Tex. Auxiliary Water Laws § 7853

If the district improvements are not carried out by the United States, the contracts for such improvements shall be let by the directors to the lowest and best responsible bidder. If more than one improvement is to be made, the contract may be let separately for each, or one contract for all such improvements. These rules shall govern the letting of such contracts: 1. Bids shall be called for by advertising the same in one or more newspapers of general circulation in Texas, once a week for four consecutive weeks, and by posting notices for at least thirty days at the courthouse door of the counties in the district and four other notices in each county. 2. Any person, firm, or corporation desiring to bid on the construction of any work so advertised, upon application to the district secretary, shall be supplied with the surveys and plans for said work. All bids shall be in writing and sealed and delivered to the president or district secretary, together with a certified check for two per cent of the total amount bid. Such deposit shall be forfeited to the district in case the bidder refuses to enter into a proper contract and make the necessary bond, if his bid is accepted or returned to the bidder if his bid is rejected. Any bid may be rejected at the discretion of the directors. 3. Each contractor shall give bond payable to the district in such amount as may be determined by the directors, not to exceed the contract price, and not less than fifty per cent thereof, conditioned that he will faithfully perform the obligations, agreements and covenants of such contract, and that in default thereof, he will pay to said district all damages sustained by reason thereof; and such other conditions as may be required by law of contractors for public work. Said bond shall be approved by the directors. 4. All contracts shall be in writing and signed by the contractors and president of the directors and attested by the district secretary. A copy of same shall be filed with the clerk of the county in which the largest portion of such district is situated.