MONTEBELLO (AP) — The Army Corps of Engineers has raised its estimation of flood risk from the Whittier Narrows Dam in eastern Los Angeles County.

The Corps said Monday the risk characterization has been changed from high urgency to very high urgency.

The earthen dam constrains the San Gabriel River and the Rio Hondo. Both are normally dry but fill during storms.

Analysis found that during an unlikely but possible storm, water released through the spillway could exceed downstream channel capacity, flooding adjacent land.

Other failure modes involve erosion from water piping through the dam’s foundation and from water overtopping the dam.

The Corps says interim measures will begin before next winter’s rains and other measures are likely by the end of 2017. Construction of final modifications is expected to begin in 2020.

(© Copyright 2016 The Associated Press. All Rights Reserved. This material may not be published, broadcast, rewritten or redistributed.)

Comments

Leave a Reply

Please log in using one of these methods to post your comment:

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s