Site Information: 

Applicant: Nick Gamble, Xcel Energy

Site Address: 1260 70th Street

Property Owner: Northern States Power Company

Lot Area: 59.58 acres

Zoning District: I-1, Light Industry

2040 Comp. Plan: Utilities

Nick Gamble of Xcel Energy has applied for a two conditional use permits; a (CUP) for an over-height structure and a utility service structure and a variance to the construction materials / design requirements to construct a 20,000 square-foot building for power generation at the Xcel Energy Blue Lake facility. The proposed development involves the decommissioning of the four existing oil-fired turbines and 2.5-million-gallon fuel storage tanks and the construction of a new facility with three reciprocating internal combustion engines, two 100,000 fuel tanks, five backup generators and other associated equipment.

Utility Service Structure CUP Discussion: 

A utility service structure is defined in City Code as: Any building or structure necessary for the operation of public or private utility services. This does not include water towers or electrical substations, or any buildings constructed to house sanitary lift station controls.

In the I-1, Light Industry Zone, Electrical Substations are a listed conditional use. Staff's interpretation regarding the zoning is that the power generation plant is a similar use to an electrical substation and requested the applicant include this application as part of their application package for a variance and over-height structure conditional use permit. Xcel currently operates a substation that is adjacent to this site that is part of the Blue Lake complex. 

This development is located on the south side of the Blue Lake facility and will impact several high priority trees. High priority trees are defined as trees of an exceptional species greater than 15" in diameter, such as White Oak, Black Cherry, or Walnut.  The applicant has worked to minimize impacts to the wooded area on the south side of the site and has agreed to replace trees consistent with City Code requirements and has provided a replacement plan that involves planting trees in some of the open areas on the south side of the site that will help to screen this facility. 

Over-height Structure CUP Discussion: 

The I-1, Light Industry zone allows for up to 45' tall structures. Structures greater than 45' in height require conditional use permits. Xcel's Blue Lake facility currently has several over-height structures, including 145' tall transmission structures and 77' tall H-structures, and the stacks for the turbine generators. 

Three four-foot diameter 95' tall stacks are proposed as part of the project for the exhaust of the three engines. The height of the stack is determined by emissions requirements. Having stacks of a reduced height is not permitted for this facility by other agencies. 

Up to an additional eight poles at 80' in height and H-structures up to 62' in height are also included in this request for connections to the transmission network and lightning protection. The silencer and equipment on the roof of the proposed engine building is 53' in height. 

City Code requires over-height structures to be setback at least half their height from lot lines. All of the proposed over-height structures are roughly 400' from the nearest lot lines (US Highway 169 right-of-way and Quarry Lake Park) and over 700' away from properties on the south side of US Highway 169. Due to the diameters of the tallest over-height structures being 4' or less and the distances from adjacent lot lines, the shadows cast off-site are very limited and only at specific times of the year for limited times because all of the structures are at least 4x their height from a lot line. Quarry Lake Park is the closest adjacent property at 400' away and city staff have no concerns about the very limited off-site shadows at specific times of year. 

Variance Discussion: 

The proposed building houses three large engines to generate electricity. Due to the amount of noise and vibrations generated by the engines, the design team for the building is requesting a variance to simplify the building design for sealing purposes for noise and the various equipment and wall penetrations required for this project. 

The proposed building is 375' from the south lot line of the site and will be located behind groves of mature trees. Off-site views from US Highway 169 of the Blue Lake facility are also obstructed by the topography of the site. The applicant is proposing to remove some of the trees on adjacent to the building and proposes to plant trees within the current open areas between the facility and Highway 169. 

Neighborhood Comments: 

Xcel Energy hosted a neighborhood meeting on January 30th. No residents attended the meeting. Planning staff received one telephone call from a resident from Classics at Southbridge with basic questions relating to the request and they had no concerns about the proposal and support Xcel Energy's request.