This ETL provides updated technical criteria and guidance for evaluation of existing I-walls. General guidance for performing I-wall evaluation is provided along with detailed updates to existing guidance that focus on three I-wall performance items: the flood-side gap that was discovered at I-walls in New Orleans after Hurricane Katrina; the rotational stability failure mode found to be the critical failure mode for most I-walls evaluated nationwide in the Phase II evaluation; and criteria for consideration of deflections. This guidance is for I-walls designed to provide flood risk reduction from inland flooding, not from coastal storm surges with significant wave and vessel impact loads. I-walls in coastal areas shall be evaluated in consultation with the Headquarters, U.S. Army Corps of Engineers.
