This culvert takes the River Roch around 450m under the middle of Rochdale.

Getting in couldn't have been easier, a hinged lid in some bushes dropped us straight into the chamber. It was a simple concrete setup, the weir had no screen, the designers choosing a grill over the dual outfall pipes instead.

ML's Upper Limits is a cluster of CSOs that drop into the mighty Motherload (NSWI) deep in the bowels of Bristol.

Dreadnought, (aka the Malago Storm Water Interceptor) is a large concrete drain that takes the flow from the Malago and Pigeonhouse Stream in the Southern part of Bristol.

This little CSO is found in Bury and has the shortest overflow pipe I've seen, the CSO chamber is only a stones throw from the outfall.

Sidedraft is one of the culverts of the Gore Brook, its mostly brick with some concrete thrown in for good measure.

This CSO serves a town to the East of Manchester, it takes sewer overflows to a big tank at the works or diverts into the local river.