No board member shall be reimbursed for expenses incurred for any travel unless the travel has been approved by the board. Board members who provide their own transportation shall be reimbursed for each mile actually traveled in attending board meetings and in the performance of district business. Any payments to board members must be in the form of a reimbursement for amounts previously paid by the board member, and receipts shall be provided by the board member in accordance with the provisions of GAN.