Great Salt Lake Minerals and Chemicals Corp. (GSL) has agreed to a final insurance settlement of $56.3 million on damage to its facilities on the Great Salt Lake caused by flooding in 1984, according to the annual report of Gulf Resource and Chemical Corp., GSL's parent company.

In May of that year, rising lake waters breached GSL's outer dike damaging bridges, pump stations and other structures and diluting brines in the solar ponds to where they were useless for production of sulfate of potash and salt cake.According to the report, advance insurance payments of $35 million had been received as of Dec. 31, 1987, followed by another $17 million in 1988. The remainder is expected in the near future.

Repair of all physical damage to GSL's lake operations, begun in the summer of 1985, is nearing completion with partial production of sulfate of potash expected to resume next year.

GSL management said the settlement is adequate to provide for full recovery of losses due to the flooding. But because of the loss, the company is no longer able to buy insurance "on terms deemed feasible" to cover any future losses.