Members of the board of directors shall serve without compensation, but each is allowed:
1. Necessary travel and incidental expenses actually incurred in performing official district business as approved by the board of directors.
2. Per diem determined pursuant to title 38, chapter 4, article 2, when away from the district on business of the district.
3. Per diem for attending meetings of the board of directors of the district not to exceed the amount prescribed by section 32-1604.