Building Timber Roads to Texas Forestry BMPs: A Landowner's Guide
By Cody Smith · · 8 min read
A road through timber land has two jobs. It has to carry loaded log trucks at harvest time, and it has to sit there for years in between without washing sediment into the creeks that cross your property. Texas A&M Forest Service publishes a handbook of forestry Best Management Practices (BMPs) that covers exactly how to do both: where the road goes, how steep it can be, how water gets off it, and how it crosses a stream.
This post walks through what those BMPs say about timber roads and what a logger will need from your road when it's time to sell. For the general build steps (clearing, subgrade, base, and gravel), see our gravel road construction guide and how to build a ranch road.
Are Texas Forestry BMPs Required?
Mostly, no. The handbook itself says BMP use is non-regulatory in Texas. They're voluntary guidelines, and Texas A&M Forest Service monitors how well they're followed on harvests across East Texas.
There are two good reasons to follow them anyway:
- Timber buyers and loggers expect it. Many mills and certification programs want BMP-compliant harvests, so a road built to BMPs is one less problem at sale time.
- Wetlands are the exception. Normal forestry work in wetlands, including building forest roads, is exempt from Section 404 Clean Water Act permits only if it's part of an established forestry operation and follows the federal mandatory road BMPs. If the work converts a wetland to non-wetland, or to a new use like a homesite or pasture, the exemption doesn't apply and a permit is needed. When in doubt, the handbook says to contact the U.S. Army Corps of Engineers.
Start With the Streamside Management Zones
Before you lay out a road, find the streams. The BMPs call for a Streamside Management Zone (SMZ) along every perennial and intermittent stream:
- Width: a minimum of 50 feet on each side, measured from the stream bank. For intermittent streams, the 50 feet also extends above the head of the stream.
- Wider where it's needed: erodible slopes, spring heads, oxbows, and upland flats can call for a wider zone. A forester sets the final width based on soil, slope, cover, and flow.
- Marked before work starts: the SMZ should be clearly marked on the ground before any equipment moves in.
The SMZ shapes the whole road plan. Roads, skid trails, and firelines go outside it, and log landings sit at least 50 feet from its edge. Other than at a stream crossing, the handbook says roads should stay at least 50 feet from any flowing stream.
Lay the Road Out on the Right Grade
Location is the cheapest BMP. A road in the right place needs less drainage work and less upkeep for as long as it's there. The handbook's guidance:
- Follow ridges where you can, with grades between 2% and 10%.
- Keep steep runs short. Sections steeper than 10% shouldn't run more than 500 feet, and slopes over 15% shouldn't run more than 200 feet.
- On highly erodible soils, keep grades at 8% or less. Short pitches steeper than 12%, up to about 150 feet long, can work if you take steps to control erosion. Gravel on the surface helps hold steeper sections.
- Avoid wet bottomland where drainage is hard to establish.
- Keep cut banks low. Cuts normally shouldn't be more than 5 feet high. Taller cuts should be sloped at least 2:1 and seeded.
- Cross streams as few times as possible, at straight sections and at right angles.
If there's already an old woods road on the property, the BMPs say to upgrade it only if it's in the right place to begin with. A badly placed existing road can cost more to keep up than a new one would cost to build.
Get Water Off the Road
Most timber road damage comes from water running down the road surface. The BMPs call for building drainage at the same time as the roadbed, not after the first washout. The road surface should be crowned or outsloped. Where a crowned or insloped road climbs more than 2% for over 200 feet, broad-based or rolling dips go in within the first 25 feet of the upgrade.
The handbook gives spacing tables for each kind of cross drain. Steeper roads need them closer together.
Broad-based dips: for truck haul roads up to 12% grade. Built right, they don't damage loaded trucks or slow them down.
| Road grade | Spacing between dips |
|---|---|
| 2% | 300 ft |
| 4% | 200 ft |
| 6% | 165 ft |
| 8% | 150 ft |
| 10% | 140 ft |
| 12% | 130 ft |
Rolling dips: for steeper haul roads up to 15% grade.
| Road grade | Spacing between dips |
|---|---|
| 2–5% | 180 ft |
| 5–10% | 150 ft |
| 10–15% | 135 ft |
| 15%+ | 120 ft |
Water bars: for low-use roads, skid trails, and firebreaks, and for closing a road down after harvest. They're angled 30 to 45 degrees across the road, so they turn the water rather than dam it.
| Road grade | Spacing between water bars |
|---|---|
| 2% | 250 ft |
| 5% | 135 ft |
| 10% | 80 ft |
| 15% | 60 ft |
| 20% | 45 ft |
| 30% | 35 ft |
Wing ditches carry water out of the roadside ditch onto the undisturbed forest floor. Generally they go no more than 200 feet apart on 2–5% grades, 100 feet apart on 5–10% grades, and 75 feet apart at 10%. They shouldn't empty within 50 feet of a stream, or straight into a gully or channel.
Neither kind of dip should be used to cross a spring, a seep, or a stream. Those need a culvert, a bridge, or a ford.
Crossing a Stream the Right Way
Stream crossings are where timber roads most often hurt water quality. The BMPs are blunt about this one: dirt crossings should never be used. Your options are:
- Culverts, sized for the drainage area, soil, and slope. The handbook's size chart starts at 18 inches and gets larger for bigger drainages, heavier clay soils, and steeper ground. Pipes should run 1–2% downgrade, sit close to the natural grade of the channel, and extend at least a foot past the fill on each end. Cover should be at least half the pipe's diameter (ideally a foot of fill per foot of pipe), and never less than one foot.
- Bridges, built with as little disturbance to the bank and channel as possible.
- Rock fords, only where the banks are stable and the stream bottom is hard. Fords should never be used for skidder crossings.
Before the crossing, turnouts should divert road runoff into the SMZ, and the road grade should change so water leaves the road at least 50 feet from the stream. Aggregate on the approaches keeps the roadbed firm and sediment out of the water. For more on sizing and installing pipe, see our culvert installation guide.
What Loggers Need at Harvest Time
A road that's fine for a pickup and a deer feeder may not work for a loaded log truck. Before a sale, it's worth asking the timber buyer or logger what they'll haul with and what they need. Usually it comes down to a few things:
- A road that holds up in wet weather. The handbook recommends restricting traffic on wet roads, and hauling only in dry weather on wet or erodible soils or on grades over 10% without erosion protection. Gravel and mats let work go on when the ground would otherwise rut. The more of your road is graveled and well drained, the fewer days the crew sits idle.
- Landings in the right spot. Log decks should sit on firm ground with a slight 2–5% slope for drainage, at least 50 feet from the edge of the SMZ, with water diverted around the uphill side. Locate them before the road is built, and keep their number and size to a minimum.
- Room for trucks to turn and pass. The BMPs don't set a turnaround size. Ask the logger what their trucks need, and plan turnarounds and pull-outs at the landings and at sensible points along a long road.
- A clean exit to the highway. Where a haul road meets a public road, gravel or mats at the entrance keep mud off the pavement.
- Sunlight on the road. The handbook suggests cutting trees along the road edge where the road needs sun to dry out.
During the harvest, keep ruts in check. The BMPs say to rework the road when ruts average more than 6 inches deep over more than 50 feet.
Closing the Road After the Harvest
When the trucks are gone, the road still needs attention:
- Reshape the roadbed if it's rutted, and make sure every ditch, dip, and culvert is open.
- Water bar skid trails and low-use spurs at the spacing in the table above.
- Seed bare soil on the road, main skid trails, and landings where it could erode. The handbook says landings should be revegetated within the first 15 days of the next seeding season after harvest, unless you're building or replanting there right away.
- Inspect it periodically. Roads not in use should be retired and checked by the landowner or their agent.
Who Can Help
Your local Texas A&M Forest Service office can answer BMP questions and point you to a forester. There are offices in Huntsville, Conroe, Crockett, Livingston, and across East Texas. A consulting forester can mark SMZs and help plan the road around a future sale.
When you're ready to build, Dura Land Solutions builds forestry access roads across East Texas with dozers, excavators, and a motor grader, and does the clearing, culverts, and gravel work. If you've got a forester's plan or a road you want laid out, we'll walk it with you. See all of our road services, contact us, or call (936) 355-3471.