Section 18. Bonds may be issued under this chapter without obtaining the consent of any department, division, commission, board, bureau or agency of the commonwealth or the municipality, and without any other proceedings or the happening of any other conditions or things than those proceedings, conditions or things which are specifically required therefor by this chapter, and the validity of and security for any bonds issued by the commission shall not be affected by the existence or nonexistence of any such consent or other proceedings, conditions or things.