The members of the board shall receive their actual expenses incurred in attending the meetings of the board and for attending any business for and in behalf of the district. Any such expense account shall be audited by the board before payment but the board shall receive no compensation for their services unless the landowners at the annual meeting shall determine to pay a compensation which in no event shall exceed five dollars per day for the time actually engaged in work for the district and five cents per mile for mileage not to exceed one hundred miles actually traveled. Mileage, if allowed, shall in no case exceed one hundred miles and shall be in lieu of all other expenses in attending sessions of the board; provided, however, that if the secretary be a member of the board he shall be entitled to compensation as provided in § 49-19-730.