Rock Revetment is a way of absorbing the energy coming from incoming waves and water. Revetment prevents and lessons the damages of coastal erosion. Revetments are sloping structures comprised of various layers of large stone and geo-textiles placed on banks and shorelines used to prevent shoreline loss.
On the Great Lakes, rock revetments are the only form of erosion protection that we will install; it is the only long-term solution. Compared to seawalls, rock revetment provides a great, even better alternative to protecting beaches, homes, and other structures along the shorelines.
Typically, armor limestone rock is used to build rock revetment solutions.
Rock Revetment Advantages & Disadvantages
- Absorb wave energy
- Effective for generations
- Protects the Great Lakes’ sand-bars and beaches from long-term damage
- Assures natural beaches will re-form when water levels drop again
- Can be cost-effective compared to other techniques
- Great for protecting backshore assets, like homes on Lake Michigan
- Costs can be higher due to expensive materials
- Installation is more challenging
Rock Revetment Construction
In order to start a project on your shoreline, you’ll need a permit from the DEQ. For more information visit this page. Permits take some time get and you’ll need coastal engineering to approve your project.
Rock revetment construction should not be done without expertise from a coastal consultant and marine construction contractors. Rock structures on the shoreline should be designed with careful consideration for the rock size, face slopes, crest elevation and crest width.
The size of rock used depends on factors of waves such as height, direction, slope, cross-sectional design and availability of the armour rock.
Crest elevation must be above the wave run-up limit during storms to prevent further dune erosion. During extreme circumstances, damage may be inevitable, but the designers will be able to determine the risk and potential damage in worst case scenarios.
Rock revetment along shores that are open to the public can be a safety hazard. Rocks can move when they get walked on and voids may be large enough to climb or fall into.
Rock Revetment Construction Costs
Revetment costs are mainly dependent on the dimensions and material used. Some constructions can provide an unlimited life expectancy while other, smaller scale rip-rap slopes will need regular maintenance. Like anything in construction, you’ll get what you pay for.
Frequently Asked Questions
What is a revetment wall?
Revetment walls are permanent structures designed to prevent shoreline erosion. By definition, a revetment is a protective covering on an embankment of earth designed to maintain the slope or to protect it from erosion.
What does rock armour do?
Riprap or rock armour or rock or other material used to armour streambeds, bridge abutments, pilings and other shoreline structures against weathering and water erosion. It is used to protect coastlines and structures from erosion by the sea, rivers, streams or lakes.