What to do if…
a retaining wall develops a fresh horizontal crack and starts seeping water

What to do now

1. Make a no-go zone. Keep everyone away from:

   • the full length of the wall
   • the area below the wall, where it could fall
   • the ground above the wall, which could slump if the wall gives way

2. Check for urgent warning signs from a safe distance. Treat the situation as urgent if you see or hear any of these:

   • the wall is leaning, bowing, bulging, or sections look displaced
   • the crack is widening or spreading
   • there are new cracking, grinding, or popping sounds
   • soil is slumping, sinking, or opening above the wall
   • water flow is increasing or carrying soil or sand

3. Escalate if people or public areas could be at risk.

   • If collapse seems possible soon and people could be harmed, call 999.
   • If the wall could affect a public footpath, road, highway, neighbouring property, or shared access, contact your local authority’s dangerous structure route as soon as you can.
   • In England and Wales, use the GOV.UK dangerous building or structure route to find the relevant council.
   • In Scotland, contact your local authority building standards service.
   • In Northern Ireland, contact your local council building control service.

4. Reduce water feeding the wall only from a safe position.

   • Turn off sprinklers, hoses, irrigation, and outdoor taps feeding the area.
   • If a downpipe, drain, or garden run-off is sending water towards the wall, divert it away only if you can do that without going near the wall or the ground above it.
   • If water is flowing constantly even in dry weather, consider turning off your internal stop tap and checking whether the seepage slows.

5. Avoid anything that increases pressure behind the wall.

   • Do not dig relief holes or remove soil yourself.
   • If you can reach a gully or channel drain safely without going near the wall, clear obvious leaves or debris so water does not pool above it.
   • Keep vehicles, deliveries, bins, stored materials, and foot traffic away from the retained ground.

6. Record the situation quickly and safely.

   • Take wide photos or a short video from a safe distance.
   • Include something fixed for scale, such as a fence post, paving edge, or wall end.
   • Note the time, recent weather, whether water is clear or muddy, and whether the crack seems to be changing.

7. Contact the right help.

   • Contact a chartered structural engineer or structural engineering practice and say: “fresh horizontal crack in a retaining wall with water seepage.”
   • Contact your buildings insurer and ask what emergency stabilisation or inspection steps they want recorded before any repair work.
   • If you smell gas or suspect gas pipe damage, call the National Gas Emergency Service on 0800 111 999.
   • If electricity equipment, cables, or overhead lines may be damaged or at risk, stay away. In England, Scotland and Wales, report it through your electricity network operator or call 105; in Northern Ireland, use the Northern Ireland power emergency route.
   • If you suspect a water main or sewer problem outside your boundary, contact your water company.

8. Tell affected neighbours in plain terms.

   • Say there is a new crack and water seepage, you are keeping people away, and you are contacting an engineer, insurer, or the local authority as needed.
   • Do not argue about boundary responsibility while the wall may still be unsafe.