The cost of the engineer’s report, employees’ salaries, costs of engineering surveys, bond counsel fees, and other initial costs and expenses, not to exceed five thousand dollars ($5,000), incurred after formation of a district and prior to receipt of its first available funds, may be advanced by another county sanitation district or districts situated within the same county, upon such terms and conditions as may be agreed upon; said funds must be repaid by the borrowing district from its first available funds.