When Small Is Not Beautiful: The Unexpected Impacts of Trees and Parcel Size on Metered Water-Use in a Semi-Arid City

Shaundra Rasmussen,Jarlath O’Neil-Dunne,Melissa Mchale,Abbye Neel,Travis Warziniack

doi:10.3390/rs13050998

Abstract

Colorado’s water supply is under threat due to climate change pressures and population growth, however Colorado has been recognized to have some of the most progressive water conservation programs in the country. Limiting outdoor water consumption is an increasingly popular approach to conserving water in semi-arid cities, yet in order to implement effective water reduction and conservation policies, more utilities and city managers need a firm understanding of the local drivers of outdoor water consumption. This research explores the drivers of outdoor water consumption in a semi-arid, medium-sized Colorado city that is projected to undergo significant population growth. We used a combination of correlation and linear regression analyses to identify the key descriptive variables that predict greater water consumption at the household scale. Some results were specific to the development patterns of this medium-sized city, where outdoor water use increased 7% for each additional mile (1.6 km) a household was located from the historic urban center. Similarly, more expensive homes used more water as well. Surprisingly, households with a higher ratio of vegetation cover to parcel size tended toward less water consumption. This result could be because parcels that are shaded by their tree canopy require less irrigation. We discuss these results to assist city managers and policymakers in creating water-efficient landscapes and provide information that can be leveraged to increase awareness for water conservation in a growing, semi-arid city.

Highlights

By the turn of the 20th century, Colorado began to experience a significantly warmer and drier climate compared with the early 20th century [1]
It is generally understood that a wide array of urban characteristics within cities can have important impacts on outdoor water consumption patterns; the main driving characteristics and their degree of influence is debated and inconsistent in the literature
Similar to other studies on outdoor metered water consumption, we found that indicators of higher socio-economic status, in our case study housing prices, were associated with more water use

Summary

Introduction

By the turn of the 20th century, Colorado began to experience a significantly warmer and drier climate compared with the early 20th century [1]. Precipitation patterns remain relatively uncertain in climate projections, while a reduction in snowpack and earlier snowmelt and runoff are already evident [2]. Such climatic changes pose a serious threat to Colorado’s water supply, yet water demand is expected to increase as a result of imminent population growth [3]. The pressures of climate change and urbanization underscore the need for innovative and sustainable water management in Colorado cities. One way to manage urban water supply is by increasing outdoor water efficiency [4,5]

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