(1) The purpose of this section is to avoid situations arising where the boundaries of an existing city and a newly incorporated city would create a situation described in RCW 35.13.310(1).

(2) A boundary review board that reviews the boundaries of a proposed incorporation may enter into an agreement with the council of a city, that would be in a situation described in subsection (1) of this section as the result of a proposed incorporation of a city, to adjust the boundary line of the city and those of the city proposed to be incorporated to avoid this situation described in subsection (1) of this section if the incorporation were to be approved by the voters. Such an agreement shall not be effective unless the incorporation occurs.

The incorporation proposal shall proceed if such an agreement were not made, but any resulting boundaries between the two cities that meet create a situation described in RCW 35.13.310(1) shall be adjusted by agreement between the two cities within one hundred eighty days of the official date of the incorporation, or the county legislative authority of the county within which the right-of-way is located shall adjust the boundaries within a sixty-day period immediately following the one hundred eightieth day.

An agreement or adjustment made by a county under this section shall include only boundary line adjustments between the two cities that are necessary to eliminate the situation described in RCW 35.13.310(1).

A boundary line adjustment under this section is not subject to potential review by a boundary review board.