Urban Growth and Water Demand in Los Angeles: A Future Outlook
Urban densification in Los Angeles reduces outdoor water demand, highlighting urban form's role in sustainable water management amid population growth and land constraints.
U.S. Library of Congress (Carol M. Highsmith)
In regions like Los Angeles County, where water sustainability is a concern, a big challenge is managing water demand as the population grows. Our research finds that the way urban regions grow affects water use. If cities grow by becoming denser, with more buildings and less green space, outdoor water use for things like lawns decreases. This is important because outdoor water use is often a big part of total water demand. In Los Angeles County, where land is limited, future population growth means higher density, which could help control water demand. This work shows how a range of future green areas in the Los Angeles region could influence future water demand, providing valuable insights for urban planning decisions.
This research explores how the shape and layout of cities, known as urban morphology, affect water use in Los Angeles County, a region with limited space for expansion. City planners must balance tradeoffs between preserving green space versus reducing it to accommodate new buildings. We are the first to link detailed population growth scenarios with changes in city layout to predict future water needs. Our innovative approach uses high-resolution models and data to show how different ways of developing urban areas can change water demand. This helps other scientists understand how city planning affects water resources. Our findings could impact fields like urban planning, environmental science, and water management, offering insights into managing water in growing cities.
In our study, we explore the intricate relationship between urban morphology and water demand for over 80 water providers in the Los Angeles region, a land-constrained area facing significant water resource challenges. By employing a high-resolution urban growth model, we project future water demand scenarios in the year 2100, considering two population growth pathways (SSP3 and SSP5) and varying urban development intensities. Our findings reveal that urban densification, driven by population growth, can significantly reduce outdoor water demand by decreasing green space available for irrigation. This effect is particularly pronounced in less densely developed areas, where intensification leads to a substantial reduction in outdoor water use, despite population increases.
Our research highlights the critical role of urban form in shaping water demand, demonstrating that land-constrained regions like Los Angeles could mitigate water demand growth through strategic urban planning. The study also underscores the importance of considering diverse factors such as climate change and water use efficiency in future water demand projections. By linking population projections, urban morphology, and water demand, our approach provides valuable insights for urban planners and policymakers aiming to balance population growth with sustainable water resource management.