In response to submissions received from the public about the City of Marion's draft 1985 supplementary development plan for the rapidly growing Hallett Cove urban area, and due to the implications of a statutory reporting mine development plan received in March 1986 by the SADME Mining Branch from the owners of the large and active Reynella quarry, the State Government set up an expert working party to try to devise measures to resolve potential land use conflicts arising between: (a) the need to preserve the historic Worthing mine, which is on the Register of State Heritage items; (b) the envisaged expansion of the Reynella quarry into the Field River valley portion of the Private Mine land surrounding the mine relics; (c) the expansion of residential development towards the Field River valley and the operating quarry; and (d) the ecological and physical preservation of the Field River watercourse.