Riprap Installation in St. Simons Island, GA

Is Riprap Required on St. Simons?

It isn't required. It's regulated, under two different laws depending on where your property sits.

Marsh, rivers and creeks

The Coastal Resources Division says a permit is needed to put riprap on any tidally influenced creek or river bank (GA DNR CRD). The marsh in front of your wall is protected, so we keep the footprint tight.

Beaches and dunes

The Shore Protection Act covers jurisdictional beaches. CRD lists rock revetments among the structures it regulates there (GA DNR CRD). The law allows stabilization only when no reasonable alternative exists, and when it's needed, it calls for low-sloping porous rock structures or other methods that absorb wave energy. On the beach, sloped rock is the kind of structure the law points toward, and a vertical wall usually isn't.

What Does Riprap Do?

A vertical wall reflects waves downward, which scours its base. Rock breaks that energy up. Riprap:

• Absorbs waves from wind, wake and storms
• Protects the toe from tidal current
• Reduces loads on the wall
• Creates rough habitat where crabs, oysters and small fish settle

Where Does Riprap Make Sense Here?

• Frederica and Mackay River frontage, where tidal current and boat wake work at the toe
• Creek banks where the tide cuts into bends
• Walls with exposed or undercut toes
• New or replacement bulkheads, where adding rock at the same time saves a separate job

Getting rock to the island takes planning. Stone comes over the Torras Causeway, which crosses the Back, Little, Mackay and Frederica rivers, or by barge. On many marsh lots, we place rock from the water side so trucks and machines stay off the marsh and your yard. On sheltered creeks with gentle flow, a living shoreline may be the better choice. See shoreline maintenance on St. Simons Island.

How Is Riprap Installed on the Island?

1. Survey: toe depth, scour, and the marsh or beach jurisdiction line
2. Permit: CRD under the right law, plus Glynn County and federal approval if needed
3. Filter fabric: keeps soil from washing out under the rock
4. Rock placement: sized for your exposure and set on a stable slope
5. Tide timing: with a range around 7.2 feet at St. Simons Light, the toe is only reachable in low-tide windows
6. Final check against the permit

How Much Does Riprap Cost on St. Simons Island?

Riprap installation on St. Simons Island typically runs $125–$350 per linear foot. A standard 75-foot residential installation costs $10,000–$25,000, fully installed and permitted. Rock volume, access over the causeway or by water, and tide windows affect cost.

Riprap or Revetment?

Riprap in front of a wall protects the wall. A revetment is a rock slope that is the shoreline. If you already have one, see revetment maintenance on St. Simons Island. Planning a new wall? Add rock during bulkhead replacement on St. Simons Island.

Our St. Simons Island seawall repair page lists every island service. We also install riprap in Brunswick.