Graphs: Flooding in the Shell Rock and Cedar Rivers September 23 - 27, 2016

by National Weather Service Advanced Hydrologic Prediction Service

A hydrograph shows how the river level changes over time at a specific location.

Record Flooding - flooding which equals or exceeds the highest stage or discharge at a given site during the period of record keeping.

Major Flooding - extensive inundation of structures and roads. Significant evacuations of people and/or transfer of property to higher elevations.


The Shell Rock River, a 113-mile-long tributary of the Cedar River in southern Minnesota and northern Iowa, crested at a record 21.51 feet at Shell Rock on Friday, September 23, 2016, surpassing its 2008 record.

Historic Crests
(1) 20.36 ft on 06/10/2008
(2) 17.70 ft on 01/01/1856
(3) 16.73 ft on 07/22/1999
(4) 16.26 ft on 03/28/1961
(5) 15.87 ft on 05/23/2004


The Cedar River near Osage set a new record on Friday, September 23, cresting at 27.78 feet.

Historic Crests
(1) 25.56 ft on 05/20/2013
(2) 25.08 ft on 09/25/2010
(3) 24.69 ft on 06/20/2014
(4) 24.29 ft on 03/23/2011
(5) 22.17 ft on 06/24/2013


Historic Crests
(1) 102.10 ft on 06/10/2008
(2) 96.20 ft on 07/23/1999
(3) 96.10 ft on 03/21/1961
(4) 95.80 ft on 04/02/1993
(5) 94.99 ft on 05/25/2004


Historic Crests
(1) 27.01 ft on 06/11/2008
(2) 21.86 ft on 03/29/1961
(3) 21.67 ft on 04/08/1965
(4) 20.78 ft on 07/23/1999
(5) 20.60 ft on 04/02/1993


Historic Crests
(1) 24.70 ft on 06/12/2008
(2) 19.30 ft on 03/30/1961
(3) 19.20 ft on 04/04/1993
(4) 18.59 ft on 06/01/2013
(5) 18.40 ft on 05/26/2004


Historic Crests
(1) 31.12 ft on 06/13/2008
(2) 20.00 ft on 06/01/1851
(3) 20.00 ft on 03/18/1929
(4) 19.66 ft on 03/31/1961
(5) 19.27 ft on 04/04/1993