The U.S. Department of Transportation, Federal Highway Administration (FHWA) and the South Dakota Department of Transportation (SDDOT) propose to construct a regional arterial roadway on the northeastern edge of the City of Sioux Falls, South Dakota. The proposed roadway is a portion of the larger proposed East Side Corridor, which has also been referred to as South Dakota Highway 100 (SD100).

WAPA’s Proposed Action would include the following items:

  • Raise and relocate multiple WAPA structures along the Gavins Point – Sioux Falls and Brookings – Sioux Falls transmission lines,
  • Modify WAPA’s Sioux Falls Substation by relocating the septic system and relocating the access driveway onto WAPA property,
  • Coordinate and execute temporary access agreements and easement outgrants to be issued to SD​​​​​DOT, and
  • Construct an above ground drainage system along WAPA’s Sioux Falls substation.

The East Side Corridor was first introduced in 1995 and was the subject of an Environmental Assessment (EA) and a Supplemental EA, both published in 2003. In 2014, a second EA provided an independent evaluation of Phase 1 (I-90 Exit 402 and Madison Street) of the East Side Corridor.  The EA was reevaluated in 2016 to provide a more in-depth description of WAPA’s Proposed Action, among other revisions.  WAPA participated in the 2016 reevaluation as a cooperating agency.  In 2017, FHWA and SDDOT completed a third site-specific evaluation to describe off-site tree and stream mitigation sites.

For more information, please contact Christina Gomer, WAPA NEPA Coordinator, at (406) 255-2811 or

Last modified on August 8th, 2023