[WJW]

We have seen exactly this scenario before, only this time the expected water levels are a few decimeter to a few meter higher (depending on the time scale). It's not like the delta works are the technological limit to what we can do. At the time, they were designed to meet the expected requirements and no further.

If the requirements change, we will rebuild them to the new requirements.

[tech-no-logical]

if the requirements say 7 meters (the sea level rise if greenland is ice free) building higher dikes will not work. and although that is a long-term scenario, it is not unlikely. hence the 'not if, but when' in the article.

[jacquesm]

Why won't dikes not work?

[WJW]

I wonder about this too. We have several dikes already that are much higher than seven metres. From everything I hear, we're not anywhere near the limits of feasible dike height, not in terms of engineerable strength nor in economic feasability (they're mostly just earth walls, after all).

[jacquesm]

That, and dikes need not be made of earth, they can have concrete as well.

The biggest risks with dikes are seepage and shifting, especially a problem with old river dikes before we properly understood how to make them.