Question: In what year was the River Lea constructed as part of the London water supply infrastructure?
Sentence (from "Thames Water Ring Main"): The Thames Water Ring Main (TWRM) (formerly the London Water Ring Main/LWRM) is a major part of London's water supply infrastructure, approximately 80 km of mostly 2.54 m concrete pipelines to transfer potable water from water treatment works (WTWs) in the Thames and River Lea catchments for distribution within London.
Relevant evidence: No