Reedbeds

I live in North West England. A major nature reserve near by (not RSPB) has a developing reedbed (around 6 years old). I am surprised that the water level has just been lowered so much that large tracts of reeds are between 6 to 10 feet away from the waters edge. I understand that at this time of year it is usual to lower water levels on wet grasslands, but the water lowering on the reedbeds has left me surprised.

I regularly visit the 2 reserves in North West England that have substantial reedbeds (RSPB Leighton Moss, and Wigan Flashes) and I have never seen the reedbeds water lowered in a similar way. I would be grateful for any observations / comments. 

Thanks