Restricted zones on charts.

[NacelleStrake]

The Severn Estuary has three circled area's, I presume, that have fly over restrictions.
EGR 154 is a nuclear power station and EGR 155 a decommissioned one.
The next one, going inland, is twice as big, and joined to the other two.
It has the designation EGW SEVERN.
Without breaching the official secret's act, which I have signed, just what do the three letter ident's mean and why is EGW SEVERN seemingly restricted?

[ShyTorque]

"EG" means it's within the UK FIR. "R" means restricted area.

I think the third area you mentioned is the Severn Estuary bird sanctuary.

[NacelleStrake]

Much obliged, Shy Torque, for your expeditious reply. Appreciated. The bird sanctuary, for migrating birds, et al, is at Slimbridge, on the south side of the Severn Estuary.

[ShyTorque]

Yes, I'm very much aware where Slimbridge is, the marked circle goes up to 4,000 feet. If that's not what you referred to, I don't know of any airspace that is restricted (Slimbridge isn't actually restricted). Where did you find your information?

[DaveReidUK]

The clue is in the colour. Lime green always indicates a bird sanctuary.

The AIP confirms that it's centred on N51:44:29 W002:24:05, which is WWT Slimbridge, with the note "Pilots are requested to avoid the area from mid-September to early April".