A City Decides to Bury Its Power Lines

Power is going underground in Leesburg, Florida. This Lake County city is the first in the state to decide to move all its electric lines below street level. The shift from an aboveground to an underground system will take 30 years to complete. Part of the decision to bury the lines was fiscal. Maintenance of the aboveground lines runs to more than $1 million annually. A 20-year plan for the electric system showed that replacements to the electric infrastructure, including poles and old conductors, comprise most of the work the aboveground system would need during the next several years.

According to Lloyd Shank, the city's director of electric and gas, the base cost of replacing aging lines above ground is about $130,000 per mile compared with about $160,000 per mile to set up the lines underground. Meanwhile, aboveground lines, especially in a hurricane- prone state such as Florida, experience more frequent power outages. "If you throw in the cost of outages and continuing maintenance, underground is less expensive," Shank says. There were also aesthetic reasons. The existing power lines interfere with the city's beloved live oak trees, which must be carefully trimmed around the lines.

In designing the underground system, the city recognized that it can be more difficult to repair buried lines when problems crop up: It can take hours to pinpoint a failure, dig to its location and fix it. So Leesburg is building a loop system, which feeds power lines from two directions and substantially reduces repair time. Leesburg's initial plan is to spend about $1 million a year on the project. As costs for aboveground maintenance drop, those dollars will be funneled into the underground transfer.