Water can reach the back of the wall several ways
- Rainfall and landscape irrigation
- High tides or storm surge through joints and drains
- Overtopping from waves or elevated water
- Leaking pools, plumbing or utilities
- Runoff redirected by roofs, pavers, grading or neighboring property
Pressure and erosion are different problems
Trapped groundwater can increase lateral pressure. Fast or concentrated flow can carry soil. A design may need both pressure relief and filtration. Simply sealing every visible opening can worsen pressure if no safe drainage path remains.
After overtopping
Inspect the landward side for rills, washed-out soil, exposed roots, settlement, debris lines and new voids. The wall face may appear unchanged even when material behind it has moved.
A seawall has a design limit
No responsible guide can promise that a wall prevents every flood. Follow local evacuation and hazard instructions. Do not remain because a seawall is present.
Primary sources
These links support the regulatory, historical or technical context on this page. Open the live official page before acting on time-sensitive information.
- Coastal Engineering ManualsU.S. Army Corps of Engineers · Engineering references for coastal processes, seawalls, bulkheads and revetments.
- Coastal Construction ManualFederal Emergency Management Agency · Technical guidance on coastal hazards, erosion, scour and resilient construction.
- National Hurricane CenterNOAA National Hurricane Center · Official tropical outlooks, watches, warnings and advisories.
This page provides general homeowner education. It does not determine structural safety, prescribe a repair or replace agency and professional review for a specific property.