Mr. Rooter has been out here to fix this problem and all they’ve done is snaked the piping from the house to the sewer main. I called the manager over there (Steven) to make sure that whomever comes out for the estimate familiar with installing backflow prevention valves. Based on what I told him, he would not recommend backflow prevention valves because the storm drain system is tied into the building’s plumbing system (even with backflow valves, floowing would happen). He proposed looking into raising the height of the sewer traps and installing an injection/tank system to deal with the rainwater.

There would be a $1,000 investigative charge for determining the city sewer depth in relation to the basement (dye testing?), talking to others on the street in order to determine who else is having problems with basement flooding as well as finding a solution to this problem. He mentioned dealing with problems arising from storm drains tied into a building’s plumbing system with a low basement which has resulting in flooding.

Overall, Steve’s suggestion makes sense, if the storm drains on the property are what’s generating the additional water “traffic” through the building’s plumbing, backflow valves aren’t the solution. Why? If hydrostatic pressure has already built up outside of the building causing the backflow valves to close, the water being captured by the building’s storm drain system has nowhere to go (but up).

This was starting to sound like anothing few thousand dollar bill coming until Niffly piped up and said “why don’t we just re-direct the water coming through the gutters as a trial.” Which seems to make a boatload of sense, reducing the amount of water coming into the system and allow what’s already in place to deal with the rest.

I wonder if gutter water distrubution systems exist — ideally, I’d like the stuff coming off the roof and 2nd floor terrace to be evenly distributed throughout the back yard.

Resource Update (It’s amazing what you find on the internet):

Basement Flooding and Proper Stormwater Management
DEP Pennsylvania: Stormwater Management Program (draft) (Best practices on Chapter 6)
D.C. Greenworks: Rain Gardens