Mexico & Nafta - April 2009 (ISSN 1741-444X)

The federal government cut off the water supply to around five million people in Mexico City on 8 April  to carry out what it said was vital maintenance to the Cutzamala supply system.

The authorities calculated that the traditional holiday season of Holy Week was a good time for major maintenance, since many residents would be out of the city.The federal Comisión Nacional del Agua (Conagua)  announced that it would cut off supplies for at least 36 hours. The supply should have been completely restored on 14 April. Around 20m people live in the valley of Mexico City.

Despite the snow, this winter has been unusually dry in central Mexico. Conagua said that the Cutzamala water system is at only 47% of its capacity when usually, by the start of the second quarter, it is at about 85%. Cutzamala's reservoirs and pipes supply 20% of Mexico City's water. Unfortunately for the authorities, the Cutzamala network supplies a lot of the unplanned (and thus poor) communities on the fringes of Mexico City. This enabled the media to polarise the crisis by showing poor people having to use buckets to collect water from cistern trucks while in richer areas of the city lawn-sprinklers could still be used.

Officials hope that after the next period of maintenance, in May, the system will be replenished by the summer rains. Mexico City residents are heavy users of water: on average they use 300 litres a day. The average in some European cities is 180 litres a day.

The issue of water supplies in Mexico City has become delicate. The city, which was built on what was originally a lake, has long had problems with its supplies.One problem is that Mexico City is so high above sea level that fresh water has to be pumped up to reach it. A second is that successive governments failed to develop systems to separate rainwater from sewage and instead pumped both out of the area to be filtered before pumping them back up to be used. A third is that Mexico City is sinking by about five centimetres a year: this settling is rupturing pipes and means that around 40% of the water in the system is lost before it arrives at its destination. A fourth is that as the valley of Mexico becomes ever more built up, more water runs off rather than drains through to replenish aquifers.

The Easter weekend cut was the third interruption to water supplies so far this year. The Easter stoppage was more serious than previous cuts but the city government appears to have warned people successfully about what was going to happen and thus avoid chaos. Conagua is warning that there will have to be another three or four day cut in supplies in May to deal with maintenance problems.

This year, surprisingly given the early heavy snowfalls, has been dry. The irony is that more rain falls in the the valley of Mexico than is used by its inhabitants. The problem is that little of this precipitation percolates through to replenish the water table (mantos freáticos, in Spanish) because its is mixed up with waste water and pumped away.

Rightwingers (and environmentalists) argue that the federal and city government should introduce a better system for water rates. They suggest setting a higher price for water, which will mean that people will think about how they use it. The city government, which is run by the leftwing Partido de la Revolución Democrática, prefers to call for people to be more aware about how they use water supplies. What is undeniable is that more investment is needed in the water industry in Mexico City. They key need is for additional sewage plants.