Roughly 10 percent of the world’s population lives below 10 meters mean sea level, which will experience the threats of sea level rise to varying degrees of uncertainty. Dikes, traditionally used to combat sea levels, may not be effective. Coastal erosion is another issue that we will face and beach nourishment, or replacing sand, is neither ecologically sound nor cost effective. Tidal marshes can be used to breach floods and deal with tidal regimes, and examples are given from Holland and Belgium. Ecosystem biodiversity is restored through these measures to supply dunes and engineer against coastal flooding. Problems related to ecosystem-based management include the large sensitivity of some of the measures to the knowledge of the natural system and social acceptance.