A squirrel did the deed, but the trees are taking the fall.
Crews with Tampa Electric Co. have removed several large trees and trimmed others along the routes between two electrical substations and Tampa’s David L. Tippin Water Treatment Facility. They’re also replacing power poles.
The work is the early stage of TECO’s $1.2 million effort to harden the power supply to the city’s water plant.
TECO and the city both want to avoid a repeat of February’s squirrel-induced power outage that shut down the water plant and led to a weekend-long boil-water notice for more than 560,000 city water customers.
The Feb. 22 outage was caused by a cascade of bad luck that began when a squirrel found itself stuck inside the metal tube covering the power lines feeding the Tippin plant.
While trying to escape, the squirrel caused a short in the high-voltage line that killed it and charred the top of the wooden power pole.
TECO crews spent the morning fixing the damage, having switched the load of the damaged power line onto the second line serving the plant. That caused the line to heat up and sag, creating an electrical arc that blew out the circuits that otherwise would have activated the plant’s back-up generators.
The water system was out of commission completely for about half an hour. Plant operators needed another half an hour to restore power through the emergency generators.
The loss of water pressure affected customers from Town ’N Country to U.S. 301 and north to the Pasco County line. The boil-water notice complicated life for restaurant owners and other businesses, as well.
Squirrels are a common problem for electrical utilities, but so are snakes and other animals that seek out electrical systems, often because of the heat they generate, said Mark McGranaghan, vice president for power delivery at the Electric Power Research Institute, an industry group.
“Squirrel guards have become relatively standard products for the industry,” McGranaghan said Friday.
TECO didn’t have a squirrel guard in place on Feb. 22. Workers installed one a few days after the squirrel found that particular chink in the armor.
Cutting down trees along the route of the power lines won’t do a lot to keep squirrels out of the system, since they can climb the wooden poles, McGranaghan said.
But taking down trees can clear away branches that might threaten lines during storms, he said.
Ultimately, improvements to limit damage from squirrels also makes the system more reliable in major storms, said TECO spokeswoman Cherie Jacobs.
“Even though this is a very strange event with the squirrel,” McGranaghan said, “you don’t want the next time a high wind comes through the area that plant to be impacted either.”
Burying the lines will also help guard against both storms and squirrels, but that comes with its own risks, McGranaghan said.
Water can get into the pipes carrying the lines and cause short circuits. Fixing those takes longer than fixing overhead lines, he said.
Nevertheless, TECO plans to bury about 1,000 feet of power lines where they cross the Tippin property near Sligh Avenue and North 30th Street to keep them out of harm’s way. That work will start in early November.
Meantime, cue the chainsaws.