How much water can a drain beside the road that is 4 inches high by 6
feet long, that feeds a 22 to 24" diameter pipe that is 50 feet long
remove from the parking lot? It used to be as much as could rain on
109 townhouses, plus their yards and streets, but now it doesn't seem to
be that much. Or it rains move than it did before.
I live in the lowest elevation house in my n'hood, and I park in the 3rd
or 4th lowest parking place.
The n'hood was built 35 years ago and I've been here 31, and until 2
years ago, the drain next to the parking lot was adquate for the rain.
About 2 years ago, it wasn't and a lake started forming and rising so
that at least 4 cars were in danger of being flooded. When I moved my
car, the water was less thand 2 inches from the door sill and rising,
and another car was apparentely damaged because it was replaced after
this (another topic for later)
After this the HOA hired an enormous vacuum cleaner on wheels (the size
of a big garbage truck, and the guy vacuumed out the pipe that goes from
the opening at the side of the parking lot to the stream bed. He
vacuumed out a couple foot-powered scooters for children and some other
things, but really the pipe was not clogged.
So I got a pick, a shovel, and an adze and I enlarged and deepened the
channel that ran from the end of the pipe to the stream itself. The
pipe is about 22 or 24 inches in diameter, and because the channel had
filled in with twigs, branches, tumbled rocks, maybe a 2x4, and dirt
over 30 years the water level never went below 12 inches above the
bottom of the pipe. I got that down to 6.
But while I was gone, the HOA President hired a small excavator
(something like a back-hoe) and the guy dug out the channel another 6
inches and widened it more, the width of its bucket, I think.
That took care of every possible obstruction, I figured. Yet last
night, the parking lot started to flood again. My next door neighbor's
wife called me at 2AM to move my car, and when I got outside, he said it
had peaked because the rain had stopped. One couldn't even see the
top of the cement cover to the drain or the manhole cover in it until
the water went down. At that point, there was a whirpool 14" in
diameter, so doesn't that mean the water was draining very quickly?
Sure seemed to be.
I thought today I would find some obstruction, but I didn't, which
leaves climate change as the only thing I can think of. Two of these
floods in 2 years, after 33 years without any.
Any idea how to stop the flooding?
We have repaved the road twice, and I'll have to look during the day,
but maybe that has raised the street level at the opening. I suppose
that means we should cut out the asphalt down to the original gravel and
put in just one layer, does that sound right? How far out into the
road will be have to go? Bear in mind that if we go too far, it will
be like a chuckhole for cars to drive into.
If we pave the road enough times so that the paving is thick enough, we
may be able to turn ownership of the roads over to the country and not
have to pay for repaving anymore. Good idea or bad?