When employing this chapter, the chairman of the drainage board in chapter 20 proceedings or the secretary of the drainage board in chapter 21 proceedings shall prepare a special assessment roll which shall contain the name of each public corporation assessed, the total estimated or actual cost of the project, the fixed percentage of the cost, if any, apportioned to public corporations and to the state or counties for drainage of highways, the aggregate amount assessed at large against all other public corporations, and if the assessment is divided into annual installments, the amount of each installment, listed separately for the state and counties and for public corporations assessed a fixed percentage if applicable, and in the aggregate for all other public corporations. After approval of the roll by the drainage board, the chairman shall then send a certified copy of the roll to each public corporation assessed.