Exclusion from district; boundary adjustments.

Upon a finding by the secretary of the district that the boundaries of a district established pursuant to the Flood Control District Act incorporate an area of less than thirty-five percent of the area of an existing voting precinct lying along such boundaries, or which minor area appears not to benefit or feasibly expect to benefit from the district, or which may not be of sufficient valuation to the extent that its exclusion from the district would materially impair the district, then the secretary shall file his findings with the board with his recommendation that the minor area be excluded from the district in order that the voting precincts for the district shall become coterminous with the voting district for the county. If the board determines that it is in the best interests of the district that such area be excluded from the district, the board shall order that the area be excluded and that the secretary shall notify the county commission, county assessor and county clerk that the district boundary and the voting precinct boundary shall thenceforth be coterminous.