Welcome to the Illinois Association of Drainage Districts Website! IADD supports and strives to maintain the integrity of Illinois Drainage Districts. As one of the smallest forms of government, drainage districts have organized local groups of landowners; successfully draining small watersheds over the years to harmonize with Mother Nature.  Not only has Good Drainage made a positive impact on the agriculture industry through the years but Good Drainage also makes a better environment, absorbs stormwater runoff and reduces the chance of water-borne diseases.