Water Balances along an Urban-to-Rural Gradient of Metropolitan Baltimore, 2001-2009

• DOI: 10.2113/gseegeosci.18.1.37
• Publication Date: 2012-02-29T16:08:12Z
• Authors: A. S. BHASKAR; C. WELTY
• Keywords: 13. Climate action; 11. Sustainability; 0207 environmental engineering; 02 engineering and technology; 6. Clean water

Urban water balances are generally unknown, yet they are necessary for assessing water availability in an urbanizing world and for understanding the effects of urbanization on the hydrologic cycle. We assess the spatial and temporal variability of water balances of 65 watersheds in the Baltimore, MD, metropolitan area during Water Years 2001–2009. Each water balance term is quantified independently and includes both natural (precipitation, evapotranspiration, streamflow) and piped (sewer infiltration and inflow [II for some urban watersheds this excess is greater than gauged annual streamflow. I&I also outweighs piped inputs from lawn irrigation and water supply pipe leakage in the Baltimore area analysis. The net effect of piped flows on the urban water balance is a watershed export ranging between 300 and 465 mm/yr, underscoring the importance of interactions between engineered water and wastewater infrastructure and natural water balance components.