Planning for water efficient cities: Landscape, microclimate, and heterogeneity in residential water demand
- Author(s): Lassiter, Allison
- Advisor(s): Radke, John
- et al.
California is confronting its largest drought in recorded history, which may signal the onset of a megadrought. An executive order mandates reduction in residential water consumption. At the same time, the state's population continues to grow. Reducing residential outdoor water use is a critical management objective to adapt to scarce water resources. This dissertation asks, to what degree can land planning contribute to outdoor water demand management? Can principles of compact development and strategic growth mitigate use? First, the dissertation reviews the literature of water demand models that incorporate landscape variables, thematically characterizing the variables and examining model spatiotemporal resolution. Next, the dissertation examines methods of quantitatively characterizing the urban environment using land cover, weather, and landform variables. It develops variables by parcel, and then defines microclimate zones of similar parcels by clustering on each parcel's microclimate signature. In the fourth chapter, it examines the contributions of landscape and microclimate to household water consumption in the East Bay Municipal Utility District of California. It evaluates 26 million observations of monthly water use data from 2005-2011 recorded at over 300,000 single family residences. It analyzes the data as a whole, and then subsets the full population by quantile of water user and by microclimate zone. Results reveal heterogeneous water demand profiles, but all models indicate that landscape type and the presence of a pool are important predictors of consumption. Less important are lot size and microclimate variables. With both high and low water users spatially distributed throughout the study area and across microclimate zones, there is evidence that many different development styles in many different locations can be water efficient.