Dave wrote:
Posted earlier about standing water in the back yard, and we are now headed
into another installment of the rainy season around here. Wondering: what
would be wrong with routing the worst of the drainage
problem into the sewer, via the drain that the washer uses. This
one, I am fairly certain, will get shot down in flames. But I have
no idea as to how or why as of yet. Anyone care to comment? I am
thinking that if I can provide sufficient filtration to catch the
majority of debris, it ought to work. I've even seen large square
drains in the middle of yards on the other side of town that can't go
anywere but the sewer. They are just larger, with (I presume) larger
pipes. Does anyone think that a 4" line could be made to suffice for
such a purpose? Please, fire away. All I am trying to do is give
the water that collects over the back sidewalk during a heavy rain
somewhere to go.

It's pretty likely to be a serious legal infraction. If everyone dumped runoff
into the sewers, there would be frequent sewage discharges into
streams/rivers/lakes during bad storms.