Warden Grotto is around 700m long and takes the Warmden Brook under South East Accrington before it joins with Woodnook Water
This small culvert carries the Swinnel Brook for around 120m on the northern side of Haslingden
The River Irk travels under Middleton town centre for around 500m in a couple of parallel concrete box culverts.
The River Calder flows through Cornholme in a few stone culverts, we had a look at the first one which was around 650m in length.
The Limey Water runs through Rossendale in a series of stone and concrete culverts.
Built sometime in the 1980s Bunker is a long concrete storm relief the outfalls to the Manchester Ship Canal