Determining the Water Baseline for the Ann Arbor 2030 District

Abstract

The effects of global warming are becoming more apparent in major cities and are requiring adaptive and mitigative efforts. Many cities across the country are working towards becoming more efficient and adapting for the future changing environment. There are currently no established national benchmark averages for water use consumption in buildings. This leaves local governments and districts to create their own methods for establishing a water baseline. One metric for setting a water baseline is water use intensity (WUI), which is calculated by dividing water used in a building by building floor area. Water use intensity is a useful metric for municipalities because they can be used to set water use reduction goals and assess progress towards them in the future. As local governments and municipalities are determining the best way to establish their water baselines, this work examines the Ann Arbor 2030 District and the process used to gather the data necessary for establishing a water baseline. The Ann Arbor 2030 District is one of 22 Districts currently operating across North America. The 2030 Districts are private/public partnerships formed to meet energy, water, and vehicle emissions reduction targets for existing buildings and new construction projects within their boundaries. The Districts were formed to create a network of high-performance districts that work together to create and improve infrastructure to mitigate and adapt to climate change. The goals of the 2030 Districts are to reduce building and infrastructure energy use, water use, and transportation carbon dioxide emissions by 50% from a baseline by 2030. The majority of 2030 Districts use a water benchmarking method very similar to that adopted by the Ann Arbor 2030 District. It is important to examine other water benchmarking methods to understand why the WUI metric was chosen for local water benchmarking. Understanding the method that the Ann Arbor 2030 district used will help other district and city managers gain a better understanding of the options available, and the potential challenges, to calculate the water baseline, specifically as WUI, of commercial buildings within their cities.