Ark. Code Ann. § 14-120-221

The duly constituted board of assessors of the levee district or drainage district, or levee and drainage district in which the flood control and drainage works may be constructed, which contains within its boundaries lands lying in more than one (1) county and which may hereafter desire to avail itself of the powers and authority and benefits conferred by this subchapter, shall constitute a board of assessors for the purpose of ascertaining, determining, and fixing the increase in value, or betterment, which will annually accrue to the lands, town lots, blocks, railroads and tramroads, telegraph and telephone lines, and electric power lines, and all other real property situated within the boundaries of the district.