Sec. 18. (a) The works board may let a general contract for the making or repairing of all sidewalks or curbs of a specified material within the unit. The contract shall include an agreed price per square yard for the sidewalk construction.
(b) If the contract is for work in a municipality, the contract may also specify the following:
(1) The price per cubic yard for excavation and filling.
(2) The price per lineal foot for curb.
(c) The letting of a contract under this section is governed by the statutes regulating contractual authority of the unit.