Are Ruts in your Road Wrecking your Ride?
Kelly Cahill, Civil Engineer
How many times have you driven on your farm road, driveway or forest road gritting your teeth while dodging potholes, ruts, washboards or soft spots. You keep saying, “I’ve got to fix this road!” and drive on, or maybe you throw some crushed rock in the potholes. But the problem persists.
Maybe the rough ride and almost never-ending mud are enough to convince you that your road needs help. If not, consider these reasons to maintain it:
- Your road may deteriorate to the point when it will no longer get you home with a minimal amount of vehicle wear and tear.
- Properly maintained roads are less harmful to our natural resources, particularly fish and other creatures in our streams and rivers.
- Not convinced yet? Roads are expensive. Maintaining your road will keep you from having to invest a lot more money later to totally rebuild when it becomes intolerable or impassable.
Don’t you deserve a smooth, solid, safe road to drive on?
Below are some tips to restore and maintain your driveway and road, as well as when to contact the Snohomish Conservation District to get FREE technical assistance for solving your road drainage problems.
A properly built and maintained road has a smooth and compact running surface. The MOST important key to getting your road to the ‘smooth and compact state’ is managing drainage properly. It’s difficult to over-state the critical effect that proper and improper drainage can have on your road.
Even if you don’t mind driving through mud and ruts, runoff from improperly drained roads is one of the leading sources of sediment in our local streams and rivers, which all eventually run into Puget Sound. Sediment in the water makes it difficult for fish to breathe (imagine breathing in a smoke-filled room), and smothers fish eggs to death.
Proper drainage structures can collect and divert surface water (rain, snow) that runs down from slopes above the road, as well as rain that falls onto the road surface itself. Sub-surface water, such as springs and seeps, can be dealt with in a number of ways, but generally this situation requires a field investigation to determine what’s best for the specific location, soils, etc.
Surface water runoff that flows from slopes above your road should be captured in a ditch and diverted to stable ground in a well vegetated or rocked location. Examples include “ditch-outs” (turning the ditch away from the road), culverts, and rocked drive-able dips that move water directly across the road surface.
If your road system has ditches and culverts, clean them regularly by removing obstructions and sediment, and make sure that water flows freely through them.
Roadside ditches should not be scraped down to soil unless vegetation in the ditch is restricting the flow. Scraped roadside ditches can dump significant amounts of sediment into streams. Ditches with grass or other small plants growing in them, on the other hand, stabilize ditch sections by reducing erosion (plant roots hold soil in place).
Indications that a drainage system is improperly sized, installed or maintained include eroded ditches, large scour holes at the outlet end of culverts, and over-topping of culverts and ditches on a regular basis. These can become serious and expensive problems, so please call us if this is happening on your property.
Once you’ve effectively dealt with surface water runoff, you need to turn your attention to the road surface itself. The surface must be shaped to shed water towards the ditch or to the outside edge of the road. A flat road surface collects water and that eventually creates potholes and soft spots.
Think of a table top — when you knock over a glass of water, much of the water stays on the table. If that table was a road, the water would soak into the roadbed. Then each time you drive over the road, your vehicle is “pumping” fine materials to the surface and pushing the rock down through the base of the road. This is how potholes are created.
Now if you tip the table just a bit to the side, all of the water runs off. If your crushed rock road has a steep grade (like a boat ramp), chances are you will start seeing some rutting after the road surface has been smoothed and reshaped to drain.
If left unchecked, these minor ruts turn into ‘canyons’, a glaring reminder of the crushed rock that used to be on your road that is now deposited at the bottom of the hill or into the nearest stream. The fine material from these ruts and ’canyons’ can end up in nearby streams.
Thinking of the table again, imagine picking one end up to represent a steep road and spilling a glass of water down it. Even if you tip the table to the side again while you’ve raised up one end, water will flow a long way down the table before it runs off to the side. This is exactly what happens on many of our roads.
It is almost impossible to keep a steep road with a rocked surface free of surface ruts — unless you use a structure (such as a rolling dip) to intercept the water flowing on the surface and direct it off the road. We can assist you by designing structures (for free) that will intercept and move water across your road surface before that water gathers enough volume and energy to create troublesome or costly ruts.
If your road wasn’t adequately built and it turns to mud after the first rain, then it’s probably time to add a new layer of crushed rock or repair the road’s foundation. This type of work is generally outside the scope of road maintenance and may require the advice of an engineer or experienced contractor to provide the necessary remedy. The material and equipment required to reconstruct driveways and roads can be expensive, so make sure you get an engineer’s advice before starting.
The Snohomish Conservation District also has staff with solid experience in road maintenance, repair and construction. Please contact Kelly Cahill at 425-335-5634 ext 111 or kelly(at)snohomishcd(dot)org with any questions you have regarding your existing road system, or for FREE assistance in planning and designing a new road on your property.