Water Problem

What type of terrain do you have? I am assuming it is relatively flat. Are you in an urban environment (ie subdivision), or a more rural area? Assuming you are in an urban environment with relatively flat terrain, I would suggest bringing in some topsoil to fill the low spots, and create positive drainage into established ditches. This would only be feasible if the low spots are shallow. There are other methods available, but this is one which would be fairly inexpensive.

As far as the basement, there are some products on the market which could help. IF your basement does not have finished interior walls, you could use a product like "dry-loc". If your interior basement walls are finished, you may want to contact a contractor who specializes in waterproofing basements.

Thanks for your thoughtful response. We have a small city lot in a suburban area. The terrain is relatively flat, sloping gradually away from the house. The farthest edge of the back yard is where the water accumulates. If the rain is very heavy and prolonged, the water fills half the yard and comes into the basement.

We had a new drain tile and sump pump installed a few years ago and the basement doesn't flood.

How do I create positive drainage? Is a French drain the way to go in this instance.

The water should be directed away from the property. see post #2 step 2.

Obviously you want to keep the water away from the house. However you don't necessarily have to drain the whole yard. If you place a drain across the yard close to the house and direct the water downhill into the street OR if you can't get the fall for that, drain it into a Large sump pit which can be pumped out to the street. the pump needs to be sized about twice the POSSIBLE rainfall x catchment. Thus if the highest ever rainfall was 12" per hour and your yard area is 20' x 20' your pump will need to shift 400 Cubic feet x 2 = 800 cubic feet of water per hour. Roughly that's 800 Gallons Per hour. this seems big but you need to allow for the water in the pit when the rain starts plus whats flowing in while your pumping it out.

800 cubic feet per hour is about 6000 gallons per hour.

The highest rainfall 12"/hr ??

isn't that a bit exagerated?

The highest rainfall we had here was 250mm over 24hr.

You should not calculate with the immediate flow but with the average over a day. and be able to store the volume so that an acceptable pump can handle it.

Imagine that you have a 55 gal sump with pump, being able to handle the rain, and

oops there goes the power. Which is not so rare in a storm condition.

Step 1 is to provide a flow path for the water.

The natural slope must be enhanced. The water should be directed to the lowest corner or the corner where the water can be discharged.

Soil can be imported or moved.

Step 2 discharge of water

The discharge route must be cleared. The problem usually is that the discharge will have to go to a neighbours property. One positive aspect is that law usually allow the upper owner right of way over the lower property for storm water purposes (consult local government). You should therefore consult with your neighbour and devise a mutually acceptable plan. A pipe or trench close to the boundary on his property may do.

Step 3 - any obstructions should be removed or an flow path must be provided for.

Step 4 - Outside sloping paving can be installed around the house.

Basement: The problem will be greatly reduced by the above steps. and sealing the walls may be sufficient.

If not a dewatering pump may have to be installed.

Note: watch the house for cracks ets. drying clay may shrink!

I would be careful with the assumption that you can shed your water to a neighbor. In many states, you can not shed water someplace it has not gone historically. Also, basement wall seepage can be something destructive if you try to merely block it. very few basement walls are designed to withstand a head of water on the outside, especially block foundations. Shed the water before it gets down next to the wall.

RichH

The lower lying property I am talking about is the property where the water used to flow over before man made restrictions were placed there.

The damming of water on his property is a typical example of some or other obstruction to the water flow.

It is a fundamental right not to be disadvantaged by the actions of another. and I the higher owner has the right to demand for the removal of any impeding structures.

However instead of forcing something onto a neighbour an agreed plan of action would be better.

If the impeding structure is on the higher property I would recommend an agreement with the lower owner because the sudden flow of water might not be to his liking.

Create a slope of at least 1:200 leading away from the house. Install drainage channels at the end of the slope to channel away the water.

The way to deal with this is dual.

You have the water on your terrain which could be guided to a pond, which could be a nice garden element. I have a lower zone with water loving plants that can live in dry soil to. When it rains the zone fills up and the rest of the garden is kept dry.

The water in your basement is probably there due the fact that you don't have drainage and water removal installed round it. The water table rises when it rains and will go above the basement floor. You should install a perforated tube below the level of the basement floor, add a water impermeable lining to the walls and fill the trench again with sand. The perforated tube needs to be collected in a pump pit and the water to be pumped out (to your pond or so)

To reduce the amount of water in you basement, make sure your down spout are not draining near the building. Try and keep them as far away as possible. (ie by hooking up a u-drain system in cased in 1" clean stone ~10-20 feet from you house if possible).

At the end of the property a bio-retention pond would work (similar to reply #7). You local conservation district or city planning office should have some free designs., or I could hook you up to some hbaker@ptd.net.

In urban areas you are likely to have regulations concerning stormwater and it's runoff to adjacent properties. The regulations most certainly take into account the local conditions.

Is there a stormwater collection system in the roadways? If so, can you gravity flow (through a pipe or swale) to it?

One possibility may be to continue the offsite discharge at the point where it historically has flowed. You could fill in the low area so you don't any retain water if the local regulations allow that. It could be that the detention time on your property has to be maintained because increasing the rate of flow off your property could affect the downstream flow of water and make problems for someone else.

You have a tough problem to deal with and the local authorities would best know how to handle it.

In your suburban neighborhood, is your property adjacent to others? ie do all the back yard fences meet? It sounds like the grass lined swale that was or should have been designed for drainage at the back of all the adjacent properties and yours has most likely been blocked by a down stream neighbor when they modified their back yard. So go down the street with flyers and ask for a meeting with your neighbors to see if this is indeed the case. From there use that meeting to make this a community concern and work together to solve the issue. DO NOT I repeat DO NOT involve any form of government, they will only use this as an opportunity to drill farther into your rights and freedoms.

Hello: I am a homebuilder in Colorado, and we have problems with swelling clay, and building in these conditions. The simplest and least expensive solution is to build up the soil around your foundation, and have a 1% slope away from the foundation for 10 feet. Cover the ground next to the foundation, with plastic, and landscaping rock. this will help aleviate the problem of your leaking basement walls. For the rest of your yard, bring in 3 inches of sand, and use a tractor to mix it thoroughly with the top 3 inches of the ground, then grade to level; bring in 2 inches of top soil for planting; within 2 months you will have a beautiful, rich, thick lawn. Good luck

The swelling clay is one of the resons why you need to replace it with sand.

Just an idle though:

Have you any idea how thick the clay layer is?

A dry well the penetrates it might be a solution.

Good question. I brought this to the attention of my Natural Sciences professor who explained that the clay was deposited by glaciers long ago and it could be very deep. I know the general area is the wettest neighborhood. I'm in upstate New York in the city of Albany.

Had I taken his course before I purchased the house I would have taken a soil sample and walked away from the deal. Live and learn they say. I say learn first and then live better.

Note to all: Always ask the power companies before you dig!

Still might be worth a shallow bore-hole.

Those glaciers left layered deposits. You might just luck out and hit sand.

The 'prof` might give you a better idea of the chances. He did say

"might be deep".

Are there any local well drillers or construction Co.s who've done

deep foundations to ask?

How about installing a moat? make a nice 'water feature'!

A cheaper way would be to look at you counties/regions soil charts. They would list the soils in the area plus and how deep they are. The charts should be easily found at your school's library. You could also dig a shallow pit 2' by 3' by 3'-4' depth that should give you a good idea what the soil layers looks like. From that point you can decide how you want to proceed. Infiltration is the best technique to use unless you have lime stone that is prone to sink holes, then I would opt for conveying the water cross the surface of the property.

Does any other people in the area have the same problem?

What is on the other side of your back fence?

What is causing the damming?

The general area I live in is known as the wettest neighborhood in the city. After a big rain storm you can drive all around the neighborhoods and see the hoses people have run out to the curb to pump excess water our of their yards.

The other side of the back fence is the neighbor's back yard which slopes up toward their house.

The damming is caused by the part of the back yard being the lowest point of the surrounding properties and also there is nowhere for the water to go. Over time it percolates down into the soil.

A contractor said what is happening is the foundation is settling, causing cracks. They would drill holes into the block from the outside and fill with cement, thus making the block "solid."
They would do the entire perimeter of the house, because if they only do the areas where water comes in, then the water would just come in somewhere else. Cost could be anywhere from $4000 - $15,000.

What do you think of this approach versus hiring a landscaping crew to grade the soil away from the house?

Why don't you build a rain garden? Slope you landscaping towards the back of the property, remove about 8 to 12 inches of soil replace with 2 inches of sand and 4 inches of organic top soil blend together and plant native species of plants in the area. This will keep the water from you foundation; the water will infiltrate into the ground at a more regulated period of time; no damming on the fence; looks nice; low maintenance; and a lot cheaper.

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