Draining a backyard that floods -- but is below street-level
How to get rid of storm-water that flows onto our low-lying property with heavy rains? When it rains, we take on far more water than falls from the sky.
Here's what I've observed since we moved here a year ago: Our house is the oldest in the neighborhood, so homes around it were (wisely) built on higher ground. I think that due to catching so much run-off (including that generated by a lot folks' partially paved yards and driveways)our property has likely sunk even lower over its 70 year history .
Critical to our problem is that our property is at street level in the front, but goes downhill in the rear. Maybe at some time the thought was to drain the gutters way back to the rear of the backyard and away from the foundation, but that just adds to the inflow of water from everywhere else in our rear and it eventually saturates the whole yeard. I mean, it can look like a 5,000 sq foot pond back there at times, rising all the way to our foundation. And the foundation is suffering from it (the dreaded settlement cracks).
Additionally, when the yard becomes saturated, the ground water eventually has no option but to swell upward and through capillaries in our basement floors. With the heavy rains in the NE since we bought this lemon - uh - home - our basement's taken on about 4" from ground water rising about 4 times.
Initially we listened to some landscapers and had a few dry wells installed in the backyard, but as I live and learn and observe and educate myself, I realized those are possibly helping drain the water from the surface faster, but after a good long soak the water is still saturating the ground and causing the water-swell from below.
We've managed to divert a good part of our own water toward the front of the house by tilting some gutters and redirecting some leaders, but in a perfect world, I'd like to be able to get the torrents of water out of the back yard and uphill into the street at the front (eventually flowing down to the storm sewer on the corner).
So what can I do?
I'd love to build a perimeter french drain around the house, but the uphill rise from the back of the house to the street would make discharge impossible. I've recently had a fantasy of digging a deep ditch in my front lawn, and dropping in a drywell of sorts, with a french drain from the back lawn running to it, draining the backyard water into it (since a french drain has to decline, the end of the french drain would end up deep underground, way at the bottom of the drywell but at the street). It's a 130-ish foot run from the backyard to the front of the house), --- does this make any sense ? Filling the drywell with water from its bottom? Would this have to be a tremendous drywell in order to take on the "pond" that my yard sometimes becomes. Otherwise, would the overflow eventually push back to my yard? Alternatively? Would it make more sense to run electricity to this fantasy-dry-well and install a sump pump in it that would pump the water out into the street as water fills inside of it from the backyard? This alternative scenario would probably require us to be able to remove the pump in the winter, since we're in the NE and it would freeze (unless we could set it really deep, below the frost-line here.)
I would love any thoughts that anyone cares to share. If any of this sounds insane, it's rain-induced-madness. I'd rather hear I'm crazy here, than from a contractor face-to-face. I rack my brains for solutions because nobody we've had out to look has come up with any ideas. Thanks!