What to do with leaking hillside?

[extrakt0r]

During the construction of our house we had to excavate down into the earth about 12' to get the walkout basement we wanted. In the process, we created a modest hill, which is about 70' from the back of our house. Ever since they cut the hill, it has been running water non-stop since April 2012 - 24/7/365 even when we had our drought last year.

Long term plan is to hopefully tap a well, short term I want to do something to clean it up, as we are getting ready to move in and I need to get grass down, and I am tired of the mud.

I plan to dig a 4-5' hole deep where the main leak is, and use black plastic culvert with a bunch of holes drilled in the sides, drop it in the hole standing up. Fill the bottom few inches with gravel, and wrap it with black road tarp. I'll need to figure out some sort of lid for it..

I am then going to drop a sump pump of some sort down into it and pump it uphill, about 100' away to a 1500 gallon tank I have. Once that is done hopefully I can use to to water my garden we will be getting in.

Would like any input on this plan, thanks.

 

[stuckmotor]

Apparently you tapped a spring when you made the cut for the basement. Do you think you'll draw down the storage tank faster than it's refilled? If you don't you'll still have to dispose of the excess water.

 

[Ehanson]

What about driving some big sand points into the hill, seal the top with a clay soil and pipe the water downhill to a fountain or water feature, or drinking tap and then to waste?

 

[Depmandog]

Hey Mike

Wondered a few times how your build was going. Figured I would have had the need to cruise past your place this last year, but the need never arose.

Concerning your spring, I think what you plan to do is fine, but once your tank is full..then what? Instead of a sump pump, you could use a windmill - if it fits into your landscaping decor.

Have you considered a French drain? Excavating a trench with a slight pitch, partially filling with rock and gravel, then covering with soil and grass. Extend the drain to a ditch or area away from the house.

Or perhaps incorporate the French drain with your idea. Pump the water when you need it, allow the overflow to be wisked away by your subsurface drain.

BTW, would love to see pics of the house.

 

[Kyle241]

I agree with the French drain idea. If you can get it dug correctly on the hillside or perhaps at the bottom, it will take away a lot of water. It's tough to tell in the pictures where you can lead it off to but I think this would work well and there are no mechanical things involved.

 

[Egon]

Maybe have a Geotechnical Engineer check it out.:

You could be looking at soil slippage, frost heaves or excessive pore pressure on basement walls.

Check the sump pump for head pressure and flow rate.

 

[extrakt0r]

I thought about the french drain, my only concern is that I would be "wasting" all that water when I can use it for irrigation. My plan is to water more than the garden, but grass around the house to. I will do something with the overflow of the tank temporary until the irrigation is 100% up and running.

The water stays far away from the house. All the dirt around the house was put there by the excavators and no water gets around the house. In fact, just a few feet away from the spring the clay is super hard.

 

[extrakt0r]

Couple more pics to help with perspective. It is a good distance from the house.

One pic from immediately after a good downpour

 

[Depmandog]

If you continue with your idea of using the 1500 gallon tank as a holding tank for your irrigation water, make sure its located higher than any area you plan on irrigating, and use the tank for the head pressure in your system. This will keep you from having to pump the water twice - and running electric to the backside of your property.

I suspect you will have to have some sort of float switch in the tank that shuts the sump pump off. Perhaps this can be done using low voltage line...??

1500 gallons, sounds like a lot of water, but it depends on how large an area you plan to irrigate and how often.

 

[kevin37b]

You people need to remember when you dig these big holes , you are dealing with MN. She will find a path for thiswater . You are creating a negetive pressure area and here comes the water . You need to arrange good surface drainage .

 

[stuckmotor]

That last photo was really helpful. Your plan of turning a libality into an asset is sounding better and better. Hopefully you have a way of getting rid of the water coming down the hill in a torential rain. If anything else has been in that tank, you might consider having it tested so it won't contaminate your garden.
Stuck

 

[dave1949]

You people need to remember when you dig these big holes , you are dealing with MN. She will find a path for thiswater . You are creating a negetive pressure area and here comes the water . You need to arrange good surface drainage .

I agree with this. Pics can be deceiving, but I would want more clearance between the leaker and the house, plus some decent slope away from the house. It looks fairly flat from house to dirt bank.

Also, the slope of the bank/hillside itself is not maintainable, it is too steep IMO.

I would be very tempted to take A LOT of soil out of the hillside and go deeper as it is dug into. Somebody stole all your rocks and your trees are missing too. :laughing: Digging doesn't get any easier than that.

 

[extrakt0r]

I am leaning towards doing a combination of a french drain and the sump pit/pump idea now. I think I will start a french drain up on the North side of the house where the propane line is laying on the ground in that pic.. Run it all the way down that hill, around the back by the main hill, and out the south side of the house, down the swale we have built.

On the top of the hill, we have a swale already, so the only "runoff" is water that lands on the hill its self during a downpour.

The wet area near the foot of the hill, is over 2' down from the rear of the house, and 70' away. It has never gotten close to the house, and good drainage is all around the house everywhere else. The big puddles are due to not having gutters installed yet, and it pooling by the house.

Few more pics from today to help visualize. How should I go about constructing the french drain? Do you bring the gravel to grade, or cover it with black paper and then grass it?

While it is steep, I can drive the Scag mower on the hill, up and down, not left to right...

 

[Birdhunter1]

Ever thought of burying the tank where the water will naturally flow into it and using a windmill as a pump to your garden?

 

[dave1949]

The french drain will not catch run-off from a downpour, but it should intercept most of the oozing water. You will need to maintain a surface swale to handle the hard rains.

Given the fine nature of your soil, I would dig the trench for the drain, then lay in a good quality filter fabric--down into the downhill side of the trench, across the bottom, and up the high side with enough left over to fold over the top of the filled trench. That would be step #1. Then put in your washed stone, drain pipe with a sock, more washed stone--up to about 8" below the surface is what I am thinking.

 

[extrakt0r]

If I brought the french drain to grade, and on the top dressed it with some river rock stones, would that help with runoff probably? If nothing else it would look good - something like this?

 

[vtsnowedin]

What is the story with the two plastic pipe ends sticking up in the ditch?

 

[dave1949]

If I brought the french drain to grade, and on the top dressed it with some river rock stones, would that help with runoff probably? If nothing else it would look good - something like this?

It does look nice. I'm not sure how you would keep the dirt/sediment from collecting in the rocks over time without some really effective erosion control plantings. It could be a mower barrier too.

 

[extrakt0r]

What is the story with the two plastic pipe ends sticking up in the ditch?

Those are the pipes that run over to where the gutters are. Once I have the final grade in the area established I will cut them to the proper height and install a cap on them.

 

[vtsnowedin]

Oh the roof drains. Very good. It looks like you have sliced into a aquafer at a point below it's recharge area. It will be a tough job convinceing that water to stay underground and out of your way. Perhaps install a toe drain as was suggested and regrade the slope with a wick layer of clean sand to collect and lead the water to the drain. The sand can be covered with topsoil and grassed over to hold the slope from eroding. The roof drains can be extended along with the toe drain out a little further and outletted into a small pond between where the pipes are now and those small trees. What you do with the water once in the pond is up to you.
Or you could build a self watering rock garden on that slope and have a stone lined toe ditch to carry any eccess off to the outlet/pond.