Anthropic activities such as agriculture, livestock, and wastewater discharges affect water quality in the Tlapaneco River in the mountain region of the state of Guerrero, México, which is a tributary of the Balsas. The river flows from the mountain region and discharges into the Pacific Ocean; the water resource in the localities mentioned is used for agriculture, recreation, and domestic activities. The aim of this study was to evaluate water quality in the stretch of influence of two localities, Patlicha and Copanatoyac. The instrument used was the Biological Monitoring Working Party biotic index (BMWP) and physicochemical parameters. Nine sampling sites were selected according to the perception of the local community with respect to disturbance; the study area was divided into three parts: high, medium, and low. Twenty-seven collections of macroinvertebrates and water were analyzed, in dry and rainy seasons, through the presence–absence of these organisms and physicochemical analysis, to evaluate water quality. The results showed that the conditions of the riverbed associated with daily activities and domestic discharges are important factors in the composition of the families. Water quality was very poor to regular, according to the macroinvertebrate assemblages collected. The BMWP index was of acceptable quality when the orders (Family) Ephemeroptera (Leptohyphidae; Leptophlebiidae; Baetidae; Ephemerellidae), Diptera (Chironomidae; Simulidae), Trichoptera (Hydropsychidae), Hemiptera (Veliidae; Corixidae), Coleoptera (Hydrophylidae), and Odonata (Lestidae) were present; in sites with poor quality, the families Chironomidae, Leptophlebiidae, Veliidae, Corixidae, Hydropsychidae, Leptohyphidae, Hydrophilidae, Baetidae, and Simuliidae were found, while in very poor quality water, only family Corixidae was present.

Anthropic activities as agriculture and livestock and wastewater discharges affect water quality in the Tlapaneco river in the Montaña region of the state of Guerrero, México, which is a tributary of the great Balsas River that flows from the Montaña and discharges into the Pacific Ocean; the water resource in the localities mentioned is used for agricultural work, recreation, and domestic tasks. The objective of the work was to evaluate quality of the water in the stretch of influence of two localities, Patlicha and Copanatoyac. The instrument used was the BMWP biotic index and some physicochemical parameters. Nine sampling sites were selected according to the perception of the local community with respect to disturbance; the study area was divided into three: high, medium and low. Twenty-seven collections of macroinvertebrates and water were analyzed, in dry and rainy seasons, through the presence-absence of these organisms and physicochemical analysis to evaluate water quality. The results showed that the conditions of the riverbed associated with daily activities and domestic discharges are important factors in the composition of the families. Water quality was very poor to fair according to the macroinvertebrate assemblages collected. The BMWP index with fair quality was when the families Leptohyphidae, Chironomidae, Hydropsychidae, Leptophlebiidae, Baetidae, Simuliidae, Veliidae, Corixidae, Hydrophylidae, Lestidae and Ephemerellidae were present; in sites with poor quality, the families Chironomidae, Leptophlebiidae, Veliidae, Corixidae, Hydropsychidae, Leptohyphidae, Hydrophilidae, Baetidae and Simuliidae were found, while in very poor quality the family present was Corixidae.

Cada día, el agua llega a los hogares sin que pensemos en su viaje subterráneo. Corre por tuberías que envejecen, atraviesa muros de concreto y, finalmente, aparece dócil en un grifo. Pero bajo la ciudad, entre fugas, lodo y válvulas oxidadas, hay cuerpos que trabajan para mantenerla viva. Este ensayo busca mirar el agua desde abajo: a través de quienes la reparan, la escuchan fluir y la devuelven al cauce urbano.