Washout-proofing a ditch

[airbiscuit]

I don't disagree. That ledge makes things difficult. We don't know exactly what he has to work with. If he does have an area in the right place where he can dig out a swale, it is a cheap fix.

 

[kpsp50]

Like digging it said the county here uses rip rap and they hold up very well

 

[denmeck]

If you've got a picture of what a "rip rap" lined ditch looks like that might help.

Had similar problem on my steep driveway. Just had professional company come in and cut 2x2 ditch down the low side and fill with 4+ rip rap. Also lines it with fabric. Then regraded the lane to pitch that way and cut down the hills a bit. Then layed modified stone and compacted it thoroughly. Holding up great so far, but the real test will come next spring.

 

[CoyPatton]

Around here the county highway dept uses straw bales in many locations. Every 75 to 100 feet down the ditch. Usually two or three bales laid across the ditch. Dirt will collect upstream of the bales. Soon grass will grow. The bales have created an almost permanent structure.

This is done to slow erosion from the water movement. Depending on the slope, is how close the bales will be placed.

 

[CoyPatton]

Would that just cause a huge unfortunate mass of water at the end points of the bales?

It slows the water flow, it does not stop the flow. During a heavy downpour, you may have some ponding happening
Would you prefer erosion or temporary ponding?

 

[CoyPatton]

I hate riprap lined ditches. You can’t mow it. I’d rather have the erosion.

This is true! But with deep cut trenches from rushing water can you mow anyway? Not to mention if the sides of the ditch ate steep and depth of ditch may in itself prevent mowing. Each must decide which evil he wishes to endure. The rip-rap is hard on string trimmer lines as well.
My approach was to spray grass/weed killer (your choice of which). Be sure to follow all safety precautions when dealing with chemicals as well as spraying on days without wind, wether drift is a concern or not, get soaked with chemicals is not good for your long term health.

 

[tree grower]

The only three things you need to know about road maintenance are drainage, drainage, and drainage -- in that order!. The common solution is to line the ditch with stone, but first you need to be sure you have adequate cross-drainage. Check with AOT website or your town road commissioner for class three highway specs. Culverts should be a minimum of 15" diameter, laid an angle to the road, and at a proper depth--usually covered by same depth as culvert diam---15" cover for a 15" culvert. That may not be possible due to your ledge. Number of culverts and spacing is very important. It depends on grade of road. In VT rip-rap usually applies to big stone such as would be used to line an eroding stream bank--too big for your needs. See what your town uses, because they are going by State specs. Don't use stone from a gravel screening process, because it is round stone--you need crushed so it can lock together. Hay bales are only useful as a temporary solution--weeks or months, not years. Your principal objective needs to be diverting the water off the road, not just slowing it down.

 

[pcman]

maybe mini ponds that breed mosquitoes.

 

[eightytwenty]

I just moved from my 1/2 mile gravel drive with a swamp halfway between the house and main road. Nothing like a U-shaped road (as seen from the side) to cause all sorts of erosion issues. It was a PITA, but over the years I got it under control. Went from 30-50 tons per year of new material to about 4.

Agree 100% on the OP's need to slow the flow. Even stepping ponds with small water falls will slow the water as the grade drops and severely slow the erosion.

Where that is not feasible, look into the 1' wide by 2" deep drive-over gravel erosion systems (similar to permeable paver systems) to line the edges of the road (under surface) and support the height of the road bed, while the water runs alongside the paver system. These systems are generally run $6-10 / LF at 2-4" high. Start where the problem is worse, strip down 4-5" of road, 18" wide.. lay the plastic "paver" grid then backfill with Item4 w/ extra fines. Do a bit at a time until your problems go away. Should not have to do the full run.. The ledge is helpful here, as its less likely the mesh gets undermined.

Another alternative would be to use those same mesh systems in the ditch to slow the water, though I've not tried that so don't have personal experience. I somehow doubt it will slow anything when the volume is highest.

The more you can slow the flow, the less of the plastic paver stuff you'll need.

Also go really heavy on the fines for any new road surface material. I would have the quarry add 1 ton stone dust to every 3 tons of DOT Spec Item4. NO, and I mean NO, round rock. No bank run. No "crushed gravel". No pebbles. Angular only. All sides. Its twice as much but lasts 20x as long.

 

[OzarkChris]

See attached photo, which unfortunately doesn't show the 10-12 vertical inch drop from driveway surface to water very well.

I have this drainage ditch along my gravel driveway feeding multiple culverts all in the hope it will keep my driveway from washing away.

Mostly it works. Most of the length of the driveway the bedrock is right at the base of the ditch. It probably is here too, the pebbles you see are the gravel it's constantly washing out of my driveway. So it's not something I can deepen with a tractor. I might be able to push it back a, but that probably wouldn't work unless I move the ditch back the whole length of the driveway, which isn't pragmatically feasible (trees, rocks, difficult spaces).

So need some way to line the driveway gravel so that the next rain won't just wash it out. I have no idea what to use. Cement / cinderblocks of some kind seems easiest, would that work? I'm looking for suggestions from people who have overcome this particular erosion problem.

I hate having to regularly throw more gravel (purchased by the truckload) at this problem.

Around here the county/state folks have used a cement poured liner over a 3/4+fines gravel lined ditch. On the steeper sections they make a kind of water slalom course in the cement (think poured cement brick shaped structures @ a 30-45 angle facing down slope) to slow down the water. So far the only thing really "trapped" in the slalom course are larger (4"+) branches, leaves etc, go through to the bottom where the culvert is. I doubt this would be an inexpensive fix, but our gravel roads haven't washed out since they put this system in place.

I don't have a pic of this but if my description doesn't make sense I could get one & post it next time we head to town.