Dutch and American environmental, planning and engineering experts, and business and government decision and policy makers explore how major 21st century water challenges facing today's coastal cities can be tackled for a sustainable future. The conference will focus on sustainable adaptation to climate change, keeping safe and dry, ensuring water quality, and building in harmony with nature for megacities in the decades to come. The focus will be on The Netherlands and the New York/New Jersey metropolitan region, but conclusions will benefit coastal cities worldwide.