How to tell if iguanas are burrowing under your seawall

The seawall is where iguanas do their most expensive damage, and it's the damage you're least likely to notice until it's a repair bill. Burrows dug into the soft backfill behind and beneath the cap slowly hollow it out, and rain and tidal action pull more soil through the gaps. By the time you can see the wall failing from the dock, you're usually looking at a marine contractor's invoice, not a patch.

The whole point of this article is to help you catch it while it's still cheap. If you're on the Intracoastal or a finger canal in Boca, Delray, Lake Worth Beach, or the West Palm and Lantana canals, walk your wall with this list in hand.

The visible signs at the wall

Start at the waterline and work back toward the grass. Burrowing leaves a pretty consistent set of tells if you know to look for them, and they show up in a rough order as the damage progresses.

• Half-moon holes at the waterline or in the grass just behind the cap, often with a fan of loose soil at the mouth.
• Soft or sunken spots in the lawn within a few feet of the wall that give underfoot.
• Hairline cracks in the cap, or seams starting to open between cap sections.
• Sod, pavers, or a walkway near the wall that's begun to settle unevenly.
• Erosion channels where mulch or soil is visibly migrating toward the water after rain.

The behavioral signs

The animals themselves tip you off too. If iguanas are basking on the cap most mornings in the same spots, splashing into the water when you disturb the yard, and especially if you're seeing fresh diggings or a female lingering near the bank in spring, you almost certainly have burrowing under way. Spring is when females dig nesting burrows into exactly this kind of soft, sun-warmed backfill.

One iguana passing through isn't this. A daily pattern — same basking spots, fresh soil at the waterline — is a resident colony working your wall.

How to check without wrecking anything

You can do a careful visual and foot survey yourself. Walk the base of the wall and the strip of lawn behind it, look for the half-moon openings and soil fans, and gently test soft spots underfoot. What you shouldn't do is start excavating along your own seawall to 'see how bad it is' — you can undercut the backfill and make things worse, and in spring you can disturb a clutch of eggs.

If you find openings, resist the urge to just shovel dirt in. Filling an occupied burrow either traps an animal or gets re-dug within days, and it does nothing for a void that's already formed under the cap.

What to do if you find it

If the signs are there, the sequence is: clear the resident iguanas, collapse and properly pack the burrows, and harden the waterline edge so they can't immediately re-dig. If the cap is already cracking or the bank is slumping, that's structural — a marine contractor's repair — and the iguana work is what stops the cause so the repair isn't undermined again next spring.

This is one of the most common reasons people call us, and the free property walk is genuinely useful here: we can tell you whether you're looking at early burrowing that a clear-out handles, or damage that needs a contractor looped in. Single visits start at $125, and pressured waterfront lots often do best on a monitored program from $99 a month with no lock-in.