Irrigation System by Tailwater Recovery on Agricultural Land in the Conterminous United States, 1992: National Resource Inventory Conservation Practice 447
This data set represents the estimated percentage of the 1-km grid cell that is covered by or subject to the 
agricultural conservation practice (CP447), Irrigation System by Tailwater Recovery (ISTR) on agricultural 
land by county.  Irrigation System by Tailwater Recovery is described as "a planned irrigation system …