Originally Posted 9/27/2016
This past Sunday was World Rivers Day- a day to celebrate natural waterways around the world and encourage stewardship of these valuable resources. Through the basin of Mexico, where the Mexico City Metropolitan Area is located, there once flowed many rivers. However, as the city grew, most of these rivers were enclosed in drains or transformed into sewers (Legorreta, J. 2009). However, there is one remaining free-flowing river and source of surface water within the city- the Magdalena River.
The Magdalena river is located in the Magdalena Contreras region, on the southwestern edge of the city. Like most rivers that run through urban areas, the Magdalena River was transformed as the city grew. Though the amount of water flowing through the river has not drastically changed, the quality of the water has. Clean water is taken out of the river and replaced with untreated wastewater (Mazari-Hiriart et al, 2014). As the river enters the urban area, the physicochemical and biological indicators such as electirical conductivity, nitrogen, phosphorous, fecal coliforms, and fecal enterococci increase dramatically (Mazari-Hiriart et al., 2014 & Jujnovsky, J., 2010). In many sampling sites within the urban area, researchers have found that the water quality does not meet the criteria required for human consumption (Mazari-Hiriart et al., 2014 & Jujnovsky, J., 2010). Additionally, the river contains concentrations of microbes that parasitize and cause disease in humans and animals (Mazari-Hiriart et al, 2014).
This information is not new to city residents and city officials and there have been conversations about the restoration of the river. A Master Plan was developed with significant public participation, and parts of it have been implemented. Transforming a river within an urban area, however, is challenging. What does restoration look like for an urban river? Knowing that it will never mimic its pre-urbanized state, to what state is it restored to? If you know of or are involved in any restoration projects in Mexico City, or in other urban environments, please comment below! We would love to hear from our readers.
Jujnovsky, J., Almeida-Lenero, L., Bojorge-Garcia, M., Monges, Y.L., Cantoral-Uriza, E., Mazari-Hiriart, J. 2010. Hydrologic ecosystem services: water quality and quantity in the Magdalena River, Mexico City. Hidrobiológica 20(2): 113-126
Legorreta J (2009) Ríos, lagos y manantiales del Valle de México. Universidad Autónoma Metropolitana-Gobierno del Distrito Federal. Artes Impresas Eón, S.A. de C.V. México, D.F. 365 p.
Mazari-Hiriart M, Pe´rez-Ortiz G, Orta-Ledesma MT, Armas-Vargas F, Tapia MA, et al. (2014) Final Opportunity to Rehabilitate an Urban River as a Water Source for Mexico City. PLoS ONE 9(7): e102081. doi:10.1371/journal.pone.0102081
A collaborative project seeking to improve capacities for risk management in Mexico City and to serve as a model for climate-change adaptation in developing countries.