Channel and Floodplain Alterations for River Restoration

Melinda D. Daniels, PhD

Fluvial Geomorphologist

Should aim to re-establish normal rates and magnitudes of Should aim to re-establish normal rates and magnitudes of physical, chemical, and biological physical, chemical, and biological processesprocesses that create that create and sustain river and floodplain ecosystemsand sustain river and floodplain ecosystems

Rivers are:Rivers are:DynamicDynamicSelf-sustainingSelf-sustainingResponsive to their watershed inputsResponsive to their watershed inputs

River Restoration

Habitats are by nature dynamic in Habitats are by nature dynamic in both space time and are controlled both space time and are controlled by physical stream processes by physical stream processes

Fundamental River Proceses

Natural River

Restored River

AlteredRiver

Driving Processes Restoration

Solutions

Fluvial GeomorphologyFluvial GeomorphologySediment TransportSediment Transport

Bank ErosionBank Erosion

Channel MeanderingChannel Meandering

Wood LoadingWood Loading

Flow RegimeFlow Regime

Saldi-Caromile et al., 2004

Nielson et al., 1994

Important to evaluate from landscape to local scales

Beechie et al. 2010

Legacy Sediments

Lancaster area, PA

Marmot Dam Removal

Major et al. Eos, Vol. 89, No. 27, 1 July 2008

Pomperaug River Study

Pomperaug River Study

Pomperaug River Study

1944

1985

1936

ChannelizationChannelization

Plan for channel reconstruction, Uvas Creek, prepared by Rosgen (Source: Uvas Creek project files, City of Gilroy, California).

Kondolf, G. M. 2006. River restoration and meanders. Ecology and Society 11(2): 42. [online] URL: http://www.ecologyandsociety.org/vol11/iss2/art42/

Cautionary Tales, or… “The road to hell is paved with good intentions”

Design for Cuneo Creek reconstruction project (from Rosgen 1991). (photography courtesy of the California Department of Parks and Recreation).

Kondolf, G. M. 2006. River restoration and meanders. Ecology and Society 11(2): 42. [online] URL: http://www.ecologyandsociety.org/vol11/iss2/art42/

Plum Run, Brandywine

Restored River

Restoration Strategies

Target root causes of habitat and ecosystem change

Restore Riparian Forests

Focus on connecting existing high quality patches

Decrease storm water and sediment runoff from urban and agricultural lands

Add large wood

Remove Dams and Stabilize Legacy Sediments

The Ten Commandments of River Restoration

1.Do No Harm

2.Direct channel manipulation should be a LAST resort

3.Hire someone who can properly assess the system

4.Look beyond the channel reach (upstream) to assess drivers of degradation

5.Manage inputs to the system (stormwater, sediment)

6.Allow the channel to self-adjust

7.Emulate natural systems

8.Use appropriate materials

9.DO NOT lock the channel in place

10.Expect and accept change