Floods & Flows in the Willamette River Basin

Within Our ReachOregon State University Alumni CH2M Hill Center

6 December 2012

Xan Augerot (MRWC) and Leslie Bach (TNC)

Marys River Watershed Council

Zones of a River System

© USACE

© USACE

Willamette Basin Project, USACE: 13 Multi-Purpose Dams & Reservoirs 132 miles of navigation channel 100 miles of revetments

© Leslie Bach/TNC © USACE

Observed Flow of Middle Fork Willamette River

at Jasper, Oregon

Lateral Dimension

Willamette River Planning Atlas (PNW Ecosystem Research Consortium)

Loss of complex off-channel and floodplain habitat

1943 FloodOregon State Archives, Oregon Water Resources Department, OWR0085

1890 Willamette Flood Oregon State Archives, Marion Co Historical Society, MJON0209

© Leslie Bach/TNC © Leslie Bach/TNC © USACE

Willamette past, present and …

1890 Flood

Future: flows shaped and targeted for habitat and floodplain restoration

© Leslie Bach/TNC

© Rick McEwan

(Tharme and King 1998; Postel and Richter 2003)

© RaptorViews Philip Bayles psb@efn.org

High flows scoured side channel, and backwatered onto floodplain

© Chris Orsinger

January 2012: it all comes together

9/1/2011

9/9/2011

9/17/2011

9/25/2011

10/3/2011

10/11/2011

10/19/2011

10/27/2011

11/4/2011

11/12/2011

11/20/2011

11/28/2011

12/6/2011

12/14/2011

12/22/2011

12/30/2011

1/7/2012

1/15/2012

1/23/2012

1/31/2012

2/8/2012

2/16/2012

2/24/2012

3/3/2012

3/11/2012

0

5000

10000

15000

20000

25000

Middle Fork Willamette at JasperFl

ow (

cs)

And after three floods on the Marys…

Photos J. Beathe, Starker Forests