A £9 million project completed last month promises to prevent a repeat of the floods that devastated the west of the borough in 1992. TOMASZ JOHNSON finds out how it all works For years, parts of Edgware, Burnt Oak and Colindale suffered from flooding during periods of heavy rain.
The lie of the land and the presence of three rivers - Edgware Brook, Deans Brook and Silk Stream - conspired to make the area, at times, a precarious place to live.
In 1992 came the worst flood of all, with almost 300 homes damaged and three people killed. The public clamour for protection from the forces of nature intensified, and the Environment Agency (EA) set the wheels in motion for a massive flood defence project.
Sixteen years and around £9 million of Government cash later, that project has become a reality.
The defences, which were finally cleared for use at the end of last month, consist of a series of dams in the rivers. When heavy rain swells the flow, the dams syphon off thousands of cubic metres of water into six man-made lakes.
Some of the at-risk area falls in the neighbouring borough of Harrow, but the final two lakes to be completed are on Green Belt land in Bury Farm and Edgwarebury Farm, in Edgware.
EA technical specialist Dak Gor has seen the project through from start to finish. He said: "The area suffered from flooding for years, but the flood of '92 really started things off.
"We undertook a study and found the storage lakes were the most cost-effective and environmentally friendly solution.
"Then we built a computer model that gave us an indication of how the flows behaved and showed what would happen if we put the dams in different places, and we came up with the sites we've used."
Mr Gor described it as a "huge" and "complex" project because it had to tackle several rivers, all of which could potentially contribute to the flooding.
"What we were trying to do is reduce the risk. We use the term flood defence' but we can't totally stop it. There's a range of degrees to which the risk has been reduced in different areas, but generally we try to take it back to one per cent, which is acceptable.
"We've got to look at the cost, which can't be greater than the cost of what it is defending. That's the key criteria. And it's got to be practical.
"You can't knock down properties and widen the rivers. It's a densely populated area and people have built right up to the banks in some places. Ideally it would be nice to widen them but it's just not possible."
Building the lakes on the sparsely populated Green Belt solved this problem, but presented another with the displacement of some of the abundant wildlife on the two farms.
That made it all the more important that the work was sympathetic to the environment, something Mr Gor says the EA was keenly aware of.
"We're the Environment Agency after all, so it's one of our duties," he said. "Ideally there shouldn't be a detrimental effect on the environment and we didn't want to destroy anything -but it's unavoidable.
"Previously, building out of concrete was the theme. Now we try to use soft materials and do things in sympathy with the environment."
While the construction of the defences is complete, the EA is now landscaping the surrounding area to create a wetland habitat, including small ponds, and encourage birds and animals to make it their home again.
"It will take time," added Mr Gor. "We are monitoring the site and understand the plants are establishing themselves really well and the wildlife is returning."
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