That in any drainage district created, organized and existing under and by virtue of chapter 215 of the Session Laws of 1905, and acts amendatory of or supplemental thereto (chapter 24, article 4, Kansas Statutes Annotated, and acts amendatory and supplemental thereto), lying within or partly within any city of the first class, and embracing within the boundaries of such district, property of the assessed valuation of thirty million dollars ($30,000,000) or more, whenever, in the opinion of the board of directors of such district, the dikes or levees are of insufficient height, or in cases where the dikes or levees are of unequal or insufficient height, strength, or width on either bank of a river or stream, or in cases wherein dikes or levees are deemed by the board of directors to be weakened, out of repair, and in need of construction, reconstruction, rebuilding or repair, and that such dikes or levees, for any of the reasons above enumerated, are insufficient to provide adequate flood protection to the inhabitants and the property or any part thereof. The board of directors of such district may forthwith proceed to remedy such defective and unsafe conditions; and they are hereby authorized and empowered to take all necessary steps to remedy such conditions and pay therefor out of the funds derived from the bond issue as hereinafter provided: Provided, however, That nothing herein contained shall be construed to change or modify the existing statutes with reference to the specific uses for which the general fund of the district may be expended.