This is why. Underground utilities, especially higher voltage electrical lines, come with a host of their own problems. Even if there is no yard where they're originally buried, there will be one day. A lot of people think they're the first person to think: "If they'd just bury those lines, hurricanes wouldn't be a problem." Oh, but they would. High water tables cause these lines to burn up and you think you were mad about the tire tracks the bucket truck left in your front yard after Irene? Wait until they dig a crater the size of a king size bed while things are still wet. These utilities are smart organizations and they have done the cost benefit analysis many times to determine whether it's cheaper to repair a lot of overheard lines vs. not so much underground and the former is cheaper and usually much faster. The biggest fans of underground utilities are the developers who build neighborhoods and the people who buy the houses from them. After a couple of decades, the regular burn outs, huge holes, exploding pad mount transformers, etc become the problem of the power company. And yes, even up North, the power companies are still often proponents of overhead lines in spite of the ice storms.
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