Instead of using concrete jax or tetrapods (as Japan does) they're basically using what would amount to concrete demolition debris (and natural rocks of differe

Instead of using concrete jax or tetrapods (as Japan does) they're basically using what would amount to concrete demolition debris (and natural rocks of different sizes) to shore up the coastline which is receding due to the damming of the Columbia River (which prevents sedimentary deposits) as evidenced from photos from the early 1900s --but despite that the author goes on to attribute it to sea level rise but never providing how much it rose by the 1900s or even today which would be informative, but I have suspect it's just the author's conjecture.