As utilities and municipalities rush to conserve water so that no one is left thirsty, the Chicago-based Alliance of Water Efficiency is reminding policy-makers and the public that saving water also means saving energy and reducing carbon emissions.
“When we save water, we also save energy,” CEO Ron Burke told Yale Climate Connections.
Those savings would accrue all along a municipality’s water system, beginning with the electric pumps that carry water from lakes and reservoirs through pipes, on into homes and businesses, and then back to wastewater treatment plants.
As explained in a 2018 brief [pdf] from the European Commission, conventional wastewater treatment operations are energy intensive (and expensive) because they rely on an activated sludge process based on aeration, which requires huge amounts of air to be pumped into treatment tanks.
In addition to encouraging, enabling and, increasingly, enforcing water conservation at all possible points of consumption, from low-flow showerheads to landscaping with drought-resistance plants, cities will also want to maximize the efficiency of their water system infrastructure.
“Some water agencies are losing, you know, 10%, 20% of their water to leaks underground,” Burke said.
Illustrating the profound connection between water consumption and energy use was an August 2021 study, also reported by Yale Climate Connections, which attributed roughly 20% of California’s total energy use to the state’s water system.
In response, the Los Angeles water department offers residents rebates on all manner of water-saving devices, from high-efficiency toilets to low-flow sprinklers. Researchers say those rebates are generating energy savings on par with those available from efficient appliances like washers and dryers.