Slope, Channel & Hard Armor
Vegetation is the default answer in erosion control, but it is not the universal one. Some ground will never hold grass — the flow is too fast, the slope too steep, or the duty too permanent — and that is where armor takes over from vegetation. This is the branch of the catalog for the channels, outfalls, and faces that need rock, block, or basket instead of another round of seed.
When is hard armor the right answer?
Armor is the permanent fix for surfaces where moving water would strip any living cover. When a channel scours out its grass twice in a season, or a slope sheds every blanket stapled to it, the answer stops being better vegetation and becomes a surface that does not care about velocity.
The permit recognizes it
Hard armor is not a workaround — it is written into the endgame. Final stabilization under TXR150000 requires uniform perennial vegetative cover of at least 70% of native background density, or equivalent permanent stabilization measures. TXR150000 names riprap and gabions as examples of equivalent permanent stabilization measures. Where grass cannot close a site out, rock legitimately can.
The armor ladder
The ladder runs from vegetated reinforcement up through rock: turf reinforcement mats where grass still does the work, riprap and articulated block where it cannot, and gabion baskets where the geometry is vertical. Start at Turf Reinforcement Mats (TRM) when vegetation just needs backup, step to Riprap for outfalls and channel linings, Flexamat where a mowable articulated surface earns its keep, Gabion Basket & Mattress Installation where the fix is structural, and Armormax Installation for engineered high-performance faces. The rest of the program lives under Erosion Control.
Frequently Asked Questions
When does a channel need hard armor instead of grass?
When the flow keeps winning. A channel that scours out its vegetation after every wet season is telling you the velocity exceeds what living cover can hold — that is the threshold where riprap, articulated block, or a reinforced lining takes over.
Is rock the only permanent option?
No. A vegetated turf reinforcement mat is a permanent lining too — grass doing the work with a synthetic matrix underneath. Rock takes over where even reinforced vegetation cannot hold the shear.
What is articulated concrete matting?
Concrete blocks cast onto a flexible mat, so the armor bends to the grade and stays interlocked under flow. It gives channel-grade protection with a surface that can be driven and maintained, which plain dumped rock cannot offer.
Request a bid
Send your channel or slope sections to bids@terradynegroup.com or call (214) 878-7392 for slope, channel, and hard armor work across Dallas-Fort Worth. Tell us the grade and what the water has been doing to it, and we will match the armor to the duty.