Except as herein otherwise provided, refunding bonds issued hereunder shall be authorized and issued in the manner provided in this chapter for the authorization and issuance of other bonds of such drainage project, and except as above provided no notice or hearing of any kind shall be necessary to the authorization, sale or issuance of such refunding bonds or to the readjustment of assessments or levy additional or new assessments as herein provided, and it shall not be necessary that any orders or resolutions of the board of viewers incident thereto have court approval.