The county legislative authority shall thereupon enter an order authorizing the contemplated extraordinary maintenance work to be done and authorizing the issuance of temporary construction warrants to pay the cost of said work as it progresses, which warrants may bear interest at such rate or rates of interest as the county legislative authority shall determine. Warrants to pay the costs of such extraordinary maintenance may be issued and sold at one time or from time to time and in such series and amounts as may be found practicable and as determined by the board.