Wasatch Residents, Officials, And Energy Companies Weigh Pros And Cons Of Burying Transmission Lines

Jun 12, 2019

View from US 40 current and potential future from a Heber Light and Power report
Credit Heber Light and Power

Heber Light and Power and Rocky Mountain Power’s permit for a transmission line project that will connect power from the Jordanelle Dam to the Midway was continued last week by the Wasatch Planning Commission. One major consideration is whether to place those transmission lines underground or overhead. 

The proposed plan will result in transmission poles that will be between 65 to 95 feet. In order to lower the overall height of the poles, the power companies are burying the distribution and communication lines where possible.

The burying of those portions raised the natural question, why can’t the entire lines be buried? The Heber Light and Power board made up of elected officials from Heber, Midway, Charleston and the county studied installing underground lines and determined that the cost is four times the price of going above ground.

One cost prohibitive issue is that two different trenches for the lines would have to be dug for safety reasons. Rocky Mountain Power Transmission Engineer Nicole Kendall says another issue with burying the transmission lines is the expense and time it takes to replace broken lines.

“Underground cable is far more expensive than anything overhead,” Kendall explained. “Say we had one of the cables go bad in between a set of bolts. You would have to go in and replace that entire cable. You can't just splice it in because the bolt is this splice. You would have to pull that whole cable out, pull a whole new one in and create two new splice points. Two new terminators, so it's not a quick fix.”

Depending on ordering cables, locating the issue and other factors the energy companies reported that replacing underground lines could take anywhere from a week to months.

Underground distribution does have its advantages. Things that normally take power out like animal interference, aren’t an issue when the lines are underground. Heber Light and Power General Manager Jason Norlen says problems such as flooding can be a long fix.

“There’s fewer problems with underground because it's buried, no trees or anything like that,” Norlen said. “It’s just when you do have a problem it can be very lengthy.”

Wasatch resident David George will be a neighbor to the proposed 10-acre substation. George argues that the cost of burying the lines will not be four times the amount of placing them on poles when you factor in a few other items.

“The easements cost is seriously underrated; it will be much more than Rocky Mountain Power, Heber Light and Power anticipate,” George continued. “That could easily close the difference between underground and above ground. I think most of us are practical. There are certainly areas that probably most effective to have above ground cables. In our little section of Wyoming where there's nobody, some cows, those areas are probably going to be OK. I think the areas where you’re surprised that the County wants these big lines right by the ballpark and down 650 and through Midway. So, maybe the actual cost of burying these things is only a fraction of the stated cost differential when you include easements and only partial underground burying.”

George said in his discussions with landowners, some had communicated they would donate their easements for free if the lines were placed underground. Officials from the energy companies confirmed at the meeting that the estimated costs for buried lines vs overhead lines did not consider the costs of easements.

Heber Light and Power and Rocky Mountain Power will come before the commission again at the July 11th Wasatch County Planning Commission meeting.