Never have heard of that.

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Permeable pavement, or a surface that allows runoff to pass through pavement and into underlying stone beds and soil, can help California and states like it preserve water, according to California Sea Grant. The grant is a collaboration with the National Oceanic and Atmospheric Administration and universities across the state.

The resource is a type of low impact development (LID), or system that uses or mimics natural processes to manage stormwater, according to the EPA.

In San Francisco, permeable pavement has already been installed on some streets. The city's utilities commission has spent upwards of $60 million on grants to help fund construction of permeable pavement and rain gardens. The city is also home to bioretention planters designed to capture water along curbs.

It's a key development and one that many urban and suburban communities filled with asphalt, concrete, and other impervious surfaces could copy.

"A lot of times, this green infrastructure that's put in place can have the benefit of not only slowing down the hydromodification, but also cleaning that water out," said Kiparsky.

"And that allows microbes to do their magic and remove some of the contaminants that are in that kind of urban water, so you're handling water quality as well as the hydromodification."

Water boards throughout the state also are advancing the effort with rain barrels and cisterns, tree preservation and rooftop gardens.

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The Hill

How does it work? Does it require more frequent resurfacing? Prone to potholes?

Thanks!

It's an interesting technology for sure, and we desperately need to get more water into the ground in dry areas, but I question its durability.

Problems: ice, ice, ice, and ice. Also ice. And erosion and stress. But mainly ice.

The mediums gaps will fill with fine dust and sand over time which will more or less end the permeability in practical terms, but it might work for a while. You

Get Off My Lawn said:

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Problems: ice, ice, ice, and ice. Also ice. And erosion and stress. But mainly ice.

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Thank you. Being a veteran of the Save Our Springs wars over impervious cover, I wonder why that technology was not emphasized.

What about costs? How much more expensive is it the install and maintain over standard paved roads?

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Prone to potholes?

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I would think so. Potholes occur because of cracks in the concrete that allow water to wash away the earth foundation underneath. If the concrete is permeable, then that would occur all the time, right?

My understanding is also that the permeability reduces over time from just being clogged with particulates. After some time it is apparently not much different from asphalt.

I agree, ice in there expanding would chip off the surface layer in no time.

Martin Q. Blank said:

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Prone to potholes?

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I would think so. Potholes occur because of cracks in the concrete that allow water to wash away the earth foundation underneath. If the concrete is permeable, then that would occur all the time, right?

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For permeable pavement there is a non-permeable base layer the water drains down to and off (or there should be).
The main benefit from said pavement is lack of ponding in/after heavy rains.
If they don't protect and provide a stable base then yes it will will fail, and fast.

The bases at which I was stationed in England during the '80s had runways made of what they called Porous Friction Concrete. It made runway conditions rated as as "dry" even when it was raining.

They worked well and did not have problems due to icing, etc.

rocky the dog said:

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No one has ever made a jump like that…




Without Dixie playing.

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just being clogged with particulates.

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the answer

As the video notes, you need to meet some important conditions first with soil types, topography, and drainage fields. Overall a good idea, but impractical in a lot of areas due to at least one of the three conditions. Like the bar ditches filling up around the coastal areas and water with no place to go.

Worked in a Civil Eng lab when I was a student at TAMU. There were a couple grad students that were testing a permeable pavement concept. It failed durability tests miserably. Would have been a cool option for walking/biking paths but was terrible for road construction. Granted that was 20+ yrs ago so they could have made something that works since then.

Maybe it would work if the water always drained away so it couldn't build ice internally to expand.

FYI - A&M back in the 80's used something around the trees on campus that looked like small stones glued together. Similar idea to the picture above. I don't believe it worked very well.

Get Off My Lawn said:

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Problems: ice, ice, ice, and ice. Also ice. And erosion and stress. But mainly ice.

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This. My father worked on a project with California on this. Came down to water trapped in the permeable surface would freeze, expand, and crack. Other things such as sediment clogging was huge issue too.

lots of issues with permeable pavement.

One: maintenance. As soon as dirt, silt, debris work itself into the pores, you have just plain old regular pavement. Having to send a vacuum truck every six months to clean out the pores makes it vastly more expensive to maintain compared to normal pavement.

Two: freeze thaw cycles. Any freezing of water in the pores will wreck the pavement instantly. If you never have freezing cycles, you're good to go.

Three: no heavy truck traffic. If your pavement is just for typical passenger vehicles, it will be fine, but the long term durability for heavy duty truck traffic will destroy the pavement long term.

Four: pollution control. There's is none. Everything that drains through the pavement will drain through to groundwater, so there's no pre-treatment.

Ms Hawg, if you had asked this question as part of a research project in California they would have paid you $60 million for your efforts. We need to work on monetizing the TexAgs knowledge base on things like this.

Also, City of Houston was toying with mandates requiring certain percentage of a residential lot penetrable. They also mandate off street paved parking, sidewalks and retention ponds and lined swells on inner city lots. We had to start designing the old school two strips of concrete driveways. Then another department brought up thats where most of the oil and fluid leaks from the cars.

Libs never fail to think through the consequences. Best option is to figure out how to latch on to their teat of free milk.

fka ftc said:

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Ms Hawg, if you had asked this question as part of a research project in California they would have paid you $60 million for your efforts. We need to work on monetizing the TexAgs knowledge base on things like this.

Also, City of Houston was toying with mandates requiring certain percentage of a residential lot penetrable. They also mandate off street paved parking, sidewalks and retention ponds and lined swells on inner city lots. We had to start designing the old school two strips of concrete driveways. Then another department brought up thats where most of the oil and fluid leaks from the cars.

Libs never fail to think through the consequences. Best option is to figure out how to latch on to their teat of free milk.

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As I stated earlier, I worked with developers during the SOS impervious cover cases back in the 90s. All kinds of restrictions, including smaller footprint based upon lot size, no three car garages with driveway access, etc.

Major PITA back then.

If folks would work to fine things that are better for the environment and also feasible at a reasonable cost, then most times all parties support. Unfortunately it seems we mandate, give some preference to some sweetheart project or study, then wind up with a bunch of wasted money with no innovation and no solution.

Or government as some call it.

Scruffy said:

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Martin Q. Blank said:

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Prone to potholes?

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I would think so. Potholes occur because of cracks in the concrete that allow water to wash away the earth foundation underneath. If the concrete is permeable, then that would occur all the time, right?

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For permeable pavement there is a non-permeable base layer the water drains down to and off (or there should be).
The main benefit from said pavement is lack of ponding in/after heavy rains.
If they don't protect and provide a stable base then yes it will will fail, and fast.

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If I am remembering correctly, this is what they put on the bypass here in B/CS.

I first saw this product about 25 years ago. Told them to comeback to me when they 1) proved had life cycle results of durability and maintenance (think a giant street sweeper that cut vacuum out everything) and 2) had City (Austin) and TCEQ approval to consider it "pervious". Otherwise it was considered impervious and had no value to me.

Fast forward, I still will not recommend it since 1) they never proved it and actually the results are the to their detriment and 2) most cities do not recognize it to be pervious except in limited cases for public sidewalks etc.

Kind of like having solar power on a cloudy day. Sounds good on paper.

fka ftc said:

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If folks would work to fine things that are better for the environment and also feasible at a reasonable cost, then most times all parties support. Unfortunately it seems we mandate, give some preference to some sweetheart project or study, then wind up with a bunch of wasted money with no innovation and no solution.

Or government as some call it.

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Developers often get a bad rap (take paradise and put up a parking lot, oowahwah) but all of the ones I worked with were all with upscale builders that didn't want bulldozed lotsand puny saplings replanted. They wanted mature trees and green spaces in their neighborhoods and spent time desiging to preserve as much as possible. Because ultimately the price of the homes would be higher with such features.

Drainage and retention ponds also figured into that design.

Now have there been high profile builders.developers in Austin in the past who have spectacularly screwed up? Yes. Two come to mind for different reasons but most did not.

Hwy 71 west of Bee Caves to around the Pederanales has the self draining pavement. During a storm it doesn't puddle and you there's not much spray off the cars in front of you. For a while afterwards you can see the water leaking out of the edges of the road.

It seems like they pave it every 2 or 3 years and I've never noticed it not working so I'm not really sure how they decide it need a redo. They plane the old top surface off and put a new one on, the base surface stays. Much better than what we do out in Burnet and Llano counties where they spray oil and cover it with gravel then you get rack chips and cracked windshields for the next couple of weeks.

sleepybeagle said:

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FYI - A&M back in the 80's used something around the trees on campus that looked like small stones glued together. Similar idea to the picture above. I don't believe it worked very well.

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Yes! It was everywhere and shiny, if I recall. After a while, it started to crumble. I think the last of it was finally removed a few years ago.

Martin Q. Blank said:

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Prone to potholes?

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I would think so. Potholes occur because of cracks in the concrete that allow water to wash away the earth foundation underneath. If the concrete is permeable, then that would occur all the time, right?

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Not exactly. A part of the problem is settlement as well. Poorly compacted base settles, the roadbed lowers, and the pavement collapses and deteriorates.

When water gets under pavement and deteriorates the base, it's because the water is soaking into the base. In this setup, it's made for the water to run off through gravel or other means of drainage. If anything, it may be more pothole resistant because the water runs off through a medium made for that instead of base that isn't.

magnumtmp said:

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rocky the dog said:

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No one has ever made a jump like that…




Without Dixie playing.

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Keanu begs to differ

Predmid said:

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lots of issues with permeable pavement.

One: maintenance. As soon as dirt, silt, debris work itself into the pores, you have just plain old regular pavement. Having to send a vacuum truck every six months to clean out the pores makes it vastly more expensive to maintain compared to normal pavement.

Two: freeze thaw cycles. Any freezing of water in the pores will wreck the pavement instantly. If you never have freezing cycles, you're good to go.

Three: no heavy truck traffic. If your pavement is just for typical passenger vehicles, it will be fine, but the long term durability for heavy duty truck traffic will destroy the pavement long term.

Four: pollution control. There's is none. Everything that drains through the pavement will drain through to groundwater, so there's no pre-treatment.

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I worked for a company that did do the pollution control. Permeable pavers over large capture boxes then treated the water before discharging it. Not a perfect solution but practically mandatory to do something similar if you want to add hard surfaces on the west coast or mid-Atlantic. It's that or you have to add giant retention ponds or storm drain treatment

It's simple, by 2030, ban road vehicles entirely and replace them with battery powered flying cars, trucks and tractor trailers!

Simple as catching a Unicorn fart.

rynning said:

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sleepybeagle said:

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FYI - A&M back in the 80's used something around the trees on campus that looked like small stones glued together. Similar idea to the picture above. I don't believe it worked very well.

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Yes! It was everywhere and shiny, if I recall. After a while, it started to crumble. I think the last of it was finally removed a few years ago.

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Yep. They called it 'prairie film', and until it started to break down, I thought it was a pretty neat Aggie idea.

Get Off My Lawn said:

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Problems: ice, ice, ice, and ice. Also ice. And erosion and stress. But mainly ice.

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Ice shouldn't be a problem in most of California.