Surface Drainage-Main or Lateral on Agricultural Land in the Conterminous United States, 1992: National Resource Inventory Conservation Practice 608

These data were released prior to the October 1, 2016 effective date for the USGS’s policy dictating the review, approval, and release of scientific data as referenced in USGS Survey Manual Chapter 502.8 Fundamental Science Practices: Review and Approval of Scientific Data for Release. This data set represents the estimated percentage of the 1-km grid cell that is covered by or subject to the agricultural conservation practice (CP608), Surface Drainage, Main or Laterals (SDML) on agricultural land by county. Surface Drainage, Main or Laterals are described as "an open drainage ditch constructed to a designed size and grade. [As] part of a water management system to collect and convey excess surface or subsurface water.