Managing Mexico´s Driving ForceWed, 02/24/2016 - 11:04
“Water is the driving force of all nature,” stated Leonardo Da Vinci in his Water Theory: On the Origin and Fate of Water, and almost 600 years later, this statement continues to hold weight. Like the ancient Egyptian empire that rose alongside the banks of the river Nile or the enigmatic city of Teotihuacan that crumbled into dust as the rivers dried up, history reminds us of the intrinsic link cultures and societies have to water. In the modern world, water continues to affect all cross-sections of society, and is an important motivator for industrial, urban, and agricultural development. As a preponderant agent in Mexico’s economic growth, one must explore the sourcing and use of this valuable resource.
SEMARNAT and INEGI agree that Mexico contains approximately 0.1% of the world’s potable water, a percentage that highlights the fact that a large section of the territory is catalogued as a semidesertic zone. In the whole country rainfall is approximately 1,551km3 of water each year. This is equivalent to a pool a kilometer deep the size of Mexico City, and 72% of this amount evaporates. While this image might be striking, on a global scale, Mexico is considered to be a country with low water availability, as 56% of the territory is semidesertic and 10.6 million Mexicans do not have access to potable water.
For time immemorial, dams, rivers, pumping plants, and natural aquifers have supplied cities, and Mexico City is an important case study that highlights this particular management of water resources. This city is a colossus in water consumption, as it receives 34,430l of potable water per second. Alejandro Martínez, Executive Director of Operations at SACMEX, also known as Mexico City Water Systems, is in charge of managing the domestic potable water, drainage, and sewerage of this complex network. “The city is supplied both internally and externally. The former consist of wells, which is due to the fact that the topography of the city makes sourcing potable water from alternative sites difficult,” he describes. The wells in Mexico City and the State of Mexico constitute 70% of the total water supply. The remaining 30% comes from three systems that belong to CONAGUA: Cutzamala (9,000l/s), Barrientos (2,200l/s), and La Caldera (600l/s). “The average consumption of the city oscillates between 30-31m3 (31,000), which is the equivalent of four water pipes per second.”
Given Mexico’s altitude, precipitation is considerable and one cannot forget that this large city is built on a lake, hence the common flooding. Over 1 billion m3 fall during the rainy season and 90% of this is lost. For many, harvesting rainwater is becoming a viable solution to make the city sustainable in its water consumption. SACMEX has developed projects for the recovery of water from rooftops by working on the drilling of absorption wells. “Unlike extraction wells for drinking water, these wells collect rainwater and a special system removes large solids from the resource,” Martínez expands. “With the help of SACMEX, municipalities like Iztapalapa, Xochimilco, and Tlalpan have drilled approximately 400 wells of this type, and these help recharge the natural aquifers,” he adds. However, Martínez points out that it only rains five months of the year, so this intermittency must be considered when deciding to invest in the construction of rainwater capture networks.
This limitation has inspired SACMEX to look for alternative solutions. “We are currently developing a water collection project for schools in Tlalpan, Xochimilco, and Milpa Alta, where rainwater is captured on the schools’ rooftops and then recycled.” The private sector is also playing a role in these new solutions. Isla Urbana is a project dedicated to finding a solution to Mexico’s water supply shortage. Created by the International Institute of Renewable Resources and Temo Foundation, it has so far installed over 1,700 systems in low-income regions and where water shortages are becoming a real problem. This movement has helped over 12,000 people spread across Mexico. According to Isla Urbana, when a family begins using its rainwater systems, their reservoir will be full for up to six months.
Access to clean water, sanitation, and water management creates multiple opportunities for underprivileged communities and is a progressive strategy for sustained economic growth. Effective water management brings certainty and efficiency across all productive economic sectors and contributes not only to the health of ecosystems, but also to the quality of life in the region. If Mexico wishes to succes in the goals it has set out to accomplish, it must first intervene in its water management; without this, its social, economic, and environmental goals will quickly evaporate.