It seems the hole in Perry vale is due to a collapsed Victorian sewer - the same one which collapsed under the railway lines earlier in the year. Certainly makes crossing the road to the station easier.....

It seems beyond belief that they can spend weeks re-routing/fixing the sewer under the railway, but the cavern that is being eaten away just a few meters further down goes completely unnoticed or just ignored.

I suspect that trying to maintain the older parts of the water and sewerage system is really just a case of fighting the long defeat.

It may take a while.

Well we are all fighting the long defeat, but the strategy of waiting for parts to catastrophically fail before we take any action, runs counter to the 'a stitch in time saves 9' common sense of the earlier generations.

Just maybe it is cheaper for Thames water to run the system into the ground, and make some nice contained projects out of the resultant mess, but what price Perry Vale being closed for weeks? What price London Rd being closed for months when the sewer collapsed there? What price the rail being closed recently? And what if that hole had flipped a thameslink train?

What doesn't help is our press reporting these things as if they are mysterious acts of nature.

Apologies if this may have been posted already elsewhere, but would anyone know if there are maps available showing the location/routes of these old sewers? Many thanks!

Thames would be able to sell you one but I don't recall how much they charge for an asset search. When local authorities looked after the sewerage system you could go the borough engineers department and ask to see the drawings.
I am not aware of any policy to systematically replace brick built sewers so I guess the wait for it to fail approach is being adopted.

When I had a minor drainage issue to investigate the Thames Water engineers had an electronic map of all registered drains. This should be available online for all rather than kept back as a company asset.

Quite enjoying Perry Vale being a little quieter at present. More pleasant on foot or by bike.

Many years ago I had the drainage book. People came in to make enquiries and I looked in the book to find the answers.

As Lewisham Council act as agents for Thames Water they may still have this book.

I find Perry Vale very easy to cross now. I hope the repairs take a long time.

The practice of only dealing with catastrophic failures brings short-term profits. But I think a more prudent approach would be to replace all he pipes and sewers, which must be at least 100 years old.

This could take months at the speed there NOT working,
I walk to the station at 6,55 every morning and return at16,30 every
day, and since the big barriers went around the hole i have never seen
anyone working, and its light at those hours ?
Now they have got there welfare/tea hut it could be the new year ??

They seem to have partly backfilled the hole.

Many thanks for the replies, interesting that these plans are apparently quite tricky to get hold of. My concern is whether or not any sinkholes could appear on, or rather under, existing housing. I know housing is unlikely to have been built directly over any of these, but presumably there is a degree of movement involved and hence location of cavities can change? (but then I really don't know much about this at all!)

I guess that is to deter sewer explorers.
Content aside, I think it would be quite interesting to follow the path of our ancient streams.

And thinking about it, although these victorian sewers were built to last forever (with a little maintenance), perhaps we would be better off now ripping them all out and redesigning the lot, totally separating grey water from sinks and showers + rainwater run-off from toilet water.
That would be a nice little project.

There already are different sewers. I can remember when Thames Water tracked where a drain had been connected to the wrong sewer.

http://bit.ly/2eCaNRm

Wonder if we'll get this one repaired in less than a month. The Japanese managed to repair a bigger one in a single week (according to the article).

An asset search for a private individual (rather than a company) seems to be £56. If you want to know what is around your house this would tell you the route and size of sewers but I don't think they highlight the age or type of the sewer itself. The one at the bottom of the pit in Perry vale is the brick built egg shaped pattern - seemed to be quite small - maybe 18" high. The sheet piling now prevents a view of it.

Interesting that particularly in Asian countries they are under the impression we are a developed and efficient Country! The Japanese repair a hole 5 times wider and deeper that the one in Perry Vale in days. Malaysia and others build a brand new airport in a couple of years and under budget, The Chinese are building a train faster and cheaper than HS2 and in less than 17 years. Not to mention the bullet train now in its 3rd/4th version

I would have thought most of the older roads in SE23 were built with a combined sewer - after all, before cars, the run off from the roads would effectively be sewage. And so no home built before 1920 will have a separate connection for the gutters.

Since then sure, they probably have added low capacity sewers (if the PV pools and gutter streams are anything to go by) to channel the road run off. Maybe some newer homes have connections to that. Where this oily run-off ends up is another question - the River Pool?

Anyway, I was imagining you could walk through these local sewers - this 18 inch sewer in PV is a massive disappointment to me.

Those countries do not respect the rights of citizens (Malaysia & China) in the same way. China doesn't give people in the way of infrastructure any rights beyond very basic compensation. In this country compensation is above property value and it takes years to work through the planning process. A huge chunk of the cost of projects is tunneling where other countries would build above ground and to hell with the view. Another big cost is land as we have a restrictive planning system that increases prices along with lax lending. Our planning system is too slow but it is better than trampling over people's lives like occurs in China.

That hole in Japan was caused by something other than a sewer collapsing. It is too big to be that. May well be an easier fix despite being larger. I reckon a hole in Oxford Circus would get fixed a lot quicker than the one in Perry Vale in any case.