The environmental changes due to the Colorado River damming, have affected the ecological functioning of the nursery river delta and consequently the population of fishermen that live of the natural marine resources of the upper Gulf of California. We propose the use of urban wastewaters as a source of nutrients to fertilize the estuary, increase the primary productivity and therefore increase the population size of the estuarine dependent species, which are important for the fisheries in the region. In this way, we could partially restore the delta's ecological functioning and thus solve environmental, social, and economic problems. With a wastewater flow of 800 l·s -1 from “Las Arenitas” treatment plant, we could increase the primary organic productivity and ~1000 metric tons (mT) of shrimp landings of the region. These calculations are just for one fishery, but in a magnitude that could also increase in others.