Hello everyone,
I built my house a couple of years ago and eveything is great except the change in the flood elevation over the past decade or so (different than the topographical map of course). The long and short is that 2 times last year, it rained so hard that the stream in my backyard (that runs through the conservation land) over flowed and came up to my walk out basement back door. Yikes.
This is not the end of the world cause it didn’t come in but my small patch of backyard which is at that elevation did get wrecked. So here is what I am thinking and I wanted opinions…
I would like to build a levee wall to keep the water out when the stream over flows. Essentially, there are two slopes at the front corner and the back corner of my house which I could build a wall between (natural elevation changes in my yard). The wall does not need to be tall and I expect that I will have to put a pump well on the inside of the wall to pump water out during floods and heavy rain. So I am thinking of the following:
Dig a trench 3 feet deep (I’m in cleveland ohio) bewteen the two slopes – the distance is about 100 feet between
Put a 16 inch wide footer at the bottom with drain tile on the inside of the wall – where the section of my backyard is.
Then I’ll have a 5 foot tall concrete wall poured on top of the footer – this leaves 2 feet above grade which would be more than enough height.
backfill stone on the inside of the wall and solid fill the outside – probably face the wall so that it looks better than poured concrete wall.
put a pump well on the inside of the wall and slope the backyard towards that pump well.
I don’t expect that I will be able to completely stop the flood waters from coming in to my backyard – just really slow it down enough to pump faster. Flood events do not last a long time (3 – 5 hours) and I believe this type of construction would likely do the trick. Heavy rain of course would get traped inside the wall (in the backyard) so I would have to pump that out as well.
Is this all folly? Sound reasonable? Is there a better technique that I could employ? Cheaper way to do it?
Thanks for any feedback in advance
Rob Kress
Replies
I did something similar to what you are proposing. It was an earthen berm with the pump on the inside. It was about 4 feet above grade and a bit higher than the road.
Guess where the water came from on the last day we lived in that house. I could see the blades of grass sticking through the water on top of the berm. The pump did a good job keeping the yard drained untill the water came over the top of the wall.
I totally understand. Sorry to hear that the wall wan't high enough but then again, how high is enough. I can honestly say that if the water comes up higher than 2 feet from grade, there will other bigger problems everywhere and in that case, there's only so much you can do. How was your berm constructed? Doesn't sound like it was as serious as I am planning. Packed clay with grass on top to hold it all together? How wide was it at the base?Yes, I would be seriously bummed if I spent a lot of money on a "wall", finished my basement, and then we had the 1000 year flood the next day (meaning the water just comes right over the top).Thanks for the feedbackRob Kress
My berm was about 300 feet long and 15 feet at the base. It worked well untill the water became higher than the berm.
technical advice is available from the Army Corps of something I think- located in Louisiana I think.
They can give you the advice that u need
Yea ask the Army Corps of Engineers. The only thing in America not over-engineered, the levees in New Orleans.
We do some berm building around here from time to time.
Generally a 3:1 slope would be used on the sides, and if you wanted the top to be flat for say 2 ft wide, the base would be about 14 ft wide, and the berm 2 ft tall.
There are all manners of culverts or drain tiles with flod gates integrated, that would keep the stream from backing up inside your berm, but would let the water out after the stream has subsided.
Depending on the size of your yard "pond", one might not need to worry with a sump.
It seems that for 2 ft of elevation the concrtet wall might be overkill, and somewhat unsightly compared to a nicely manicured berm.
BTW a 3:1 slope would be easily mowed.
If you are in a semi-rural area, the county soil and water conservation agency can hook you up with catalogs, as well as free plans and advice.
Rob, I've notified the EPA about your intentions re altering a Wetlands and they are asking for a street adress.
Please post if here forthwith.
Joe H
"Rob, I've notified the EPA about your intentions re altering a Wetlands and they are asking for a street adress. "LOLActually your little joke may not be far from the truth. Some years ago a farmer in So Calif had a low-lying field that became flooded one winter during especially heavy rains. Migrating waterfowl landed on his temporary lake and he was prevented by wildlife protection agencies from draining his "wetlands".BruceT
That's compleatly un-necessary.
His backyard will show up on some satellite imagery.
http://www.nrcs.usda.gov/
Hi Rob,
In 1972 I worked with the US Dept of Soil Conservation (now part of the NRCS, link above) on a 300' long earthen dam and pond, as part of a larger building project for a client. That department then had a private property owner program which provided free engineering for the dam and pond. In addition they paid a fairly substantial amount of it's construction costs.
It may be that a similar program is still available. I would suspect that levees are even higher on their priority list. Using their web site, it shouldn't take much time for you to find out.
I learned a lot, working directly with their engineer. Since it's completion, the dam has withstood one very large rain event, the type the engineer referred to as a hundred year rain.
PS: another post reminds me that we got in touch with the the soil conservation people through our county agriculture office. That's a step which may be worth following.
Edited 3/26/2007 9:43 am ET by Hudson Valley Carpenter
Sounds like it would require a rather large pump - a 2" or a 3"?
I teach a bit of earth science so I am going to weigh in with a different perspective, with levees you are effectively making the property that is being protected in a bigger bowl, so when a large enough storm comes and overtops the levee a much greater amount of damage is done.
Water exerts an amazing amount of pressure and can do extroidinary damage, could you landscape the back yard with flood hardy plants?
Just a thought from a slightly tired science teacher....
The NRCS recommendation is a good one, also if your county has a Soil and Water Conservation District they can often provide technical assistance for free.
Good luck.
We have to deal with creeks and ditches on a pretty regular basis, so I may have some useful suggestions. Kinda hard to know without having seen the situation.
My first thought is - Is there something downstream that's slowing the water flow, and making it back up at your place? Something like a bunch of trees have fallen into the stream channel, etc. If there is, removing the obstruction may help you out a great deal.
Do you own the ground the stream is on? If you do, widening the channel may help lower the water level at your location. Depends on the stream, though.
Since there's flowing water, whatever you put on the stream side of the levee will have some scouring action from the water flow. The best solution for that is some big rocks, or "rip-rap".
Are you on an outside corner of the stream, or on a straight stretch, or what? If you're on an outside corner, you may want to stabilize the streambank before you build anything. A sound levee can get undermined if the ground under it gets washed away.
a concrete wall as you described would also work. But an earthen levee would likely be less expensive.
If you do build an earthen levee, allow for settling. The dam may settle unevenly, and you'll end up with one place that the water will run over.
Is there anywhere downstream that you could drain your back yard to? Like a 6" diameter drain line that goes to a point where the stream drops enough to allow the water to run out? I hate to think of a backyard that's solely dependent on a pump to empty the water. What happens when the pump quits, or when you're not home?
As someone already mentioned, there are ways to put a culvert through the dam with a valve that only allows a one way flow. I don't rememebr what they're called, but they're out there.
Any chance we could get a few pics of the situation? That would likely get you some more effective suggestions.
wow, thank you all for weighing in.I did laugh about the wet land comment and in fact my "conservation land" is a wet land of sorts. Indeed I do have a partner on my property, the conservation people but I like it that way because I believe that they and I are trying to do the same thing. Unfortunately, what they are trying to conserve is flooding my backyard.In that regard, I am eager to save as many very mature trees as possible by drying up the water which was not present 20 years ago. To that end, I have already successfully drained one of the biggest puddles (ponds) on my property by hand digging a 6" drain tile through the middle of it and to the stream. I back filled with stone and covered appropriately and it functions perfectly. I will do the others this summer. My conservation partners to not know about these efforts.I do need to talk to them and have already opened the conversation but I have not gotten all the way through yet. ok, on the the levee....The stream that runs through my property is literally 6 to 8 feet below my basement elevation 364 days and 16 hours a year. The other 8 hours of the year it is flooding sqare miles of flood plain. Flood plain is really a little misleading though because really it's a fully grown forest that gets over washed. Of course my house and all of the others in the development are the reason for the change in the water table so I feel very compelled to keep as many trees as possible.While I believe that and earthen berm would be much more cost effective and probably look a whole lot better.....1. I'm not so sure that my conservation partners would allow me to take 15" of our precious land for an earthern berm and the berm would be very close to me house.2. I would have to kill a lot more trees to build a sound earthern berm / levee that would function properly3. a concrete flood wall is about as perfect a solution that can be constructed4. a concrete solution can be completely contained on my side of the fence so to speak.I can envision a 6" drain tile with a valve (check or gate) that would close in the wet event and automatically drain to the stream in the dry. That makes a lot of sense. I just thought that pumping would be a more sure solution. I know then there are power concerns but we have never had any serious power outages that have lasted for longer than 1/2 hour and that was an odd event. My belief is that the flood wall would slow the flow enough so as to not be a problem.Widening the stream is not an option and I have indeed cleared up and down the stream nearly 1/2" mile of tree falls. Unfortuneately, when the stream leaves my property, it travels only about another 1/2" mile before it enters a fully grown forest which is all protected. So there is no way for me to do any more clearing that would be meaningful. I'm not really too worried about scouring on the wet side of the wall because the wet event is really not rushing at my back door. It is rushing about 100 yards away where the stream is intended to be. Still I understand that I need to be mindfull of that.Well, thanks all for the great suggestions. I will follow the links that some of you gave and go forward in my conversations with a little better idea. I am going to try to attach some photos. If they do not work out, let me know and I'll give another try.Rob Kressokay, balls I have no good pics, I'll take some tomorrow and post them.
I just had one other thought to add.Since I obviously haven't seen your property, I don't know what you own and what you don't. But I'm wondering if you can slow down any of the water coming downstream?This is something I posted pics of a few years back:http://forums.taunton.com/n/find/findRedir.asp?webtag=tp-breaktime&mg=DAEA52B3-E8BC-4BE7-B12E-7BD1AD451A81I don't have any idea if it would work in your situation. But if it will - She soil conservation service will pay for 60% of the cost of building them.
Let us not become weary in doing good, for at the proper time we will reap a harvest if we do not give up. [Galatians 6:9]
Has man EVER won against a river?
No, not indefinitely, and that raises a good point, sooner or later, that flood wall or berm will likely act in the opposite manner as it was intended.To the OP, In your situation it is very hard to fight against old mother nature, I would encourage you to think about a way to drain the water in a different direction if possible,(paralell to the stream to a point of lower elevation) and also to consider a flood hardy landscap as another suggested.Many hardwood trees, like black and green ash, and most of the oak family actually enjoy wet feet on occasion, and as you can tell from their presence thrive on the swampyness.One more thought, as an active farmer with a working knowledge of the feds and their conservation departments, I would tread very carefully, and be sure all the i's are dotted and t's are crossed, they have been coming down very hard on wetlands violations in my area lately.A medium to large guy named Alan, not an ambiguous female....NOT that there is anything wrong with that.