Help With Driveway Drainage

[paulsharvey]

On the sloped berm next to the cut I’m planning on seeding with something that’ll do well in the summer (Bahia or Bermuda…open to suggestions but it needs to tolerate sand), and then getting some erosion control rolled fabric to lay over the top while it germinates.

Inside the cut, I’ll just do some sort of stone. I don’t necessarily care if it sinks some, as the point of the cut is to be lower than the drive. There are a lot more experienced guys on here than me, so far I’ve changed my plans a few times based off the posts here.

Edit: trench is 85% done and shaped, image below

View attachment 799367

I would seed with Argentine bahia, and pearl millet, here in my part of the world. I can't tell what kinda slope you have, but if it drops more then about 3 feet over 100 ft; it might be worth having 6" high "ditch blocks" to slow water down. Erosion is driven by flow, soil weight, and Velocity. You can't really change your soil type, and the flow is kinda built in, but you can change the velocity. Only would worry about it if you see erosion before your grass gets established.

Edit; a slightly wider, flat bottom ditch erodes less then a V bottom.

 

[UOFan]

I would seed with Argentine bahia, and pearl millet, here in my part of the world. I can't tell what kinda slope you have, but if it drops more then about 3 feet over 100 ft; it might be worth having 6" high "ditch blocks" to slow water down. Erosion is driven by flow, soil weight, and Velocity. You can't really change your soil type, and the flow is kinda built in, but you can change the velocity. Only would worry about it if you see erosion before your grass gets established.

Edit; a slightly wider, flat bottom ditch erodes less then a V bottom.

Never heard of Pearl millet, gonna look into it. Thanks for the suggesting on the ditch blocks…assuming that’s just a ledge, or is that actually putting in stone? And yes, I need to take the shovel and run the bottom of the ditch flat.

Priority right now is to get the ditch 100%, then bring in some drainage rock to fill it in. Then get a load or two of crush and run to set a driveway base on the dirt side.

 

[2manyrocks]

I wouldn't add rock or fabric until I was certain it is going to flow water as planned and doesn't require any final retouching or change in grading. If it doesn't wash, adding rock is more work and makes it harder to mow or regrade that area in the future. Can you say what grade the ditch is? It doesn't look as steep as one of our roads that hasn't washed despite being all dirt.

It looks like you essentially moved the berm from the driveway side to the other side. The ditch is now all that stands between your house and that flow of water. My thought was to have diverted the water from the road without changing the berm itself. Not knowing how much water there is, I'd want to keep my options open if I had to regrade this for some reason.

 

[UOFan]

I wouldn't add rock or fabric until I was certain it is going to flow water as planned and doesn't require any final retouching or change in grading. If it doesn't wash, adding rock is more work and makes it harder to mow or regrade that area in the future. Can you say what grade the ditch is? It doesn't look as steep as one of our roads that hasn't washed despite being all dirt.

I can measure it tomorrow, but off the top of my head the angle of the actual ditch is probably 30-40 degrees.

I’m going to go take a picture, but basically I have an 18-24” wide ditch, then I have the berm off to the high side. The slope of the berm ks significantly less than the ditch.

 

[2manyrocks]

I can measure it tomorrow, but off the top of my head the angle of the actual ditch is probably 30-40 degrees.

I’m going to go take a picture, but basically I have an 18-24” wide ditch, then I have the berm off to the high side. The slope of the berm ks significantly less than the ditch.

Sorry to be confusing, but I meant the slope that the ditch runs down the hillside.

 

[UOFan]

Alright see below for pictures:

Photo 1 is looking down the drive. Center you can see the small ditch, then immediately right of the ditch is what I’m calling the berm, even though it’s just a slope:

Photo 2 is looking UP the drive, from the downhill side. Ditch is to the center and berm to the left in the photo. Just a better view to show the ditch and berm.

Photo 3 shows the hastily measured angle of the berm. About 20-25 degrees.

Photo 4 shows the angle of the ditch, about 30-35 degrees.

And here’s another photo for reference:

 

[paulsharvey]

Pearl millet is a fast growing summer grass that dies off; think of it as the summer version of rye. I did about 2 seconds of googling, and what they described is a lot taller then what they put in "summer blend contractors seed" that I'm used too.

The ditch blocks are just a 6" high, maybe 24" thick, compacted "berm" across the flow line of the ditch, slowing water down. They can also use rock or concrete, but I wouldn't start with them if not needed. I couldn't find a good picture to show. It also allows a good portion of the slowed down water to naturally perk into the soil (if your soil perks).

 

[3Ts]

The ditch blocks are just a 6" high, maybe 24" thick, compacted "berm" across the flow line of the ditch, slowing water down. They can also use rock or concrete, but I wouldn't start with them if not needed. I couldn't find a good picture to show. It also allows a good portion of the slowed down water to naturally perk into the soil (if your soil perks).

Kinda like a miniature dam just to cause the water to slow down and stop periodically. You can also see this on road construction where they put rock "dams" and cover with wire mesh (to hold the rocks) in the drainage ditches to keep erosion under control.

 

[Rockbadchild]

it’s going to be challenging to get grass to grow on that soil … it would be worth to Hydroseed

 

[2manyrocks]

I apologize again for not communicating well. I meant to ask how much the grade of the ditch falls over its length from one end to the other--like from A to B.