Two stretches of Sonoma Mountain Road off of Adobe Road near Petaluma are dotted
with potholes after being turned into dirt last summer. Road Warrior photo

Sonoma County’s test of turning paved roads into dirt is earning an A and a F for durability.

Last summer, the county Transportation and Public Works Department took three pothole-patched stretches of Sonoma Mountain Road and after grinding, pulverizing, injecting a hardening enzyme and compacting, crews left a hard-surfaced, dirt road to see if it could improve poor roads without having to completely rebuild them. If the test is successful, department officials say, more of the county’s rural roads will be turned into dirt.

A 600-foot segment between Bennett Valley and Kenwood appears to have survived the winter storms so far largely unscathed, with only a handful of tiny potholes. Definitely a success.

But to the south two other test stretches of Sonoma Mountain Road off Adobe Road near Petaluma are a mess, dotted here and there with significant potholes. Definitely a failure.

Rob Houweling, operations coordinator for the roads department, said the difference in how well the test sites are performing boils down to that asphalt grindings were incorporated into the Petaluma-area segments but not in the Kenwood-area one.

He said the enzyme, biodegradable Perma-Zyme11x, didn’t bond well with the asphalt grindings, leaving pockets that fell victim to the weather. He said that after potholes started appearing crews reworked and smoothed the southern test sites, but it rained shortly afterward, preventing the enzyme from drying and hardening. Crews also have spread base rock on the southern sites to try to smooth out the road.

The next major step is this summer to again rework the southern sites but add finer material for the enzyme to bond with. Until then, he said, he may send out a road grader to again smooth out the road.

Howeling said also to blame for the potholes are motorists who drive too fast, which causes the road to wear out.

Signs at the test sites set a 15-mph speed limit, but few drivers seem to be following them on the lightly traveled sections. As the Road Warrior last week bounced through the Petaluma-area potholes at 15 mph, a luxury SUV passed going twice as fast or faster.

Howeling said the county has received some complaints about the test sites, including dust during the dry season, but he’s had just as many calls about problems on paved sections of Sonoma Mountain Road.

David Brown of sonic.net last week had to drive down the southern part of Sonoma Mountain Road to visit a client and wasn’t thrilled by the potholes.

He said he’s driven the road two or three times before and had considered driving his Jeep but went with his Audi TT sports car for its comfort. He complained that the road, like many in the county, “tears up” cars.

Also not a fan of the dirt test is Nicolas Ceja, who works at a ranch along Sonoma Mountain Road near Petaluma. He said he’s come across accidents that he said were caused when the drivers lost control on the dirt.

To see a Perma-Zyme11x video of how the road improvement process works, CLICK HERE.

To read last summer’s story on the roads being pulverized, CLICK HERE.

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  1. Dan Brown

    I would like to see the Supervisors take a road trip and see what a complete mistake it was for them to listen to a couple people talk them into spending taxpayers money (and alot of it) to have six men spend two days grinding asphalt on Sonoma Mtn. Rd. near Glen Ellen. We could have potholed the exhisting road for several years for the same cost, not to mention using what few people we have left on this project. They still have had to fill several holes with asphalt. It is unsafe even at the new reduced speed you must go.
    Before you spend our money unwisely,please investigate on your own.This was a complete waste and not thought out!!!

    February 22nd, 2011 8:29 am

  2. rl

    compromised thinking for the county to not be maintaining county roads, they should at least be making an attempt to provide a value to taxpayers but obviously have not and it looks like this has been going on for decades if not longer. county voters do not want a 3rd world infrastructure or status and are tired of the flim-flam excuses of “it’s not my job” or “we have so many other priorities” or “there’s not enough tax dollars to go around”. taxpayers deserve far more respect than they are getting.

    February 22nd, 2011 10:04 am

  3. Gerry2280

    I wonder how the County is going to deal with it when these neglected roads start eroding big time and silt the creeks. That is the big issue with letting the roads deteriorate–silt from the roads fills the creeks and kills the fish. When you have to clean that up, it costs much more the upkeep on the raods in the first place.

    February 22nd, 2011 2:12 pm

  4. John

    Soon we’ll have roads the equal of any 3rd world country. County voters are getting what they deserve by continually re-electing the likes of Valerie Brown and electing folks like Shirley Zane.

    It isn’t going to change until you vote these folks out of office.

    February 22nd, 2011 2:45 pm

  5. Joe H.

    I drove down to Mexico’s Cabo San Lucas and the road surface was great. All paved and smooth.

    Sonoma County has fallen well below 3rd world status.

    Every single person who supported this should be fired immediately.

    February 22nd, 2011 2:51 pm

  6. Heidi

    I lived in Tanzania, East Africa for 2 years as a Peace Corps Volunteer. My main road was compacted dirt at the time, but now it’s nicely paved. How ironic that Sonoma County is being passed up by a developing nation!!

    February 22nd, 2011 4:40 pm

  7. Dan Brown

    I wish the Press Democrat would do their job and investigate. We see contridictions everyday of where the county spent money on something, but the next day they don’t have money for something as important as roads. It is ironic that we are spending so much on freeways, only to get off of them onto a county gravel road.
    I thought this was the Prestigous Wine Country, but I guess we can let Napa have the best roads also!!!

    February 22nd, 2011 5:20 pm

  8. John

    I’m still waiting for those 100 miles of important roads in this county to be transformed into ‘good’ condition…or even just for destructive potholes to be filled in a timely manner.

    February 22nd, 2011 6:07 pm

  9. Tracy Hammerich

    The road to my house has pot holes so big, you could lose a small child in them….The county has fixed 3 holes in our road, But only in the beginning of our road, But the worst ones are further down and they dont come down far enough….Come on County wake up and do your jobs,and quit spending my taxes dollares on stupid experiments and fix things right!!!!!!!

    February 22nd, 2011 6:56 pm

  10. Rex

    The director of the TPW makes almost 200k a year. Turning roads to dirt would embarrass me if I had this position…especially if the road to my probably ostentatious home were nice and smooth…I might sense that my department was a failure…I might look at the fact that the top ten employee earners in this department cost the same amount of money each year as Measure M brings in…
    Similar to school administrators cutting teachers and class time…turning the roads to dirt is making the cuts at the wrong end of the scale…we need the basics, not suits behind desks…if these departments were run like football teams, we’d be firing the coach. If run like a business, management’s pay would be biased against output…what do you do with all that money, Phil? I struggle for a quarter of that…
    So, if I bend a wheel on a Sonoma County road, who do I send the bill to?

    February 22nd, 2011 7:43 pm

  11. Rick Olson

    I’d like to see the people in charge of maintaining all of our roads actually drive around on all of them to see what a horrible job their workers are doing. Then start to hold people responsible for their shoody work. If these type of results happened in the private sector, they’d be out of a job.

    February 23rd, 2011 7:32 am

  12. T. Martin

    I’d like to see the people in charge of maintaining all of their vehicles–especially drivers of pickup trucks and SUVs–actually drive around in less-taxing ways and see what a horrible job they’ve done to the roads. THEN start to hold people responsible for (any) shoddy work. There’d be a lot less “work” to have to gauge if they mixed in more low-impact means like feet, public bus, bicycle, motorcycle, scooter, or small car. Roads getting pounded to death by people driving too fast, too many miles, and in vehicles much heavier than normally necessary are no small factors in the deterioration of roads. Let’s all hold a mirror up and quit blaming “the government” for everything. We’re all responsible.

    February 23rd, 2011 1:44 pm

  13. noname

    um someone tell me why here in america, in one of the wealthiest counties in northern california, they are turning roads into DIRT instead of PAVING THEM WITH ASPHALT LIKE EVERY OTHER CIVILIZED NATION?????

    September 13th, 2011 5:12 pm

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