Drained

The water level of the pool has been lowered by approx 1.4 metres and you can see the difference here.

I read a bit about it on a local wildlife website. The main body of water has been drained for some time awaiting repairs to a dam wall. This, what I call outlet pool, but is officially 'Jeffrey's Swag' is fed by a little brook which is still running.

Think the water has been taken to top up a canal which would normally get water from the main pool - will double check and update this with a link.

***it's more complicated than I thought, but there's a bit about it on the Chasewater Dam Blog ***