At the date appointed for the hearing the clerk of court shall hear and determine any objections that may be offered to the report of the viewers. If it appear that there is any land within the proposed levee or drainage district that will not be affected by the leveeing or drainage thereof such lands shall be excluded and the names of the owners withdrawn from such proceedings. And if it shall be shown that there is any land not within the proposed district that will be affected by the construction of the proposed levee or drain the boundary of the district shall be so changed as to include such lands and such additional landowners shall be made parties plaintiff or defendant, respectively, and summons shall issue accordingly, as hereinbefore provided. And any landowners whose lands were within the original levee or drainage district, who were not summoned by the clerk when the petition was filed and whose names have since been ascertained by the clerk, shall be made parties plaintiff or defendant, respectively, and summons shall issue accordingly, as hereinbefore provided. After such change in the boundaries is made, the sufficiency of the petition shall be verified to determine whether or not it conforms to the requirements of the statute as provided in § 49-17-220. The engineer and the other two viewers may attend this meeting and give any information or evidence that may be sought to verify and to substantiate their reports. The efficiency of the drainage or levee may also be determined and if it appears that the location of any levee or drain can be changed so as to make it more effective, that other branches or spurs should be constructed or that any branch or spur projected may be eliminated or other changes made that will tend to increase the benefits of the proposed work such modification and changes shall be made by the board of viewers. If necessary the petition, as amended, shall be referred by the clerk of court to the engineer and two viewers for further report.