Iowa Code § 468.531
The compensation of the trustees and the clerk of the board is hereby fixed at an amount not to exceed two hundred dollars per day each and necessary expenses, to be paid out of the funds of the drainage or levee district for each day necessarily expended in the transaction of the business of the district, but no one shall draw compensation for services as trustee and as clerk at the same time. The board of trustees of a district may by resolution establish for themselves and for the clerk of the district a lower rate of pay than is fixed by this section. They shall file with the auditor or auditors, if more than one county, itemized, verified statements of their time devoted to the business of the district and of the expenses incurred.
Iowa Code § 468.531