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Draining a backyard that floods -- but is below street-level

Posted by rosemariesayvers (My Page) on
Wed, May 5, 10 at 13:16

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!

Follow-Up Postings:

RE: Draining a backyard that floods -- but is below street-level

Do the streets have storm drains? If so, the city may permit you to install a drain that goes directly into the storm drain.

It sounds like you have a major issue and after you've noodled with some ideas on the internet you need to contact a local pro who can come out and look at your site. Not a landscaper -- a drainage contractor.

RE: Draining a backyard that floods -- but is below street-level

I know this post is from last year, and you may have solved your drainage our problem already, but if not, you may want to ask a local expert whether a sump pump or sewage grinder could be added to your French drain system. The pump would cost a little up front and would use a little electricity, but would only click on when the water reached a certain level and would force the runoff uphill into the storm drain.

RE: check local zoning

P.S., always remember to check with your local zoning office and water/sewer authority to see what is permitted and if you migh need a permit

RE: Draining a backyard that floods -- but is below street-level

might be worth checking out a sump pump.

RE: Draining a backyard that floods -- but is below street-level

I actually have this exact same problem. Anybody dealt with something like this successfully before? I've got a drainage specialist coming to look at it, but would like to know if anybody has experience with this.

I'm thinking of a small sump pump, but am not sure what that would entail.

Thanks in advance.

This post was edited by Swiftgruve on Mon, Apr 15, 13 at 11:13

RE: Draining a backyard that floods -- but is below street-level

A sump pump, while better than doing nothing, can only be looked at as a temporary solution because power has an inconvenient way of going out in rain storms. Water would not pond in your yard unless a feature of your yard, or a feature of your neighbor's yard prevented it from leaving. You need to determine what feature is responsible for water not leaving your property. Investigate your yard to find out how--the path--water would logically leave your property. You may have a legal issue if the culprit yard feature is the result of a neighbor's activities. (I'm not implying that a neighbor intentionally set out to cause you harm. If they built something that stops water from leaving your property, they may be oblivious to its effect.) If you wish to pursue it further on this forum, you should start a new, separate thread for it.

RE: Draining a backyard that floods -- but is below street-level

I purchased a ¾ acre lot (125 x 260 feet) 6 years ago with a similar slope and woods on the back half. The front of the house is at street level but the back of the house is about 3 feet above grade. The lot continues to slope down another 2 feet to the back property line. During construction, I discovered the back half of the lot flooded with over 3 feet of water that remained all winter. The developer graded the subdivision but did not grade the woods. (I wouldn’t have any trees if he had.) I was left with what the locals call a frog pond.

I tried adding about a dozen loads of sand to the lowest areas but I was afraid I would smother the trees if I added too much. After several unsuccessful attempts to get the developer to help I called the county board of supervisors. The county engineer was called in to inspect and the developer was “encouraged” to assist me. Luckily, the drainage ditch at the front of the property was about 5 feet deep and the developer was able to install 200 feet of 15 inch culverts from the drainage ditch to the back yard. The slope is only about 1-1/2 feet for the 200 foot length but it is enough to allow the yard to drain.

It’s not perfect, when we have a lot of rain the yard holds about 10 inches of water for a day but the trees get plenty of water that way. I built a cinder block catch basin and had someone dig a shallow trench with a ditch witch from the middle of the backyard to the catch basin near the property line. I make sure the culvert doesn’t get blocked with sticks/leaves after a storm and I clean out the trench about once a year.

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