Nick wrote:Hey mate,
A lot of drains are like this, very few have convenient egress unless they're part of a buried river or something that carries large volumes at the entrance and exit. Your standard drainage systems flows like a tree, with a big trunk (the outflow) and lots of branches spilling their way up to the gutterbox in your street. That doesn't need to be a large pipe, because BassCannon's street's drain needs only to carry the drainage needs of your street, whereas the outfall needs to carry your street and thousands of others.
(Source, sat in on a stack of Civil Engineering Lectures)
Popping man holes can be a bad idea. Most manholes are on roads, a car falling into a manhole is a bad thing, a car hitting you in the face is a bad thing, and getting sliced by a car while climbing out of a manhole is also a bad thing. Round manholes can't fall in and crush you (though they can swivel and stuff up your fingers), and square ones can. They're also heavy.
Walk up, then walk back, simple as that.
Yeah Okay thanks for that Nick