Introduction to Stream Restoration

Week 1

Copyright © Andrew Collison 2002

Photo from Alberta Fish Habitat Manual

Course logistics

• This is a quantitative topic: math as required

• In-class work: GIS, field work & report

• Quick notes

• Skills test

Wide range of projects called “Stream Restoration”

Small-scale bank stabilization or revegetation

Complete channel realignment or redesign

Arlington, VA Dept. of Environmental Resources

SR is not well defined but there are several consistent elements

Arlington, VA Dept. of Environmental Resources

• A desire for a more “natural looking” channel

• Integrate ecology & geomorphology with engineering

• Work with natural processes (self-sustaining design)

• Avoid hard structures

Bassett Creek case study

Bassett Creek case study

Bassett Creek case study

Bassett Creek case study

Bassett Creek case study

Bassett Creek case study

Bassett Creek case study

Bassett Creek case study

Bassett Creek case study

Bassett Creek case study

Bassett Creek case study

Primary reasons stream restoration is done in the United States

WQM – Water Quality Mgmt.RM – Riparian Mgmt.IHI – Instream habitat improvementFP – Fish PassageBS – Bank stabilizationFM – Flow modificationA/R/E – Aesthetics/recreation/educationCR – Channel reconfigurationDR/R – Dam removal/retrofitSM – Stormwater mgmt.FR – Floodplain reconnectionISM – Instream species mgmt.LA – Land acquisition

From Bernhardt et al., 2005

Current Status of field• >$1 billion is spent each year on stream restoration

projects (Bernhardt et al., 2005)• Little predictive science to back up restoration designs• Few post-project assessments done (funding)• High rates of design failure

– Survey of 161 fish habitat structures in Oregon/Washington found 18.5% failed and 60% were damaged in 2-10 year event (Frissell and Nawa, 1992)

– Survey of 400 habitat enhancement structures in Alberta found that 33% had low or zero effectiveness (O’Neil and Fitch, 1992)

• Vast majority of projects are designed using “natural channel design” coupled with the Rosgen reference reach approach

There is a current “standard method” for stream restoration,

called Natural Channel Design, or the Rosgen method

Dave Rosgen, P.H., Ph.D

Wildland Hydrology

Ft. Collins, Colorado

Dave Rosgen,

monitoring biologicalfunction !

Unstable C4 Stream Type

Stable-Reference Reach - C4

So why don’t we just teach the Rosgen method?

• It’s a little too “cook book” in our view

• Insufficient emphasis on basic process understanding

• There are plenty of other places where you can learn it (for a fee…)

Elements to the Uof M/NCED* approach

• Emphasis on design based on analysis and prediction, not analogy

• Emphasis on placing SR projects in watershed context

• Emphasis on integrating historical records

*NCED is the National Center for Earth-surface Dynamics, an NSF Sci-Tech center devoted to surface processes, including SR. More about NCED later.

Basic steps to a restoration project – most of these steps require an interdisciplinary approach

• Problem identification – what is wrong? Is it actually a problem?

• Societal context –stakeholders interests, funding sources, regulations, cultural issues, etc.

• Define achievable goals - be specific• Assess site at watershed-level (best to act at watershed

level if possible, or at least understand constraints on system), and at the reach-level, including longitudinal and lateral connectivity

• Identify alternatives, evaluate, and choose design • Implementation – including construction monitoring• Monitoring and assessment; Adaptive management

Goals of this course/program• Balance basic fundamentals of fluvial geomorphology,

hydrology, and ecology with practical information • “EMT” level of understanding for restoring damaged

streams• Focus on ability to evaluate and critique restoration

project (learn from past failures and successes)• Tools to design relatively simple restoration projects on

small streams• Turn you into effective team members on restoration

projects• Give you the tools to do both a watershed-scale

assessment and a reach-scale analysis of a potential site and make you think about a river over multiple temporal and spatial scales.

This program will NOT teach you…

• How to design large-scale restoration projects: this requires a team of subject-area experts and years of experience

• How to work in highly urbanized settings, where life and property are at risk

• Rosgen’s toolbox for natural channel design: There are numerous short courses to learn this tool, including a series by the MN DNR

Common major considerations in restoration design

• Habitat:– Water temperature– Topographic complexity– Desirable ranges of U, h

• Channel stability – ability to convey high flows without major changes in form

• Pollutant reduction (e.g. susp. sediment)• Nutrient processing – especially N, P• Esthetics & recreation

Overall Words of Advice for the River Restorer: FIRST, DO NO HARM!

“There is renewed emphasis on recovering damaged rivers (Baringa 1996). Along with this concern, however, people should be reminded periodically that they serve as stewards of watersheds, not just tinkerers with stream sites. Streams in pristine condition, for example, should not be artificially “improved” by active rehabilitation methods.

At the other end of the spectrum, and particularly where degradation is caused by off-stream activities, the best solution to a river management problem might be to remove the problem sources and “let it heal itself”. Unfortunately, in severely degraded streams, this process can take a long time. Therefore the “leave it alone” concept can be the most difficult approach for people to accept (Gordon et al. 1992).”

From FISRG, 1998, Stream Corridor Restoration, p. 8-2.

Some additional perspectives…

Restoration State of ArtCraig Fischenich

• State of practice generally lags state of art by about 10 years – not true for restoration

• Stream restoration has evolved as a practice rather than a science

• Current practice generally reflects the state of art from about 50 years ago

• Progress is slow and redundancy rampant

Restoration is the return of the form and function of an ecosystem to some pre-disturbance condition.

We Can’t We Can: (or Won’t):

Characterize evolutionary changes in streams

Develop sophisticated analytical tools and models

Identify specific causal mechanisms of disturbance

Optimize habitat for a particular species or guild

Determine when they will occur or quantify magnitude

Get practitioners to use them

Assess the cumulative effects of multiple causes

Optimize habitat for a community across trophic levels

We Can’t We Can: (or Won’t):

Stabilize channels and banks

Identify project objectives

Design systems that mimic reference conditions

Characterize ANY action as restoration

Allow for a full range of dynamic processes

Relate these to meaningful standards or metrics

Ensure that they are appropriate or functional

Fully restore both the form and function of most systems to pre-disturbance

We Can’t We Can: (or Won’t):

Identify broad ecosystems in need of restoration

Develop monitoring plans

Use multi-disciplinary approaches in design

Acknowledge risk and uncertainty

Execute comprehensive, integrated restoration over large spatial areas

Fund and execute monitoring plans

Use inter-disciplinary approaches in design

Quantify and manage risk and uncertainty

Some Reflections on River Restoration and Research Matt Kondolf, University of California, Berkeley

Six Points in Ten Minutes:----------------------------------------------------------------------1. Extent of river restoration, scale of investment2. Lack of monitoring and evaluation3. Most projects designed using empirical approaches from 1950s, need to update (But it’s not just hydraulics/sediment – big picture!)4. Recognize changed conditions of rivers continuum: wilderness ---- fully urban5.Cultural preference for stable, meandering channels?6. Implications for goals, assessing success---------------------------------------------------------------------

Southwest Catchments in Rio Grandeand Colorado River Basins Shah, Dahm, Gloss

California - Sacramento-

San Joaquin Basin Kondolf

Northwest Pacific NW, Interior Columbia BasinNorthern Rockies Goodwin, Stanford, Clayton, Relyea

SoutheastGeorgia, North Carolina, South Carolina, Kentucky

Sudduth, Meyers

Chesapeake Bay NY, Penn, MD,

VA, WVA Hassett, Palmer, Bernhardt, Hart

Upper mid-westMichigan, Indiana, Wisconsin

Alexander, Allan, Gergel

Central US Large RiversMissouri and Mississippi River Basins

Galat

Extent of Restoration in USNRRSS (National River Restoration Sci Synthesis)Seven nodes covering 20 states

Extent of Restoration: NRRSS results

Nationwide: 38,000 records fr 20 states includedData sources mostly large data bases

Testing completeness by checking with local watershed experts

In California, one test is the Russian River basin -211 records in database vs 878 from grad student’s detailed surveyExtrapolating: up to 400,000 projects nationwide

Conservative estimate: $15-17 billion (Palmer et al in review)

Given the magnitude of the investment to date Surprisingly little objective post-project appraisal

Only 14% NRRSS projects indicated monitoringIn California (4,000 records): 22% indicated monitoring, but only 11% of those included specifics that make it credible

Very few studies assessing restoration success. Only studies with large ‘n’ are surveys of habitat enhancemt projects in western N. America – these suggest appx 50% success rate - lower success rate for older projects

Thus, no reason to assume that our projects succeed

Why so little objective monitoring/evaluation?

Most agencies prefer implementation (many funding sources only to implement)

No payoff in going back, esp if you find “failure”

A question of culture: Engineering project vs scientific experimental “Failure” stigma vs “Learning Success” concept

Institutional difficulties e.g., restoration projects done for mitigation (failure not ok!)

Prevalence of designs based on - empirical relations (40-y old concepts) - stream classification

More recent science not widely integrated in restoration projects. NCED to the rescue!

Caveat: restoration doesn’t necessarily imply physical alteration of the channel - catchment changes - better understand system, may not need to intervene

Recognize changed conditions of rivers continuum: wilderness ---- fully urban

Goals and Objectives should depend on CONTEXT - need to be realistic about what’s possible and appropriate in a given context

River ‘restoration’ is fundamentally a social activity - highly urban project as ‘gardening’ – that’s OK - in less altered settings, may be possible to preserve/restore physical/ecological processes Usually restoration trajectory different from degradation trajectory. Examples plotted on 2D field connectivity-dynamics

Social FactorsTheir importance in restoration now widely appreciated. - But it’s not just about stakeholders, surveys, and interviewing local residents

Cultural preferences may be driving many of our restoration designs, though we may not realize it

e.g. a cultural preference for stable, single-thread meandering channels?

An Example:

Cuneo Creek,Tributary to Bull CkHumboldt Redwoods State Park

Basin logged in1950s-60s, high sediment yields.

Aggradation, braided channel

Cuneo Ck

Bull Ck

Another example: Uvas Ck, California. View downstream from Santa Teresa bridge Jan 1996.

Same view July 1997 (after washout in Feb 1996)

Eight themes1. Drainage basin & hydrology (discharge)

2. Channel pattern

3. Channel x-sectional geometry & slope

4. Grain size & sediment transport regime

5. Flood plain & relation to channel

6. Biota: in channel & flood plain

7. Engineered structures

8. History and context