A cobble/boulder beach design utilizes natural material less susceptible to being washed away to protect the shoreline and bluff from erosion. It involves adding a layer of natural boulders or cobbles to the existing shoreline to supplement material on the beach.
This is similar to the beach in Concept Design Option 3: Groynes with Beach Fill, but would use a larger stone size.
Key Benefits
Coarse shoreline material prevents some movement
Variable width to accommodate site-specific erosion concerns
Advantages
- Maintains a natural shoreline consistent with what already exists along some of the waterfront
- Becomes damaged gradually, allowing for continuous minor maintenance
Disadvantages
- Cobbles can be hard to source in large quantities
- Because of sourcing difficulty, costs can be uncertain
- More limited resources for design guidance
This option is currently preferred for Reach 7 & 8, and has a rough costing of $31,000/m.