Manage water in a green way

Reliance on “hard,” human-engineered structures—“gray” infrastructure—has been the conventional way to manage water needs for economic development. But building dams, piping water, and constructing protective barriers is capital intensive and may address only a few water problems ( 1 ). Gray infrastructure often damages or eliminates biophysical processes necessary to sustain people, ecosystems and habitats, and livelihoods. Consequently, there is renewed focus on “green” infrastructure, which can be more flexible and cost effective for providing benefits besides water provision. Supplementing or integrating gray infrastructure with biophysical systems is critical to meeting current and future water needs. Gray and green infrastructures combined are synergistic and can have superior results to one or the other.