Hallowmere Playing Fields are located a few hundreed yards up the road from Hallowmere House (both stand along Hallowmere Road). Until the 1970s, the field was a piece of undeveloped public land which was also the site of a copse, at the centre of which was a small pond ('mere' of course being the Old English word for a shallow lake or pond).
The Hallowmere, as it used to be known, was popular amongst local dog-walkers. However, after the mysterious disappearance of a number of dogs in the vicinity, alongside claims in the local press that cowled figures had been seen entering the copse at night. At this point in the 1970s, the British tabloid press (notably the execrable - and now thankfully defunct - News of the World) were responsible for manufacturing a moral panic, claiming that traditional British values were being eroded by a wave of witchcraft and devil-worship that was supposedly sweeping the nation.
As a consequence, it took little effort to persuade Horsingdon council to cut down the copse, drain the pond, and redevelop the land as playing fields. This also occured around the time that the Church of Starry Wisdom was evicted from St. Ormond's.
As an aside, I am reminded of events which supposedly occured in Clapham Wood in West Sussex (not far from the A27) around the same time, where devil worshippers and various paranormal interlopers were held responsible for the disappearance of a number of dogs, and even the death of the local vicar. Interested readers are directed to Toyne Newton, Charles Walker and Alan Brown's The Demonic Connection.
An acquintance of mine, who happens to be part of of the Sodality of Shadows (a loose network of writers and esoteric practioners, all of who have links with London's occult underground - and about which I shall say more in the future), has also previously undertaken occult investigations in Clapham Wood.
Having delved somewhat deeply into the local history archives of Horsingdon Central Library, I have yet to uncover any additional information regarding the matters of either Hallowmere Playing Fields, or St. Ormond's Church - or whether, indeed, the two events are in any way related. However, I will note that a portion of the minutes relating to council meetings covering this period are no longer available For public scrutiny. I have not yet received a response regarding my queries about this - nor do I expect one to be forthcoming anytime soon.