The Environment Agency is investigating the robustness of the Thames Barrier, which protects more than a million people from flooding, after it breached the recommended annual limit of 50 closures for the first time this winter.
So much time is being spent opening and closing the giant floodgates that essentialmaintenance is being missed.
Designed in the 1970s on the basis that it would only need to close once or twice a year, the barrier was shut 28 times last month alone as record amounts of winter rainfall and rising sea levels tested the system well beyond what was envisaged. So far, the barrier has coped with the extra pressure, protecting 1.2 million people and 200 billion ($394 billion) worth of property, but experts say the system could be threatened if the intense use continues.
"If the number of closures keeps being over 50 every year we will not be able to maintain it properly," said David Wilkes, who was the EAs manager for the Thames Barrier from 1994 to 2000 and is now associate director of the Chartered Institution of Water and Environmental Management.
"Maintaining the barrier is a full-time job, with most staff operating on a typical 37-hour week and a skeleton staff working around the clock. The process of closing the barrier from making the decision, shutting it, waiting for high tide to come and re-opening it takes eight to 10 hours," he said.
"While the staff are working away on this, they can't be doing tests, diagnostics and other maintenance work. You can't then ask them to do their day job you've got to send them home to rest so that they can come back the next day," Wilkes said.
Wilkes said it was too early to tell if this winter was a blip or a sign of things to come.
