'Stealth' structure to replace Eagan water tower

Eagan's landmark Sperry Water Tower is about to give way to a slimmed-down "stealth" communications structure.

A preliminary version of the new look shows wraparound rings that will hide cell and radio antennas. It could feature colored lighting, and the time of day.

The new structure, which the City Council unanimously approved last week, likely won't rise until 2016, according to a projection from Russ Matthys, the city's public works director

That's in part because council members, with public advice, first must decide on the aesthetics.

Options include colored rings or colored internal or external lighting of the rings.

Council Member Paul Bakken suggested looking into the cost of having the rings display the time of day. Council members likely won't be able to schedule an informal discussion on the structure's appearance until February, Matthys said.

Construction, expected to take eight to nine months, likely wouldn't begin until May, putting the possible completion date in February 2016.

The 500,000-gallon, 146-foot-tall pillar tank has stood since 1967, but gone unused since 2009. It will be removed as part of the project.

The new structure will replace the Sperry tower as an antenna base for private cellphone service and ­public users, including Dakota County and the city of Eagan. It will go on city property just south of the existing tower.

It won't please everyone.

Eagan resident Roger Holm, said he and his wife live "in the shadow of the present tower" and would prefer keeping it or any of three other proposed designs over the stealth approach.

His wife described the stealth design as resembling "a tin can on top of a Tinkertoy tower." He said it reminded him of water towers "in economically disadvantaged parts of the country" where "that's the best they could afford."

But maintaining the old tower as an antenna base costs more than building a new one for that purpose.

"What we're trying to do is to kind of right-size the equipment to its function today," Maguire said. "We'll talk about the aesthetics and how to gussy it up."

The 194-foot stealth tower would cost $1.2 million to build but would pay for itself in nine years, Matthys told council members in presenting a ­consultant's cost analysis.

Cellphone companies and other private users will pay for the new tower through their lease fees, officials say; taxpayers are not footing the bill.

Reconditioning the Sperry tower would cost $764,000 and would require increasing levels of maintenance over a 20-year life span, Matthys said.

The stealth design also would have space for additional antennas, which could increase the city's revenue from the new tower, Matthys said. "We can't do that with the existing structure," he said.

Antenna income has been rising and is expected to average $217,000 a year in each of the next 10 years. The city estimates that antenna revenue from private users this year will top $155,000.

The rings can be any color the council chooses, Matthys said, as can internal or external lighting on the rings. Council Member Cyndee Fields said she would prefer internal lighting and overall colors like those of the city's other water towers, which generally blend into the sky.

Addressing Holm, Maguire said he believed the tower can be "very innocuous and even attractive."

"There are ways both with lighting and with coloring to do that and to keep it within a reasonable cost and still reap the financial benefits of an earlier payback and a more sustainable long-term revenue stream to the city, which is ultimately what we're trying to protect here," Maguire said.

The other designs under consideration were building a monopole antenna tower or a self-supporting tower.

Each was estimated to cost $680,000. But both would require relocation of some private antennas and leave remaining antennas exposed, raising aesthetic concerns.

Another option, billed as the "green approach," called for getting rid of the existing tank but reusing the existing pillar and hiding antennas behind stealth rings.

That was the most expensive proposal, at a cost of $1.65 million, and would require more-expensive future maintenance.