After consultation with the Commissioner of the Virginia Marine Resources Commission, the Department may offer to finance the construction of fishways for any local government which owns a dam or other artificial impediment to the free passage of anadromous fish. The Fund will pay for seventy-five percent of the entire cost of the fishway, and will lend the balance of the cost to the local government. The loan shall be repaid over ten years at no interest or over twenty years at an annual rate of interest which shall be two percentage points below the rate for municipal bonds given in the latest Bond Buyer Twenty Bond Index appearing before the loan is made. Any balance of a loan not paid off as required by this section shall be paid off as provided in § 29.1-101.4. The Department shall approve the design of the fishway prior to the making of any grant or loan from the Fund pursuant to this section. All local governments borrowing money from the Fund are authorized to take any action, adopt any proceedings and make and carry out any contracts that are contemplated by this chapter. Such contracts need not be identical among all local governments, but may be structured as determined by the Department according to the needs of the contracting local governments and the Fund.