Question
Hi there,
I purchased an old house last year and have noticed issues with flooding into the basement. It would seem that the backyard is slanted and most of the rain runs toward the house and because of the old foundation we have leaking issues (its not the basement door because we had that replaced). How big a job is it to have the area pitched so the water runs toward the driveway and down to the street. We're talking about maybe a 6' X 6' area. Or possibly there is another solution? We've asked the opinions of several contractors and have gotten varying answers.

Thanks for your help

Answer
As I have not seen your yard and your description is a little vague but here are my suggestions:

Option one, re-grade your yard so that there is a swale directing water around your house. The center of this swale should be a minimum of six to ten feet away from your house. That means the soil around your house must slope a minimum of 1/4" per foot away from your house all the way around. Where the soil meets the walls of your house should never be the lowest pot.
The difficulty and price of this depends on the ease of access, existing materials and plants that must be removed and or replaced after grading, and soil conditions, roots, rocks, etc.

Option two is to excavate the soil around your house down to the foundation or footing. Then waterproof the walls using the latest fluid applied or spray on water proofing (requires a professional but is the best and only way I would do it). Then apply a drain mat and ploy liner against the water proofed wall so that when water is moving through the soil below the surface it will be intercepted and directed down to the bottom where a pipe will collect the water and drain it to a low spot in your yard. Google NDS products, wall drains, french drains, etc to learn all about these types of products.
Cost and ifficulty of this is high. Probably a minimum of several thousand dollars to many thousands.

Option three, install area drains in your swales(from Option one above) or create depressions with area drains to intercept the water running towards your house. Pipe this water away from and around your house to a lower spot in your yard. NDS offers area drains and they are sold through most home supply stores. I recommend 12x12 or 18x18 drain boxes for serious problems. Google NDS area drains for more on this.
This is not to hard to do and materials should be around a few hundred dollars.

Honestly, drainage is a serious issue and is not easy to fix without a professional's help. Digging hundreds of feet of trench and laying pipe and gravel is not easy. Not to mention getting the grade right without a level and rod and experience is not going to be easy.

If you have areal problem you probably need to consult with a drainage expert or a landscape architect in your area.

But best of luck,


Sean J Murphy, LA,ISA, LEED AP
Please check out my blogs and articles on landscape topics like this on my websites.
http://www.seanjmurphy.com
http://amenityarchitects.com