Sioux City - Big Sioux River LB
Sioux City, Woodbury County, Iowa. On the Big Sioux River. USACE records 2,973 people living in the area this system is built to protect.
The federal record
What this page does not tell you
It does not say whether any particular address is protected. A FEMA accreditation status describes this system measured against a design flood event, and USACE states that the database may not represent the totality of levees in the United States. If you need to know what applies to a specific property, your local floodplain administrator holds that answer. How to read an accreditation status.
Where it is
Source: USACE National Levee Database, system 4705000028. Refreshed 2026-09-10. Values are reproduced as published. USACE updates the database irregularly and without a change feed, so the refresh date above is the age of what you are reading.