Drainage across driveway

[paulsharvey]

So when I suggest a swale or someone said, a V in the concrete, you want it spread over a pretty decent area, maybe 5 ft transition down, 5 ft back up; maybe 3ft and 3 ft; but you don't want a true valley gutter. A true valley will create an annoying bump, and also really focus water, volume and velocity, into a since area; causing future erosion issues at the outside corner area. It doesn't take much at all; I don't mean a 3" deep swale, literally just a minor low point, with a mild cross slope.

 

[LittleBittyBigJohn]

I did actually have them slope the whole driveway downhill on the cross slope section. I'll throw the laser on it to see how much fall it's got. I'm thinking an inch or so over 20'.

 

[bigtiller]

As others said, a swale in the concrete is best. I have one in my approach to the tin shed that drains half the house and a parking area. During dry times it is hard to see so I sprayed a paint spot on both ends so I can find it....I sometimes shovel snow by hand just for exorcise.

 

[CliffordK]

So when I suggest a swale or someone said, a V in the concrete, you want it spread over a pretty decent area, maybe 5 ft transition down, 5 ft back up; maybe 3ft and 3 ft; but you don't want a true valley gutter. A true valley will create an annoying bump, and also really focus water, volume and velocity, into a since area; causing future erosion issues at the outside corner area. It doesn't take much at all; I don't mean a 3" deep swale, literally just a minor low point, with a mild cross slope.

Thinking of the design of my parent's house, there was a moderate slope down towards the house entry. I'm not quite sure why we didn't raise the house more, although that would have thrown the back entry and porches out of whack.

We had drainage along the driveway which then went through a culvert and was directed down a ditch about 50 feet in front of the house. That would take the bulk of the water away from the house.

Then the driveway moderately sloped towards the house. So about a foot in front of the garage, a V depression was put into the driveway that directed water to the side of the house. I'm not sure if there is a drain picking up that water beyond the driveway. The depression is visibly noticeable, but really isn't any kind of inconvenience. It doesn't take much to keep the garage dry.

In our case, the "V" was fairly sharp because we were forming with 2x4s. However, if one had planned better, one might have formed with 2x6 or 2x8 boards and put in an "S" curve into the forms with a jig saw or band saw.

For the OP, it appears as if there is a significant slope down from the shop. So runoff on the concrete won't be a huge problem if tilted off from level.

I would probably put in a small French Drain in the curved area and direct the water under the driveway.

Then, landscape so that the ground level is even with the edge of the concrete, and thus no place for the water to pool.

 

[Streetcar]

I would put a pipe under driveway if you can get grades to work. Arkansas can get heavy rain or freezing weather. Both can cause issues with overland drainage

 

[LittleBittyBigJohn]

I'm leaning towards getting a roll of 3 or 4" corrugated pipe and putting it under the driveway so it's there. Then if i can't get the grade to take the water over the driveway at least i have a backup.

 

[2manyrocks]

I'd recommend 4" solid pipe instead of corrugated because it's harder to pitch corrogated without bends/dips and water/debris flows better through solid pipe. Solid pipe is also more resistant to collapsing.

 

[ruffdog]

The 4" probably would flow twice what the 3" would....go bigger.

 

[ponytug]

I'm leaning towards getting a roll of 3 or 4" corrugated pipe and putting it under the driveway so it's there. Then if i can't get the grade to take the water over the driveway at least i have a backup.

Don't use corrugated pipe; it is prone to clogging, the walls are thin, and it just does not have any sort of longevity. Use a 4" or better yet a 6 or 8" pipe. It is hard to go too big with a pipe.

As @paulsharvey mentioned suggested above, I would however vote for a concrete swale over a pipe. They don't clog, and they can't be overloaded when that extra heavy rainstorm/ hurricane remanent that sweeps in.

All the best,

Peter

 

[2manyrocks]

A broad swale can't be crushed like a pipe, especially a pipe that isn't buried very deeply.