Observations focused on the problems of an underdeveloped country, Venezuela, with some serendipity about the world (orchids, techs, science, investments, politics) at large. A famous Venezuelan, Juan Pablo Perez Alfonzo, referred to oil as the devil's excrement. For countries, easy wealth appears indeed to be the sure path to failure. Venezuela might be a clear example of that.

Blog Stats

An attempt to answer the question of whether the critical level of the Guri dam will be reached

March 6, 2010

Recent Picture of the Guri dam

All week, I (we) have been worrying about whether the Guri dam will or not reach the “critical” level of 240 meters above sea level at which point it will have to be shut down. In El Nacional there was an article on Friday in which one person talked about simulations and another gave a very definite date of something like April 4th.

This post is an attempt to answer that question. I start by looking at a graph I already published once:

This is the historical behavior of the flow of Rio Caroni that feeds Guri. As you can see, the minimim historical flow, shown in the green line, had a low around May 10th. Thus, unless this year represents a minimum in historical flow, this should be the worst possible scenario we may expect.

As usual, friend Moses came to the rescue yesterday linking to this post in Noticiero Digital which has a table of the level of Guri day by day since January 1st. This is how the water level has dropped so far this year and until Feb. 25th.

You can see that the daily drop is accelerating, which I noted yesterday because in January the daily drop was 8 or 9 centimeters and Chavez quoted 14 centimeters in February. Thus, because of a number of factors, conical shape, lower water inflow, lower levels, the change in not linear, the water drops faster as the days go by.

Instead of lloking at the level, it is better to look at the daily change as a function of time:

as you can see, there is a lot of scatter in the plot, due mostly to the fact that the data only has two significant digits. I did a fit to it and it looks quite good with a simple linear fit, the water level dropping accelerating its drop by about 0.594 mm. per day, that is it takes about 16 days to add a centimeter to the daily drop.

This is the the data for the first two months of the year extrapolated all the way to June 16th.:

As you can see, the fit is pretty good and looks linear. In any case we can monitor in the upcoming days whether the model predicts the correct level day after a day and adjust accordingly.

Of course, I can now extrapolate using the model what would be the level into the future and how the date compares to the May 10th. cut off of the first graph above. Using the model, I get:

The plot above shows the orignal data in red below the water level data in blue generated by the model. The crossing of the 240 mts. level (I am not sure the exact number) takes place on May 29th. two weeks after the historical minimum. To give you an idea, I only used data up to the 25th. of February and today, the OPSIS page says that the level is at 254.20 and my model says 254.22, not bad at all, it does not seem to be accelerating or changing.

Given that May 10th. is the historical minimum for the water flow and the model says May 29th. it seems quite unlikely that Guri will have to shut down.

The curve predicts 240 meters near the end of May. But it is probable that close to this level (lets say 245 meters) the generation will be throttled down to avoid damage by cavitation to the Francis Turbines.

Thanks for the analysis. One caveat: the shape of the reservoir below the current surface level can further accelerate the rate at which the level drops. If certain areas start to fall dry, the drop rate will accelerate and this can not be predicted from recent measurements. If there is a depth map of the reservoir it is possible to check if there are significant areas that are to fall dry in the coming weeks.

The first would be to offer a comparison of the angles of decline of the minimum historical water flows at Guri in Image 2 with that of what I will describe as “year to date” in Image 3. This appears to indicate that the current level of decline is steeper, suggesting an accelerated rate of decline over previous historical levels of water flow. I do not have the figures to look at, but I have a copy of the EDELCA presentation with the image graphics including the one Victor Poleo uses (2nd image on page) at:

The level of decline on that image looks identical to yours, so I know that your figures are correct, but I am wondering about the distinct assumptions which distinguish your conclusions here, with the projection shown on that image. And I am not suggesting any flaw in your analysis, these matters always come down to assumptions.

My second comment is really a continuation of my last paragraph about “distinct assumptions,” which is really an ecological critique. I honestly do not know what current consumption levels have become after the recently-mandated blackouts–I’ve seen bits and pieces here and there which say it is only a minimal drop–nor am I aware of the rainfall totals for this year, and then there would be additional data regarding economic activity and more with respect to consumption. I am also unaware of what progress may have been made to get the thermoelectric generating plants producing more power to ease the demand on Guri either. I’m just wondering about these things and if you could make a general comment, I would appreciate it.

I think your analysis here is focused on the wrong number. It doesn’t matter when the inflow gets off its minimum level. It could go up from the minimum level but still be below the outflow and hence the water level would still drop. The key number is when does the inflow start to exceed the outflow and hence the water level stops dropping.

So you need to know what the outflow is from the dam in cubic feet per second and then try to find out, based on historical records, when the flow of the Caroni is likely to exceed that.

OW The key number is when does the inflow start to exceed the outflow and hence the water level stops dropping. So you need to know what the outflow is from the dam in cubic feet per second and then try to find out, based on historical records, when the flow of the Caroni is likely to exceed that.
The December 2007 Boletin Informativo Mensual for OPSIS has the most readable “Aportes Diarios del Embalse de Guri,” for obtaining river flow into Guri. Following are annual averages for “caudal de turbinado,” flow through turbines out of Guri. December issues for 2008 and 2009 provide the data, which I averaged. For 2006 and 2007, I got data through December from the November 2007 issue for flow through turbine.
2009 4962
2008 4920
2007 4770 ( through November, from Nov 2007)
2006 4647 (through November, from Nov 2007)

Avg 4824 cubic meters per second
I am ignoring outflow that doesn’t go through the turbines.

This would be around the 15th -20th of May from the Dec 2007 graph . Average daily flow hits 5000 cubic meters /sec around May 20th.

1. How does the power rationing equate to less water used? I understand how it normally would with Guri taking turbines off line or throttling back to conserve the level above the dam. I understand from reports that the turbines are limited by mechanical issues, and knowing a little bit about how these people work, believe if they had another repaired, they would put it online without regard to the level.

2. Is it possible that under the guidance of chavismo, that they could be opening up gates without power generation to lower the level to hide the mechanical failures and to back up the whole “El Nino” excuse.

Before they officially started rationing electricity, it was clear that they could not provide enough uninterrupted power. There were constant outages and it has been over six months since there has been sufficient feed to the house. 220 volt runs about 190 with all appliances taking the brunt. The rationing was only a way to provide a more stable feed, not to conserve water in Guri. This is a mechanical issue and it is a failure of Chavismo to keep up with the maintenance and production demands after they took over the electrical sector. Just like the “new PDVSA” can not be at fault for their dismal production or constant failures, the electrical sector will not be found at fault either.

Does anyone else believe they are dumping the level to prove their excuse that this is an environmental disaster and not incompetence?

I have been hearing about the catastrophe from several sources: from a priest working in the area, a biologist, I was also there twice before Hugo and I could see the threat already (but it seems it is way way worse now). One of your readers here also put a video that shows part of the destruction (although not in the same region but more to the North, closer to El Dorado)

Miguel, good analysis. I have a much longer data set and it shows more or less the same thing. Before they shut down the basic industries, we were zooming down past the 2003 (historic minimum) curve and were on track to run out. When they made that move, we started tracking the 2003 curve almost exactly.

We’ve been rolling along at about 30 cm below the levels for the same date in 2003. So with normal rainfall we’re ok. There are still no good forecasts for rainfall in late spring because Feb-March-April form what in meteorology is known as the “spring prediction barrier” in which El Niño’s behavior is (with today’s knowledge) unpredictable. But given the showers around the country in recent days, and the increasing inflows into Guri, I think you’re right.

Another thing I did the other day was to look at the EDELCA document that got passed around — the Situacion Actual from Jan. 5 — that showed two curves, one in which Guri ran out and one in which we scrape through. While I don’t have original data, I printed the page and drew perpendicular lines to see where dam water level should be on March 1, and it seems like in the month of Feb we shifted from the bad curve to the good one.

In response to “concerned”: your ignorant paranoia is the sort of comment that makes ni-nis and Chavistas think “oppos” are a bunch of morons, thereby setting back your own cause. Please google “salto angel seco” if you don’t believe there is really a drought in Bolivar. You can also look on the OPSIS website for the amount of water released without going through the generating stations — none since early 2009. You can also go to the dam and watch the relief gates. I haven’t done that, so please report on your findings.

Kepler – diversifying from hydro not only should have been evident years ago. It was! The plans were all written in the 2001-03 El Niño. Chavez, Ramirez etc decided to put their money & energy elsewhere. Not good government.

I’m curious where you get data on forests. I’ve seen destruction myself — including a kid chopping down virgin forest about 10 meters from a pristine little stream in canaima national park so his boss could plant yuca — but I have no sense of how widespread it is or how much it’s affecting the area’s hydrology.

I got to the Gran Sabana area first in 1990. I went back in 1997, spent daysg into the jungle and off the beaten-track in the Upper caroni region.
I talked to Pemones and to miners. I kept asking them a lot of questions about how they mine there.
I haven’t been back there, but I saw a huge difference between 1990 and 97 and I could see things were going to get worse if no stringent measures were taking. Some relatives have gone back and my bro told me about the differences.

I know a catholic priest who works with the pemon indians and I know a pemon couple and they have told me about the issue.

As I said, there was a video another reader posted here some weeks ago. I wanted to save it to show it within a comprehensive post with all kinds of maps, but haven’t had the time. It should be worth assembling the data and marking the areas currently destroyed and the ones coming next.

Venezuelans are really screwing their environment on a massive scale and they don’t realise it. The level of pollution in the Morrocoy national park is HUGE, but nobody cares: the guys with their yachts in their marinas shitting the whole place, the thousands of lanchas that come with people, the growing villages…

One does not need to be a tree hugger to see how Venezuelans are destroying it all. It is a pity, we have some of the most beautiful environments on Earth.

One of the first things Humboldt wrote when he arrived to Venezuela with Bonpland was this:
“we are running from one place to the other (discovering new plants and animals)…we will become crazy if these wonders don’t stop appearing”.

Venezuelans are destroying those wonders and they still have the Dona Barbara mentality, thinking the place is huge and it can regenerate easily.

I have no dsl since las night, will answer and comment later. On the flow I am assuming quick recovery like historical one. In the first plot yoy can see that average is 3,000 m^3/sec by May 1st. You need 4,000 (thats outflow today). This year id not the worst ever, inflow is at 500-600 so we are tracking above green line so far. The
most important factor is what Moses say, they dam will be slowed down way before the critical level. If the flow drops like the green line above , i.e. This is like the worst year in drop and recovery, we are scrwed

The first would be to offer a comparison of the angles of decline of the minimum historical water flows at Guri in Image 2 with that of what I will describe as “year to date” in Image 3. This appears to indicate that the angle of the current level of decline is steeper, suggesting an accelerated rate of decline over previous historical levels of water flow. I do not have the figures to look at, but I have a copy of the EDELCA presentation with the image graphics including the one Victor Poleo uses (2nd image on page) at:

The level of decline on that image looks identical to yours, so I know that your figures are correct, but I am wondering about the distinct assumptions which distinguish your conclusions here, with the projection shown on that image. And I am not suggesting any flaw in your analysis, these matters always come down to assumptions.

My second comment is really a continuation of my previous paragraph about “distinct assumptions,” which is really an ecological critique. I honestly do not know what current consumption levels have become after the recently-mandated blackouts–I’ve seen bits and pieces here and there which say it is only a minimal drop–nor am I aware of the rainfall totals for this year, though your data would likely show its results, unless there are anomalies with respect to consumption. I am also unaware of what progress may have been made to get the thermoelectric generating plants producing more power to ease the demand on Guri either. I’m just wondering about these things and if you could make a general comment, I would appreciate it.

I never said there was not a drought in the region. I was merely asking was Chavez milking the drought to the last drop to cover his mismanagement. “Chavez, Ramirez etc decided to put their money & energy elsewhere. Not good government.” That’s an understatement.

Chavez shouldn’t get off the hook as easy as just blaming El Nino.

This is a man who has repeatadly tryed to pick a fight with Colombia to divert away from his problems at home.

For someone who would take this country to war to cover his own ass, would it be so far fetched to ask if he would drop the level above the dam to do the same?

I understand from reports that every turbine that will run at the dam is on line with the rest down for maintenance. Yes or no, this is a question? If that is correct, how is water being rationed in line with the power rationing? It does not sound like they are down to conserve water level.

And if I sound paranoid, I only became so after living here eleven years with each day a little more unbelievable than the day before.

Concerned – well put. I use understatement because it works. Sorry I read something into your statement that wasn’t there. It’s just I’ve heard too many people claim El Niño is a hoax and I had to vent a little.

Don’t worry, Chavez isn’t getting off the hook. His negligence is obvious to all.

And yes, it’s far-fetched. The Colombia stuff is theater. There isn’t a chance in hell of a war. The dam, as he and we know, is the real deal. They are putting all efforts into preventing a deeper crisis. They have been running 500 to 1000 cubic meters per second less water through the dam than normal so as to conserve water.

About which turbines are being maintained and which are running — that would probably be the case. Usually if there’s a turbine off line it’s for maintenance. There is no way to take more turbines off line without more rolling blackouts. There just aren’t enough other sources of power, and nobody seems to know how to design a good conservation program around here.

Worst drought in 100 years
Here is some historical data for annual average flow at Guri station. I
Figure 3. Historical flows of Caroní river at Guri Gauging Station, 1950-2003, from “The Influence of El Niño Phenomenon on the Climate of Venezuela,” flow in cubic meters/sec.

For 2009, from the Boletin Mensual of OPSIS for January 20010, the 2010 average flow was 4153 cubic meters/sec. While currently river flow is slightly above historical lows, the above data shows that it is way too early to call it the “worst drought in 100 years.”

From el-nino-how-strong-is-it . Link to “The Influence of El Niño Phenomenon on the Climate of Venezuela” by Prof Guevara in the comments.

Poor Miguel. Are you back to dial-up? That has to stink like the economy.

There is no reason why those funds should have been diverted by Hugo to something else besides building up power production and distribution.
Its also pretty strange that an oil producing country didn’t build an oil-fired power plant as a back-up somewhere along the line.

I guess thats another reason its called the Devils Excrement, you start thinking the money never ends and you never plan for that eventuality.

There are 2 technical considerations in the Guri system:
1) The current and future Water Level on Guri reservoir
2) The current operational conditions of the turbines.

If the Guri recovers water level, but turbines are not in good shape to operate, there is no much Venezuela can do providing power service.

If the Guri does not recovers water level and turbines are not repaired or adjusted to operate properly, hen, the same outcome, no power to be supplied.

One thing is the lack of water supplied to reservoir – which government can’t control- but the other is the lack of accumulated unsolved problems on due maintenance of turbines, transformers and high-power lines.

Venezuela can have all the primary energy resources, renewables, fuels, everything !!!, …. but if there is no a responsible and technically prepared government to convert those resources into modern and reliable energy services, forget about progress and revolution, the final outcome is involution and a very expensive price: lose of competitiveness.

Government is accountable for what is happening in the energy sector and what is happening is no good.

I have asked a few questions about the state of the turbines at the dam. In a simpler form…If the level above the dam were magically 10 mtrs. higher tomorrow morning, would there be turbines to put in service where there would be sufficient electriciy to prevent outages or undervotages?

Think of that water level as a big battery. That battery not only has to carry the load during the dry season, it also has to have extra reserve for bad years of low rainfall. Obviously they have not maintained a sufficient reserves.
Most Hydro plants rarely run at 100% . The reason for so many generators is to handle Peak loads and late at at night only a few might be running. There are Hydro plants that only run a few hours a day and sell peak power. The rest of the time they let water buildup behind the dam to recharge the battery for the next day. Even if they had the water they probably could not do much peaking.
What is stupid about all this is that there should be a South American power grid or two ( you can’t grid more than about 1500 Miles) that would stabilize energy sources. But, last week they all have a meeting and all they do is kiss Castro II and bitch about the US.

The risk is that weather pattern may be abnormal. Meteorologists (I’m not one) don’t have a lot of exact historical cases where an El Niño broke up at exactly this time of year. Will it bring an early rainy season or a late raining season to Venezuela? In Australia, they have just gone from severe drought to severe flooding.

My understanding is that the current El Niño is decaying, but that its influence may be felt until June or July — until all the heat it discharged over the atmosphere in the Pacific completely dissipates. The big risk is that the normal raining season comes three weeks late. Good luck!!

I seem to have had some trouble posting on this thread, possibly due to an electrical power shutdown that occurred–Good God! I’m in Louisiana, not Venezuela–that may have left cookies disabled in my browser. If this comes up multiple times, just delete the previous two tries.

This is an excellent post. Yesterday I published a “blog link” post on my own site specifically linking to this entry, as I have been posting on the electrical power crisis myself.

The first would be to offer a comparison of the angles of decline of the minimum historical water flows at Guri in Image 2 with that of what I will describe as “year to date” in Image 3. This appears to indicate that the current level of decline is steeper, suggesting an accelerated rate of decline over previous historical levels of water flow. I do not have the figures to look at–though I see that some are now posted above–but I have a copy of the EDELCA presentation with the image graphics including the one Victor Poleo uses (2nd image on page) at:

The level of decline on that image looks identical to yours, so I know that your figures are correct, but I am wondering about the distinct assumptions which distinguish your conclusions here, with the projection shown on that image. And I am not suggesting any flaw in your analysis, these matters always come down to assumptions.

The second comment I had yesterday is in part handled today by some of those who have posted some statistics, so I’m going to shorten what I originally wanted to say and just mention that the heart of what you appear to be using are a series of simple regressions, which have motivated some of those commenting on external factors not considered, which is essentially an “ecological regression” critique. But the big one I would want to know would be what progress, if any, has been made on increasing power output from thermoelectric sources, since I know that their declining production has been a major factor in overloading Guri.

The report from Caracas Gringo is the one that I was referencing. 7 out of 20 turbines at the time of the report are out of service for maintenance issues.

I will ask the same question again…If the water level were magically increased by 10 meters, would Venezuela’s electrical problems be cured?

The unexpected outages and undervoltages that have plagued us for the last seven months have not all been a result of El Nino. It is just an excuse to hide the problems. Yes, there is a drought…it happens every year…it is just a little more severe this year.

If I sound a little irritated, I have lost a TV, microwave, and computor monitor to undervoltage. I haven’t seen any attempt by the electric company to compensate me for their poor service, so for the time being I have bitching rights. This doesn’t even scratch the surface of the inconveniences from the scheduled blackouts nor the economic losses of the power rationing so many times pointed out in this and other posts.

[…] power plant thereSome clarifications on the post of when the Guri dam will reach the critical levelAn attempt to answer the question of whether the critical level of the Guri dam will be reachedA rant about how little happened in Venezuela this week, but what a week!Venezuela’s Final GDP […]