30 Mar 2016

Save the Earth humanity for $0.44/gallon? No thanks!

In a comment to yesterday's post on climate change's much worse, much sooner impacts, JP asked:
Has anyone computed what sort of per gallon carbon tax would be required to both reduce GHG discharges and to pay for mitigation and adaptation costs for some reasonable scenario?
Well, many people have, as it's easy, i.e.,
At US$50/ton CO2e, that would work out to about $0.44/gallon (EIA source). The tax* covers mitigation, but the revenue could be used for adaptation, lowering income taxes, etc.
Bottom Line: The "cost" of mitigating (reducing) our impacts from GHG emissions is small relative to the damages but politicians (helped by lobbyists from the fossil fuel industry) have presented it as a "kill your kids" intervention. So sad.

* I call it a Pigouvian fee because it corrects for a problem, rather than causing one (i.e., deadweight losses).

29 Mar 2016

Life is about to get much worse

Climate change is hard for people to understand or take seriously because its FUTURE impacts will be so vast in scale and intensity. It would be easier for people to "believe in" face if its signs were more local and present (one reason I suggested rebranding it "local warming" years ago).

Sadly, it seems that we're about the arrive in that moment of vast intensity a lot quicker than previously forecast.

Last week, James Hansen (one of the first scientists to bring CC to public attention) and many co-authors published an article (link in this summary) explaining how previous estimates of glacial melting in Antartica and Greenland need to be updated to consider positive feedback effects that are hastening the process. These effects are due to the slowing of ocean circulation that will simulataneously mean warmer seas near the Antarctic ice shelves (helping those glaciers slide into the water more quickly) as well as colder seas near Northern Europe (as the "conveyor" of warm water from the Caribbean shuts down).

The upshot of their estimates (which combine data from a past era that had similar GHG concentrations to today's except that today's have accumulated far faster) is that temperatures and storms will be getting much worse in the next 10-20 years (if not now), while sea levels will rise by at least 2m (6 feet) and as much as 6-7m (20 feet) by 2100 -- far higher than current IPCC restimates of 1m.

Unleash the kraken
At least it's not an alien invasion
These results are far more pessimistic than anything the IPCC has put out for three reasons. First, the IPCC operates by consensus, meaning that the most conservative estimates are used. Second, IPCC data and models are in "uncharted territory," so it is not easy to decide if natural systems are going to retard or reinforce man-made trends. Finally, the law of averages means that hundreds of co-authors will tend to agree on a business as usual, linear path of change, rather than the new normal, exponential path that Hansen et al. predict.

What makes me so worried about Hansen et al.'s dire prediction is a separate paper that I was reading in advance of my upcoming class. Martin Weitzman has been heavily involved in CC economics for several decades, and his 2011 paper "Fat-Tailed Uncertainty in the Economics of Catastrophic Climate Change" [pdf] explains how we (economists) have underestimated risk on 4-5 dimensions, meaning that our models are inaccurate. As an example, Weitzman explains how an average 10 degree increase in temperatures -- a change that would mean "the earth was ice free, while palm trees and alligators lived near the North Pole" -- shows up in models as a 0.1 percent drop in long run GDP growth (from 2.0 to 1.9%). Weitzman points out that such models are incompatible with results where "half of today’s human population would be living in places where, at least once a year, there would be periods when death from heat stress would ensue after about six hours of exposure... i.e., temperatures that would represent an extreme threat to human civilization and global ecology as we now know it."

The upshot is that economic cost-benefit models may be radically understating the cost of climate change (in exactly the same way as they failed to predict the financial crisis), which means that most discussions are far too conservative about the need to act quickly to reduce GHG emissions.

What will the Dutch do?
These two papers put a fine point on the dangers that threaten human civilization, let alone "life as we know it". Although I am sure that some humans will be around in 2100,  I am also pretty sure (given the total lack of meaningful action to reduce GHG emissions) that they will live in a different world. The Dutch, for example, will be forced to abandon two-thirds of their country. Americans will lose half of most coastal cities. San Franciscans will live in the hills, yes, but will they survive the hurricanes and ice storms? People in the developing world will face violence, famine and misery.

Back in 2006, James Lovelock (Mr. Gaia) predicted that 80 percent of humans would die from climate change. More recently, he says that he may have been too pessimistic, except that it's also a good idea for humans to retreat to climate-controlled cities (reminds me of The Water Knife) -- a prediction that many would still find alarming.

Bottom Line: A few years ago, I wrote that my dad's lifetime (roughly 1930-2030) was probably the best century we will ever live. Now I wonder if we're more likely to regret than enjoy the next few decades.*

* I was thinking of adding some advice about pricing water or carbon, etc., but I've said this often enough, without seeing much change. There's nothing new to add. Sorry.

28 Mar 2016

Monday funnies

L: "This weekend the clock must be reset" ("a hassle") R: "Officially we should do that around 2am" ("It's fine!")

My recent post on how governments are hardly likely to "fix" climate problems when they cannot even stop screwing up the time.

25 Mar 2016

Eight years of aguanomics!

Done. Never again.
As is the tradition (praise be praise be), I am here with the annual report on the blog: where it's been and where it's going (last year's report).

Why I do this
I started blogging in 2007 because I wanted to write in an immediate manner for an engaged audience. Academic publications take far too long to write and publish, and they are hardly good for debates (see this recent disaster of where authors "decline to respond" to my critique of their flawed paper). Newspapers are slightly better but overly local in their focus. Blogging was (and still is) superior to those outlets as well as Facebook, Twitter and other social media that are limited in their access, terrible in their archiving, and anti-conversation in their formatting.

Over the years, I have written about 5,300 posts (there are 400 guest posts), mostly about water, and this process (writing, responding to comments, revising my opinions as I learned from readers, reading and thinking) has done so much for me. That's why I do it, and I hope that readers (just over 500,000, of which 60% came only once) have gotten something from my ideas and suggestions. Indeed, they seem to, if you think about the 10,000+ comments (probably 40 percent me responding to someone).

So, yes, I do it to please myself, but your participation has doubled or tripled that pleasure. Thanks!

Last June, I announced a change in tempo, where I would put out fewer posts per week in an attempt to save you time from reading too many posts (that's what you do, right?) and save me from a constant need to keep the posts appearing regulaly. Back in 2008-9, I was doing about 100 posts/month. Now, I am doing about 30 posts/month -- including the all-important Monday Funnies and Friday Party! This change in pattern has been helpful (especially in the crazed teaching period just completed), but it's dropped visitor activity (comparing the recent month to one year ago) by about 50 percent. On the positive side, people are spending about 10 percent more time on the site when they do visit. I'm not fussed about these numbers because I do not make advertising revenue. I merely hope that visitors find what they are looking for -- and perhaps something extra and useful.

Here's a short overview of the statistics [pdf], which shows that most readers are still coming from the US, and here (for the first time!) is a list of the all-time most popular posts (views in right column):

Jan 23, 2013, 55 comments

Jan 9, 2009, 3 comments
Nov 8, 2010, 13 comments

The guest post on "old guys, young girls" has amazing traffic (and comments) based on a huge disagreement on (mutual?) exploitation. The golf courses post was popular years ago while the posts on pricing tap water and happy birthday (the one where I announce that Living with Water Scarcity could be downloaded for free) are those that reflect an ongoing interest in water (go to this page for a summary of my publications, organized by water use).

Daylight savings? Man, I hate it.

The road river ahead
Although I am definitely busy with teaching and research, I will continue to blog here first, because there's no end of water stories and second, because water is such a huge and important issue for people today (e.g., drinking water) and in the future (climate change, the environment, etc.)

If you have ideas or questions suitable for blogging (or that are just bugging you), then please email me. (You can also follow me on twitter or via newsletter, where there's different material on a daily and monthly basis, respectively.)

Bottom Line Blogging is fun and informative enough to keep me going :)

24 Mar 2016

Get prices right if you want a strong society

JB asks:
How is the regulation of scarcity surcharges for a public resource such as potable water[1] similar to a policy that could internalize the true social cost (e.g. medical externalities) into a consumer "good" such as Pepsi?[2] Both hypothetical policies in this question aim to represent the best-approximated true cost of something to affect market forces for the sake of sustainability and public health respectively.

The way I see it, a true cost makes sense either way as it puts the burden of explicit-and-hidden costs on the immediate actors of the economic exchange (and not some person/place/creature elsewhere who has no choice or nothing to do with the exchange), altogether fostering responsible economic relationships. But how might I be wrong? Would reflecting the true cost of something like Pepsi in its per-can-cost, in this example, not have any affect on the broken health system and subsidies of addiction in America, as someone like me would hope?[3] Lastly, another way to ask this is: are there any commodities in which reflecting or regulating the true cost of it is not ethical and efficient?[4]
I'll start by agreeing that it's helpful and important that people face the true social cost (or benefit from the true social value) of their actions. After that, it gets a little tricky:
  1. Scarcity surcharges on water supplies to your tap (or higher market prices for a farmer) are meant to help users understand, via paying more money, the scarcity of the thing they are using. These water sources are "private goods" (excludable from others, and rival -- i.e., depleted -- in consumption) according to economists, BUT they are often underpriced due to government regulations that allow water prices to reflect the cost of service but NOT the value/cost of the water itself. (For farmers, prices are "too low" because farmers get as much water as they want, via permits or pumping, or buy it at subsidized prices from the government). For more, see my (free) book.
  2. The negative externalties of Pepsi consumption (higher public health costs, not an individual's suffering from obeisity, which is "internalized") is not in the same category, since they fall on the (cross-subsidized) health system (more on THAT here). It's not that we want people to drink less Pepsi. It's that we don't want them to get sick -- and cost us money -- as a result of drinking too much. 
  3. That said, a "sugar tax" that paid for public health programs -- especially for diabetics -- might be effective at countering the harm from the overuse of that product. Using sugar taxes to subsidize the consumption of candy bars would be a bad idea, of course, but that's what "we" (Americans but other countries too) do by spending gasoline taxes on roads. Those taxes should be used for protecting forests and subsidizing bicycles, not encouraging MORE driving.*
  4. Should we subsidize some commodities? Sure -- education and public health should be provided at less than "full cost" to users if we believe that educated, healthy people are not just happier themselves (on the private good side), but ALSO because those people provide value to others, e.g., participating in community management, helping neighbors, raising better children, etc. All of those "positive externalities" contribute to public and common pool (shared, i.e., non-excludable) goods that define Society (as opposed to the educated, healthy individual stuck in the woods, alone, somewhere).
Bottom Line The price you pay may not reflect the true cost or benefit of your action. You should know why there's a difference and why it should be eliminated or kept.

Pigou writes about charging motorists for their use (see section II.IX.17), but notes that the funds are put into NEW roads, thereby expanding the benefit of driving. That's counterproductive!

21 Mar 2016

Monday funnies

Funny reminder that you should not let the government "backdoor" your phone or other communications.*

* If you worry about WhatsApp leaking your info to the NSA (they're owned by Facebook), then check out Telegram, Sicher or Signal

Time to shut Westlands down.

Time to resign, Tom?
I heard (and tweeted) that Westlands Water District had paid $125,000 in a "settlement with the Securities and Exchange Commission over accounting procedures that the SEC said exaggerated the district's ability to cover its annual debt payments."

The story goes on to say:
Westland's general manager, Thomas W. Birmingham, joked during a 2010 board meeting that the adjustments amounted to “a little Enron accounting,” a reference to the massive fraud that caused the 2001 collapse of that Houston energy and commodities company, according to the SEC.

The penalty was the largest to be levied by the SEC against a municipal bond agency. Birmingham was assessed a separate $50,000 civil penalty, and the district's former treasurer, L. David Ciapponi, received a $20,000 fine.
Now these fines are the result of illegal (and unethical) behavior (OTPR has more to say), but I want to know what happens next, especially since Westlands is a government entity [pdf]:
As defined in the California Water Code (CWC) Section 10701 (a), “local agency” means any city, county, district, agency, or other political subdivision of the state for the local performance of governmental or proprietary functions within limited boundaries. On September 8, 1952, the Fresno County Board of Supervisors declared the District formed. Westlands formed under California Water District Law (Sections 34000-37856 of the CWC) in 1952 upon petition of landowners of 400,000 acres located within the District proposed boundaries.
What I see here is a clear case of "government workers" gone wild in breaking the law to finance a losing operation.

If Westlands was a private corporation, its directors would be fined, fired and perhaps jailed. If Westlands was a private company, it would go bankrupt.

So why is this not happening to Westlands? Is it that the government (in Fresno, Sacramento or DC) does not want to punish employees who lie about finances? Is it that the government would prefer to bail out, rather than shut down, a failed project*?

Bottom Line Westlands has done a "little Enron accounting" to cover up its fraudulent fianancing of a defective business model. Time to shut down Westlands and sell its assets in bankruptcy.

H/Ts to LC and EG

* A project that has ripped off citizens and taxpayers for years for the benefit of millionaire, subsidized farmers.

18 Mar 2016

Friday party!

This is fun

Here's some great footage from the REAL swing era, with some amazing dancing guys (better than Astaire and Kelly, but they were black).

16 Mar 2016

The first step to saving the planet

We are in the crazy "time savings" season right now, meaning that people are facing needless confusion, missed flights and numerous "whoops" emails as some countries switch their clocks this week, some next week and some not at all.

Daylight savings, like "fat is bad for you," was invented as a means of saving energy based on a very simple model of how people sleep, work and spend their evenings. There's abundant evidence that the "tradition" does not actually do that any more (if ever), but the policy stumbles along like a zombie, reliabily screwing up our schedules twice a year. (I'm not sure if it's better or worse that all my computers automatically change their time, but my microwave does not. I just stand there, confused.)

Anyway, the title of this post suggests that we humans need to make a few brave steps if we are going to act as a community in saving the planet. We know that it's necessary to reduce use of fossil fuels, stop deforestation, and so on, but those steps are "too complicated" for governments that are either too corrupt or incompetent to plan for their citizens' (near) future.

I therefore suggest that we start by ending daylight savings, to show all the countries in the world how we, as a species, can indeed join hands, sing Kumbaya, and end such a hopeless, barbaric, wasteful and destructive practice.

Bottom Line A long journey begins with the first step: End the Daylight Savings failure.

15 Mar 2016

WaterSmarts -- ignorance leads to community failure

Update (Sep 2016): Archived WSC website

For the last activity of the 2015 WaterSmarts calendar, I asked people to describe what they learned during the year.

Only one person replied (see below), and that makes me a bit sad. It's not that I put a lot of effort into the calendar (and got $2,000 in pledges to get it done). It's that it seems that people who may be  quick to "like" or "subscribe" but not so quick to spend 1-2 hours per month learning about their local water situation.

That "conclusion" makes my head hurt, as it implies that "water geeks" do not have the (unpaid) time or intrinsic motivation to participate in water-related discussions. Results like these encourage me to direct my energy elsewhere.

I really care about good water management and policy, but I am not interested in tackling these issues alone.

But maybe I'm wrong or missing something, so please correct me.

Here's one set of answers from someone in Ireland:

[In the past year,] what has surprised you?
  • I was surprised by the Shannon water abstraction scheme here in Ireland. I hadn't expected it to be such a significant project with so little publicity or public protest. I found it surprising because the Irish population is currently fairly sensitised to lots of other things that the government imposes on them, from property tax, to pylons carrying electricity transmission lines, to wind turbines, to water charges. So why is such a big engineering project sliding under the radar. Why are the conservationists and the Shannon river people letting it become a fait accompli? I was also initially surprised that it was necessary, but was interested to then go and look at the Dublin water catchment area, and then it didn't surprise me so much.
What do you still want to know?
  • I still want to know whether there's been a good cost benefit study on the Shannon abstraction scheme.
  • I still want to know how long the California drought is going to last (ours in Melbourne lasted ten years with half the average annual rainfall).
  • I still want to know why the reaction in Ireland to water meters is so virulent.
  • I still want to know how supposedly rational people can say, straight faced, that water is an essentials of life and should not be charged for
Where is more action needed?
  • Explaining the basis for the Shannon abstraction scheme.
  • Understanding Irish/Dublin water usage, and why it's twice Melbourne's per capita water usage, while Dublin uses essentially no water for watering gardens at all (many houses don't have an outside tap, most have only one) and it's one of the largest individual usages of many Melbourne households.

    Anything else?
    It's been fun and interesting thinking about water... albeit sporadically :(
DZ's Bottom line: There are many questions worth asking and mamny topics worth discussing when it comes to water management and water's flow through our lives, but none of those questions will be answered or topics discussed unless people devote their time to the issue. Ignorance is an option, but ignorance leads to polluted drinking water, water shortages, dead ecosystems, food shortages, and community failure.

Addendum (16 March): Thanks, those of you who have taken time to email me with support. I didn't realize that this post sounded so isolated, but maybe it's good to know that someone's listening (even if they're too busy to tell you :)

11 Mar 2016

Time to drop money on normal people

Here's my micro/macro perspective on "addressing" the Great Recession:

Interest rates in the US, EU and elsewhere are near (or below) zero because central banks seem to think they can stimulate growth via supply-side (cheap money) policies. I would argue that growth is stalled on the demand side (i.e., weak business climate, debt overhang, and underemployed workers).

Current stimulus policies are poorly directed and too timid.

They are poorly directed because cheap money to banks has only led to bankers buying stuff they like (financial instruments, luxury goods and politicians). What we need instead is to give money to normal citizens who will spend it on a diverse range of goods (including paying down their debts). Funding to citizens will also reduce inequality.

Current policies are too timid because monetary expansion (AFAIK) is sterilized by proportionate increases in government debt or central bank balance sheets. I suggest just printing money (say 1 percent of a broad measure of supply) without bothering to create offsetting liabilities. This is known as the "dropping money from helicopters" solution.

Yes, I am saying that we should ignore fears of monetary inflation and the money illusion. First, we surely need inflation, so extra money is no bad thing. Second, the money illusion will not just result in equal price inflation across the economy. Instead, there will be demand-driven inflation (prices rising from demand, not more money) in places where people see value. Such a result is socially efficient because it uses the price mechanism to allocate additional funds to reward relative value.

Who can lose from this idea? Debtors who will see their "relative wealth" diluted by the distribution. Germans, for example, will "lose" relative to Greeks if both add €1,000 to their accounts (Germans with a net worth of €50,000 each go up by 2 percent; Greeks with €5,000 each go up by 20 percent). This should not matter too much because Germans will also be getting money, Greeks are hardly paying Germans back now, and some Greek spending is sure to end up in German pockets (and perhaps vice versa).

Bankers and politicians will also lose, of course, as current policies are (1) inflating the value of financial assets bankers hold and (2) keeping politicians busy because those policies do not work.*

Bottom Line Many people are stressed by debt and lack of funds at the same time as governments are trying to make money so cheap that people will borrow and spend it. Skip the borrowing and give people money if you want them to spend, reduce problematic inequality,  and boost useful parts of the economy.

* Just saw "The Big Short," which is a good movie about the crazy instruments Wall Street invented to make money for themselves. (Here's my Aug 2007 -- pre-Lehman bankruptcy -- prediction that the subprime crisis was going to get worse.) Don't also forget that incompetent corrupt government (and some corrupt economists) had a lot to do with the crisis. I suggest listening to this interview with Luigi Zingales, one of the clearest thinkers on government failure (yes, he's Italian).

Friday party!

Diplo continues to put out great vibes...

(and here's the one with Justin Bieber, which deserves its 500+ million views)

8 Mar 2016

From cities for cars to cities for people

Cornelia (my girlfriend) is a very talented "urbanist," i.e., expert on what makes cities great.

She's just been featured in this Calgary-based article, and here's an excellent video on her insights on how Amsterdam was not always a city of cars...

Bottom Line: Cities are for people, not cars

7 Mar 2016

You can't change your mind without a dialogue

A few weeks ago, I posted a reply ("Four billion facing severe water scarcity? I think not") to Mekonnen and Hoekstra's article in Science.

My eLetter has not yet been published because the editors are waiting for a reply from the authors.

Although I understand their desire to "further the discussion," I consider Science's policy counterproductive, as it has implied, for the past few weeks, that nobody has any objections to the article. Even worse to me is that this process prevents "the community" from talking over the article. I have heard -- via emails, comments and face-to-face conversations -- many complaints about that article's flaws. Sadly, none of this response (ignoring whether it's correct) is on display for other people who may lack the background to understand the article's flaws. They may see it as "peer reviewed knowledge" when that's not a widely-held perspective.

Going further, I have to worry that the authors may be stalling or trying to ignore these objections. As I pointed out, they are both "involved" with an organization that charges for the footprinting services they recommend in the conclusion to their article. That's a pretty big conflict of interest for "authors [who] declare that they have no competing interests."

Turning to a more positive note, I can't exactly blame them, as it is awfully hard for academics to "betray" their research conclusions. As Russ Roberts says here:
Part of what I'm arguing for here is how hard it is to do that [change your mind on a topic]. For any human being. And certainly for a professional economist or an academic who has got a reputation and a track record of past pronouncements, I think it's very hard for us to do that... My claim is, is that we use that empirical sophistication as a way to dress up our lens -- to the outside world, to make us look a little less naked. Right? As you said, it's very hard to argue about this long history of personal experience and narrative --, so, say, 'Well that's not the real reason I believe these things. The real reason is I have evidence. I have science behind me.' ... we have these sort of vague ideas that come from our personal experience. They are not made up. They are not biases --it's just sort of convenient for us. They are just an accumulation of lots of stuff. Some of it evidence, some of it fact, some of it comforting because of the way we want the world to work. And then we dress it up with these studies.
I know that I've changed my mind on a few big things (the Peripheral Canal and increasing block rates, among others), so I can see why Mekonnen and Hoekstra might be hesitating.

Bottom Line The academic approach to understanding and knowledge won't work unless people are willing to talk... and admit that they may not be right.

Monday funnies

This is awful... and hysterical

4 Mar 2016

Friday party!

Disney did a number of these. Fun from 1935...

2 Mar 2016

Poverty Inc -- the review

I saw this documentary last year, at Amsterdam's IDFA documentary film festival. It's a brilliant film on the failure of paternalistic international aid (=most of it).

I began my aquaintance with aid, development and bureaucratic failure over 25 years ago, when I read Lords of Poverty as an undergraduate. The thesis there stil holds, i.e., that "development professionals" are more interested in their programs than in the putative beneficiaries of those programs. Since then, I have traveled to nearly 100 countries, read Confessions of an Economic Hitman (correct in its jist if not its facts), published on problems of aid failure ("Save the poor, shoot some bankers"), suggested that water managers "drink their own product," described how poor governance violates a human right to water, explained why people have more phones than toilets, worked on water projects in places like Ukraine, and so on...

This documentary is accurate in explaining the problems of paternalistic aid and how "empowerment" will allow disadvantaged people in poor countries to succeed -- mostly by getting out of their way, i.e., trade not aid.

Poverty Inc is available at iTunes and other places for viewing. Go watch it.**

Bottom Line: I give this film FIVE STARS, as you are hardly likely to find a better diagnosis and treatment to the problem of "aid" making people more, rather than less, poor.

* If you'd like to read a nice farce of these guys, then you could do worse than "The Development Set" [pdf]
** I'm not getting any money from these guys. Indeed, I asked our school to buy the $500 educational edition.

1 Mar 2016

WaterSmarts: Water in the environment

Sorry for the long delay in getting this analysis out, but the topic is certainly not stale.

I tell people that (1) we'd all die if we took no water from the environment but also that (2) all water abstractions have a detrimental impact on the environment.

With those thoughts in mind, I asked people using the WaterSmarts Calendar for their answers to these questions on the November 2015 activity:

Question: Where does the water come from near your house? (Find your “watershed” on a map. This webpage doesn't load very well -- hover over the colored squares to find continents -- but it works!)
  1. What is the largest river in your watershed?
  2. How much water does it carry over the course of the year?
  3. Where does the water come from and go to?
  4. How much is diverted on the way?
  5. Comments/notes?
Here are the answers:
  1. Rio Grande (USA)
  2. ~1 million acre feet (1,233 MCM)
  3. Mountain snowpack to the ocean
  4. All of it

  1. River Erne (Northern Ireland)
  2. 102 cubic metres per second (3,216 MCM)
  3. Catchment area rises in the area around Cavan town and runs north through Fermanagh, through Upper and Lowe Lough Erne and to the sea at Ballyshannon
  4. 115 ML/day (42 MCM year)
  5. We live in the wettest county in the UK, it is also one of the most sparsely populated and least industrialised counties in the UK. So water scarcity is not currently a problem. Agricultural runoff, external fertilisers and cattle manure from cattle sheds, is the major water quality problem. "Deployable Output is the measure of available water and it is the sustainable abstraction based on the most severe drought in recorded history. Recorded history is defined as the longest set of meteorological records in Northern Ireland which is from 1853 to present." See this and this pdf for more information.

  1. Rio Bogota (Colombia)
  2. Average 27 m3/s (851 MCM)
  3. It's born in a mountain (3,000 m) near Bogotá and flows into the bigest Colombian river at 150 km from Bogota
  4. It is used to feed another two small water utilites and in agriculture
  5. Although Rio Bogotá is the largest river it is not the principal waster source to Bogota water utiliy that needs 16 m/s. Of that 13 m/s comes from reservoir (dams) which are fed by small rivers.
Bottom Line No river is unique and most rivers are dramatically affected by human interventions.

Lasst chance! If you've learned anything about water in the past year (who hasn't?), then please fill in this form.