitrates, sulfates, and chlorophyll-a, were measured using standard methods. The TSI results show the pond is mostly eutrophic, with nutrient levels varying over time and between sites. Station S3 had a peak TSI of 83.49 in April 2024. The findings emphasize persistent pollution, requiring urgent intervention.