Ark. Code § 14-121-411
In case any land in any drainage or other improvement district is benefited, and for any reason it was not assessed in the original proceedings, or was not assessed to the extent of benefits received or in case any corporation, individual, or other drainage district organized under this or any other general or special act, outside the limits of any district organized or operating under the terms of this act, shall drain land into any ditch belonging to any district formed or operating under the terms of this act, the commissioners of the drainage district shall assess the benefits or the enhanced benefits received by the land, and the proceedings outlined in §§ 14-121-402 - 14-121-405 for assessing benefits to lands not included within the boundaries of the district shall in all matters be conformed with. However, this section and § 14-121-808 shall not operate to interfere with vested rights to natural drainage.
Ark. Code § 14-121-411