This is the third article in a four-part series that examines the complex relationship between green spaces, public policy and the urban heat island effect, while highlighting citizen-led strategies to mitigate the sweltering heat.

In Butchertown, these short trees have been planted underneath low-hanging power lines | Photo by Elijah McKenzie

Excessive urban heat is a condition unique to cities like Louisville, which has staked its entire economic future on automobile infrastructure.

Scholars have said this trend began on July 11, 1916, when President Woodrow Wilson signed the Federal Aid Road bill into law, which instituted a system of taxpayer-funded roadways that favored one mode of transportation in particular: the car.

Although this development presented a host of challenges like traffic congestion, air pollution and sprawl, things have slowly improved in recent years. Newer generations of working-class Americans have returned to the ethics of human-scale design, making urban environments desirable once again. Still, we remain tethered to our troubled past via outdated laws like anti-pedestrian zoning ordinances and parking requirements.

In an article for Streetsblog NYC, reporter Noah Kazis explained how these car-centric regulations are often stipulated by lending institutions that finance new developments: “In many parts of America, efforts to build transit-oriented, walkable communities are foiled because financing can’t be secured for projects that differ from the templates lenders have become used to since World War II.”

According to a recent study conducted by two U.S. Forest Service scientists, American cities have seen a rise in the use of impervious pavement at a rate of about 167,000 acres per year between 2009 and 2014. Meanwhile, during the same time period, those same cities have lost an average of 36 million trees each year.

Make no mistake — the widespread use of heat-absorbing asphalt in our city is a direct consequence of the prevalent over-reliance on cars and is a reason we’ve seen a decrease in tree coverage. But utility companies shoulder some of the blame for this as well.

As mentioned in the first installment, cities are designed for dense human activity, which often requires electricity to keep things hygienic and civilized. This necessitates the construction of power lines and utility poles that occupy easements along sidewalks and other public rights of way.

That’s not to say power lines and trees can’t coexist. In fact, Louisville Gas & Electric and Kentucky Utilities introduced the Plant for the Planet program in 2009, which offers grants of up to $5,000 for tree planting and landscape beautification efforts in urban, suburban and rural communities throughout its service area.

A residential tree has been trimmed in an ‘L’ formation to fit around power lines in the Highlands. | Photo by Elijah McKenzie

Strategically placed trees can provide shade and maximize social activity along high-volume pedestrian thoroughfares — all without disrupting utility wires overhead. So why do so many neighborhood streetscapes seem to be caught in a tangled mess of overgrown branches and power lines?

According to Harold Adams, a communications specialist for Louisville Metro Department of Public Works, there are no limitations on how many utility poles are allowed to be concentrated in a given area. None whatsoever. However, every new street in Louisville is required to provide joint trenches to accommodate underground utilities.

“A few of the overlays require newly installed utility services for non-residential developments to be underground or at the rear of lots along alleys,” Adams said, referring to guidelines in the Development Review Overlay Districts of Floyds Fork and Bardstown Road. In many ways, these provisions are an attempt to clear the overhead area of power lines to accommodate new tree growth.

Natasha Collins, director of media relations for LG&E and KU, said its “Right Tree, Right Place” guideline helps their workers determine which trees would be most ideal to plant adjacent to power line easements. The eastern redbud, for instance, grows to maturity at a height that falls five to 10 feet below distribution lines.

Collins confirmed that Louisville Metro does not impose any limits on utility pole density, noting that LG&E and KU’s pole placements are consistent with industry standards and regulations set forth by the Federal Energy Regulatory Commission.

“The number of utility poles in any given area is typically determined by the infrastructure, equipment and facilities necessary to serve the residential, business and other customers throughout the area,” Collins said in an email. “There are also federal regulations that require trees be kept a safe distance from overhead transmission lines to prevent them from falling into or even close to those lines, which has the potential to cause a widespread, large-scale power outage and is punishable by fine.”

Unfortunately, the aforementioned regulations have not been effective in determining how much sidewalk space can be forfeited to make room for a utility pole. Aside from being a potential impediment to canopy growth, overcrowded pole placements can also hinder pedestrian safety.

Two utility poles are obstructing nearly half the sidewalk in the St. Joseph neighborhood. | Photo by Elijah McKenzie

For proof, visit the St. Joseph neighborhood and take note of the large retaining pillars built right in the middle of the sidewalks. These utility easements have created bottlenecks along some of the busiest sidewalks in the areas surrounding the University of Louisville campus.

Clogged pathways like these are extraordinarily unsafe for non-motorists, particularly those who require wheelchairs or strollers to get by. These conditions discourage pedestrian mobility and force some of Louisville’s most vulnerable citizens directly in the path of danger just to circumvent the obstruction caused by utility poles.

With all the problems created by power lines, the question typically turns to the feasibility of burying the cables underground. After all, it would provide much-needed relief in heat-stressed areas that lack adequate tree coverage while storm-hardening the grid. The problem, as is often the case, is about the bottom line.

LG&E and KU estimates the cost of burying all transmission lines at about $1 million per mile, but that doesn’t mean it can’t be done. All it takes is a request from service customers, and LG&E and KU will look into the process of placing overhead wires below ground.

“The process begins with a request from the customer interested in having the lines buried,” Collins said in the email. “We work with the customer to address the request and the cost is borne by the customer making the request for the work.”

A study from the U.S. Energy Information Administration (EIA) asserts that underground lines would cost nearly 10 times more than the standard overhead variety, but that many of the expenses depend greatly on geographic settings.

Subterranean lines are generally more vulnerable to flooding, which can be problematic for cities that have high water tables like New Orleans. Alternatively, mountain towns like Colorado Springs are built on granite foundations that make it especially expensive to dig, drill and bury power lines.

It should be pointed out, however, that the EIA study was largely based on fieldwork from the Edison Electric Institute, an association that represents investor-owned utility companies like LG&E and KU. Industry studies of this nature rarely include estimates provided by publicly owned electric cooperatives, which raises questions regarding the true cost of power line burials. Indeed, energy co-ops throughout the U.S. have contended that industry experts inflate these prices.

Even short trees like the ones planted along this Butchertown sidewalk can provide a little bit of shade from the hot sun | Photo by Elijah McKenzie

A different study conducted by the Institution of Engineering and Technology — an organization based in the United Kingdom that currently does not represent the interests of private utility companies — estimated that burying transmission wires underground was only four to five times more costly than installing them overhead. That’s nearly half what the EIA study projected.

Places like Chicago and New York have found some success in burying their utility cables for relatively cheap by piggybacking off of construction projects that have already broke ground near buildings. Although this approach would weather-harden Louisville’s energy grid, the fact remains that underground infrastructures are most often successful in urban areas because it requires density to make it work.

Louisville stretches 399 square miles across Jefferson County and usually ranks last in terms of population averages when compared to similar Midwestern cities: Nashville has 24 percent more people than Louisville, Indianapolis has 37 percent more.

Denser cities require fewer miles of wire to service their populations, which is ideal considering how roughly six percent of power is lost by the time electricity reaches its farthest destination. With these circumstances in place, a decentralized energy network might still offer hope for a durable, more efficient grid.

For now, the possibility of installing buried power network appears to be somewhat troublesome given our city’s proclivity for sprawl. In the next and final installment, we will wrap up all these themes by delving into the possibilities of alternative energy systems and how such a thing could help offset the urban heat island effect.