I think you meant “dikes.” Building “dykes” is accomplished by participation and grooming through girls sports.
So that’s why aol censors used to stop me from talking about Dick van Dyke! But anyway, if the oceans rise, you build dikes, which requires some people with strong backs to lay down pilings and sea walls at low tide. Heavy machinery and quick drying cement will get the job done fast. But the Dutch managed with considerably less back in the day.