Reclamations as well as floating structures are used to create new coastal areas for development of housing, industries, or recreation. Subsea tunnels or bridges are normally applied as offshore traffic connections to provide smooth access to these new areas. The mitigation of environmental impacts and reduction in the use of natural resources are important issues for consideration of these waterfront developments. This paper provided two types of sustainable solutions on the reduction of environmental impact of large waterfront developments by design: first is the reuse dredged material from the Immersed tunnel trenches for land reclamation and nature development; and second is a polder solution as alternative to the traditional land reclamation design. Three hallmark projects are presented to demonstrate the solutions that are successfully applied.