Why the 'Best' Power Line Route Won't Work

There’s an adage that with enough time and money, we could engineer anything.

The classic example is, “We could build an elevator to the moon” — if it weren’t impossibly expensive.

But why can’t American Transmission Co. run a power line along what most people think is the most direct and sensible route from the source of power to the place it’s needed?

Apparently, it’s impossibly expensive.

The wide and straight Plank Road route

In the ongoing debate over how to , one route has stood out from the beginning, to nearly everyone involved, as the best and most obvious choice.

The additional power, one of two new 138,000-volt lines, could come straight down Watertown Plank Road.

The grid power lines — 10 heavy wires supported on twin sets of towers — run north and south between North 119th and 120th streets where they cross Watertown Plank.

From there, it is a straight shot along the wide thoroughfare to the We Energies power station across from the Milwaukee Regional Medical Center. The new power line will go, by whatever route is chosen, to a new substation behind that power plant.

The clear logic is that if you’re looking for the cheapest underground route, it should also be the shortest. According to City Attorney Alan Kesner, it is estimated that buried power lines of the capacity required in this case cost about $4 million a mile.

So, any deviation from the most direct route — including the currently proposed modified route along Walnut Road — will add significantly to the final cost.

There is also the argument that Watertown Plank is wider, is a thoroughfare as opposed to a purely residential street, and is already a utility corridor. The lines could be buried under the roadway with minimal interruption of commerce, the common thinking goes.

As a final point in its favor, a lot of the work could theoretically be done while much of that stretch of Watertown Plank is being rebuilt anyway during the Zoo Interchange Project.

Insurmountably costly impediments

So, again, why didn’t American Transmission Co. propose it in the first place, and why are consulting engineers hired by the city not proposing it now?

As late as last week, during a presentation by Kesner on alternate routes, Ald. Jason Wilke expressed some frustration that the Watertown Plank route was being dismissed without much discussion.

“People keep asking, ‘Why not?’ and we’re not getting an answer,” he said.

Kesner said he would try to oblige, prefacing his remarks with, “I am not an engineer, so I’m taking on faith what I’m being told.”

Engineers, he said, identified two insurmountable impediments along Watertown Plank between the grid and the County Grounds.

The first to be encountered, he said, is the “stack” of infrastructure where Watertown Plank crosses Underwood Creek just west of North Mayfair Road.

Too low to go under

Starting from the bottom and going up, first there is the creek itself. It’s a natural feature, but hardly in a natural state.

Underwood Creek beneath Watertown Plank Road runs through an artificial, V-shaped concrete channel carved deeply below the surrounding grade.

So deep is the bottom of the channel, Kesner said — or so engineers told him — that directional boring beneath it would be prohibitively costly.

The base of the channel may even be perched upon or just above the hard dolomite bedrock of the area, although Kesner said this week that he could not confirm that from any information he’s been given.

Running just west of the creek channel and closely parallel to it is the double-track mainline of the Canadian Pacific Railroad. A buried route would have to pass deeply under that as well, adding more directional boring, as opposed to cheaper trenching.

Above that is the split, elevated roadway of Watertown Plank Road itself, running on long, twin overpasses that stretch from North 113th Street almost to Mayfair Road.

Apparently, suspending the power line beneath one of the overpasses is also not considered an option, deemed insecure. ATC wants its lines either safely underground or swooping high above ground.

Too high to go over

Even the prospect of bringing the line back into the air on towers for a short distance there is stymied — because the “stack” keeps going up.

Above even the soaring Watertown Plank overpass is the double-track Union Pacific Railroad trestle, a huge steel lattice that stands like a fortification between power source and power need.

Towers tall enough to pass safely over that wall of rusty metal would have to be tall indeed, and even above the rail trestle — well above — there is already a thick web of older utility lines serving the area.

Even if there were a way to get past that terrific tangle, another more or less invisible one lurks a few steps away.

'The spaghetti bowl' of Mayfair Road

The second major impediment is the intersection of Watertown Plank and Mayfair roads, although you couldn’t tell just by slowing down to look at it.

If, however, you could somehow peer underneath the pavement, or slice the intersection open and see in cross-section what’s below it, you would view what Kesner called “a spaghetti bowl” of existing utilities crowding the right-of-way from side to side and top to bottom.

So many oversized sewer, water, gas and existing electrical lines, communications conduits, and all their feeders going every which way, converge under that intersection, it is something like the cardio-pulmonary system of the area.

Considering that much of that utility infrastructure does serve the Medical Center and , with their critical needs for each and every one of those services, uninterrupted, the analogy is apt.

There is just not room for more, Kesner said the engineers have told him — except, again, at a prohibitive cost.

Settling on, but under, Walnut Road

The result of the city alone — or even any combination of the group of “intervenors” allied with Wauwatosa in opposing the two original ATC route proposals — insisting on the Watertown Plank route at any cost, would be for the Public Service Commission to reject it, Kesner said.

The city would likely then be left facing one of those two routes considered so objectionable that it .

They are: Overhead wires along a considerable stretch of ; or underground lines along four blocks of Walnut Road and buried in the public right-of-way fronting the homes on the street’s north side.

Kesner, speaking not only for himself and the city’s consulting engineers and attorneys, but also for the consensus of the intervening group of entities, has asked the Common Council but buried beneath the roadway rather than through residents’ front yards.

The intervenors registered to challenge ATC’s proposed routes in front of the PSC are, besides Wauwatosa: the City of Milwaukee, Milwaukee County, Milwaukee Montessori School, Wisconsin Lutheran College and People Friendly Power.

What's next

The next debate of the power line routes, and possibly the first committee recommendation to the Common Council, will come next Tuesday before the Community Development Committee, meeting at 8 p.m.

If there is a recommendation next week, the question would go to the full council a week later, on July 17.