Assembly Constitutional Amendment 18. Authorizes legislation regulating use, acquisition and development of water and water resources, including electric energy, and disposition thereof, by State or State, agencies; permits incurring State indebtedness therefor as provided by Constitution, payable within seventy years, provided contracts be first made to sell projects water and electric power sufficient to repay cost within seventy years; grants eminent domain rights. Requires Legislature provide ad valorem tax on nonexempt property within State agency to meet State\u27s liability on any defaulted obligation of such agency, making tax lien prior to other tax liens