The board of viewers shall also assess the benefits that will accrue to the right-of-way of the company by affording better drainage or a better outlet for drainage, as provided in § 21-359, in the case of highways; but no benefits shall be assessed because of the increase of business that may come to the road because of the construction of the improvement. The benefits shall be assessed as provided in § 21-334, and it shall be reported by the board of viewers as an assessment, due from the railroad company; and unless the same is paid when due by the company as an assessment, it may be collected in the manner of an ordinary debt in any court having jurisdiction; but the board of viewers of each drainage project shall have the right to enter into contracts with any such railroad company looking to a further assessment by virtue of the benefits received under this chapter.