Understanding Property Drainage
by Phil's Excavating -Your Excavating Partner
Do you have a wet yard or flooding basement?
You're not alone. Here's a brief explanation of what can be done to stop the flooding, including property drainage and land grading.
If the cellar floods in one area, look for cracks in the foundation. Cracks can be sealed by mortar mix or new epoxy fillers. Normally it's best to seal the cracks from the outside, but it may be worth trying to seal them from inside the cellar. Also, see if you have a slight slope on your property that will allow rain water to flow away from the basement. Improper slope next to the foundation is a major cause of flooded basements. Your property should slope about 6" every ten feet to allow water to drain away from the basement. The slope shouldn't be much less but can be more, although a steep slope may cause washout in a heavy rain.
If your basement floods evenly around the edges, it may be a high water table and the best solution is to hire a specialist in wet basements. He may install a French drain around the inside of the cellar walls to collect the water and redirect it to a pump. A French drain is a trench that has crushed stone added to let rainwater pass easily into drainable sand below the basement. Sometimes a perforated pipe is added near the bottom of the stones to help move the water to a pump.
Downspouts shouldn't drop water next to the foundation, especially if your property has very little slope. The water should be dropped a distance of 10 feet from your house. A downspout extender can help keep the water away from your house.
Some people have a downspout drain installed to help the water soak naturally into the water table while avoiding ugly downspout extenders.
If the wet basement is caused by yard flooding, a possible solution is to install a perimeter drain, an exterior French drain, next to your foundation. It helps direct the water from the house to either a lower area on the yard where the water can harmlessly sink into the soil or into a dry well.
A wet yard is generally handled in a similar manner. The land should slope at least 2 1/2" every 10" and should have no low spots to collect water.
Sometimes water rushes into your yard from a hill near your property and it has no where to go but your yard, basement, driveway or patio . A swale can be constructed to redirect the water to a benign location. A swale is a low area in the yard that is made to help the water flow away naturally (see photo, above left). If there is no place to divert the water, a curtain drain may be constructed. A curtain drain is a French drain that is constructed in a location that catches the water before it floods your yard or driveway.
Should you hire someone to install a drain or do it yourself?
Normally, if you are an able bodied person in good health, you can install a drywell yourself. But if you need many drains or a curtain drain, it's usually better to hire an excavating company. Consider that the stone put in the drains weighs about 2700 pounds per cubic yard and a drain 1 foot wide by 3 foot deep built around an 1800 square foot ranch requires 7 cubic yards yards of stone weighing almost 18,000 pounds. That's a lot of shoveling and the soil removed weighs almost as much and it has to be disposed of.
Very wet and flooded yards are usually best left to an excavating contractor with extensive drainage experience. Whether you hire someone to install the drains or do it yourself, make sure landscape fabric is installed around the stone so that the soil doesn't mix in with the stones and clog the drain. If a perforated pipe is used, the perforations should be face down, not on the top. Keep in mind that good land grading that allows the water to naturally runoff and drain into the water table is preferred over yard drainage systems which will eventually clog up and need cleaning.