Green infrastructure programs can be hard to implement because of a lack of data demonstrating green infrastructure's benefits, costs and performance; lack of design standards and best management practices; lack of financial incentives; and regulations that can be overly prescriptive and inflexible.

These conclusions are included in a September report by the Washington, D.C.-based Clean Water America Alliance highlighted at the second Urban Water Sustainability Leadership conference, held on Oct. 3-5 in Milwaukee.

One of the report's key recommendations is directed to the Environmental Protection Agency, said Ben Grumbles, Clean Water America Alliance president and a former EPA assistant secretary of water. The agency could use the post-construction stormwater rule, currently in development, as a “driver for green infrastructure,” Grumbles said. “There's a lot of very positive work EPA can do in its upcoming stormwater rule to provide … flexible national standards with innovative neighborhood solutions,” rather than an overly prescriptive, one-size-fits-all approach. EPA has said it will release a proposed rule in December.

Peter Yakimowich, senior consultant with the Chattanooga, Tenn., office of Malcom Pirnie/Arcadis, noted, “Although, there is a very important role for government at the federal, state and local levels and even for certain non-governmental organizations to provide leadership … this leadership movement really needs the participation of the private sector [for it] to really take off and become part of an national approach.”

Municipalities, think tanks and non-profits at the conference compared notes on successes and roadblocks in implementing green infrastructure programs.

James Parrott, executive director of the Metropoltian Sewer District of Greater Cincinnati, said his city is embarking on a $1-billion combined sewer overflow program. The project will combine elements of innovative green and traditional “gray” infrastructure, but his team will be working to ensure that all of it is sustainable.