A report by the authority’s Health and Environment Committee urges Ofwat to take a longer view of the economic, social and environmental costs of supplying water when it determines a sustainable level of leakage and sets company targets.
It calls on water companies to install water meters in all properties by 2025 and asks the Department of Energy and Climate Change to reconsider cold water efficiency measures as part of the Green Deal.
Murad Qureshi AM, chair of the health and environment committee, said: “Water is a precious resource that is in limited supply and more must be done to preserve it if we’re to avoid a repeat of drought restrictions in future years.
“Our report sets out practical steps that can be taken in London to ease the pressure on our water supplies by reducing leakage and consumption in the home.”