What is this?

[Sepher]

Hi,

Currently digging out for a decking area in the sunniest spot of the garden. Unfortunately a drain sits in middle of it and I've decided to deck round it keeping the deck level with drain. I'll put a plant pot on it to disguise it a bit.

Yesterday curiosity got better of me and decided to lift the drain cover up. Never expected to find a cavern underneath it! So it's a circular structure I'm guessing 10 foot wide and possibly 20 foot deep. Looking online I suspect it might be some kind of storm drain/giant soak away. I am in a new build which is now 8 years old and I am the second owner. I dont believe this drain came up in the searches and I wasnt too concerned about it at the time.

Picture attached. I wondered if anyone had any experience with this and knew what it was, how it works etc? Guessing again it has a solid roof to hold the earth above it so hopefully no issues building deck over it.

 

[HERTS P&D]

Catch Pit:

A catch pit is an empty chamber built into a drainage system to 'catch' silt and other debris carried along the drainage pipe by water. ... A catch pit is designed to collect silt and debris before it enters any drainage system.

Andy

 

[lonner]

+1 if you have grandchildren or small kids fit a secure cover. Screw down ect so it can't be got into easy.

 

[mattylad]

You can say that again Andy.
Oh - you did

Also if you are decking over it, you may want to create an access hatch in the decking so that it can be accessed when its full or for maintenance.
Otherwise a utility company may well rip your decking up to get to it.

 

[Sepher]

Cheers for this. No issues with kids, I struggled to get the lid open myself with a bar not knowing what was underneath it was a good job I didn't drop the lid inside it!

Decking round the lid for now as wanted to keep deck level with grass and also access issues for it in future. Plant pot, paint it, furniture will cover it.