Apr 092012
 

A recent report from researchers at the National Autonomous University of Mexico (UNAM) and the Metropolitan Autonomous University (UAM) confirms that the height of the water table below Mexico City is dropping by about one meter a year, as more water is pumped out of the aquifer than the natural replenishment rate from rainfall. About 60% of Mexico City’s drinking water comes from wells, with the remainder piped into the city, mainly via the Cutzamala system. The researchers say that up to 65% more water is taken from some parts of the Mexico City aquifer than the amount replaced each year by natural recharge.

As we reported in a previous post – Why are some parts of Mexico City sinking into the old lakebed? – this has resulted in parts of Mexico City sinking more than seven meters (23 ft) since 1891, with implications for water pipelines, drainage systems, building foundations and the city’s metro network, as well as an increased incidence of ground subsidence.

According to this latest research, the clay soil of the former lake bed below the city is sinking by between 6 and 28 cm/yr in most places, with rates in the southeast part of the city (where numerous wells have been drilled in recent years) sinking by up to 35 cm/yr.

How can the problem of sinking ground be resolved?

The report emphasizes the importance of conserving as much green space as possible within the city, to reduce runoff (and demands on the city’s drainage system) while simultaneously recharging aquifers. The three major alternatives, some combination of which is needed to resolve the problem are:

  • introduce more water-saving strategies so that demand does not continue to increase
  • bring more water from outside the Valley of Mexico (this would be costly and unpopular)
  • feed more wastewater back into the underground aquifers via “surface soaks”. As one example, the National Water Commission (Conagua) has announced plans to build a 200-million-dollar wastewater treatment plant (“El Caracol”) that will inject water back into the aquifer after treatment. It would be Mexico’s first ever large-scale reinjection project.

Perhaps not surprisingly, Mexico City residents pay more for their water than users anywhere else in the country, with an average water rate of US$1.23/cubic meter. Elsewhere, the two states sharing the arid Baja California Peninsula also have higher than average rates of $1.05/cubic meter (Baja California Sur) and $0.94/cubic meter (Baja California). The lowest rate in the country, well below the true cost of supplying water, is in Nayarit, and is just $0.25/cubic meter.

Within Mexico City, access to potable water is far from equally/fairly distributed across the city, as revealed by this thought-provoking quote :

In a study of water access in Mexico City, geographer Erik Swyngedouw found that “60 per cent of all urban potable water is distributed to three per cent of the households, whereas 50 per cent of the inhabitants make do on five per cent of the water”. Critical geographers like Swyngedouw ask us to take note of the spatial nature of power imbalances revealed in patterns of city design and growth: “mechanisms of exclusion… manifest the power relationships through which the geography of cities is shaped and transformed.”  [quote comes from page 31 of Nature’s Revenge: Reclaiming Sustainability in an Age of Corporate Globalization ; the reference is to Erik Swyngedouw’s Social Power and the Urbanization of Water: Flows of Power (OUP 2004).]

This grossly unequal distribution of potable water remains a critical problem that successive administrations in Mexico City and the surrounding State of México have done little to resolve.

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Mexico’s political system at the state and municipal levels

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Apr 072012
 

In a previous post – Mexico’s political system: the basics – we looked at the country’s federal political system. In this post, we look at how the political system works at the two other levels of government: state and municipal.

According to the Constitution of 1917, powers not granted to the Federal Government are reserved for the states. State constitutions roughly mirror the federal constitution. Each state has a popularly elected governor who serves one six-year term and cannot be re-elected. The popularly elected members of the state chamber of deputies serve three-year terms. Non-sequential re-election is permitted. Governors generally have more power than the chamber of deputies. State governments depend on the Federal government for much of their revenue, some of which they funnel to municipal governments. Each state has a Supreme Court of Justice with judges appointed by the state governor.

States are divided into municipalities. There are currently 2458 municipalities (counting Mexico City’s delegaciones or boroughs as municipios) which vary greatly in size and population. For example, the average population of Oaxaca’s 570 municipalities is about 6000 while the average population of Baja California’s five municipalities is over 500,000. Each municipality elects a new president and local council every three years.

Municipal governments have taxing authority but rely very heavily on financial support from state and federal sources. Municipalities are responsible for a variety of public services, including water and sewerage; street lighting and maintenance, trash collection and disposal, public safety and traffic, supervision of slaughterhouses, and maintenance of parks, gardens and cemeteries. Municipalities are also free to assist state and federal governments in the provision of elementary education, emergency fire and medical services, environmental protection and the maintenance of historical landmarks.

Greenpeace demands action to clean up Mexico’s surface waters

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Apr 052012
 

Greenpeace activists chose the Juanacatlán Falls (“The Niagara of Mexico”) for their latest protest to call attention to the poor quality of Mexico’s rivers and lakes. They cited government statistics that show 70% of Mexico’s surface water is contaminated. Most of the pollution comes from industrial dumping, rather than municipal sewage.

It is hard to imagine a better choice. The activists, clad in protective clothing and wearing masks to avoid inhaling toxic gases, paddled kayaks into the River Santiago immediately below the malodorous falls and unfurled banners with slogans such as “Mexican rivers, toxic rivers” (see image).

Greenpeace activists at El Salto de Juanacatlán, 22 March 2012. Photo: Greenpeace.

The activists called on the government to commit to a policy of zero dumping of toxic substances into rivers and lakes by 2020, with sanctions for actions leading to pollution and its effects.

In a coordinated action, thirty NGOs in Jalisco announced the creation of the “Broad Front in Defense of Water and Against Privatization ”, demanding actions towards a fully sustainable use of water. They asked government to take the lead in cleaning up the Santiago River and provide urgent medical attention for residents of communities affected by its high level of pollution (see this blog post). They also called for an end to the privatization of water services.

José Luis Luege, the head of Mexico’s National Water Commission (Conagua), the government body overseeing all Mexico’s water resources, recently presented a portfolio of programs for the country’s 13 water regions which are designed to make Mexico’s water usage sustainable.

Conagua calculates that Mexico currently uses 78.4 million cubic meters of water a year. Of this amount, 66.9 billion cubic meters is taken from surface and underground sources (and is fully sustainable), while about 11.5 billion cubic meters come from the unsustainable use of aquifers, where the rates of abstraction exceeds replenishment. The new programs are designed to reduce and eventually end unsustainable aquifer use, replacing it by a mixture of water-saving programs and by building the necessary infrastructure to obtain more water from sources believed to be fully sustainable.

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Which tectonic plates affect Mexico?

 Excerpts from Geo-Mexico  Comments Off on Which tectonic plates affect Mexico?
Apr 022012
 

The theory of plate tectonics suggests that the earth’s crust or lithosphere is from 5 to 65 km (3 to 40 mi) thick and divided into about a dozen large tectonic plates, tabular blocks that drift across the Earth in different directions and at various speeds (up to a few centimeters or inches per year), probably as a result of thermal convection currents in the Earth’s molten mantle. Most plates consist of a combination of both ocean floor and continent, though some are entirely ocean floor.

Each tectonic plate is moving relative to other plates. The movements are not independent because the plates smash into and scrape against one another. Areas in the center of tectonic plates, far from the boundaries, have relatively little seismic activity, but the boundaries between plates are seismically very active, creating earthquakes and volcanoes. The level of seismic activity depends on the relative speed and direction of the plates at the boundary.

There are three distinct kinds of boundaries between plates. At divergent boundaries, along mid-ocean ridges, plates are being steadily pushed apart, with new crust being added by volcanic activity to the rear of each plate as it moves. At convergent boundaries, plates collide and parts of the plates either buckle or fracture or are subducted back down into the molten mantle. The third kind of boundary is where plates are neither created nor destroyed but are moving side by side. The resulting friction as they rub against each other can produce large earthquakes.

Almost all of Mexico sits atop the south-west corner of the massive North American plate (see map). Immediately to the south is the much smaller Caribbean plate. The North American plate extends westwards from the Mid-Atlantic Ridge, which runs through Iceland and down the middle of the Atlantic Ocean, to the western edge of North America. In a north-south direction, it extends from close to the North Pole as far south as the Caribbean.

Mexico's position in relation to tectonic plates

Mexico's position in relation to tectonic plates.Map: Geo-Mexico.com; all rights reserved

While most of Mexico rests on the North American plate, it is also influenced by several other plates.

The Baja California Peninsula is on the gigantic Pacific plate, which is moving northwest and under the North American plate. The intersection of these plates under the Gulf of California causes parallel faults which are part of the famous San Andreas Fault system. Thus, the Gulf of California is an area of heavy seismic activity.

The small Rivera plate, between Puerto Vallarta and the southern tip of Baja California, is moving in a southeasterly direction and rubbing against the Pacific plate; it, too, is moving under the North American plate.

The Cocos plate and tiny Orozco plate are ocean crust plates located off the south coast of Mexico. The collision of the Cocos plate and the North American plate has had several far-reaching consequences, including both the disastrous 1985 earthquakes that caused such severe loss of life and damage in Mexico City and the much more recent 2012 earthquake that, fortunately, was far less destructive.

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