The Portland and Vancouver areas are no strangers to rain but this years rainfall could lead to increased flooding and landslides. Overall warm temperatures contributing to snow melt in the mountains and soils throughout the northwest being completely saturated from all the rain we’ve been getting are the primary culprit but there’s another culprit to these landslides.
KGW reported some findings from PSU geology professor Scott Burns: landslides caused by old and failing retaining walls.
Many older retaining walls are not properly draining water due to clogged weep holes and allowing water to build up behind them. This is causing weight and pressure to build up and overflow the walls.
A retaining wall is more than just a decorative barrier of stacked rock and stone. They are designed to keep soil from shifting between two elevations, these complex structures require careful planning and, if installed correctly, provide necessary soil retention to keep your sloped lot from encroaching on your home.
Burns anticipates we’re going to start seeing a lot more sinkholes as well as landslides due to failing retaining walls. It’s up to homeowners, in many cases, to make sure their retaining walls are draining properly.
In some cases, landslide and flood prevention can be as simple as keeping your retainer wall drains clear but the overall build and drain set up could also be an issue. In these cases, it’s recommended you hire a Geo-technical engineer to asses and help with the process.