Shorelines erode where waves and tidal currents remove material faster than it is replaced. Seawalls, roads, pipelines and landfall sites near the coast are all exposed.
Rock bags are used as toe protection for coastal revetments, as armour along intertidal banks and as protection at pipeline and cable landfalls. They are placed from land or from the water, and they keep working in salt water and strong sun.
Where rock bags are used on the coast
- Toe protection at the foot of seawalls and revetments, where scour undermines the structure
- Intertidal bank armour on creeks, lagoons and reclaimed land
- Pipeline and cable landfalls, where the asset crosses the beach
- Emergency protection when a storm has exposed a structure
Hot-climate and Gulf coasts
On Gulf coasts, materials face high UV, heat and saline water at the same time. Synthetic materials that degrade in sunlight are a poor choice above the waterline.
EVO Rock Bags use a polyester net designed for UV and abrasion resistance. Ask for the Service Life & Durability Summary when you plan a coastal job, so the design life can be set against the exposure.
Waves as well as currents
The ratings in our size table are for currents. On an exposed coast, wave height and period also govern stability, especially in the breaking zone. Send the wave climate with your enquiry and we will advise on bag size and layout, or work with your coastal engineer.
Habitat
The gaps between the rocks inside each bag give shelter to invertebrates and collect fine sediment. On a living shoreline design, rock bags at the toe can be combined with vegetation higher up the bank.
Questions
- Are rock bags suitable for wave action?
- They are used on coastal revetment toes and shorelines, but wave stability has to be checked for the site. Our published ratings cover currents only, so send the wave conditions for advice.
- How do rock bags hold up in Gulf heat and UV?
- The net is made for UV and abrasion resistance. Ask for our Service Life & Durability Summary for the figures that apply to your design life.
- Can rock bags be placed from the shore?
- Yes, with a crane or long-reach excavator. Each bag is lifted by its ring and set in place.
Published by EVOSNT Trading FZCO, manufacturer of EVO Rock Bags. Product figures are from our technical specifications. General guidance only; the project engineer is responsible for the final design.
