To assist financially in the construction of the aforesaid local distribution and drainage systems by irrigation districts and other public agencies the Secretary is authorized, on application therefor by such irrigation districts or other public agencies, to make funds available on a loan basis from moneys appropriated for the construction of such distribution and drainage systems to any irrigation district or other public agency in an amount equal to the estimated construction cost of such system, contingent upon a finding by the Secretary that the loan can be returned to the United States in accordance with the general repayment provisions of sections 485a(d) and 485h(d) of this title and upon a showing that such district or agency already holds or can acquire all lands and interests in land (except public and other lands or interests in land owned by the United States which are within the administrative jurisdiction of the Secretary and subject to disposition by him) necessary for the construction, operation, and maintenance of the project. The Secretary shall, upon approval of a loan, including any loan for a distribution and drainage system receiving water from the San Luis unit, Central Valley project, authorized by the Act of June 3, 1960 (74 Stat. 156), enter into a repayment contract which includes such provisions as the Secretary shall deem necessary and proper to provide assurance of prompt repayment of the loan within not to exceed forty years plus a development period not to exceed ten years. The term “irrigation district or other public agency” shall for the purposes of sections 421a to 421h of this title mean any conservancy district, irrigation district, water users’ organization, or other organization, which is organized under State law and which has capacity to enter into contracts with the United States pursuant to the Federal reclamation laws.