I located the large gated outflow of this drain with the help of a friend while out on a run on some local trails. Me and @Esoteric Eric had previously explored a longer culverted section of Meers Brook further downstream (known here as Stoopatron). However, I hadn't imagined that there'd be anything worth seeing this far upstream. After Stoopatron the brook breaks off in various directions to its multiple points of origin. As such, the large outflow that we entered here isn't immediately evident on maps, so I'd not identified this as a possibility; the brook continues almost in parallel with this culverted section along another open branch of its course, meaning that there's no clue that there would even be a culvert in this location.
A bit of a wander above ground afterwards revealed that this culvert runs from behind a council rubbish dump where the inflow is hidden from view by a tonne of branches, plastic children's vehicles and general detritus. We entered from the outflow. It's only relatively short - approximately 200m according to google maps, if you draw a straight line between two points. However, its winding course feels much longer. And what it lacks in length it more that makes up for in aesthetics, with the bright yellows and oranges of the iron deposits present throughout pretty much the whole drain. This is presumably from old mine workings in the area: a 1924 OS map is marked with a brick works and 'old coal shaft' further upstream, which certainly supports this idea.
The land above the culvert is currently a nature reserve, and older maps suggest that this has always been natural space, so I can only assume that part of the brook was culverted at some point in order to act as some kind of combined sewer overflow - there's definitely hints of sewer at points along the way, and a bit of a smell of fuel too.
These photos are from a visit with @Esoteric Eric, after an earlier partial recce where I only had my phone camera handy.
The drain starts off from the outflow as 6ft RCP that feels smaller due to the buildup of silt and god knows what under foot. Disappear here...
Looking back out...
The drain basically consists of lengths of RCP, firstly 6ft, shortly reducing to 5ft for the remainder. Progress is necessarily slow, partly due to the sto0p required, but also because it's sooooo slippy. The sections of RCP are connected by four chambers along it's course; I'll deal with these each in turn, as they are the most interesting bits.
CHAMBER ONE:
Not long after entry on my first visit, my borrowed torch lit up the odd looking formation on the left in the distance, which gave the drain it's alien inspired name. Closer inspection reveals it's an old manhole shaft that's now entirely packed full of branches and tree roots. You can see in the first pic here that 6th turns into 5ft pipe with a slight incline meaning that the water is much shallower from here on in. I already had wellies full of water by this point, but as it's now shorts weather I didn't mind so much....
Some sections of RCP were connected by short brick sections. I'm not sure if this indicates that at some point the whole tunnel was brick, or if it's for some other reason. Looks nice, though and makes a good change from concrete...
CHAMBER TWO:
Chamber two featured more iron deposits, and a rather decrepit looking ladder.
Then onwards to more RCP. Leaky connections in parts led to some nice stalactites.
CHAMBER THREE:
Chamber three was my favourite. An unbelievable amount of iron deposits here making it look from certain angles more like a cave or grotto than a drain chamber. There was a small incline here meaning water flowing fast in my direction made progress slippy and more tricky. As well as the main flow a small inlet from the left ran with what looked like clear water. Another ladder to the right leading high above - water was dripping quite fast down the shaft too making it hard to look up without getting an eye full.
CHAMBER FOUR:
This chamber was less stained by iron deposits than the others. A brick chamber with a ladder leading high above to a manhole cover. To the left was a small inlet flowing with a small trickle of fresh water. I got the feeling that this water wasn't always necessarily so clean though, and is possibly the source of the smell....
'Do you even Manfrotto?'
We didn't have the time to go and work out where these manholes led up to. This one possibly led up to a road, which suggests that the drain's course is less direct than it feels when you're walking it - a straight line drawn between inflow and outflow would make this entirely below turf...
TO THE INFLOW:
Approaching the end I could see a shaft of light. As I got nearer it became clearer that we weren't going to make it out this way. The whole inflow grid is absolutely covered in rubbish...
Looking inwards from beneath the inflow grid...
I did poke my head through where the shaft of light is coming through, finding just another layer of rubbish and no escape.
And so we made out return out the way we came. I'll end with a crap pic of the inflow, showing just how clogged up this part of the brook is. Potentially needs some attention! Ruined my trainers climbing in here too, argh!
Really enjoyed this one, but I guess I probably say that every time! :-)