Utility Lines are frequently laid in sand that provides a direct path for water to reach the foundation.

Swales and french drains . The means of transporting water away from the house besides sheet flow ( when the surface is effective running water ) are the swale and French Drain. A swail is a small valley formed by two sloped soil surfaces . Swales must me pitched ,or they become ponds. A swale should be located away from the building, and it is often used to divert sheet flow coming from uphill.

A french is a trench filled with rock or gravel that a collect water and transports laterally. I prepare the bottom of thtrench so thats smooth and carefully pitched toward the outlet. Mix dry cement with the soil in the bottom of the trench make it less permeable, and fill the trench with whatever clean gravel is locally available . I hesitate to used road stone , a blend of gravel and stone dust, because water passes through it slowly . If the gravel is to be exposed. I try to cap it with an attractive rounded stoned . If the drain is to covered m I provide graduated layers of smaller stone toward the surface , then perhaps, filter before the sod covering .

I sometimes use 4 inch smooth wall perforated plastic pipe in a french drain , particularly if I expect it to carry a big volume of water , say runoff from the futures. There are fittings that connect downspouts directly into this pipe . If you do this, install cleanest at least every 50 feet ad keep in gutters clean . Otherwise the can pipe can become clogged with leaves . I don’t use corrugated pipe for drainage because it is more easily and is more difficult to clean.

Concrete patios , stoops , driveways , and side walks abutting the foundation present problems . It is important to design them so that the gravel beneath the drains outward ,a perfect use for a French drain. You way dined that the driveway is one of most convenient site for a French drain. Driveways usually pitch away from the house , and a French drain can be integrated with the driveway so that it will not call attention to itself.

Where should the water go?

To my knowledge , municipalities mo longer provide storm sewer service for a new residential run of . In my area , they do mot receive the output from sump pumps. They receive and treat storm water to keep streets open, and that’s about it . If the isn’t enough elevation difference between the house and a point on the lot where a pitched drain can come to daylight , then another solution is needed . Theoretically , if the pipe never pitches back, you don’t
need more than the diameter of the pipe in elevation difference difference . Practically , more is better and 1’4 inch pipe .

Because have the pitch below grade, run off can go to dry wells. Drainage structures must buried somewhere on site .