The Day We Set the Colorado River Free | Hacker News Reader

The Day We Set the Colorado River Free

outsideonline.com

191 points_wp3r30 comments

Really great article. I love the weekend reading on HN.

This part of the article really caught my eye:

>>> Current “use it or lose it” water laws don’t allow farmers to sell any surplus allotment, so they end up growing as much alfalfa as they can and selling it on the global market. Peter Culp estimates that 50 billion gallons of water—1.5 pulse flows—is shipped to China each year in the form of alfalfa, and even more to Japan. An open water market would allow both cities and environmental groups to pay farmers far more than they currently make growing alfalfa. <<<

Terrible! The US West has been fighting water scarcity problems for 10+ years and we're exporting billions of gallons of water overseas?

There is also a new documentary out called DamNation which looks quite interesting. http://damnationfilm.com/

One of the (supposed) reasons why farmers in the United States get so many privileges, subsidies and water rates at 5% of market rates in some cases, is to promote food security.

The theory is, that by ensuring we have a broad set of food stocks that we can potentially draw on should circumstances dictate, then we are capable of maintaining the basic elements of survival. (Energy Security is another one on the list - it's why we have aircraft carriers in the middle east).

Those farmers might be shipping Alfalfa to China right now, in the face of that thing called "Free Markets", but faced with a food stock collapse in the United States, it would take little more than a few strokes of the pen to require that same alfalfa go to American cattle.

Cattle for food security makes sense only on marginal land, where rain is so scarce that you can't plant crops, and the only thing you can do is extensive cattle ranching. Look at the American West, Australia and so on.

Also, look at Upstate New York and Northern Pennsylvania if you are interested in food security. This used to be the grain basket of the country, but the farmland is all abandoned and reverted to forest, the hilly country is too difficult to farm with large machinery. But it's rain-safe, unlike further out west. I think in the face of climate change, farmland in that area is a most excellent long-term investment.

My fathers specialty was alfalfa, and he made a good thing out of not growing any. The government paid him well for every bushel of alfalfa he did not grow. The more alfalfa he did not grow, the more money the government gave him, and he spent every penny he didn't earn on new land to increase the amount of alfalfa he did not produce.

Couldn't resist. Not often alfalfa comes up in conversation.

You should mention that this is a quote from Catch-22.

I submitted this a few weeks ago and it quickly died, but you might find it also interesting: http://www.azcentral.com/news/wildfires/yarnell/arizona-wild...

A common misconception is that hydroelectricity has the advantage over other renewables of requiring less land. This is not the case. The surface area of Lake Mead is 640 square kilometers -- this much ecologically viable land was destroyed to make way for hydroelectricity. The power generation capacity afforded by the Hoover Dam on this lake is roughly 2 GW.

A solar panel produces roughly (we're lowballing) 100 watts per square meter. Solar panels to produce 2 GW -- the power output of Lake Mead -- would cover about 20 million square meters, or 20 square kilometers. If we assume the solar panels only operate at capacity for a third of a day, that's 60 square kilometers. If we also assume that only half of the used land is actually light-capturing, that's 120 square kilometers.

Even under the most pessimistic of assumptions, solar still uses five times less land than hydro. Realistic solar installations would probably be significantly more efficient than I've assumed. Batteries are also significantly more space-efficient than hydroelectric storage.

Interesting. I suppose it makes sense, in a way: solar power captures solar energy directly, whereas hydro captures solar energy only indirectly, through the water cycle.

Do you have any ballpark ideas about how the cost of producing the dam (most concrete, I guess) compares to the cost of producing 120 km^2 of solar panels + 'enough' battery capacity, in terms of some kind of ecological footprint?

My intuition is that the ecological capital costs of solar panels greatly exceed the capital costs of the dam, but I have little faith in my intuition....

Ballpark cost of developing small high head hydro plants with a weir (no dam) is 3-5 million dollars per MW.

But these usually flood a minimal area like 10000 square meters.

Public companies that develop hydro power projects annual reports is a good place to look for this type of information.

Yes, but Lake Mead serves an additional valuable function as a water storage facility.

I'm guessing that is it's primary value. The power generation is secondary.

It's also a misconception to equate huge-reservoir hydro with all hydro. The Norwegians have incredibly high head, phenomenally efficient hydro in the mountains with minimal environmental impact. We have run of river hydroelectric in the states that diverts some water via penstock, as well as canal-based systems and those that utilize Army Corp dams. In fact, there is significant non-powered dam resource available: http://nhaap.ornl.gov/content/non-powered-dam-potential

I'm actually working on national-level hydro assessments at a national lab. We don't really predict more huge reservoir installments, but there is plenty of capacity out there. These set-ups (particularly non-powered dams) are also generally pretty cheap per kWh generated over their lifetimes (which in some cases reaches 70+ years).

> We have run of river hydroelectric in the states that diverts some water via penstock

Do you have wildlife issues to consider in the design? E.g., are the dams on rivers fish migrate up?

Well, run-of-river installations actually don't have dams, and you can prevent most fish with just some mesh, so you're avoiding that impact entirely.

Ah cool, that's good to hear (so long as flows are sustainable, unlike some of our proposals for 'harnessing all that wasted water')

Why only 70 years? Does the dam actually crumble to pieces, or is 70 years how long it takes for maintenance costs to equal construction costs?

Some last longer, some die quicker, it depends on the conditions and upkeep for a particular installation. I threw out 70 years off the top of my head to demonstrate that they tend to last a relatively long time. It also depends on what you consider to be "replacement" vs. "repair". Sometimes all you have left is a concrete shell with rusted out turbine husks, in other cases you just need to replace a few parts. Hydroelectric generation (and water-power in general) has been around for a pretty long time, and there are a lot of different local implementations out there when you get into the details.

The badger hydroelectric plant in Wisconsin is 86 years old, and that's just one I happened to know because I collected data on it recently. If you go further east in the states and then across the Atlantic, the plants can get older than that as well. http://www.kaukaunautilities.com/about_us/default.asp?Catego...

EDIT: Oh, and in terms of cost, when planning out capital expenses most hydro projects are assuming a shorter lifespan than actual. I don't have numbers in front of me, but I feel like costs are generally accounted for a 20-40 year lifespan (weighted towards 20), although they do expect the plants to operate for 2-3x as long.

You can turn hydro on and off quickly and it works during the night

Also, traditionally you install solar panels on steel pillars set in concrete in the ground, but theres no electrical reason you can't mount them on top of the hydro lake, on floats.

There are engineering concerns with waves and the usual problems anytime you mix water electricity and metal.

There are biological concerns where polluted water is already anoxic enough so blocking light is not going to help.

Still there's no inherent reason the land can only be applied to one tech.

Maybe if you have an infinite supply of cheap incredibly tall concrete pylons you could mount windmills too, although that's sounding unlikely.

So it makes me wonder, could we place floating solar panels on lake Meade?

> A common misconception is that hydroelectricity has the advantage over other renewables of requiring less land.

Is this really a common misconception? Has no one ever seen a dam? I can't think of any other form of energy production whose sole requirement is massive amounts of land to flood.

Brazil's debate on hydroelectric dams (and we have a lot of them) are solely bound on the flood areas and environment/habitat destruction they cause.

I really doubt that's a common misconception.

Hydro was not the purpose of making Hoover Dam, so the rest of your argument fails.

Being just a tourist to Hoover Dam it was explained to me that the main purpose of the dam was to regulate the water and have it available for people and farmers. Power generation was only ever a secondary consideration.

This is amazing! It's unfortunate that we can't have the dams constantly open or at least a few to keep some water flow. I would love to fund something that would allow us to do this yearly or even more frequently

If you're a US citizen, you already do fund such an entity with your taxes.

If it's important to you, let your legislators know, and vote accordingly.

You "already fund" something, but need to vote for it to be funded?

You can always stop funding something.

No, you need to vote for it to take the decisions you'd like taken.

Yes, approximately once a year.

>>> hamburgers are a particularly stupid thing to make out of the Colorado. Each hamburger takes about 500 gallons of water.

I will be eating fewer hamburgers after reading this.

Yea ~1500 gallons of water for every pound of beef

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