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In defence of dams

Building river barrages remains environmentally controversial, but Australian expert Graeme Kelleher tells Isabel Hilton what matters is how you do it.

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Engineer and water-resource expert Graeme Kelleher is the former chairman and chief executive of the Great Barrier Reef Marine Park Authority and a former vice-chairman of the International Union for Conservation of Nature (IUCN) World Commission on Protected Areas. Here he talks to Isabel Hilton about management of Australia’s Murray-Darling river and the social importance of sound dam construction.

Isabel Hilton: Tell me why you support dam building?


Graeme Kelleher: The reason is that, without dams, the human population that can be supported by almost any river system is very low. Without dams along the Murray-Darling [in south-eastern Australia] for instance, no more than around 200,000 people could be supported. At present, with the dams, it supports the two million people who live there and provides food for 40 million people through export. Without the dams, because of Australia’s climate, you might have no river flow for two years and it wouldn’t even support 200,000. The people would have to migrate to the coast, as the aboriginals did.

IH: So the dams distribute the availability of water over time.

GK: Yes. Without the dams, you would get a flood and lose all the water to the sea. Then it’s hardly used by humans at all. That does create wetlands, but if you operate rivers correctly, you can still maintain wetlands. This is being done along the Murray-Darling River right now.

IH: Nevertheless, many environmentalists are opposed to dam-building and there are sound environmental criticisms of dams. How can we sort out the positive from the negative effects?

GK: The only way to do it is for environmental-impact assessments to be carried out according to the original criteria of the United States’ National Environmental Policy Act of 1969. Under that act, the definition of “environment” was: “all aspects of the surroundings of man, whether affecting him as an individual or in his social groupings”. A proper environmental-impact statement will look at the whole ecology, as well as the whole social arena, in addition, of course, to the financial cost-benefits.

Unfortunately, most cost-benefit analyses have measured only financial transactions, or things that are assessed in monetary value. For that reason, many decades ago, the United States introduced multi-objective planning, which required several objectives to be combined into one plan. These might be, for instance, a reliable water supply to maintain the ecology and to maintain or improve the social environment. When I worked with the US Environmental Protection Agency in 1972, we used multiple-objective planning. It’s the only way to do it. Unfortunately, most agencies are given single objective tasks, so you need to get cooperation between the various organisations and most organisations don’t do that voluntarily.

To take the Murray-Darling River Basin for example, for 50 years there has been a Murray-Darling Commission, run by six [state] governments. Even with that commission, with all its persuasive powers, we did not get enough cooperation. So the Australian federal government has now established the Murray-Darling Basin Authority with executive powers. It makes a difference when you have to deal with a recalcitrant state.

There’s another great model in the Great Barrier Reef Marine Park Authority, established by federal law. The provisions of that law override conflicting provisions of other federal or state laws. I was chairman and chief executive of that for 16 years and we never had to override federal or state laws because everybody knew that, if they didn’t cooperate, we had the powers to compel them.

IH: So just the power to do it kept everyone in line?


GK: Yes. It’s the iron fist in the velvet glove. It works marvellously.

IH: Looking at the extensive dam-building programmes worldwide – in Africa, China, or the Himalayas – how many projects would you say respond to your criteria of multi-objective views with responsible environmental-impact assessments?

GK: I know that the Asian Development Bank and the World Bank operate on those principles. But now, because of external pressure, the World Bank has abandoned  funding dams, which I don’t agree with. Even democratic countries, left to their own devices, build dams.

IH: And where dams are being built without ADB or World Bank Funding, what sort of standards are being applied?

GK: It’s absolutely variable and you can’t generalise. For instance, the Three Gorges Dam is vilified, rightly, because the conditions under which they moved the people who had to leave the storage areas were not acceptable on any basis of justice. But later dams that are being built by the Chinese do meet the criteria. The Three Gorges Dam is vilified and people look for reasons why it should be destroyed, including the allegation that it caused the 2008 Sichuan earthquake – as indeed it may have. But remember, the Three Gorges Dam saves the burning of 26 million tonnes of coal every year and saves thousands of Chinese people from being drowned in the floods of the Yangtze River every year. The people who criticise the dam ignore these facts.

IH: On the Mississippi River in the United States, dams built in the 1940s cut the siltation, with the negative effects that we see in the delta. Do you think that will happen on the Yangtze?

GK: Yes

IH: So should the city of Shanghai be worried?

GK: It happens with every dam, but whether the effects are positive or negative varies with the situation. For instance, the Murray-Darling carries little silt, but it’s so dry that it doesn’t outflow. In order to get enough outflow for the Coorong Lakes [a network of lagoons in south Australia] to survive – they are partially saline and have been for tens of thousands of years – we have to dredge. If we didn’t have the dams and couldn’t dredge, the Coorong would have died in the last 10 years. It’s important to look at the positive.

I am not saying that all dams are good or justified. I am saying you have to look at all of the costs and all of the benefits in order to make the decision. Anybody who has ever built a dam knows they accumulate silt. The dams are designed with that in mind, so to be surprised that this is happening is completely absurd. Now they are developing technologies to remove the silt as cheaply as possible and they are doing it in many parts of the world, including Australia. I am sure we will come up with methods of doing it that are not horrendously costly. Canberra couldn’t exist without dams. It now has a population of 350,000. Before the dams were there, it had a summer population of no more than 1,000 aboriginals.

I think the construction of water-retaining structures is one of the major reasons why countries have become socially and environmentally viable along every major river.

We are going from one extreme to the other: the old extreme was where you build dams all the time without regard to the social or ecological costs. You need to take into account all the social and ecological costs and benefits and decide whether to build the dam.

To give one example of how you can change a dam regime: generally speaking, along the Murray-Darling, the water was released from the lower levels of the dams, so it was cold water. They introduced species such as carp, which is not a native species and which damages the river basins significantly, and they bred very rapidly because they like cold water. The local species that required warm water at the breeding season were dying out. So now, the operational regime has been changed and the water is released at the top of the reservoir. It’s warm and it’s released in the breeding season to protect local species.

IH: So it’s about intelligent management?


GK: It’s about intelligent design, decision making and management.


Isabel Hilton is editor of chinadialogue.

Homepage image by Vanessa Pike-Russell

Patricia Adams of Probe International responds to Graeme Kelleher here

Also in this series:
John Briscoe praises Chinese finance abroad

Peter Bosshard urges smart infrastructure
BG Verghese speaks on third pole rivers
Joydeep Gupta looks at tension in south Asia

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评论通过管理员审核后翻译成中文或英文。 最大字符 1200。

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评论 comments

Default avatar
匿名 | Anonymous

拦河建坝:错误的选择

建在南澳大利亚墨累河的大坝引起了巨大的环境灾害。这些建于19世纪40年代的大坝阻挡了海水,并且使入海口变成了一个服务于农业的淡水湖。当洪水来临的时候,比如说现在,大坝会造成酸性硫酸盐土壤暴露在氧气中,引来大面积的破坏和灾害。更多信息,请登录www.Lakesneedwater.org.

Barrages a mistake

The barrages at the end of the River Murray in South Australia are the cause of a huge environmental disaster. Built in the 1940's, these barrages keep the seawater out and have turned an estuary into a freshwater lake for agriculture. In times of drought, like today, this is causing widespread destruction by exposing acid sulphate soils to oxygen. For more information www.Lakesneedwater.org .

Default avatar
匿名 | Anonymous

理论是对的,可是无法实现

从人类自身长久的利益出发,人类不可能不利用自然。格莱姆 · 凯莱赫的理论知识和观点是正确的,但是大坝建设中,对环境的评估,对管理的需求,对未知因素的估计等等问题,在建设之初无法得到系统的考虑。建成之后的管理者是否会考虑环境就是另外一回事。这是文中没有详细表明的观点。

Theoretically correct, operationally impossible

It is impossible for human not to exploit the nature from the long term interest of human kind.Graeme Kelleher's theory and viewpoint are correct however it is impossible to give a systematic consideration,in the initial phase of the dam construction, on the environmental evaluation, management evaluation and unknown factors because the dam is under construction. It is another issue if the managerial staff would consider the environmental issue. Those are the points need more elaboration in the article.

Translated bu Bo Ge

Default avatar
匿名 | Anonymous

十八万人?

把英文remember, the Three Gorges Dam saves the burning of 26 million tonnes of coal every year and saves on average 180,000 Chinese people from being drowned in the floods of the Yangtze River every year. The people who criticise the dam ignore these facts.

翻译为“三峡工程每年节约两千六百万吨煤、也保护十八万中国居民免于长江水涝之灾"。不太准确,容易让人感觉长江是年年泛滥,每年都要死18万人,非休大坝不可。

ecoliugy

180,000 people?

To Translate "remember, the Three Gorges Dam saves the burning of 26 million tonnes of coal every year and saves on average 180,000 Chinese people from being drowned in the floods of the Yangtze River every year. The people who criticise the dam ignore these facts." as "三峡工程每年节约两千六百万吨煤、也保护十八万中国居民免于长江水涝之灾"。is not accurate. It might mislead people to think the Yangtse river floods every year and 180,000 people die every year therefore the dam must be repaired.
ecoliugy

(Translated by Bo Ge)

Default avatar
匿名 | Anonymous

减低环境受害的方法

我赞成在策划水坝的阶段、在水坝建设还未有承诺之前,水坝对环境的影响是应当被评估的。根据美国、澳大利亚和其他很多国家的法律需要,这是当然的。

事实上,很久以前在发展与发展中国家,在没有妥当地评估了环境所受的影响,便已经建了很多水坝。很多这样的水坝现时还在运作,而减低环境继续受害是要有行动的。其中可做的便是在水坝旁边建筑构架,让通常往上游产卵的鱼类有此能力去做。这是已经做过、而继续在北美的很多河流这样做的,例如鲑鱼便因此受益。(smc翻译)

Ways to minimise environmental harm

I agree that the environmental effects of a dam should be assessed during the design phase and before any commitment is made to build a dam. Of course, this is required under the laws of USA, Australia and many, many other countries.

It is also true that in the old days, many dams were built in developed and developing countries without a proper assessment of environmental impact. Many such dams still operate and action needs to be taken to minimise continuing environmental damage. One such action is to build structures next to old dams which allow fish which traditionally move upstream to give birth the ability to do so. This has been done and is continuing to be done in many rivers in North America, for example, to benefit salmon.

Graeme Kelleher