It is Hazlecopse you are talking about?
Great fishery and some great fishing to be had.
Buzzers work well there, suspended under a bung or on a washing line. Small black or green nymphs can also work well and dont neglect the depths as the bottom lake is deep.
Montanas can also work well as can a white fritz lure worked deep and slow for some reason.
dont be afraid to step up to an 8lb leader as there are some big boys in there. This was teh fishery famed for stocking 40+lb salmon at one stage
Wilf, the farmer/owner will also tell you what is/ has been working well but dont get him started on the EA or the Goverment
Ben