Mich. Comp. Laws § 280.477

Sec. 477. If, for any reason, the original assessments shall not be sufficient to pay the principal and interest on bonds issued in anticipation of the collection thereof, then the drainage board shall make such additional assessments therefor as may be necessary, apportioned as in the first instance, it being the intention hereof that the collections on assessments shall, under all circumstances, be sufficient to pay said principal and interest.