Water is a vast biomolecule in the systems, it can come from surface water or from underground abstraction, in order to consider it pure, it is necessary to evaluate its physical, chemical and biological characteristics, since it is directly linked to the health of the population. The objective is to evaluate the main chemical and physical parameters in order to compare and verify the quality of the natural waters that are distributed to the population of the municipality of Boquira-Ba, making a comparison between the dry and rainy periods. The physical-chemical parameters analyzed were: hydrogen ionic potential (pH), electrical conductivity, turbidity, resistivity, total dissolved solids (STD), hardness and alkalinity. The data obtain ed were compared to the values established by the Resolution of the National Council for the Environment (Conama) 357/2005 and Ordinance of MS 2914/2011. The samples collected during the dry season when compared to the rainy season showed a variation in the results, but remained at the maximum allowed values, thus proving to be quality water for consumption. Only two periods in the dry season (P3 and P4) and (P9 and P10) rainfall presented a variation in conductivity, resistivity and hardness, thus compromising the quality of this water.