Municipal water systems are organized around three major water uses: drinking water, wastewater, and storm water systems. All three systems share a common infrastructure based on watershed geography. Indeed, a watershed management approach has emerged as best practice across the country. Other key elements in municipal water systems include sources (groundwater vs. surface water), and treatment processes. Sustainable water policy at the local level addresses i) the need for cross-jurisdictional collaboration, ii) maximizing non-potable water for uses other than human consumption, iii) promoting decentralized rain harvest practices, iv) protecting water sources from pollution, and v) limiting impervious surfaces.