Saturday, August 11, 2007

Mexico City and the Environment

Mexico City has a reputation as an environmental catastrophe, and to a certain extent, this is obviously true. The problem du jour seems to be that overuse of water is leading to a rapid depletion of the aquifer below the city, leading to rapid settling and sinking. Many of the old colonial buildings found in the city center, not to mention the pre-Hispanic buildings, are tilted and sunk. But apparently large parts of the eastern half of the city could sink and flood in sewage water following just the right kind of rain.

On the other hand, there have been a few areas of serious progress. In addition to an extraordinary metro system, with 11 lines, Mexico City built a "metrobus" line a few years ago. It took a major street (Insurgentes) and prohibited any small street buses from operating there. Removing all of these old buses greatly reduced emissions in the area of that street, and they were replaced with a very smart system. The median of the street has been converted into a series of shelters and the adjoining lanes have been made into bus-only lanes. The metrobuses run up and down those lanes, so they don't have to worry about traffic, creating an additional advantage to the bus by making it relatively more attractive when compared to driving. Another benefit is that emergency vehicles can use the lanes to get down the street quickly. The biggest problem is that there aren't enough buses to handle the number of people who want the service, which makes them packed at almost any time of day. The city is considering many more lines like this, which are obviously much cheaper to create than an actual metro. It is an idea that I'd like to see copied in American cities. One might object that this will create more traffic problems, and this might be true. In a US city there won't be reduced levels of traffic because of pulling lots of little buses off the street. But still: the people on the buses won't be stuck in traffic, and so more people will use the bus, pulling cars off the street and hopefully reducing emissions.

The other thing to notice is Xochimilco, at the end of the city, which used to be the site of watery gardens that fed the Mexica empire. Today this area is the only part of the greater city area that retains the aquatic character the city would have had 500 years ago - there are boatmen and canals here like Venice. Twenty years ago the land was a polluted, swampy mess, but some treatment plants were built and whole areas were replanted. Although people still feed the ducks far too much, the environmental health of this area has clearly improved. Small reasons for hope.

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