Editor's Note:

The proposed Xiaonanhai Dam on Jinsha River, the westernmost of the major headwater streams of the Yangtze River, would be located in the experimental zone of the Upper Yangtze Native and Rare Fish Reserve, which is considered by many experts the last habitat for some of the endangered and local fish species. Some scientists have proposed other alternatives.

The following is an interview by Global Times (GT) reporter Wang Yuan with David Harrison (Harrison), senior advisor to The Nature Conservancy's Global Freshwater team.

GT: What are the values of the Upper Yangtze Native and Rare Fish Reserve?

Harrison: It's very hard to quantify. Nobody knows how to quantify ecosystems. We do know that it's very important to the long-term economy and well-being of any country and region.

There is lots of talk these days, internationally and in China, about ecosystem services. What is the value of a functioning ecosystem? You can't put a price on it. It's not something you can go to the marketplace for.

But left alone, the ecosystem would last forever. It provides fish and breeding stock for the many species of fish that are unique to the Yangtze.

We do know that a lot of people depend on the fishery now, not only in the reach above Chongqing but also in the river below. All of those fish have to have a reproduction habitat somewhere.

GT: How will the Xiaonanhai Dam damage the native fish reserve?

Harrison: I am worried that it may effectively ruin the whole fish reserve.

If the Xiaonanhai Dam is built, I estimate that the reservoir it impounds would be about 120 kilometers long, taking out about a third of the fish reserve, which is about 300 to 400 kilometers.

Will the part of the reserve remains ecologically viable? Is it above the ecological threshold of what's needed? We don't know the exact answer. It needs studies.

There is difference between reservoir water and flowing river to the fish, which have floating eggs and need a minimum distance of free flowing river to survive.

Our scientists concluded that those fish with floating eggs need a flowing river of at least 400 kilometers. To go below that would be very risky.

It's not a simple case of losing a third of the habitat and a third of the fish, but instead of losing all of the fish, since they depend on each other and on the wider ecosystems.

GT: When there are contradictions between a planning construction project and environmental protection, what steps do you think we should follow?

Harrison: In many countries, not just in the US or Europe, the first step is to see if there are alternatives that could accommodate both, giving them the energy and keeping the fish reserve.

Studying of all other alternatives is missing in this case. It seems that they decided at first that the Xiaonanhai Dam should be built, and then thought about justifying it, rather then asking the question "Should it be built," or "Are there better alternatives?"

If a dam is to be built, they should try to map the important ecological conservation lands and important hydropower development sites, then try to put things together, and figure out if there's a development plan in which we can get most of the hydropower and protect most of the ecosystems.

Just keeping every dam site, regardless of the ecosystem, is not sustainable development.

GT: Do you think it is necessary to build the Xiaonanhai Dam?

Harrison: The Xiaonanhai Dam is not important. The amount of energy that this dam would produce will not take care of the entirety of Chongqing Municipality's energy needs by a long, long way.

They have to bring electricity in from the outside in either event, whether they build this dam or not.

I don't know for sure why the Chongqing municipal government is insisting on this project. I speculate that they feel like they need to own their own piece of electric generating capacity, so that they know it's available and can control the price.

It's been also suggested that maybe the real reason for Xiaonanhai is to create jobs. Yet there are lots of ways of creating jobs. In my opinion, ruining the last fish reserve is not a particularly good way to create work. I would love to see them create jobs through development that is sustainable. And there are options for that.

GT: Since we do need some dams on the river to produce electricity, are there any scientific criteria by which we could make a better choice between building a dam and preserving fish reserve?

Harrison: Yes, there are scientific and objective ways to measure the value of the dam compared with other aspects.

We call it sustainability, which is quite interesting globally today, and China is participating in this in a very important way to come up with objective criteria to define the sustainability of hydropower.

It's not simply measuring the environment versus the dam. It's a bigger evaluation than that. It is that hydropower is recognized to be of great importance to humanity, and it's a relatively carbon-friendly technology.

But it's potentially very damaging to ecosystems, and upsetting social and cultural values that may exist in that area.

So the idea of sustainability is to look for a dam that does a good job in meeting all of these aspects. We talk about triple bottom-line – economic, environmental and social – and balancing out those values.

The China Three Gorges Project Corporation (CTGPC) is a very important member of the International Hydropower Association (IHA). The association set about defining criteria for the measurement of the sustainability of hydropower projects.

It crosses many different aspects of sustainability, like environmental, downstream flows, impact on fishery, and so on. It concerns environmental factors as well as social factors.

For example, people will have to be relocated. If so do they have a place to go to? Are they well compensated, and are they better off than before after being resettled?

Economically, is this the best use of investment for producing clean energy that fits well the demands of the region or of the country?

So you have all of these different criteria to measure the sustainability of a project.

I would love for Chongqing to re-assess the Xiaonanhai Dam with these criteria. If they do that, I am pretty sure at least they will consider our alternative, because it's not a really good dam.

GT: What are the alternative options to the Xiaonanhai Dam?

Harrison: I would like to propose the following alternative to the Chongqing government.

If they would actually enter a joint venture agreement with CTGPC, and build other dams on Jinsha River, like the Xiangjiaba Dam, the Xiluodu Dam, the Baihetan Dam, and the Wudongde Dam, with bigger turbines, they could participate in CTGPC dams with the same amount of money, and get much more capacity.

Actually, the Xiaonanhai Dam is a small dam on a very large river, but costs about $3.5 billion.

The dam has to be built strong enough to pass the whole flow of the Yangtze River at that point, so has to have as much spill way capacity as a much larger dam, because of the size of the river.

So they have to build a very expensive dam. It can't be very high because of the location, so they can get only a relevant small amount of electricity out of this very expensive dam.

If they could participate in the Xiangjiaba Dam and the Xiluodu Dam, it would be much more efficient. They could get two, perhaps three times, as much electricity for the same amount of money.

That's why we propose that they should study very carefully before they make a decision to go ahead with the Xiaonanhai Dam, and risk ruining the fish reserve.