How the damage actually happens
Seawall damage is the single most expensive iguana problem we see across Palm Beach County waterfront, from the finger canals off the Intracoastal in the Boynton Beach and Delray Beach area to the older residential walls in Lake Worth and West Palm. Iguanas dig burrows into the soft backfill behind the cap and along the base of the wall, because that graded, well-drained soil is easy to move and sits right next to water and sun.
Each burrow is a void. Once you have a network of them, tidal action and rain flush the sand and soil out through weep holes, panel joints, and gaps under the footer. The wall was engineered to hold back a solid, compacted mass of soil; when that mass is riddled with tunnels and the fine material keeps washing out, the wall slowly loses the thing that holds it upright.
What owners notice first
The wall rarely fails overnight. What owners usually see first is a cap that has begun tilting toward the water, a hairline crack in the cap or a panel that keeps widening, or soil settling and sinking in the yard behind the wall. A depression where the sod used to sit flush, or pavers along the wall that have dropped a fraction of an inch, are common early tells.
By the time the movement is obvious, the backfill loss is usually well advanced, which is why we push owners to look at the wall the same week they first spot iguanas basking on it rather than waiting for a crack to grow.
Why waterfront walls are the worst case
A canal or Intracoastal seawall gives iguanas everything at once: soft ground to den in, water to drop straight into when startled, and a warm concrete cap to bask on in the morning sun. That combination is why waterfront lots carry the heaviest iguana pressure in the county.
- Soft backfill behind the cap is the easiest digging on the property
- Open water is an instant escape route, so the animals feel safe denning there
- The concrete cap holds heat and doubles as a basking platform
- New iguanas arrive by swimming the canal, so a single removal rarely holds
What a durable fix looks like
One trapped iguana does not protect a seawall. What protects the wall is knocking the resident population down and keeping it down with a monitored trap line, then collapsing and backfilling the burrows so water no longer has a path behind the wall. Structural repair — regrouting joints, sealing weep holes, or rebuilding a section — is contractor work, but it only lasts if the animals reopening the tunnels are gone first.
Common questions
Can iguana burrows really collapse a seawall?
Over time, yes. The burrows let backfill wash out through joints and weep holes, and without that soil packed behind it the wall can lean, crack, or fail. That is why seawall repair on a Palm Beach County canal often runs into the thousands rather than a quick patch.
How do I know if iguanas are behind my seawall problem?
Look for burrow openings along the cap and at the waterline, soil sinking or sod dropping behind the wall, and iguanas basking on the cap itself. Those three together point to iguana-driven undermining rather than a wall simply aging out.
If I fix the wall, will the iguanas just come back?
If the animals aren't removed first, yes. They re-dig the fresh, loose backfill a repair crew leaves behind, sometimes within weeks. Removal and burrow collapse before or alongside the repair is what keeps the work from being undone.
