My wife and I have just purchased a new house. It is our first house so we aren’t very experienced with many things. Our house has a particularly long (100 yards or so) gravel driveway. This did not seem to be a big problem to us when we were looking at this house, but when spring rolled around, incredible rains caused massive water washing across it. In one particular area, it has begun to very seriously wash out. There is a culvert there, but it is clearly not enough for high rains. Clearly preventative measures need to be taken before we get trapped.
I talked to a driveway guy this morning, but he said that he generally didn’t deal with gravel driveways. He suggested I talk to somebody with a back hoe (sp?) to dig out trenches and what not to stabilize it. Unfortunately, I’m not a civil engineer, so I really couldn’t tell you what really needs to be done. The driveway is just to long to pave. What is the prescribed aaction in a situation like this.
OK. I don’t claim to be an expert, but I’ll give this a try. Our driveway is gravel and it’s 3/4 of a mile long. We’ve seen many things happen and go wrong over the years.
Ideally, you need to find a local who deals with gravel roads (duh!)
Barring that, how often do you get the type of rains you just experienced? If that occurs on a regular basis, you need to consider having a larger culvert put in. If it was a 20 year event, then the culvert is probably OK. Then you just need some gravel hauled in and probably a grader to put a proper crown on it.
Well, i live in Springfield Missouri and our rains have definitely been unusual. Nevertheless, I think the washout is permanent. I have shoveled the stones back into place one time and it worked great until it massively rained again. Now it is at least as bad as it was and most likely worse than it was. If we don’t do something ASAP, this thing is going to become an emergency quickly. What do I look under in the phonebook to find somebody that specializes in this type of work?
Also, our driveway is actually an easement. Naturally we have a right to access the road, but legally what agreements do I have to obtain from my neighbors to do work?
What sort of gravel do you have? I grew up on a 300 yard gravel driveway that used to wash out regularly when we had the tiny little pebbly stuff in there. We eventually brought in railroad gravel (big ol’ honkin rocks) to fill, and the problem was gone. Now to be fair, we lived less than a mile from some tracks that had just been taken out of service, so the gravel was readily available – I have no idea how hard that stuff would be to get otherwise. Oh, and the first month was less than fun, what with having to pull railroad spikes out of various things. Perhaps combining the railroad gravel with a more serious culvert would solve the issue?
Are you saying that what we need is bigger stones? I have bigger stones and since my wife is the (err) provider, I’ve plenty of time to redistribute them. Some of the current stones are actually pretty large so I wonder if that is what the previous ownersw did.
AF Civil Engineer (by trade, but I’m not licensed) here.
It may not be compacted enough, allowing the rain you’ve got to more easily seep into the top few inches and be swept away. Is it built up, i.e. is the driveway raised in comparison to the grade around it?
How big are your culverts? Are they 12" or bigger? When was the last time they were cleaned out or flushed (the Fire Department may do this occasionally). Is the grade around them level, or just kind of flat?
I can’t offer you a definitive answer, but I may be able to describe something reasonable for ya.
Tripler
“Colonel, you can have it fast, good, or cheap. Pick two of the three.”
Yes it is built up a bit, but not enough that water doesn’t run down it in a storm. One of the things I would like to correct is the way water runs down it in a storm. In order to do this, I think I will need to dig a trench along side it.
The culverts are 12" in diameter. For the amount of water we have seen, it is not enough.
Two weeks after we bought this place the driveway started to wash out. The first thing I did was clean this culvert out.
I think this might be part of the problem. The culvert goes under the driveway, but it is basically just a trench under the driveway that goes back to level on the other side. It doesn’t really matter what the culvert does if it just fills up then goes nowhere. I think the trench needs to be completed all the way to the stream.
That still wouldn’t fix the way that water runs lengthwise down the driveway. Somehow I need to watch this and figure out how to divert the flow without creating another washout.
I’m not an expert, but I’ve had a couple of gravel roads built, and seen others built, with various results.
Look for neighbors with good gravel driveways, stop in to say Hi (which is a good thing to do anyway), and ask about who did theirs, and how they liked the work. Also ask around the local farm supply stores, cattle auctions, etc., to find out who folks are using. If you’ve got a USGS map of your area, see if any gravel pits are marked near your place and swing by to see if they’re still active. Failing that, look up “gravel” in the yellow pages, especially for someone whose display ad says “roads” or “driveways.” They ought to know someone who will build your road, if they don’t do that themselves.
Gravel is a very local thing, so YMMV, but here in Texas we’ve got something called caliche in fairly good supply. If you wait 'til the dry season and can get a gravel and caliche mix laid in, well packed, and well drained (and a freak flood doesn’t wash it out while it’s still soft), then, well, you better hope you never have to take it out!
We replaced the top surface of our gravel driveway about 4 years ago. It is about 50 yards long and about two car widths wide that ends in a small circle, The initial investment was about $300 in gravel and a day of hard work to put it into place with shovels and firm rakes. However, this season has destroyed it and we have true ruts. It has to be built upon again. We used pea gravel the first time. It is fairly attractive but snow plowing tends to screw it up. We are thinking about something called hard pack that people told me about. It isn’t mostly rock. It compacts well and is almost like the base of a highway. I haven’t made up my mind yet.
Still kind of difficult to know what specifically is going on without seeing a map of it. Just how much area is trying to drain through that culvert? What condition is the culvert? Is the culvert a concrete or clay pipe of some kind, or corrugated metal pipe, possibly rusted away?
What’s the slope and permeability of the drainage area? Just how fast is how much water trying to drain? There are calculations for figuring these things, but they’re necessarily site / local area specific.
Sounds like the drive doesn’t have much of a crown now, so at least part of it acts as a gutter. Sure, that would tend to wash away the gravel. If you could build up the center of the drive to get all the water to go through the (enlarged) culvert, would it be possible to improve just the part of the drive near the culvert, where overflow water would do the most damage?
How’s the soil under your driveway? Clay? Silt? Or what?
Could you find a local roadway / engineering contractor that may have some roadway millings, where they’ve ground off some pavement for the local highway department? Those millings have got some asphalt in them, and especially when compacted, can sometimes hold together slightly better than ordinary gravel.
IANAL, but I’d say you have the right to make ordinary improvements to allow the driveway easement to be used for its purpose. 'Course, it’s not a bad idea to stay on good terms with your neighbors, if you can, so it wouldn’t hurt to (at least try to) discuss any plans with them.
Oh, I’m not licensed as an Engineer in your state. You could try calling the local public works department to see if they have any advice. They should be familiar with local conditions.
If you hold the easement for access, you have the right to do work to maintain that access. You might check with an attorney to make sure.
I’m familiar with this type of problem (rainfall, runoff & hydraulics are my bag). If you are getting washouts then one of several things could be happening:
Culvert stopped up (you checked this, I see)
Culvert outlet channel slow- or no-draining
Culvert too small
Road too low
Roadside ditches blocked
etc.
This is possibly the key:
. I’d do that first, then turn to other solutions.
As a geographically displaced (and effectively blind) engineer-type, I completely agree with Civil Guy, we’d need a map at the least, or a walkaround of the site at best.
I originally thought of this too, but hesitated to ask, thinking the OP might not know soils that well. . .
My initial $6.40 answer for a quick fix? Compact the hell out of it. Have someone with a grader come in, grade the existing gravel flat, and then run a steel-wheel roller over it several dozen times. I’m thinking the increased compaction of the road base (which is basically what it is at this point) will prevent water from soaking in the top few inches, and will help divert it to the culvert. Once you compact the hell out of the base, spread a new inch or two of gravel on top for a wearing course, and then compact the hell out of that again. Essentially, you’re adding a new lift to the road. I think this’ll buy you some time to either have a more professional and complete solution for the drainage issue.
Tripler
It’s not the $64.00 answer, but I’m running a special this week on Internet-based consultations.
Before the OP pays someone a chunk of change to come compact the driveway, he’d do well to cut that outlet ditch. That culvert is not going to function at capacity without a free outlet.
I agree that the driveway probably should be raised as well, especially in the washed-out areas. That’s not going to do anything for the erodibility of gravel, however. The best scenario is one where the water doesn’t cross it.
Railroad gravel (“ballast”) is designed for really good drainage. Apart from providing a level footing for the unequal loads a passing train can bring to bear on the track and roadbed, its main reason for being is to provide good drainage (waterlogged track messes big time with the signalling circuits). Railroaders know their drainage stuff.
But I can’t help thinking it would suck to driver over in most road vehicles, even in a SUV. Maybe you could get some for use as a base with road gravel overlaid?
BTW, the railroads use this stuff VERY LIBERALLY. You’re talking a pretty thick layer here. I reckon if you can afford and/or acquire at least a foot thickness of railroad ballast, and then another generous layer of normal gravel, your problems would be solved. The brute force approach here.
I think if you use ballast you want to dig out and lay it under your gravel road surface to help keep it dry. It might work to lay in enough ballast to fill in where the water pools, so you’re laying your gravel/clay mix above the water. But I agree with the others that it’s probably most effective to improve the outlet ditch so water doesn’t pool around your road base.
Otherwise it’s sort of like Swamp Castle in the old Monty Python movie. Just keep building one castle on top of the other until you’ve got one that doesn’t sink.
I think the OP mentioned water running down the road and cutting gulches lengthwise. I’m not sure how to correct that, except it doesn’t seem to happen if the road is packed hard and has a good even “crown” to it, so water doesn’t collect anywhere, but flows smoothly in a sheet off to either side. There’s doubtless an art to getting the right mix of gravel sizes and clay binder.
A set of pictures posted would make it a lot easier to give good advice.
Need to get the road up and crowned as has been said or ditched on the sides and the water a path to follow or you’ll fight this for the rest of your life. Keep any water from going on the road other that what actually falls on it. Reduces the amount that can flow down the wheel tracks.
In vest in or build an little drag blade to work the drive on a regular basis. A small lawn tractor can do a lot with patient and repetitive work.
I have a gravel driveway and had storms wash it out where it met the asphalt roadway. I used a trick my grandfather had at his ranch in SE New Mexico. I removed a large section of the gravel drive where the washout was occuring and filled in that space with Railroad ties. I anchored them using Rebar driven into the ground and at an angle for the ones over the culvert and then placed another tie at an angle to the set to direct water to the culvert under the ties. Have not had a problem since and have had many neighbors stop by and use the set up at their house.
Essentially it looked like this with the normal water flow direction being from right to left.
Thanks for including that link! My wife and I, who travel an approximately 8 mile dirt/gravel road to and from work have been wondering about this for a couple months now.
My dad put a length of aluminum chain link fencing as wide as the driveway over the bare dirt where the gravel washed out most often. He drove in iron rebar hooks at the corners, and along the edge here and then. Then he had the gravel replaced, right over the fence sections. (He used crusher run gravel, rather than washed gravel, but I don’t know if that was important.)
The driveway was on a steep slope, but for a number of years it was just fine. After about three years you could see the fencing here and there, and an broken place, or two, from wear in the travel ruts. But the gravel stayed there, for years.
