Just sharing this, from Caroline Simpson of the BPCA. Fascinating stuff!
"As many local people will know, we have a brick-built tunnel which carries the New River under a rise in the ground between Myddleton Road and Station Road, Ally Pally. This usually gets inspected once every ten years or so, but hasn’t been done since the early 90s. This used to involve a chap going through on a flat-bottomed boat and inspecting the brickwork – which is the high quality work for which Victorian engineers and brickies were famous. Health and Safety regulations mean that the boat cannot be used, and so the tunnel is to get its very first full clean-out since the tunnel was finished in 1858 during this next inspection.
Starting Monday 17th, a damn will be created just outside the tunnel entrance in Myddleton Road, with another at the Ally Pally end. The water will be drained out and the fish carefully put into the water at either end. 154 years of sludge and general rubbish will then be cleared out of the circular, pipe-like tunnel – an estimated 400 tons! Then the brickwork will be inspected and repaired or re-pointed where necessary, and then the damns taken down and the water will flow again.
In order to get the debris and sludge out of the tunnel Thames Water contractors will install a large vacuum tube at the Myddleton Road end – above the tunnel entrance. This will bring the debris up to tankers which will take it away. The sludge will be sorted, and any cans and bottles and prams and non-biodegradable rubbish removed, and the rest will be turned into fertilizer. There will be a similar installation at the Ally Pally end.
Just in case there are still a few bats roosting in the tunnel, the work of actually clearing the tunnel cannot be done my machines, and so we are back to time-honoured traditions of men with shovels and wheel barrows who will go in and out the 1km length of the tunnel. An average of 70 men was employed in 1857 and 1858 making the Tunnel; far less will be employed cleaning it out.
The work is likely to take 4-6 weeks. During this time the New River Path between Whittington and Myddleton will have to be closed. People living and working in properties adjacent to this section of the New River and the tunnel entrances will get a letter in the next few days from TW explaining the works and giving contact details should they wish to know more.
Do take extra care crossing Whittington Road to the Garden as there will be big tankers coming in and out of the TW land. They will also be using the land behind the painted gates for parking – and then we hope to install the gym soon after they have left.
It will be messy, hard work, but will help ensure the safety and viability of our wonderful 150 year old Victorian treasure for another 150 years.
I am sure that any offers of tea and cakes would be much appreciated by our temporary workers."