Angel flooding drama mains pipe wrongly listed as low-risk
Investigation into incident that led to dozens of homes and businesses being damaged by water finds that pipe’s meters failed to trigger warning
12 May, 2017 — By Koos Couvée
Flooding in Upper Street last December
THE water mains that burst in Upper Street last December, causing massive flooding, had been incorrectly logged on Thames Water’s risk register, a review has found.
The independent review, led by Paul Cuttill, who has more than 30 years’ experience in the utility sector, was commissioned by the water company after dozens of homes and businesses were damaged by flooding.
Mr Cuttill found that at the time of the burst the main was placed at number 44,198 in Thames’s rankings of pipes at risk of failing. But this was due to it being confused with an adjacent pipe following a previous burst, “which would have significantly elevated its rank had it been properly monitored”.
As a consequence, the pipe did not have advanced monitoring equipment attached to it, the report said.
A review of the incident established that meters recorded a 20 per cent increase in water flow following the burst. But these were not monitored and did not trigger an alarm, which “may have delayed the overall response time”, Mr Cuttill concluded.
It took the company almost four hours to stop water gushing into shops and homes.
Simon Hughes, the privatised utility’s head of strategy planning, said that if it had been recorded properly “the Upper Street [pipe] would have been in the top 20,000 at-risk trunk mains”.
“Under the current intervention approach it would have fallen short of monitoring or replacement, which would have been considered for the next five years,” he added. “Nothing would have changed in terms of the December breach.”
However, Thames’s existing approach is under review following a series of mains bursts which caused severe flooding in London at the end of last year.
The re-laying of just under a kilometre of new pipe to replace the burst mains – not in use since the December floods – has been under way since April 18.