How can markets help get water to your sink? Photo by Steve Johnson, used under Creative Commons licensing.Reposted from Sustainable Waters with permission City water planners are finding it increasingly difficult to secure additional water supplies in many water-short regions. Although overall water use in the United States has been relatively stable since the 1980s, urban water demands—driven by population growth and expanding economic production—continue to rise in many cities, outstripping gains in water use efficiency and other demand-management strategies. The ability to acquire new water supplies by purchasing permanent water rights or leasing water on a temporary basis is providing new options for city water planners in some parts of the world, including the western United States. By purchasing or leasing water rights, many cities have been able to avoid or postpone investments in more expensive or complicated water supply options such as long-distance water importation, water reuse, or desalination. The ability to buy or sell water rights does not exist everywhere, but as water becomes increasingly scarce around the globe, many governments are moving toward water-rights systems that may provide opportunities for water trading in the future—i.e., the establishment of a water market. This article presents a brief overview of the regulatory systems and policies that generally help to facilitate water trading and highlights some of the potential benefits and pitfalls of water markets.