Dear Sir,
I’m confused about the new Purgatorio dam. The recent Reporter article states that the new dam “would significantly reduce extractions from Lake Chapala,” but gives no explanation of how, why or by when.
The new Purgatorio dam will probably be completed within the next 10 years, and that is only when the government has enough money. We do not know what will be done for Lake Chapala in the meantime. The dam will provide two-thirds of the needed water. It does not say if this takes into account the growth of Guadalajara in the next 10 years. This still leaves one-third of the water needed, and the only place this large quantity is available is Lake Chapala. The cost to build the dam should be compared to the cost of building a second pipeline from Lake Chapala.
It seems that there will be no impact to Lake Chapala as claimed. The real problem for Lake Chapala is the lack of water coming down the Lerma River as it is taken by the some 500 dams now built, not the one foot of depth taken by Guadalajara. The Jalisco Governor and the National Water Commission (CNA) could develop a new program to charge for the water taken from the Lerma river, to limit the amount of water taken in order for lake Chapala to maintain 80 percent of its capacity, and to use the money to increase the efficiency of the watering methods of the farmers from flooding their fields to drip irrigation and to encourage other more profitable crops. This would provide a win-win situation for all.
Rick Cowlishaw, Ajijic