Why doesn't New Jersey bury power lines underground?

Tuesday's Tropical Storm Isaias toppled trees and sent branches hurtling into utility lines, leaving thousands of residents all across the region without power.

It's an all-too- familiar scene in the Northeast.

So why can't those utility lines be buried underground, safe from trees and winter ice storms?

After a freak Halloween snowstorm in 2011 left 750,000 customers across New Jersey without power for days, then-Gov. Chris Christie said there is “not an iron-clad solution” for every problem. That's true of burying power lines underground.

Here's what the experts say about the downside of underground utilities.

Cost to bury power lines

One consideration is money.

PSE&G spokeswoman Karen Johnson said "undergrounding" the system carries considerable cost. The U.S. Energy Information Administration, a government agency, says underground power lines cost on average five to ten times more than overhead distribution lines. Those costs are much higher in built-up areas, and cheaper in new developments.

In 2011, Christie said he had received an estimate of “$1 million a mile” to put the state’s power lines underground. The costs would borne by ratepayers.

Then, there's the mess and the inconvenience. PSE&G, on its website, says burying power lines is disruptive to communities, and Johnson added that the work would take considerable time before bringing any meaningful reliability improvements. Those large-scale programs require regulatory approval as well, she said.

Story continues below gallery

Can you lose power with underground lines?

Even in cases where the lines are buried, outages can still occur. When they do, they take longer to fix than overhead lines, according to the Energy Information Administration.

Buried power lines are protected from the wind, ice, and tree damage.

"But buried lines are more vulnerable to flooding, and can still fail due to equipment issues or lightning," the Energy Information Administration notes. The agency says underground utilities tend to have a shorter life span than overhead lines.

Underground lines are not necessarily safe from trees, either — uprooted trees can disrupt service by damaging underground conduits.

In 2016, Anthony Hurley, then the vice president of operations at Jersey Central Power and Light, said that underground transmission lines are much tougher to maintain.

Since 2009, the utility has invested more than $290 million to upgrade and reinforce existing, aging underground transmission circuits throughout the state, including in communities in Essex, Passaic and Bergen counties.

However, moving lines underground in some especially vulnerable areas can be part of the solution, according to officials at PSE&G and Rockland Electric. Projects in towns such as Ringwood and West Milford, where roads pass through dense woods, are part of Rockland Electric upgrade plans.

Many Northeastern cities have grappled with whether to go underground. Washington, D.C., in 2015, launched a $1 billion program to bury power lines after a series of massive outages caused by a succession of storms, including a destructive derecho in 2012.

Closer to home, PSEG in Long Island has a program for communities that are interested in underground electric facilities that lets the community pay to replace overhead electric service.