Don't chicken out now. Just add eligidly to it and you are good.
there is a concept called buoyancy when it comes to civil structures in the ground.
Anything buried will experience lifting forces. Regardless of how heavy, the water in the ground will lift it.
There is a fabulous paper on buoyancy calculation on the NET.
I downloaded it and wrote an excel program to calculate buoyancy for large structures that I sold. To overcome buoyancy you need to add a ring at the base of the structure (Manhole, catch basin, etc.) or add other means to hold the thing down.
Once you do the calculation, you realize that most, if not all structures need a buoyancy ring. Top of grade, water line, slope of pipe, discharge level, all impact the design of a system. And in Ottawa, WE HAVE A 2 m FROST LINE TO CONSIDER. So most pipes are 2 M deep, making most structures 2.2-3 M deep.. Guaranteed to float (push upwards).
And so as you walk around the city, you will notice damage around sewer structures, or as a minimum, lumps.... because no one adds floatation (more like anti-floatation) rings...
No one checks... no ones asks for verification...no one does it on their own, because it COSTS.
so come and visit me in River Side South, we can walk around and see the damage. Or the boobs in the ground
Child's play to calculate buoyancy requirements...no one does it..no one is asked.. and we get damaged streets. Damaged parking lots. Damaged sidewalks.
As you move about in our fair city, take a look at every manhole cover, catch basin, etc. See the lumps and see the damage in the area immediately around the cover.
all of this is allegedly and sources are alleging.