Data center substation on Kimball Bridge Road goes to council

A data center owner wants to build a Georgia Power substation 40 feet from Kimball Bridge Road to power an expansion at 4905 North Point Parkway. City staff recommend approval. The Alpharetta City Council is scheduled to decide Monday, Oct. 26.

The request is from GI Partners, the city’s staff report says. It is in the packet for the Planning Commission’s Oct. 1 meeting, which heard the case. The city has not yet posted the commission’s minutes or its recommendation.

The site is the 38.68-acre data center at the northeast corner of Kimball Bridge Road and North Point Parkway, in the Royal 400 office park.

Why a substation, and why there

The expansion is not new. The city approved a data center of up to 245,200 square feet on the site in 2008, and the existing 184,947-square-foot building was built in 2009, the report says. The 60,200-square-foot addition now planned fills out that approval.

The city issued a land disturbance permit for the addition in August 2024, and site work started right after. According to the applicant, Georgia Power then asked it to build its own substation on the property, to free up capacity at the Georgia Power substation across Kimball Bridge Road that serves the site now. Work stopped until the city decides.

Staff asked the company to look at a less visible spot. It drew one on the south side of the building. But Georgia Power needs a 300-foot-wide corridor for overhead lines from there, which would cut through hundreds of trees along North Point Parkway, the report says. So the company kept the Kimball Bridge Road location. It also told the city that hydrogen fuel cells were not workable because of noise and emissions.

Staff could not find another data center in the city with its own on-site substation.

What the company is asking for

The requests are numbered MP-26-13, CU-26-11 and V-26-19. They would:

• add “utility substation” as an allowed conditional use in the Royal 400 master plan
• allow a substation of about 220 by 290 feet, roughly 1.5 acres, in the northwest corner of the site
• cut the undisturbed tree buffer along Kimball Bridge Road from 100 feet to 40 feet where the substation goes
• allow screen walls up to 22 feet tall around it, against the city’s usual 8-foot limit

According to the applicant, 22 feet is about the height of the tallest equipment. The road sits above the site, so the wall would stand about 20 feet above Kimball Bridge Road, the report says. Nearly two-thirds of the wall would be at least 100 feet back from the road.

What it would cost in trees and traffic

The 1.5-acre substation would take about 4,528 caliper inches of trees, based on the applicant’s sampling, the report says. One of the site’s 17 specimen trees, a 36-inch water oak, would be removed for the building addition.

The applicant estimates the expanded data center would generate 26 trips in the morning peak hour and 21 in the evening peak hour.

The conditions staff want

Staff recommend approval with 29 conditions. The new ones include:

• the substation may serve only this property, with no other connections
• a noise study proving the substation meets the city’s noise ordinance, before the expansion can open
• heavy replanting between the road and the walls where the buffer is sparse
• a 20-foot landscape strip along the existing Georgia Power substation across the road, instead of the screen wall the company offered there

Staff also want to drop a piece of the 2008 approval: a six-story, 175,000-square-foot office building and parking deck at the corner of Kimball Bridge Road and North Point Parkway. The substation takes up about the same land, so the site would be limited to the data center and its expansion.

Staff argue the arrangement puts “the financial burden of electrical grid upgrades with the data center and not with the energy provider or its customers.”

The applicant mailed letters to owners within 500 feet and received no comments, the report says. Nobody commented at the community zoning meeting June 10. Staff did get questions from the public about the plan.

What it means for you

• If you drive Kimball Bridge Road near North Point Parkway, this is where a 20-foot screen wall and a thinner tree line would appear.
• The decision is the City Council’s. The meeting is scheduled for 6:30 p.m. Monday, Oct. 26. The agenda is not posted yet; it will be on the city’s meetings portal.
• Read the whole file, including the site plan and the wall designs, in the Oct. 1 Planning Commission packet.
• Our building permits and zoning guide explains how rezonings and variances work in Alpharetta.