Planners approve Great River Energy’s Pilot Knob substation upgrade; variance granted for enclosure setback

The Eagan Advisory Planning Commission on Dec. 19 recommended approval of a variance to the minimum structure setback and a conditional use permit for Great River Energy’s planned rebuild and upgrade of the Pilot Knob substation at 4380 Pilot Knob Road, voting unanimously on both actions.

Pam Duzyak, the city planner presenting the application, said Great River Energy proposes to rebuild, expand and modernize the existing Pilot Knob substation and to upgrade about 8.5 miles of transmission line between Pilot Knob and the Burnsville substation to allow future capacity increases from 69 kilovolts to 115 kilovolts. The project includes removal of older equipment, installation of new equipment and an approximately 55-foot eastward expansion of the existing gravel pad.

Duzyak told the commission the tallest proposed tower structures are 57 feet with lightning rods extending to 67 feet. The electrical enclosure building would measure about 24 by 36 feet and is shown at roughly 20 feet from Wilderness Run Road, which is short of the normal 30-foot setback from a public right of way; that proximity requires the requested variance. Within the Public Facilities zoning district, Duzyak said, a 50-foot setback applies to structures over 25 feet tall and that required setback would be met for the taller towers and other equipment.

Duzyak also noted tree-preservation issues: several on-site trees — including three amber maples identified as a specially regulated invasive plant in the staff memo — would likely be removed. Public utilities are generally exempt from tree-preservation rules, Duzyak said, but the staff report asks the applicant to provide an effective screening plan for views from public rights of way and adjacent residences.

Engineering and utilities: city staff said grading the extended gravel pad will establish a drainage swale along the east side; a grading permit is not required and post-construction stormwater requirements do not apply. Surface runoff is expected to drain to the northeast into the public storm sewer system and ultimately to Carlson Lake. City Well Number 15 sits on the property; staff said Great River Energy must provide easements for well access and maintenance.

Great River Energy project lead Anson Belcourt said the substation has reached the end of its useful life and needs rebuilding independent of the capacity upgrade; the expansion is needed to increase load capacity to customers in the Eden area. Belcourt said the initial rebuild will remain at 69 kV and quieter transformers are planned; when transmission work later shifts the line to 115 kV, the existing 69 kV transformers will be removed.

Neighbors’ concerns and screening: resident Mark Strohfus asked whether the new equipment would be larger or more visually intrusive. Great River Energy representatives said trees on the north side of the parcel and plantings in yards already block much of the view and committed to exploring landscape screening options; arborvitae plantings approximately 5 feet from the fence line were specifically discussed as a potential screening solution.

Public outreach: staff and Great River Energy said notices were mailed for the hearing and that the company conducted two open houses for residents during earlier outreach. No members of the public spoke during the hearing and staff reported no written comments in the record for the meeting.

Commission actions: Commissioner Whitfield moved to recommend approval of the variance to the 30-foot setback with three conditions; the motion passed 6-0. Whitfield then moved to recommend approval of the conditional use permit for the substation in the Public Facilities zoning district subject to eight conditions; that motion also passed 6-0. The applications are scheduled for Eagan City Council consideration on Jan. 7. Staff recommended the conditions in the planning report be included for city review and permit follow-up.