Maintenance Procedures for Ranch Roads - By Fred Martin
“Water is the sole decayer of your whoreson’s dead body” - Hamlet
Water is the single most destructive element for dirt and gravel roads. Roads that are regularly used in the rainy season need careful and thorough maintenance to keep them passable. Maintenance should not be just to provide a smooth surface but should structure the road to keep it free of standing water which can soften the surface and open it up to erosion and destruction with the passage of vehicles. Moreover, it is important to keep in mind that the power of water to erode increases with square of its velocity and volume. Thus maintenance should be directed to prevent channeling and accumulation of water on the road and to aid in dispersing the water over wide areas.
The purpose of this checklist is to establish a guideline for maintaining dirt and gravel roads. We have put this into categories of maintenance, each with its own features and schedule.
CULVERTS
There are two classes of culverts: stream crossing and ditch relief.
1) In the fall, inspect all culverts for clearance and remove obstructions.
2) Following a major rain storm, check the stream crossing culverts to make sure they are clear of trash. Remove the trash from around the trash rack.
3) Also, check the ditch relief culverts and unplug any that have been plugged.
4) Trash racks are an important need for many culverts. The simplest and very effective rack is a single, sturdy post driven securely into the ground about 1.0 to 1.5 culvert diameters above the inlet to the culvert. Limbs and sticks whose lengths about match the diameter of the culvert will move through it if they are aligned to the culvert. This single post will often align woody debris to the culvert, while stopping larger pieces.
CUT BANK DITCHES
In the fall, inspect the cut bank ditches and clear them with a light touch by a grader. Remove brush and trees growing in the ditches.
Grassy growth is beneficial as it slows the flow of water. If there is heavy erosion it will be necessary to armor the ditch with 4” to 9” rock.
BERMS
Berms channel water increasing its volume and velocity and thus contribute to the erosive power of the water. Berms are best removed and the road sloped to drain the water directly to the down hill slopes.
The berms that remain must be well breached at 20 to 50 foot intervals; semi-annually check that these breaches are clear and well structured.
ROLLING DIPS
Rolling dips are formed as shallow swales across the road with an outslope of 3% to 6%. They are typically two or more car lengths long and no more than eighteen inches deep. They are almost unnoticeable to the vehicle and its driver.
Rolling dips convey water from the road and in some cases from the cut bank ditches to the down hill slope. Some of them are located at stream crossings, these are labeled as critical rolling dips and serve to handle water that spills over the road if the culvert becomes blocked in a storm. This preserves the road and the deep end fill slope.
Frequent use of rolling dips will keep the road well drained and many dips may not need maintenance every year. However, some convey considerable water with evident erosion. These will need reshaping and rock every season. Be sure to maintain the gradient for adequate drainage.
SETTLING BASINS
Settling basins are constructed adjacent to the road where there is heavy runoff from a steep section from curves. The basin catches the water, slows it, and allows the sediment to deposit in the basin.
Inspect the basins annually and any that are full of sediment, remove the sediment with a backhoe and deposit it in the grassy areas along the road.
GRADING
There are three levels of grading for roads. Here we assume that water for grading is only available in the rainy season.
1) Thorough Grading:
Apply 2 or more inches of clean 1.5 inch, minus, rock 10 feet wide on the road. Rip the road to 3 inches deep, mix in the rock with appropriate moisture and grade. Complete the process with a compactor to consolidate the surface. One may also apply the enzyme, see below. Make sure that all rock is well imbedded in the clay and leave no loose rock on the surface.
2) Regular Spring/Fall Grading
This is normally done without the application of rock. The road is smoothed and rolled with appropriate moisture. Make sure that all loose rock is well imbedded in the surface and leave no loose rock on the surface. One may also apply some enzyme, see below.
3) Summer Smoothing
Grade the road sufficiently to remove the washboard. Move the loose material into a berm along the cut-bank for storage. Leave no loose rock on the surface of the road. In the fall move this material back onto the road and imbed it into the surface.
4) General Requirements
The roads are outsloped in most locations and “crowned” in others. Always maintain the out-slope: 3 to 4 % for level or near level road gradient, increasing to 6% when the road gradient increases to 8%, and out-slope to 8% at grades above 10%. Where there is no cut-bank ditch, make sure the road surface merges into the cut-bank so that water from the bank comes on to the road and moves across the road and onto the down hill slope.
ENZYME TREATMENT
We have seen roads treated with PERMAZYME 11X, a product manufactured by Pacific Enzymes, Inc.
This enzyme is designed to strengthen the top six inches of the road surface to make it more durable and erosion resistant. It does not however control dust.
The examples of roads treated with Permazyme appear to be very durable and require much less in annual maintenance. The product itself is not very expensive but its application does involve ripping the road to six inches and applying the Permazyme with water then grading and rolling.
When grading these sections, it is recommended that a dilute application of Permazyme 11X be applied in the spring to reconsolidate the surface of the road.
Also, some road departments have applied it when merely grading the road as described in #2 grading. Over several seasons the road surface becomes more durable and erosion resistant.
See the web sight www.pacificenzymes.com for details and additional information.