using geotextile fabric on a dirt and gravel road

Aloha Permies,

I live on a 1 mile long dirt/gravel road in Hawaii.  Over decades the road has been maintained by yearly applications of gravel.  By the middle of the year, potholes are forming again in the flat areas, due to the rains and gravel getting pressed into the surface and pushed out of the way by car traffic.  In some years there's been grading and scraping of the road in places, but I feel this hasn't helped much.  The road is a single lane doubletrack with a width of about 12-14 ft in most places.  There are no potholes in the center of the doubletrack anywhere.  The problem areas are fairly isolated, and in those areas will be single potholes and strings of adjacent potholes.  About half of the length of the road has problems (the flatter part), while the other half not so much (more slopes).

Our neighborhood cannot afford a proper resurfacing of this road, so I'm looking at ways to address the problem areas.  We also cannot afford the geocell type plastic permeable pavers.  We also can't afford much excavation, nor would it be possible in some areas due to near-surface bedrock.  So I'm considering geotextile fabric covered with a layer of gravel.  Our best available local gravel is called blue rock and comes in various sizes of base course.  For the fabric, this looks pretty good HERE and free delivery (super important here in Hawaii).

I would appreciate any feedback and insight into how to properly lay and cover the fabric.

thanks!

Hopefully one of our road experts will speak up, however, in preparation for that, I'm going to ask some questions:

1. Where does the water come from and go to on the pothole sections? (yes, some comes straight from the sky, but does any come onto the road from surrounding surfaces?)
2. Looking at the picture you posted, does the water run off the road to the Right, to the Left, or just sit there seeping in and softening the surface?
3. Is the flat section of road running through a bog?

For example, when I first moved here, there was a huge puddle all winter on the path I biked the kids to school on. I started hauling all the surface rocks that were in our field to the puddle and tossed them in. It swallowed every one of them as if it was a light snack. Clearly it was very deep and was acting like a small pond. I recall doing that for the whole first winter we were here (which I admit was one of the wetter ones we've experienced) and eventually it was at least less of a pond. Geotextile would have just been swallowed up until I had enough bigger rocks to support it.

Similarly, I remember reading about someone, somewhere, who had a wet area in their road and nothing seemed to work. Finally, they got some second hand chain link fencing and put it down and then old carpet over that and then gravel. The combination of fencing and carpet was enough to stabilize the base of the road. That ended up being a very cheap fix as well!

Hi Jay, thanks for your response.

1. Where does the water come from and go to on the pothole sections? (yes, some comes straight from the sky, but does any come onto the road from surrounding surfaces?)

I would say almost exclusively from the sky in the problem areas that are flat, with tree canopy sometimes also dripping in areas.  The surrounding earth is very water permeable.  In fact, we have no natural lakes, ponds, or streams in our area.

2. Looking at the picture you posted, does the water run off the road to the Right, to the Left, or just sit there seeping in and softening the surface?

There's nowhere for it to run off to... no drainage.  Most of the entire road has no crown, which would be very difficult or impossible to create by grading the existing surface, because of buried rocks and near-surface bedrock in many places.  (Local soils are very rocky.)  Laying down a sufficiently thick layer of gravel, all along the flat areas, and running a heavy roller on it in order to create a crown, would be way too expensive for us.  The last bill for gravel alone was $2,700 and that was spread as a relatively thin layer over several sections—enough to fill potholes, but not enough to "resurface" the road.  The center of the doubletrack, and the road edges, wind up having persistent gravel, which is sort of an expensive waste.

3. Is the flat section of road running through a bog?

No, we don't have any bogs.  There are a couple low places in the more hilly section of the road, which tend to collect a bit of water, but those can easily be addressed with larger gravel.  The gravel will stay in place more because it's in a low place.  Surrounding areas, as I say, have very permeable soil.

Geotextile would have just been swallowed up until I had enough bigger rocks to support it.

That wouldn't be the case in our situation.  Most of the problem areas are relatively small diameter potholes that start out shallow, and some get deep enough to be irritating to drive over.  I'd like to eliminate the strings of potholes that occur in one or both tracks of the doubletrack.  It's usually one track.

I remember reading about someone, somewhere, who had a wet area in their road and nothing seemed to work. Finally, they got some second hand chain link fencing and put it down and then old carpet over that and then gravel. The combination of fencing and carpet was enough to stabilize the base of the road. That ended up being a very cheap fix as well!

I like that idea a lot!  A low pile carpet I think would be the best.  Also the carpet could be fastened to the chain link fencing with zip ties.  The chain link could be the up side.  If water would seep through the carpet easily, and not get clogged, I think it would work.

thanks!

J. Calvert wrote:...

Jay Angler: I remember reading about someone, somewhere, who had a wet area in their road and nothing seemed to work. Finally, they got some second hand chain link fencing and put it down and then old carpet over that and then gravel. The combination of fencing and carpet was enough to stabilize the base of the road. That ended up being a very cheap fix as well!

I like that idea a lot!  A low pile carpet I think would be the best.  Also the carpet could be fastened to the chain link fencing with zip ties.  The chain link could be the up side.  If water would seep through the carpet easily, and not get clogged, I think it would work.  thanks!

You're very welcome! May I suggest you choose a short problem area first and do a test??? Pretty please? I'd hate for you to do a pile of work only to discover that what worked in one ecosystem, didn't transfer well to yours! What would worry me about the chain link on top is that if any of the wire gets worn through, it could puncture tires. The place the idea was used, if my memory is correct, wasn't a high traffic area.

Try some different ways even - 1. fence on top, carpet on bottom, 2. carpet on top, fence on bottom, 3. fence sandwiched between carpet, are the 3 I might try.

Hi Jay,

I'm not set on that solution.  I'm specifically seeking answers about installation of geotextile fabric.  The chainlink fence and carpet idea is interesting, but I only have a small amount of old chainlink and used carpet is a scarce commodity in my area because people use it for a variety of applications, such as underneath a pond liner.  I looked on Craigslist and there's no free carpet advertised at the moment.  It would be an effort to try to find the stuff, and same goes for old chainlink fencing.  These two items may come along at some point, and I could experiment with it, but I feel like I can't depend on those materials.

Geotextile fabric is relatively inexpensive and is very effective at separating the gravel layer from the underlying soil of the road bed.  This has been used on roads since the 1960s.  Geotextile fabric prevents the gravel from sinking into the road bed during rains, which is why the "rutting" occurs (i.e. the potholes).  The installation involves laying down the fabric and covering it with gravel.  What I need help with are the specifics of doing this, given the conditions of my situation.

So, I hope your road experts will chime in here!  Is there a way to "tag" them to this thread?

thanks

We just had our road repaired due to a lot of rain.

Dear hubby is in the process of putting ditches in to keep the water off the road.

I bet some ditches would benefit your road.

I dont know anything about geotextile fabric though unless it is buried under a lot of rock I am not seeing much benefit.

Folks need to get the water off the road to keep from having those potholes.

Hi Anne,

Geotextile fabric is commonly used for roads, for this reason, and no you don't need a huge amount of gravel covering it.  I think 4" is the recommended minimum.  The key is what's called separation—keeping the gravel and the road bed separated.

In our situation, the road bed is on flat land for about 2,000 ft.  There's nowhere for water to drain to.  In an ideal situation, the road would be resurfaced, meaning raising the road bed with a thick layer of gravel and grading it to create a crown—high in the center, sloping off slightly to the sides.  Also using a heavy compaction roller.  However, our neighborhood can't afford that.  The gravel alone is super expensive.

Even though the road is on flat land, the potholes only appear in certain areas, not on the whole 2,000 ft.  Our road is about a mile long, and 2,000 ft of that are flat land, while the rest is hilly and a lot less susceptible to rutting.

Ditches running along the side of the road, on both sides, is a good idea; however, that would also be super expensive for us, and I'm fairly certain it wouldn't even be possible because of near-surface bedrock in some areas, and very rocky ground.  The road would need to be resurfaced to create a crown.  Also there are trees lots of trees close to the road, so there would be huge problems with roots.

There is stuff called Geo Cell that is made specifically to reinforce ground so that when the large weight of a vehicle rolls over it, the material can't squish out sideways. It can be found on Amazon and similar places. Given that the tires of heavier vehicles usually aren't rolling over every square inch, you don't absolutely need to do the entire width of the road, only a bit wider of an area than where the tires make contact and cause potholes. I've also seen people do DIY versions of this with various pipes, cans, or whatever else they had on hand. It would be nice if there was something made from a plant based plastic or something, but I didn't find anything like that.

You can also find or make it in various thicknesses. Given the issues with bedrock being close to the surface, it might be beneficial to go a bit thicker and add more gravel so there is sufficient room for water to go through and not create puddles. It can have issues when installed on slopes, but if your main problem is in the flat areas then this might be the way to go.

EDIT - I guess the other thread that you dug up has more information on this.

Hi Daniel,

Yes, I have considered the geocell type permeable pavers, however

We also cannot afford the geocell type plastic permeable pavers.

So, I'm looking for specific information about the installation of geotextile fabric, which is a lot less expensive.

thanks

The stuff in the other post and what I linked is not a paver, it's similar in price to the fabric. I don't think the fabric alone is going to stop gravel from migrating sideways. Especially in places where the ground below is already reasonably hard, you may not need the fabric, just the cells to hold the gravel in place. It seems to me like the same money but more effective. I haven't actually used this first hand, but I've seen it used a number of times and appears to work better than a lot of other options. Hopefully someone in the other thread gets back with more info.

OK, I understand.  Yes, I've seen the geocell... it comes in fat strips, and then you stretch it out into shape and pin it to the ground in many places.  I decided against it, after reading that some people had a lot of problems with it.  It's a finicky installation, and if the stuff gets pulled up anywhere, you're screwed.

I don't think the fabric alone is going to stop gravel from migrating sideways.

I actually don't think migration is happening so much as the gravel just sinking down into the roadbed, which is what the fabric stops from happening.  In the particularly flat areas on our road where the potholes form, rainwater hits those areas and pools up, then cars drive over those areas, and the gravel gets pressed down into the softer roadbed.  Sure, some gravel also gets pushed out in these conditions.  The best solution would be fabric under the geocells, or a geocell-type roll product with the fabric already part of the system.  I think I found a product like that, but it's very expensive.

Calling John Daley :-)

J. Calvert wrote:In our situation, the road bed is on flat land for about 2,000 ft.  There's nowhere for water to drain to.

That is why the road bed needs some ditches.  The ditches can be parallel to the road and/or some can be place at angel going away from the land.

That is what I did at the place we used to live.  My neighbor came over and yelled at dear hubby about the rain water washing onto his property.  We were at the bottom of a slightly sloping land.  The water was coming from all the other neighbors.

While it was raining I took a hoe and made drainage ditches so I knew where the water was going.

Until water is removed from that road bed even with that fabric I feel there will be a problem.

There is even a PEP BB for that:

https://permies.com/wiki/147316/pep-earthworks/Build-Ditches-Move-Water-earthworks

Hi Anne,

It rains a lot here, and sometimes very hard.  For what you are describing to be effective, we'd need to hire a back hoe to dig sufficiently deep trenches diagonally to the road, and then fill them with gravel.  The back hoe would run into rocks of all sizes including near-surface bedrock, as well as tree roots.  Some trees are right next to the road.  The trenches could only be max. 10 ft long, because of the width of our easement.  This would need to be done in many, many places due to the various locations where the rutting is happening during the rains.

This would be quite expensive, and even if it could be accomplished, there's the issue of draining the rutting areas into the trenches.  For that, you need a crown on the road, which can only be done by adding a thick layer of gravel, grading it, and running a compaction roller over it.  We can't effectively grade the existing road bed because of all the rock, and that's not a good solution anyway—a new gravel surface is needed.  This is all too expensive for our neighborhood.

The root problem with all this is that a very long time ago when the road was created, it wasn't engineered properly.  Doing so would have been very expensive, and the residents who co-own the easement apparently couldn't afford that work.  Over time, low-quality gravel was dumped on the road every year, which got ground into fines, and the road bed became softer and softer.  Then a transition to high-quality (more expensive) gravel was made, which helped firm up the road bed.  Over time, trees, shrubs, and weeds encroached on the road bed.  And that's where we are now.

So, this is why geotextile fabric is a good idea for us, and I'm welcoming any advice from folks who have knowledge or experience using the stuff.  It is used effectively on roads where other drainage techniques can't be used.

thanks

Jay asked me to pop in and say something.

One look at the pic and it is obvious ....    and I see it has already been mentioned several times here, so what I am going to say is to simply agree with some of the comments:


you need a crown, and you need ditches on the side.


It has been my experience that 99% of people cannot take the steps from hearing about crown and ditches, to implementation.  I don't know what it is - some sort of wacky mental barrier.  

(I thought i made some simple drawings in the past, but I can't seem to find it)

Hey Paul,

I actually just explained that myself, and said that we can't afford that, in all the areas on the road that need to be addressed.

I also just said that geotextile fabric does work, but I guess nobody listening to this thread believes that, or maybe nobody can stomach the fact that it's not an ecological solution.  Or maybe it is, given all the diesel fuel that's been consumed hauling and dumping gravel on the road year after year and spreading it out.  In India they use woven coconut fiber mats—giant mats that are rolled out and serve the same purpose as the synthetic geotextile fabric that I'm talking about.  They have big machines there that create the fiber from coconut husks, and then other machines that turn it into cordage and weave it into mats.

I'll see if I can shoot John Daley an message.

water is able to dig down.

You do not need gravel filled trenches.

And if the gravel is being consumed, that's a sign that the subsurface on the road is not bedrock.

I have maintained a lot of roads with a tractor and a back blade.

Dumping gravel on the road without shaping it into a crown will make it have a very short life.  Dumping gravel on the road and shaping it into a crown, will make it last for decades.

Easement:  sounds like you need a visit with the property owner.  If you cannot do that, then you make the best of it.

Doing a really good job to make a good, long last road, is about taking the time to do a good job every ten feet.

It has been my experience that 99% of people cannot take the steps from hearing about crown and ditches, to implementation.  I don't know what it is - some sort of wacky mental barrier.  

If you have decided that it cannot be done, then that is your choice.

Every person of that 99% has their own interesting way of not doing it.  

Hey Paul,

I take it you've never used geotextile fabric?  Do you believe there are situations where it does work if other options are not possible?

And if the gravel is being consumed, that's a sign that the subsurface on the road is not bedrock.

Yes, the gravel is being consumed in some of the flat areas where water collects.  But the subsurface varies greatly over the ~2,000 ft of problematic areas—some areas have near-surface rock and bedrock.  Some areas have soil.  It's a mixture.

I have maintained a lot of roads with a tractor and a back blade.

That's great... I very much appreciate your feedback.  What we have here is a unique volcanic surface geology that's very rocky.  The subsurface volcanic terrain (if you will) is very chaotic, with some of it reaching the surface.  There are pockets of soil, areas of near-surface bedrock, big rocks lurking under the surface, etc.  (From what I can tell, the road bed never was designed to be higher than the surrounding earth, which of course would be the ideal solution.)

This all makes grading of the roadbed itself difficult, and in some areas, impossible.  I believe it has never been attempted on our road, in the problem areas, to put a crown on the roadbed, and then add a sufficiently thick layer of gravel, and then put a crown on the gravel, and hit it with a compaction roller.  Never been done.  Some grading of the roadbed has been attempted in the past (attempt to add a crown where possible), and then gravel put over that.  The gravel has been consumed.  Not in all areas, mind you, but in some of the areas.

Now, we both know what needs to be done, BUT the financial aspect clearly can be a show-stopper as it is in our case.  So the question becomes, is there an alternative?

Dumping gravel on the road without shaping it into a crown will make it have a very short life.  Dumping gravel on the road and shaping it into a crown, will make it last for decades.

What if the roadbed itself cannot be crowned?  What if the mushy roadbed continues to consume gravel, even with the crown?  Again, it rains A LOT here, and sometimes very hard.

Doing a really good job to make a good, long last road, is about taking the time to do a good job every ten feet.

Understood.  Our situation is not about "taking the time".  As a neighborhood, we simply don't have the funds to resurface this road.  The last expenditure of $2,700 was for gravel alone, and there was additional cost to spread the gravel.  That amount of money was from volunteer donations.  We can't just say, well the bill now is going to be $20,000, and people will be able to cough that up.  Not going to happen.

Now, you could say that if we don't have the funds to "do it properly", then we are screwed.  But is that really the answer?  I'd like to know.

So, nobody here has experience with geotextile fabric, I take it?  That's fine.  Let's hear from somebody who does have experience.  Can anyone contact John Daley?  I think he has some civil engineering experience.

thanks.

Jay, I am happy to try and help.
Geo textile is best covered by road material and is usually applied during construction, retro installing would involve a lot of road material
needed to be purchased or moved.
I have a few questions;
- will the other landholders help with the repairs?
- why is no money available?
- do they spend it on other items?
- a bad road will add to the cost of maintenance of all vehicles?
- what speed is done along this road?
 Speed wrecks roads.

A couple of other things, delivery can never be free, the total price you pay is the important figure.

Hi John!  Thanks for chiming in.

Geo textile is best covered by road material and is usually applied during construction, retro installing would involve a lot of road material
needed to be purchased or moved.

I was thinking to make these improvements in sections, so that we can afford it over time.  So for example if a 200 ft stretch of road had one or more of these problem areas, like in my photo above, we would fill the ruts and lay the geotextile over those areas, and then lay on blue rock gravel (hard, high-grade).  I hear that 4" is the minimum.

At the same time, we'd continue to fill potholes individually, from piles of gravel on the side of the road.  There's actually even free gravel from a nearby area where road construction was done.  It's volcanic, hard, and irregular.

will the other landholders help with the repairs?

A subset of the landholders have been donating every year.  I'm hoping more will donate if they see an affordable plan that will increase the lifespan of the gravel.  I think we'd have volunteers for the labor as well, no problem.

why is no money available?

Money is available, but we live in an economically depressed, remote rural area.  This pattern of lack of funds has been going on for decades.  Even if there were some neighbors with deep pockets, everyone knows what's been going on with the road situation for decades, and nobody has stepped forward to fund a full resurfacing of the problem areas.

do they spend it on other items?

ha ha... I have no idea.  The fancy homes here are just basic homes.  The non-fancy ones are relics from the 1970s that people are still living in, or inexpensive, unpermitted jungalows.

a bad road will add to the cost of maintenance of all vehicles?

Oh yeah, for sure.  The road is a killer of older cars—I am a direct recipient of that unhappy eventuality.  It's not a 4x4 road, but it can be on the threshold of that at times.  4x4 trucks can easily handle our road.  The thing is, mostly non 4x4s use the road.

I am doing an assessment and analysis of this whole problem and documenting it, in order to put forth a new plan that's better and less expensive than what's been done up until now.

what speed is done along this road?

I would say 12-15 mph is about the average.  You can go 20 in some places, but not for long.  There's just a lot of rough spots.  Also rock outcroppings, which nobody has really dealt with, and that's part of my new plan to deal with those as well.  (Another potential can of worms, but I think way easier to deal with than the rutting.)

A couple of other things, delivery can never be free, the total price you pay is the important figure.

Of course, and we all realize that gravel needs to be purchased and hauled here.  That's what's been happening every year for decades.  If geotextile is a good solution, and straightforward to install it, with gravel over top, then it looks like we can greatly reduce the overall cost of gravel and delivery over time.  Perhaps a test is what's needed, but the show must also go on because the ruts are in full swing now, and the rainy season is approaching.

Thanks for your help, John!

My guess is that when you break the road down into 500 pieces, then 80% of those pieces just needs a bit of shovel and/or tractor love.  15% will need that plus a bit of gravel.  And the remaining 5% will need something more.

My impression is that you don't wanna think of it as 500 pieces, but as 1 piece.  And you want one solution for the one piece.  And I am choosing to step away from that conversation.

No need to guess there, Paul.  I've described the situation in quite a bit of detail.

About 38% of the road is problematic, because that part of the road is built on flat land, where water collects in some places.  This 38% amounts to about 2,000 ft of road.  In that space, there are areas of rutting, and areas of no rutting.  Some of the rutting areas (the most serious) are strings of potholes.  There are also some more isolated potholes here and there.

These areas with the rutting (potholes) need something done differently than has been done for decades, which has been to dump gravel on the road surface in these general areas.  In these areas the road bed is soft, so the gravel sinks in when it rains, and potholes are eventually formed once again.

There aren't 15% of this and 5% of that... these are the areas that need attention.  There aren't 500 of these areas.

If I've got a string of potholes in location A, and another string of potholes in location B... I should treat those in different ways?  No.

I'm trying to come up with a system that breaks us out of this cycle of having to continually fill potholes, year after year.

Yeah, the problem is not me... I'm just a guy trying to maybe do the impossible, instead of just repeating the same thing that doesn't really work.

Is it impossible?  Apparently geotextile fabric will provide a solution.

By the way, to any of the good folks receiving emails from this thread...

Please don't feel compelled to answer.  I know this is a tough problem, and I'm just looking for any insight from folks who have knowledge of the application of geotextile fabric.

Thank you Paul for providing this great permaculture forum... one that until a few days ago I didn't know existed.  I will spread the word.

I've been a permie for about 20 years, and the last 12 of that, a homesteader as well.  I've met in person some of the big names in permaculture.

peace out.

Rutting and potholes are the sign of softer materials.  Materials that can be shaped to a crown the drainage ditches on the sides.



no crown. No ditches.

potholes.

Math.

paul wheaton wrote:Rutting and potholes are the sign of softer materials.  Materials that can be shaped to a crown the drainage ditches on the sides.

no crown. No ditches.

potholes.

Math.

Yep, we've established that already.  The problem is, a soft roadbed, and heavy rains, also translates to erosion.  Potholes.  What we really need is to move some of the soft material out of the way, and create a hard road bed with new material.  Keep in mind that decades of soft material were dumped on this road bed, which was only switched up to hard material in the last maybe 6-8 years.  All absorbed.  As I said before, the road wasn't engineered properly from the very beginning.  Yes, ditches would be great.  But it takes a firm surface for the crown to be effective and lasting.

Add to the equation that it's a loose community of neighbors responsible for this road, not one person.  So there's a human, group factor, involving group politics and money issues.

Add to that all the traffic the road is getting (even though it's a dead end).

Add to that 80-100 in of rainfall per year, and sometimes very heavy rains.

Over the last 7 years let's say, shaping of the surface has been attempted in areas where that's possible.  And gravel applied.  But the money factor prohibits the "bigger moves" from being made.  Potholes start to reappear mid-year.

In short, this road needs to be resurfaced... and the money for that simply doesn't exist.

So, give up?  ... or geotextile fabric. :-)

Jay are locals happy to help?
I think one thing may help, in the absence of heavy road equipment.
I use it on my own driveway is to place loose 11/2 inch rock into each pothole, slightly heaped.
Traffic will push it in, but because its bigger it will most like not disappear.
And repeat later if needed.
I have it loose in a trailer and just cruise along off loading the rock at each hole.
I am surprised people travel at 20mph, in Australia it would be 45 to 60 miles per hour

John C Daley wrote:Jay are locals happy to help?
I think one thing may help, in the absence of heavy road equipment.
I use it on my own driveway is to place loose 11/2 inch rock into each pothole, slightly heaped.
Traffic will push it in, but because its bigger it will most like not disappear.
And repeat later if needed.
I have it loose in a trailer and just cruise along off loading the rock at each hole.
I am surprised people travel at 20mph, in Australia it would be 45 to 60 miles per hour

Hey John, John C. here... the OP.

Yes, locals can help, and I like the idea of gravel in the potholes.  Good advice on 1-1/2" rock.  I was thinking keep piles of gravel along the bad parts, on the side of the road., and everyone can pitch in and distribute it.

Do you have any more thoughts about the geotextile fabric?  Could you maybe elaborate on this a bit?

Geo textile is best covered by road material and is usually applied during construction, retro installing would involve a lot of road material
needed to be purchased or moved.

Wouldn't it just involve filling the existing potholes, laying down the fabric, and then adding a layer (4"?) of gravel on top?  What I'm thinking is to localize this treatment to the pothole areas only, and one area at a time as we can afford it.

thanks,
JC

step 1: crown and ditch on this piece

step 2: next year, might need a bit touching up

step 3:  evaluate if what has been done is enough.

I suspect there is a high probability that this section of road will need nothing more.  

It is true that the material on this stretch is soft.  But it looks to me that if you can get 95% of the water to the ditches, then a crown will hold its shape.

Paul's thoughts are correct if you have equipment and materials to carry out the work.
Having ditches along the flat section of the road will need to drain somewhere, which sounds like it cannot happen, so any pavement will need to be built up with culverts to allow water movement.
Geo textile works best when used over large areas, not patches.
I suggest not bothering about it and see how my suggestion works.

I get a trailer load of 11/2 inch clean aggregate, about 3/4 cubic yard and cruise along the pot holes filling them and leaving them heaped about 11/2 inches.
Sometimes I have plastic buckets I fill with rock and carry a few feet to the pothole from the trailer to speed the process up.

Thanks, John.

Having ditches along the flat section of the road will need to drain somewhere, which sounds like it cannot happen, so any pavement will need to be built up with culverts to allow water movement.

Wow, OK... so some kind of perforated drain pipe under the road surface?  PVC?

Do you mean bury 4" perforated drain pipes in the existing road bed, such that they are slightly sloping to the road edge, and then build up the height of the road surface using gravel?  It seems like a gravel mixture would be good... maybe "rock down to fines"?  About how much height do you think?

Geo textile works best when used over large areas, not patches.

I'm looking at 12.5 ft x 100 ft for $200. HERE

Do you think that's a large enough area?  I think we could afford maybe 2 or 3 of these at a time, plus the cost of covering it with gravel, maybe 4 inch deep.

I suggest not bothering about it and see how my suggestion works.
I get a trailer load of 11/2 inch clean aggregate, about 3/4 cubic yard and cruise along the pot holes filling them and leaving them heaped about 11/2 inches.
Sometimes I have plastic buckets I fill with rock and carry a few feet to the pothole from the trailer to speed the process up.

I'm still liking that solution, except for us it would be piles of gravel on the side of the road, in convenient locations.  That way we can stop the car, grab a bucket and fill holes, or bring out a wheelbarrow.  Maybe someday I can also look into getting a trailer.

I'll likely propose to the neighbors that we try out a stretch of geotextile as a test, and then use your hole filling suggestion as well.  We'll find out if the geotextile works out, and if it does we can continue to install more sections going forward, as funds permit.

John, from an engineering viewpoint, considering the nature of our particular road surface, do you think filling the existing holes—which by the way seem to appear in the same areas over and over again—will be as effective, or more effective, than for example laying down a thin layer of gravel over the whole road surface (in these rutting areas)?

RE: filling the potholes by hand... Is it best to just fill the holes with the gravel, heaped slightly as you say; or is it a good idea to disturb (rough up) the pothole and a bit around it with a pick axe (mattock), and then fill and mix in the gravel?

thanks and aloha from Hawaii!

Jay, I need to think about how to write my answer clearly.
Gravel is not 11/2 inch rock or aggregate.
From; https://soilyourself.com.au/how-is-gravel-made/
What is gravel?

Gravel (also known as crushed stone) is a collection of loose material that’s primarily made of rock fragments. The most common types of rock found in gravel are basalt, limestone, and sandstone. Gravel is used in a wide range of industrial and construction applications, from home building to road paving, and come in two types: granular or pebble. In nature, gravel is any rock structure that is unconnected to other rocks; it can be tiny stones in streams or gigantic boulders. Commercial gravel, however, is a collection of crushed rocks that are roughly 2 ½ to 7 cm in size.
A small fraction of Australian gravel is naturally formed rock harvested from streams, riverbeds, and other geographical formations. The most common types of natural gravel include bank, bench, creek, and plateau gravels. And as for the rest, mining companies around the country are responsible for producing gravel in areas where naturally crushed rock cannot be sourced.
Creating construction-grade gravel undergoes a lot of processes. The process begins by gathering large rocks and breaking them down into smaller fragments using heavy machinery. What you’re left with are small, irregular-shaped fragments that can form a pliable yet durable surface. The original rocks are mined from several different sources and are stored in quarries, where they are crushed or exploded (depending on their intended use) before being mixed with stone powder.

Building gravel ranges in diameter from millimetres to several inches, with various sizes being optimal for certain situations. For example, coarser grit gravel is most suitable in railway ballast, as the larger diameter particles stabilise the rails and hold the ties firmly in place. Residential and commercial walkways, on the other hand, need smaller particles that are 5-6 cm in size for construction purposes.

Culverts allow water to gravitate to the lowest area.
If water banks against a raised road it can soak the base and allow the road to sink.
culverts are not perforated and are usually 12 inch diameter.
Perhaps look at a few well made roads nearby.

Culverts need a minimum amount of cover usually another 12 inches.
A trial with geo textile and road base on half the length and 11/2 aggregate may be worthwhile, with no culverts installed.

The advantage of dropping aggregate from a trailer is that you are not double handling it, and the trailer can be located right at the pot hole, try it with a few buckets of stone 11/2 inch.

Gravel is not 11/2 inch rock or aggregate.

Sorry... I was just using the term "gravel" loosely.

What we have here are blue rock aggregates of various sizes.

We can get 3/4", 1-1/2", 2-1/2" "base course", also called "minus" (e.g. 1-1/2 inch minus).  This is called "rock down to fines".

We can also get "drain rock"... 3/4", 1-1/2", 2-1/2", also called "clean or wash rock".  For example, 1-1/2" drain rock is 1-1/2″ to 3/8″ rock with no sand/fines.

I hope you can by just 11/2 inch aggregate which has no fines.
It is large enough to press into soft soil and form a strong lower base.
Anything with fines will not consolidate to a hard firm base.
In Australia, 11/2 inch road base has a range from 11/2 inch to fines.
We do not have anything defined as drain rock.
Where do you buy it, I can ask in different language and see if it is obtainable!
I had a look at this supplier
https://www.soilpluskona.com/rock-products
They have this
1" - 1.5"
Drain Rock
The 1 ½” Drain Rock is crushed gravel that can be used as an element of a French drain to prevent flooding in yards and driveways.
Drain Rock is great for muddy roads, to help fill and compact any potholes in the area.
The Drain Rock can also be used as ground cover for landscaping projects.​

Please note, some pieces will be bigger than 1.5", possibly 3" to 4".
I think 3-4" rock will be too big for your potholes.

From Puna Rock, I found this
1 1/2″ Drain Rock (Size #4) – $30.75/ton
1 1/2″ Drain rock or often called clean or wash rock. Sizes range from 1 1/2″ to 3/8″ with no sand in the product.
It is often used in areas with mud or areas affected by water run-off or settling.
Product is often used for driveways, parking or landscape.

Hey John, thanks for your responses.

I hope you can by just 11/2 inch aggregate which has no fines. It is large enough to press into soft soil and form a strong lower base. Anything with fines will not consolidate to a hard firm base.  

Thanks.  No worries on that... we have some options for purchase here.

Culverts allow water to gravitate to the lowest area.
If water banks against a raised road it can soak the base and allow the road to sink.
culverts are not perforated and are usually 12 inch diameter.
Perhaps look at a few well made roads nearby.

Culverts need a minimum amount of cover usually another 12 inches.

Yeah, there's no way we can build such things.  We'd need to raise the road bed quite a lot, and the water would need to drain away from the road.

I think the best way to describe our road situation here, in the flat areas, is that the rain soaks everything—road and surrounding earth.  And there's nowhere for the water to drain away to, and it just sinks into the earth.  The water on the road pools some before sinking in, and those areas develop ruts.  Strangely, puddling occurs on the road more than it does anywhere else.  The soil in our area is volcanic and very porous.  It's rare to find puddles anywhere.  No lakes, no streams.

A trial with geo textile and road base on half the length and 11/2 aggregate may be worthwhile, with no culverts installed.

This is the main reason I posted to this forum... to see if anyone had specific info about the installation of geotextile fabric, for a situation such as ours—as you say, a retrofit.  How's this for a trial plan... for a 100 -or- 200 ft section of rutting road, fill existing potholes with 1-1/2 rock, lay down the fabric, put a 4" layer of 1-1/2 rock over the fabric?  How do you think this would hold up?

The advantage of dropping aggregate from a trailer is that you are not double handling it, and the trailer can be located right at the pot hole, try it with a few buckets of stone 11/2 inch.

Understood... those buckets would be very heavy.

thanks!
JC

20L buckets are plentiful, old paint containers 10, 15 L also can be 1/2 filled to suit.
n the test bed  would try 11/2 rock and 1/2 and 11/2 inch road base with fines on the other 1/2 and observe the performance of both.

John C Daley wrote:20L buckets are plentiful, old paint containers 10, 15 L also can be 1/2 filled to suit.
n the test bed  would try 11/2 rock and 1/2 and 11/2 inch road base with fines on the other 1/2 and observe the performance of both.

Good idea on the side-by-side comparison.

OK, I think you are saying for the whole length of the fabric, try 1-1/2 drain rock on half, and 1-1/2 base course on the other half?

Do you think 4" of material over the fabric is sufficient?  I just read that 6" is recommended.  ...now I will have fun calculating the cost difference :-)

It's a good question... which is better over the fabric, drain rock or base course (rock down to fines)?  Intuitively it seems like base course would be better, but I'm not sure why.

EDIT:  OK, did a bit more research... 1-1/2 "base course" would be the preferred to place on the fabric, and then "surface course" or "top course" on top of that—3/4" base course would do.

thanks again :-)

I would sample 1/2 the length and change material for the other 1/2.
It would be too hard the alternative way.
6 inch would be better, thicker the better.
It is best to fill the potholes when the ground is soft from rainfall, it gets pushed in easily and will not fly around.

John and others, thanks for your comments.  I'll leave it here for now, and try to remember to update the thread if and when we try geotextile on our road.

I found some helpful information by googling:  "geotextile fabric" "road maintenance" rural

have a great day!