Bob Zimmerman, Executive Director of the Charles River Watershed Association; Weston, Massachusetts. Founded in 1965, CRWA is a private nonprofit environmental research and advocacy organization using science and the law to protect and enhance the Charles River and its watershed. Zimmerman joined CRWA in 1990. During his tenure, CRWA has become a leading authority on the science of water in urban watersheds, and he has developed programs that address storm-water pollution, water quality, low instream flow, nutrient loading, habitat protection and restoration, community zoning, suburban sprawl, sustainable development and water demand, the economics of water infrastructure transformation, and climate change mitigation and adaptation.