(2) Such drainage district or its assignee shall be entitled to a tax deed for said lands, in the same manner and subject to the same equities as if a private purchaser at said tax sale, upon the payment to the county treasurer at the time of demanding said deed of such sum as the board of county commissioners of such county at any regular or special meeting may decide for the payment of any delinquent general taxes, and if said deed is demanded by any assignee of the drainage district, then such assignee shall also pay to the county treasurer such additional amount as may be specified by the board of directors of the drainage district, as payment for any delinquent drainage district taxes.

(3) In case the owner of said lot or parcel of land, or interest therein, desires to redeem the same at any time before said tax deed is issued, the same may be done in the same manner as provided by law, in case said lot or parcel of land, or interest therein, has been purchased by a bidder at said tax sale or has been struck off to the county, and in such case the county treasurer shall forthwith issue a certificate of redemption therefor and notify the secretary of said fact, who shall thereupon make a suitable transfer entry upon his record aforesaid, and return the certificate of sale to the county treasurer for cancellation.

(4) In case any person desires to obtain such certificate of purchase so issued to said drainage district, the same may be done in the same manner as provided by law in case said lot or parcel of land, or interest therein, had been purchased by a bidder at said tax sale or had been struck off to the county, upon payment to the county treasurer of the required amount in cash, or in cash together with warrants not in excess of the drainage district and redemption fund tax, or in cash and in warrants and bonds and coupons respectively, not in excess of said respective funds.

(5) After any certificate of sale or tax deed has been issued to any drainage district, such drainage district or any assignee thereof may at any time commence an action in the district court in the county wherein the major portion of said drainage district lies, for the purpose of determining the validity of said tax sale. Such action shall be conducted in the same manner as an action to quiet title to real estate under the laws of the state; and after the final determination of such action, the validity of the taxes for which the property was sold and the legality of the proceedings taken in the sale of the property involved shall be incontestable between all persons and parties whatsoever.