How to patch up potholes
And what to look at before you start fixin'
Raking gravel back into potholes and road ravines works only until the next big storm washes down the lane. Before you patch, have a good look at erosion’s path and use it to map out more enduring solutions.
Where water has carved its track along the lane, in a wheel rut, for example, it needs an easier exit at the sides. Snowplows sometimes cause this problem by scraping up gravel with the snow and depositing berms at either side, turning the roadway into a wide shallow ditch. The proper fix is to grade those side ridges back to the centre, into a slightly raised crown. You might be able to rake the scrapings back into a crown right after the thaw, when they’re still fresh and loose. Or, add spring regrading to the plowing contract.
It’s trickier when the natural runoff has to cross the lane on its way downhill. When you find that tell-tale cut across the road, petering out in a puddle of silt on the downhill side, you’ll have to provide a less destructive crossing. With lots of fellow travellers and a road budget, you might consider a culvert here. If you’re on your own and don’t have a snowplow to worry about, a surface sluice is a simpler proposition.
Start with the channel that nature carved. With a pick or mattock, square the bottom and sides into a straight cut 15 cm wide and at least that deep. Make a U-shaped gutter of 2 x 4s for sides, and a 2 x 6 bottom. Screw six-inch steel mending plates across the top at 60 cm intervals; without these top braces traffic will soon collapse the sluice. If you have any clay or cement around, mix up a wet batch and line the cut with it before you settle the sluice into place. Otherwise, loose fill around the outside of the sluice will soon wash away.
Finally, dig a catch basin at the uphill end of the sluice. This can be as simple as a wide spot in the ditch or bathtub-sized depression, lined with rocks to protect the sides. It provides a place for the run-off to slow down, pool, and drop its sediment before draining away through the sluice.
Be sure to clean out the leaves from both the catch basin and the sluice in the fall so it will be ready for spring runoff.
This article was originally published on September 17, 2009