Idaho Code § 42-2913: Compensation.

The drainage commissioners shall receive for their services such sum as the board of drainage district commissioners fix by resolution for each day they shall actually be engaged in the business of their office, and actual and necessary expenses. In addition, the commissioners shall each receive a mileage allowance computed at the rate established by the state board of examiners for employees of the state for each mile driven and such allowance shall be the full amount allowed for travel expense.