Greening Cities, Conserving Water

Low-Impact Development: a strategy for water woes

Robert Wilkinson

Water shortages resulting from changes in snowpack and runoff are among the most critical challenges arising from global climate change. A new paper published by the Natural Resources Defense Council and co-authored by Bren adjunct faculty member Robert Wilkinson suggests that greening our cities will be a key strategy in reducing climate change and the water shortages that will likely result from the higher temperatures associated with it.

The 53-page paper, titled "A Clear Blue Future: How Greeing California Cities Can Address Water Resources and Climate Challenges in the 21st Century," focuses on a strategy referred to as "low-impact development" (LID). The authors say that fully implementing LID could increase water supplies by billions of gallons per year, "providing an effective and much-needed way to mitigate global warming’s impact on California."

LID techniques include such practices as rainwater harvesting, which the study suggests could increase local water supplies in the San Francisco Bay area by some 405,000 acre-feet of water per year by 2030, a volume that represents roughly two-thirds of the volume of water used by the city of Los Angeles each year, according to the authors. Water savings then translate into savings of energy that is not needed to move water across the state or desalinate ocean water.

Overall, the collection, distribution, treatment, and safe disposal of drinking water and wastewater consume tremendous amounts of energy nationwide and release approximately 116 billion pounds of carbon dioxide per year, equivalent to the amount of greenhouse gases emitted per year by 10 million cars. The report found that 1,225,500 megawatt hours of electricity savings can be achieved each year through use of LID practices in California, representing enough energy to power more than 102,000 single-family homes for a full year.

The NRDC report includes a fact sheet offering practical solutions that consumers can implement now.

Read the report

Read the fact sheet