(1)    Competitive bidding required. Except as otherwise provided in this section, all work to be let relative to the construction, repair or maintenance of a harbor or harbor facility and all purchases of equipment, supplies or materials relative to carrying out the purposes of the statutes relating to harbors shall be by contract awarded to the lowest competent and reliable bidder in accordance with the laws of this state and ordinances then applicable to such municipality with reference to the letting of public work.

   (2)   Board of harbor commissioners to have charge of letting contracts. If a municipality has established a board of harbor commissioners, such board shall be in charge of the letting of contracts relative to construction, repair or maintenance of a harbor or harbor facility or the purchase of equipment, supplies or materials relative to carrying out the purposes of the statutes relating to harbors, in lieu of the officer or agency which otherwise would be in charge of the letting of public work, except that if the board determines that it is not equipped to handle the contracting formalities required under this section, it may by resolution delegate all or part of its functions under this section to the agency which ordinarily performs such functions for the municipality.

   (3)   Exceptions to competitive bidding. Subsection (1) does not apply in any of the following cases, and work to be done or equipment, supplies or materials to be acquired may be contracted for or acquired without competitive bidding and in such manner as the officer or agency in charge of the work or acquisition may direct:

      (a)    The work to be done or equipment, supplies or materials to be acquired will cost less than $25,000.

      (b)    The work to be done or equipment, supplies or materials to be acquired involve marine construction or repair work requiring the use of floating scows, pile drivers or other floating equipment and will involve an expenditure of less than $50,000.

      (c)    The equipment, supplies or materials to be acquired is a patented article or process or an article or process made by one party only.

      (d)    The work to be done or equipment, supplies or materials to be acquired involves an emergency repair as set forth in sub. (4).

   (4)   Emergency repairs. Whenever repairs become necessary to any harbor facility which, in the judgment of the official having executive charge of such facility, constitutes an emergency in that it interrupts the ordinary use and operation of such facility, such official may order such repairs to be made by some competent party without compliance with sub. (1) or the intervention of a formal contract. In all cases of such emergency repairs the official causing the repairs to be made shall report the circumstances thereof, including the agreed price or estimated costs of the repairs, to the officer or agency in charge of the operation of the harbor and shall also forthwith send a copy of such report to the clerk of the municipality or, in the case of a city, to the chief auditing officer. Whenever any party is liable, under a lease or otherwise, to reimburse such municipality for repairs or cost of maintenance of such harbor facility, the official causing the repairs to be made shall also send a copy of such report to the party so liable.

   (5)   Competency and reliability of bidders. Whenever any bidder for any work to be let by an officer or agency in charge of a harbor is, in the judgment of such officer or agency, incompetent or otherwise unreliable for the performance of the work for which the bidder bids, the officer or agency may accept the bid of the person who, in its judgment, is the lowest competent and reliable bidder for such work, stating its reasons therefor, or may relet the same anew. Such officer or agency may permit a sum of money or a certified check payable to its order to be filed with any bid or proposal in such an amount as in its judgment will save the municipality from any loss if the bidder fails to execute a contract pursuant to law, in case the bidder’s bid is accepted and the contract awarded to the bidder.

   (6)   Contracts to provide for liquidated damages. Every contract executed pursuant to sub. (1) shall contain either of the following agreements on the part of the contractor and the contractor’s sureties:

      (a)    An agreement that in case such contractor fails to fully and completely perform the contract within the time therein limited for the performance thereof, the contractor shall pay to the municipality as liquidated damages for such default, a fixed sum to be named in the contract, which shall be such a sum as in the judgment of the officer or agency in charge of letting the contract will save the municipality harmless on account of such default and insure the prompt completion of the contract; or

      (b)    An agreement that in case such contractor fails to fully and completely perform the contractor’s part of the contract within the time therein limited for the performance thereof, the contractor shall pay to the municipality as liquidated damages for such default, a definite sum to be named in the contract for each day’s delay in completing such contract after the time therein limited for its completion, which daily sum shall be such an amount as in the judgment of the officer or agency in charge of letting the contract will save the municipality harmless on account of such default and insure the prompt completion of the contract.

   (7)   Contracts to be executed by sureties. Every contract executed pursuant to sub. (1) shall also be executed by at least 2 sufficient sureties, or a surety company, to be approved by the officer or agency letting the contract. Such sureties or surety company shall guarantee the full performance of the contract by the contractor to the satisfaction of such officer or agency, according to the plans and specifications of such officer or agency, and shall be liable for such performance of the contract, as sureties, in an amount equal to such officer’s or agency’s estimate of the aggregate cost of the work.

   (8)   Payment before completion of contract. When a contractor proceeds properly and with due diligence to perform a contract, the officer or agency which let the contract may, in its discretion, from time to time as the work progresses, grant to the contractor an estimate of the amount already earned for the work done, withholding in all cases until final completion and acceptance of the contract 15 percent of such estimate when such estimate is less than $100,000, and 10 percent of such estimate when such estimate is $100,000 or over, which shall entitle the contractor to receive such estimate less the amount withheld.

   (9)   Optional contract provisions. The officer or agency in charge of negotiating the contract may insert in the specifications of the work reasonable and lawful conditions as to hours of labor and the residence and character of workers to be employed by the contractor and especially, so far as is practicable in the judgment of such officer or agency, such reasonable and lawful conditions as will tend to confine employment on such work, in whole or in part, to permanent and bona fide residents of this state. The officer or agency may do any part of such work by day labor under such conditions as it prescribes. The officer or agency may demand of such bidders and contractors that all contracts shall be let subject to chs. 102, 103 and 105, to the end that the officer or agency and municipality shall be held harmless. The officer or agency may reject any or all bids or parts thereof for any such work or supplies or materials.

   (10)   Conflicts with federal regulations. Contracts for projects involving federal funds shall be let under such regulations and conditions as are prescribed by the federal agency controlling such funds, so far as such regulations and conditions conflict with this section.