NOVA

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Narrator

In Holland, the hard lesson of building hard structures to keep the floodwater out, is prompting a sea change and thinking, if you will. We are thinking it's like judo. We now reuse the forces of Mother Nature to help us create a safety instead of fighting it. It's like a balancing act. -

Narrator

Biologist Mindert De Vries is a specialist in an emerging field called eco engineering. We are a little bit behind in our understanding how these natural soft defenses are contributing to safety, and how this is interacting with climate change. Yes, we do not know too much about it, but that is what we are now catching up. -

Narrator

Mindert works for Deltares, a nonprofit research institute in the heart of the Silicon Valley of water management, the Dutch city of Delft. Using giant water flows, they're testing ideas on how to design flood control systems with nature in mind, protecting it, using it. Simple ideas like planting trees in front of a dike, instead of making it higher. Two types of the dike is meant to compensate the water level, and a third of the dike is meant to compensate the waves that are working against the dike. And what we will see now is that there is an effect of the trees and from our experiments we know quite precisely how much trees you need to get rid of a certain fraction of the waves. -

Narrator

Using the force of nature not fighting it. Judo, It all seems so obvious now, but for years engineers here overlooked it. Changing the strategy, the landscape here will not be easy. I think that is a very important lesson to learn that if you put in a earth safety structure, that you will have to deal with all the changes of ecosystem fixing behind the structure and that you will be less flexible in the future to adapt again to a different circumstances that you are not really sure of now.