The water firm released its 2024 draft water management plan, but the EA said it “must deliver” on leak reduction as “a plan is nothing without delivery”.
The EA added the company leaked more water than any water firm in England and “struggled” to control issues.
Thames Water says “reducing leakage is a priority”.
Thames Water’s plan outlines what it aims to do to respond to water supply issues including drought, leaks and increased demand.
Among the proposals are building a new reservoir in Oxfordshire, as well as taking water from the River Thames at Teddington, using what is known as abstraction, and replacing that water with recycled sewage effluent from the Mogden treatment works above the Teddington Weir.
However, a similar abstraction scheme was rejected by the EA in 2019 due to concerns about “unacceptable impacts on the environment”, and the agency says it still “has a number of reservations”.
The water company also suggested transferring water from the River Severn to the River Thames, but the EA cited doubts about the Severn’s resilience given low river levels in the summer of 2022.
The EA said in a response last week that a review published in 2019 already showed Thames Water “needed to improve its leakage reduction, reduce its outage and deliver on its commitments”.
‘Nothing without delivery’
The agency added the water firm’s 2024 plan had hinted at future improvements, but noted Thames Water’s 2019 scheme had “set out similar ambitions but had not delivered”, adding: “A plan is nothing without delivery.”
It also criticised Thames Water’s management of its water desalination facilities, which remove the salt from seawater.
Although the technology is something the EA says “a number of other water companies plan to use” to safeguard future water supply levels, Thames Water “has not managed the asset well and this vital resource has not been working for many years”.
It said the company “must either commit to improving the asset to ensure it is reliable for regular operation, or decide to decommission and select a new option”.
A spokesperson for Thames Water said: “Reducing leakage is a priority for us and is one of the foundations of the plan.
“Even with an ambitious target of halving leakage by 2050, we still need more storage in the future to account for growing population demand and climate change. ”
The spokesperson added the company was already “repairing over 1,300 leaks per week” and has met its target leakage reduction for the past three years.