Las Vegas -- The flooding in the northwest valley isn't just causing washed out roads; it's also causing some other problems. One neighborhood is reporting a strange foam actually "gurgling foam" from storm drains.

The foam is near Ackerman and El Capitan. Residents say they noticed this foam around 7:30 Monday morning and it won't stop growing. The foam has reached a size of 40 feet wide and 4 feet high.

Residents say the Las Vegas Water District has looked at the foam, but has not released any details about its cause beyond saying it is due to flood water near a storm drain.

Las Vegas Public Works has been contacted, and they are trying to determine what is causing the foam to increase in size.