Quite a unique site! We found it from a tip-off by a very knowledgeable local, and with help from some of Jersey's few elite urbexers :)
This Victorian reservoir has a capacity of roughly 100,000 gallons and is made almost entirely from brick, with granite in a few places.
At the bottom of the granite spiral steps, the first thing you see is this input/output valve, with it's maHOOsive opening!
Think of the reservoir as a giant toilet cistern, complete with ballcock *snigger*
The second valve is cornered by overly neat granite blocks, with slots for pieces of wood to raise the level?
My favourite shot shows the impressive support pillars, the amount of labour and attention to detail used for a place that no-one normally sees is quite amazing!
The original thread that sparked my interest, with more pictures by other urbexers!