To cooperate with Federal, State, territorial, and other public agencies and local nonprofit organizations in developing plans for a program of land conservation and land utilization or plans for the conservation, development and utilization of water for aquacultural purposes, to assist in carrying out such plans by means of loans to State and local public agencies and local nonprofit organizations designated by the State legislature or the Governor, to conduct surveys and investigations relating to conditions and factors affecting, and the methods of accomplishing most effectively the purposes of this subchapter, and to disseminate information concerning these activities. As used in this subsection, the term “aquaculture” means the culture or husbandry of aquatic animals or plants. Loans to State and local public agencies and to local nonprofit organizations shall be made only if such plans have been submitted to, and not disapproved within 45 days by, the State agency having supervisory responsibility over such plans, or by the Governor if there is no such State agency. No appropriation shall be made for any single loan under this subsection in excess of $500,000 unless such loan has been approved by resolutions adopted by the Committee on Agriculture, Nutrition, and Forestry of the Senate and the Committee on Agriculture of the House of Representatives. A loan under this subsection shall be made under a contract that provides, under such terms and conditions as the Secretary considers appropriate, for the repayment of the loan in not more than 30 years, with interest at a rate not to exceed the current market yield for outstanding municipal obligations with remaining periods to maturity comparable to the average maturity for the loan, adjusted to the nearest ⅛ of 1 percent. Repayment of principal and interest on such loans shall begin within 5 years. In providing assistance for carrying out plans developed under this subchapter, the Secretary shall be authorized to bear such proportionate share of the costs of installing any works of improvement applicable to public water-based fish and wildlife or recreational development as is determined by him to be equitable in consideration of national needs and assistance authorized for similar purposes under other Federal programs: Provided , That all engineering and other technical assistance costs relating to such development may be borne by the Secretary: Provided further , That when a State or other public agency or local nonprofit organization participating in a plan developed under this subchapter agrees to operate and maintain any reservoir or other area included in a plan for public waterbased fish and wildlife or recreational development, the Secretary shall be authorized to bear not to exceed one-half of the costs of (a) the land, easements, or rights-of-way acquired or to be acquired by the State or other public agency or local nonprofit organization for such reservoir or other area, and (b) minimum basic facilities needed for public health and safety, access to, and use of such reservoir or other area for such purposes: Provided further , That in no event shall the Secretary share any portion of the cost of installing more than one such work of improvement for each seventy-five thousand acres in any project; and that any such public water-based fish and wildlife or recreational development shall be consistent with any existing comprehensive statewide outdoor recreation plan found adequate for purposes of chapter 2003 of title 54; and that such cost-sharing assistance for any such development shall be authorized only if the Secretary determines that it cannot be provided under other existing authority.