The Adaptation Primers are a four-part manual that provides basic information on adaptation, one of the most complex challenges facing decision-makers in this first half of the 21st century. Primer Four examines preventative and protective measures to rising water, whether it is fresh water (overland flooding) or the result of rising sea levels and/or storm surges. Perhaps the most important component of the Primers is the reference material provided for each Chapter. The resources cited are intended to deepen understanding, share experience and, ultimately, to provide inspiration for innovative approaches to policy, planning, and design. It is hoped that the Primers can aid decision-makers as they advocate the need for change and the positive potential of change.