The General Assembly finds and declares that an adequate supply of pure water is and will always be essential for the health and safety and economic well-being of the state, that lands acquired for public water supply purposes are and will in the future be necessary to protect the public water supply notwithstanding the availability of water filtration plants; that some of such lands have been acquired by water companies having the power of eminent domain, that such lands are in imminent danger of being disposed of by water companies for residential and commercial development, that such lands constitute a significant portion of the remaining undeveloped and open space lands in close proximity to the urbanized areas of the state, and that it is in the public interest that there be established criteria for the orderly disposition of such lands. The General Assembly further finds and declares that in order to protect the purity and adequacy of the water supply the Department of Public Health should be directed to revise its procedure for the review of applications to sell water company land located on public drinking water supply watersheds, that the disposition of such land prior to the revision of application review procedures would jeopardize the public health and welfare, and that therefore the prohibition against sale or development of water company land located on the watershed should be extended for a period of three years from June 26, 1977.