Re-Inventing Urban Watersheds
Currently half of the world’s population lives in cities and the United Nations estimates urban populations will rise to sixty percent within the next two decades. This increase in urbanization and subsequent increase in demand for water and sanitation has the potential to be a great challenge for urban water managers. Without innovative and efficient approaches to manage water, many cities may struggle to overcome this challenge. To help facilitate a paradigm shift in how we view and manage water, the U.S Forest Service recently proposed expanding the definition of an urban watershed to include built infrastructure in a recent study published in Urban Ecosystems titled The Urban Watershed Continuum; Evolving spatial and temporal dimensions. By making the connections between the built and natural environment, and treating them as one system, urban water managers will be able to more effectively meet urban water demands while at the same time protect water resources.
Michael T. Rains, director of the Northern Research Station, states, “Urban ecosystems are a critical part of the landscape and influence the environmental health of entire regions.” Co-author Ken Belt, a hydrologist/aquatic ecologist with the Forest Service’s Northern Research Station, and Sujay Kaushal, an assistant professor with the University of Maryland’s Department of Geology and Earth System Science Interdisciplinary Center, describe a large part of the urban watershed to be below ground, where thousands of miles of storm, sewer, and water pipes run. The depth in the pipe’s location, if they are leaking, and what they are leaking creates a complex underground ecosystem which has a great effect on the surface above. Simultaneously, the surface, underground, and watershed create one large ecosystem, all affecting one another.
This urban watershed ecosystem presented by the study demonstrates the need for integration in water management. The new definition classifies engineered headwaters as part of the ecosystem and links them to streams and receiving waters. The article states, “Given interest in transitioning from sanitary to sustainable cities, it is necessary to recognize the evolving relationship between infrastructure and ecosystem function along the urban watershed continuum.” This new definition moves decision makers closer to a “one water” management of stormwater, drinking water, and watersheds. The utility managers can integrate their operations for water efficiency and sustainable cities which protect the watershed.