After twenty days from the adoption and publication of such resolution of necessity, unless the referendum be invoked or unless a written protest shall have been filed with the auditor or clerk signed by the owners of more than fifty-five percent of the total tax-assessed valuation of the property subject to assessment, the governing body shall have the power to acquire property by lease, gift, or purchase, to cause such improvement to be made, to contract therefor, and to levy and collect special assessments therefor as provided by chapter 9-43.
SDCL 9-53-12