How long would it take for electricity and water (or general utilities) to stop being functional in an apocalyptic setting?

Question

I have this idea for a story were the surrounding infrastructure is intact. Now barring regular maintenance, how long would it take for existing infrastructure to not function? How long could a house run on existing utilities?

Thanks for the help!

In: Engineering

Answer 1

**Power:** hours if you’re unlucky. Days if you’re pinch less unlucky.

But six months to a year, and power is guaranteed to go out, possibly system-wide never to come back. The reason? **Tree and foliage growth.**

Power transmission operators are supposed to fly over each high voltage line route at least twice a year to check on any obstructions, like trees and brushes and trim them. That’s a lot of territory to cover on foot with hedge trimmers and an axe. In practice, many of the power transmission companies are currently behind on that chore.

Perhaps you might recall the **Northeast blackout of 2003**, but it happened because a high voltage line sagged onto an overgrown tree and shorted and triggered a cascading failure compounded by lack of communication and a badly timed lunch. Within hours, **55 million people lost power** for up to 4 days.

A guy at MISO (basically a traffic controller for power transfers in the grid) flipped the automated “state estimator” system to manual mode to correct something. The system was meant to balance the flow of power between regions. He then went out to lunch sometime after 1 o’clock and forgot to flip it back before leaving.

While he was out at lunch, a 345 kV line nearby got hot and sagged about 4 and a half feet, then shorted after touching an overgrown tree that maintenance guys hadn’t yet gotten to. Because of that “state estimator” being disabled, techs/engineers reacting to the outage were doing the wrong things and a cascading failure spread through the grid, tripping more and more things.

So power plants aside, the crux of the problem is that the high-voltage electric grid used to transmit it has to be carefully managed and someone needs to be behind the wheel to regulate and route it constantly. And when it goes out, it’ll go fast and it’ll take some real expertise and manpower to bring it back online.

PDF of the ’03 post-mortem, 124 pages: [https://www.nerc.com/docs/docs/blackout/NERC_Final_Blackout_Report_07_13_04.pdf](https://www.nerc.com/docs/docs/blackout/NERC_Final_Blackout_Report_07_13_04.pdf)