Background.

The water quality index (ICA) is a practical and useful tool to estimate the quality of water bodies, this method has been used in many countries.

Goals.

Evaluate the water quality of the Ayuquila-Armería river basin, based on two categories of possible use of the water resource, use in agricultural irrigation, protection of aquatic life and drinking use.

Methods.

The analysis of physical and chemical variables, analysis of heavy metals and nutrients and the characterization of anions and cations were carried out; In addition, the variables were complemented with the use of a biotic integrity index based on families of aquatic macroinvertebrates, to estimate organic contamination and the determination of fecal coliforms, in the forty sampling sites along the upper, middle, and lower part. of the basin.

Results.

Of the forty sites, the quality of the water for use in agricultural irrigation presented ICA ranges of regular (35%), good (27.5%) and excellent (37.5%) conditions. Regarding the comparison made for the quality of water for the protection of aquatic life and drinking use, it was found that eight sites (44.4%) present poor-quality conditions, another eight sites (44.4%) present good quality and only two sites (11.11%) an excellent quality condition.

Conclusions.

For the use of water in agricultural irrigation, there is no site that presents poor quality of the resource, in addition, by using different parameters related to agriculture, it can be ensured that there is no risk of loss or damage to crops by using water for irrigation. In the case of water quality in terms of the protection of aquatic life and potable use, in general the basin presents poor conditions. In this sense, aquatic organisms are suffering effects both in their habitat and in the physicochemical conditions that can decrease their populations, on the other hand, human communities near watercourses will be more susceptible to health-related problems.