There are clumps of five, seven and 11 manholes on nearly every block of Alder. Each intersection has multiple clumps, which means we're talking about 25 to 40 manholes every city block. What gives with all the freaking manholes? —Amie
I think the mistake you're probably making, Amie—with plenty of help from the movies and TV—is assuming that every manhole on the street opens into some large underground chamber full of sexy vampires lounging on sectional sofas—or, at very least, into some sort of tunnel system providing wide-ranging access to the city's innards.
If that were the case, it would indeed make little sense to have so many manholes; they'd all open into the same space. But unfortunately for Portland's vampires, the rambling catacombs so beloved of suspense writers mostly don't exist. Mainly, what's down there is a) pipes and b) dirt.
"Natural gas lines, conduits for underground power lines, drinking water pipes, and sewage or stormwater pipes all have to be buried in the public right of way," says Linc Mann of the Bureau of Environmental Services. "Lots of underground utilities owned by lots of different agencies equal lots of manholes."
The folks responsible for maintaining the pipes and conduit need to get at them, ideally without having to tear up the street in the process, so they put a manhole over each individual thing they figure they might wanna screw around with later.
To save money (and deprive pesky dark wizards of habitat), these manholes are made not a whit bigger than they need to be. In fact, many aren't manholes at all, but "inspection chambers," which not only aren't large enough for a doomsday weapon and a chained-up blonde, they won't even hold a person—you just open 'em for access and work from the street.