Dear Sir,
At the “No to the Aqueduct” meeting held January 12 in Ajijic, the guest speaker focused 90 percent on the water supply and wastewater treatment ills of Guadalajara, rather then the future of Lake Chapala. In his presentation he raised the point of rainwater collection. While I would agree this could be a worthy pursuit for residential application, it is not very feasible for an urban area like Guadalajara.
The cost of storing collected rainwater is of course the key issue that idealists seldom consider seriously. The speaker’s message included no cost data, making it difficult to be taken seriously by professionals charged with managing a city of four million people. His allegations that much of the ills are due to corruption closes even another door to meaningful discussion.
As to the lake, the key remains that while Guadalajara may waste four to five percent of the water coming from the Lerma River via its passage through Lake Chapala, the 40-percent waste due to the inefficient irrigating practices by famers along the Lerma River is the real factor on which to focus one’s attention. It was these farmers who by 2001 had reduced the lake to 20 percent full, not Guadalajara which removes only about 8 inches off the lake per year, in addition to the 50-60 inches a year that nature takes by evaporation. If Guadalajara did not need this lake, the farmers would soon shut off the Lerma River via the 200-plus dams along that river and the lake would disappear in four to six years.
While Guadalajara should be chastised for not reducing the leakage in its 7,000 kilometers of water lines about the city, its eternal need for the lake is the best insurance we will ever have that the lake remains 60-percent full, a level now in its sixth year. Never in history has the lake had six such years of stable surface area. Prior to 1982, when the lake depended on only the rainfall nature provided, the lake levels varied greatly depending on what rainfall came our way. Since 1982, with the hand of man over the gates of those 200-plus dams on the river, we have seen what can happen for good and bad. When the hand was that of the minister of agriculture we witnessed the non-stop decline of the lake from 1992-2001/2. That draw down of the lake is also 90-percent responsible for the loss of the majority of the fish in the lake. The water’s allocation compromise we now live under with the aim to keep the lake at least 60-percent full is clearly due to Guadalajara standing up for the lake because their other choices are economically and politically unworkable.
Dr. Todd D. Stong
Professional Engineer