Updated 10:08 a.m. to make table readable.
Caracas’ water system made headlines in the fall when Alexander Hitcher, then president of the water utility Hidrocapital, went on television to say that he would impose mandatory water savings measures to reduce the flow to the city by 25%. The rainy season had added almost no water to local reservoirs and demand was growing. While the public whined about the nature of the rationing — 48 hours a week without water for most residents — I heard many people say that at least he was taking responsibility and doing something before the city ran out of water completely. I met plenty of people who at least said they agreed with my assessment that at 400 liters a day per capita, Caracas water consumption was unnecessarily high, and could easily be reduced.
Hitcher was promoted to minister of environment when Yubiri Ortega quit a few months ago, with the president saying that Hitcher had done a good job. He was back in public at the beginning of March to say that Caracas had successfully cut consumption by 30%. A week later, his vice minister of hydrology came out to say that people were using water more rationally, protecting the country’s reservoirs.
Meanwhile (to their credit) Hidrocapital continues to post periodic updates on the level of water in Caracas’s reservoirs. (March 1 presentation is here.) Looking at them breaks some of the tranquility one might feel after listening to the minister and his aides.
The biggest reservoir, Camatagua, declined at the exact same rate as it did in each of the prior four years up until the end of March. Since then, the rate of decline has slowed, but water level has continued to fall. Its current level is well under half of capacity. The reservoir has been exploited at an unsustainable rate since 2006. That was the last year when rains let the reservoir recover all of the water used in the prior dry season. Since then, each rainy season has failed to fill the reservoir, leaving the city with less and less margin for a very dry year like last year. There is now no margin for a multi-year drought — hopefully the nice people at Columbia University’s IRI are right to predict a heavy rainy season.
The Lagartijo reservoir has been dry all year, so consumption of its water has been essentially zero.
The Taguaza reservoir normally, keeps its level constant until the end of March. This year, its level began to drop in January and just began to level off with the recent rains.
Let’s do the math. Sadly the presentations don’t give exact numbers, so we have to guess based on the PDF provided. So I’ll use few significant digits. Also, the April tables are all off by a factor of 1000, but I’ve fixed that.
In other words, water levels declined by 20 million cubic meters, or 12%, more under our supposed conservation regime than they did the prior year. Now this doesn’t show that Hitcher & pals are lying — when the creeks start out dry, lower outflows can still lead to lower levels at the end of the season. But it does show that whether or not we’ve been conserving, the situation is dire.
The worst case would be a rainy season like last year’s in which the reservoirs simply failed to recover their losses from the previous dry season. Rains last year barely covered daily consumption while they fell, and when they ended, the curve started promptly downward. In that case, consumption of more than 50 million m3 a month would not last the upcoming year. It is impossible to imagine a city like Caracas simply running out of water. Yet that’s the worst-case scenario, and one with a more than marginal possibility at this point. Even in the Columbia University probabilistic forecast, there remains a 20% or higher chance that this year will land in the driest tercile rather than average or wet.
The decline rate for the first 100 days of the year was an average 1.89 million cubic meters a day. At that rate, all the reservoirs would dry up in 340 days.
The best case is a year like 2006, in which Tacagua increased its level by 10 million and Camatagua by 250 million while Lagartijo fell by about 20 million cubic meters in the period of April 1 to Dec 31. The net, in eight months, was a gain of about 240 million cubic meters. The reservoirs are currently about 967 million cubic meters short of being full. That means we’d need four consecutive years like 2006, combined with water rationing at the current level, to get the reservoirs back to the level where things are truly secure and prepared for the kind of multi-year drought that hits Venezuela regularly. All this, of course, without taking into account population increase.
I have no idea if Hitcher and crew are telling the truth about the reduced water consumption in Caracas. For my part, I know that they cut my neighborhood’s water completely on the weekend for about a month and then stopped bothering. So hopefully the “rationing” has been just as virtual as the electricity savings.
On the other hand, if they really are rationing water, that just adds to the scariness of all this. Because if the reservoir levels are declining at the fastest rate in at least 5 years, even with water-saving programs in place, what does that mean for when authorities eliminate water rationing, which they may do to try and win a few votes in the Sept. 26 election?