Firstly and most unfortunately the bird has GONE , but the story is thus:

Arriving with intentions of checking the gull roost this evening at this strictly permit only site, Pete Berry and I settled down in the hide until at approximately 3 pm he suddenly hollers 'PETREL' ! Sure enough there on the far side of the reservoir is a Leach's Petrel, fluttering about trying it's best to avoid the Black-headed Gulls that continually harrassing it. Pete then goes on to flatten his mobile phone battery ringing all and sundry and we continue watching the bird while we wait for them to arrive. Simon Johnson lives closest (a couple of miles or so) and makes it in time to see the incredible visitor and after a while I open the hide door to see five other permit holders making their way briskly to the hide, but not fast enough as Simon watches the petrel fly over the reservoir walls on the north-east side and unbelievably, dissappear for good!

Whilst this particular bird has departed, given the numbers currently being recorded on the north-west coast it may be well worth trying your local reservoir or flash tomorrow morning or as soon as you can, Audenshaw's probably favourite, whilst Pennington or any other are distinct possibilities.