U.S. Department of the InteriorU.S. Geological Survey

Geomorphic floodplains and the use of process domains to guide restoration strategyRose WallickJim O’ConnorKrista JonesMackenzie KeithCharles Cannon

Brian Cluer (NOAA Fisheries)Anne Mullan (NOAA Fisheries)Leslie Bach (The Nature Conservancy)

Thinking outside of the channel (from the perspective of a geomorphologist)

Willamette River Basin (Photos courtesy of Freshwaters Illustrated)

Emerging management challenges require floodplain framework

Gravel pits

Willamette River

Floodplain

1 km TNC’s Willamette Confluence Project, Middle Fork of the Willamette River

What is the geomorphic floodplain?Suite of geomorphic surfaces created and shaped by

fluvial processes by ‘modern’ climatic regime

Pleistocene alluvium

Holocene(or geomorphic)

floodplainActive

channel

Holocene alluvium

What is the geomorphic floodplain?

Upper Willamette River

Floodplain(Fine sediment deposition)

Active channel(Annual erosion & deposition)

Pleistocene Terrace(Rarely inundated)(Photo courtesy Freshwaters Illustrated)

Process-based definition; not a regulatory boundary

Why use the geomorphic floodplain?Broader context for site-based restoration

Sprague RiverPhotograph by Patricia McDowell, UO

2000 channel1940 channel

Geomorphic floodplain

Meander cutoffs

Avulsion

Sprague River(mapping by UO and USGS)

Why use the geomorphic floodplain?Broadly similar bank materials & landforms

South Fork Coquille River

Upper Willamette River

Bank height, vegetation and particle size may vary, but

Holocene alluvium is typically unconsolidated & very erodible

Why use the geomorphic floodplain?

Chetco River 1939-1995(mapping by USGS)

1995

19391943

Geomorphic floodplain

Active channel changes over time

Bare bars and wetted channel

Static, repeatable spatial reference frame

Active channel tricky to define

Applegate River, 2009

Vegetated bars & side channels

How do we map the geomorphic floodplain?

Simple approach Map floodplain from

existing datasets (see metadata for methods)

Identify landforms of interest

Floodplain transects (‘SLICES’) provide spatial units for tracking change, storing data

Holocene Floodplain

Upper Willamette Floodplain(mapping by UO & OSU)

SLICES framework

1995 channel

1km

How do we map the geomorphic floodplain?Comprehensive approach Define the geomorphic

floodplain Contiguous mapping of all

landforms Relate landforms with

process Relate ecosystems with

landforms

Landforms

Bar and scroll morphology

Columbia River:Sauvie Island

Mapping by Charlie Cannon (USGS)

Upper Willamette RiverMapping by Sarah Schanz

Historical channels

Revetments

• Relict processes or events (volcanism, landslides)• Historical processes (large floods, channel migration)• Ongoing processes (altered flow, sediment, wood regime)

Applications:Linking landforms with processes

Columbia River

Sandy River Delta

Lower Columbia RiverMapping by Charlie Cannon & Mary Ramirez

Active erosion

& deposition

Applications: Re-naturalizing complex floodplains

Hanson Russian River Restoration Project Site

(Photograph by Brian Cluer)

Applications: Process-based monitoring framework

McKenzie River floodplainTwo-year flood inundation provides pragmatic monitoring framework while still capturing floodplain characteristics

Geomorphic floodplainActive Channel

2 year flood inundationInundation map courtesy of River Design Group

Acknowledgements

Stan Gregory (OSU)Dave Hulse (UO)Sarah Schanz (Univ. Washington)Joseph Mangano (Colorado State Univ.)Patricia McDowell (UO)Pollyana Lind (UO)Christine Rasmussen (USGS)Pam Wiley (MMT)Eric Jones (MMT)Ken Bierly (OWEB)Jenny Ayotte (BSWCD)Jeremy Monroe (Freshwaters Illustrated)Pete Klingeman (OSU-retired)Greg Taylor (USACE)Steve Smith (USFWS-retired)

Funding:Benton Soil and Water Conservation District, Meyer Memorial Trust, Oregon Watershed Enhancement Board, BPA, USFWS, USACE, Oregon Dept. State Lands, USGS

Gordon Grant (OSU)Steve Cline (EPA)Kathryn Boyer (OSU; NRCS-retired)Joe Moll (McKenzie River Trust)Chris Vogel (McKenzie River Trust)Dan Bell (TNC)Jason Knuckles (TNC)Chris Budai (USACE)Rick Bastach (City of Portland)Scott Wright (RDG)Troy Brandt (RDG)Janine Castro (USFWS/NOAA)Rob Markel (NOAA Fisheries)Brian Bangs (ODFW)Kirk Schroeder (ODFW)

Assistance and insight to floodplain issues:

Questions? USGS geomorph projects:

Rose Wallick (rosewall@usgs.gov) Krista Jones (kljones@usgs.gov) Jim O’Connor (oconnor@usgs.gov)

Russian River Restoration: Brian Cluer (brian.cluer@noaa.gov)

TNC Confluence Restoration site: Leslie Bach (lbach@tnc.org)

Willamette GIS datasets: http://ise.uoregon.edu/slices/main.html

USGS GIS floodplain coverages with metadata:http://water.usgs.gov/lookup/getgislist

• Chetco River• Coquille River Basin• Hunter Creek• Rogue Basin

• Umpqua Basin• Sprague River• Tillamook Bay tributaries