News

California begins to restore its rivers.

Waits for Bren students.

River Restoration

What is it?

Why is it done? (~$1billion/yr)

Where is it done?

How is it done?

River Restoration

• Instructor Tom Dunne

• Availability Open-door policy and appointments by email

• Schedule: Each Thursday at 8:00-9:50 am.

– 50-min lecture followed by 50-minute student-led discussion of case studies

• Reading material to be distributed on website

Syllabus

• Apr 1 What is river restoration? Where does it happen? How does it happen?

• Apr 8 Geomorphic principles relevant to river restoration

• Apr 15 Restoration of river flow regimes

• Apr 22 Sediment management

• Apr 29 Sediment transport in channels and floodplains

• May 6 Channel and floodplain engineering

• May 13 The role of vegetation and large woody debris in channels and floodplains

• May 20 Water temperature and light

• May 27 “Wetlands”: floodplains, swamps, mountain meadows, estuarine marshes

• June 3 Long-term context of river restoration

Untouched issues

• Water quality

• Food webs

• Ecosystem structure

• Political and legal processes, including regulation

• Financing

• Large-scale planning and management processes

• Most of the course will deal with physical processes and their manipulation because these are the easiest (and therefore the most common) manipulations to make

– Moving water and dirt and predicting expectations is easier than manipulating and predicting biology or even chemistry.

Readings for second class

(Rules: everybody reads and comes ready to discuss. Each appointed leader comes ready to summarize one paper in 10 minutes)

• “River restoration approaches in California” by Haltiner, Kondolf and Williams, in River Restoration: Guiding Principles for Sustainable Projects, (eds. A. Brookes and F. D. Shields), 1996

– Three people to summarize three sections

Altering the form and behavior (or structure and function) of river channels and floodplains to increase production and biodiversity of organisms and enhance recreation.

Often collateral to:

• Improving water quality

• Removing or re-designing dam operations

• Ensuring the safety of communities.

What is River ‘Restoration’?

Palmer, M.A. and J.D. Allan. 2006. Restoring Rivers: The work has begun, but we have yet to determine what works best. Issues in Science and Technology 22:40-48.

Degrees of restoration

Degrees of Restoration

“Original”

state

Current

state

Resto

ration

Rehab

ilita

tio

n

Enhan

cem

ent

Creat

ion

Natur

aliz

atio

n

(incl

. min

ituriz

atio

n)

Terminology from A. Brookes and F. D. Shields Jr. (1996) River Restoration, John Wiley & Sons Ltd.

Where is it done?

• In river basins of all scales from a few hectares to regional-scale rivers such as the Missouri

• Mainly in wealthy countries, but recognition of need gradually expanding into developing world

• Rivers are restored in many, differently functioning, parts of a landscape …

Upland zone: High sedimentsupply and low storage.

Alluvial transport zone: sediment transport rate ≈ sediment supply rate. Significant transient sediment storage in valley floors and tributary fans. Multi-threaded channels in upper, steeper reaches; single-thread, meandering channels on lower gradients. ‘Free’ alluvial landforms.

Alluvial accumulation zone: sediment transport capacity decreasing downstream; floodplain aggrading.

Outlet: fans; deltas, estuaries.

Length scale Amazon to Atascadero Creek. Depends on plate tectonics,…. Again and always! [ESM 203]

Why is it done?

• Loss of aquatic or riparian habitat and response to ESA – e.g. FWS tells USACE “Your operations on the Missouri R. are

threatening pallid sturgeon and (some) tern, so you will create 2000 acres of shallow water habitat and 2000 acres of sand bar habitat every year for the next 15 years!)

• Watershed rehabilitation for control of flooding, erosion, and water quality, including after fires– Santa Barbara watersheds; Requirements for TMDLs

• Urban development requiring control or realignment of stream

• Dam removal (for various reasons). Matilija Creek, Elwha R., WA

• Re-settlement of populations and regional development• Bona fide conservation (e.g. Nature Conservancy purchases

on Santa Clara)

Why is it done?

• Loss of aquatic or riparian habitat and response to ESA

– Determined that habitat not good for spawning, rearing, or passage of Chinook salmon

Central Merced R., Central Valley, CA, CA Dept Fish & Game and CA Dept. Water Resources

Expected trajectory of habitat and ecosystem development

Disturbance Regime

Population dynamics

Initial Ecosystem structure

(SIMPLE)

Later Ecosystem structure

(COMPLEX)

Population dynamics

Disturbance Regime

TIME

Stimulated by Frank Davis

Why is it done?

• Watershed rehabilitation for control of flooding, erosion, and water quality– Clearcuts, road failures

and debris-flow tracks, N. Cascades WA

– “Hydromodification” of urban watersheds

Greenwater R, WA Cascades after intensive harvest and 1978 flood

“Hydromodification” to mitigate effects of urbanization on runoff and channel

erosion

Why is it done?• Urban development requiring control or

realignment of stream

Read: Combination of flood risk reduction

and ‘river restoration’• American Rivers www.americanrivers.org National Riverfront Revitalization

Movement

• Napa River, CA. Flood costs 1960-200 was ~$540 million. CBD flooded in 1995 and 1997

– Upto 1995 (i.e. even after 1993 Mississippi flood) Corps proposal to deepen channel by continual dredging, raise and riprap levees for 11 km through Napa

– By 1999 Corps proposed ‘flood hazard mitigation and river restoration’– After intense debate, coalition of Corps, local agencies and NGOs proposed a ‘living

river’ concept with terraced marshlands and lower wetlands and greater connection of channel and floodplain at lower stage

– $80 million already allocated for the simple project. New plan needed $190 million – required raising local sales tax. $Tax increase $6 million/yr; projected to save $20 million/yr in flood costs

– Breached levees ‘protecting’ 200 ha of grazing land restoring tidal marshes and setting them back, minimize concrete to protecting a few critical downtown landmarks and stabilizing a few river bends. Condemned buildings near river and redesign bridges to increase conveyance capacity

– A lot of very careful hydraulic design and monitoring needed to control flooding levels and sedimentation

Why is it done?

• Floodplain rehabilitation for regulation of flood hazard or contamination

Why is it done?

• Re-settlement of populations and regional development

Mesopotamian MarshlandsChange of inundation regime

1973 2000

One flood season of unplanned re-watering of

Mesopotamanian marshlands

MODIS

Processed by Leal Mertes

Why is it done?

• Dam removal (for various reasons)

22 hours of change; 10 minute frequency of shots

http://gallery.usgs.gov/videos/21

Matilija Dam, N. Fork Ventura R.6 millions tons of sediment stored

Why is it done?• Bona fide conservation (e.g. Nature

Conservancy purchases)

Brede R., Jutland, pre-1991 restoration(Brookes and Shields, 1996)

Brede River, Jutland, post-1991 restoration(Brookes and Shields, 1996)

Doñana Marshland, Andalusia Change of water supply and inundation regime for migratory

birds, and resident endangered species (e.g. lynx) 1990 1995

Doñana Marshland Restoration Proposal (Ministerio de Medio

Ambiente, 2001)

Doñana Marshland Restoration Proposal (Ministerio de Medio Ambiente, 2001)

Plans for increasing connectivity between channels and floodplain and deltaic wetlands

California Bay-Delta Ecosystem Restoration

Program

Change of ‘everything’

Watershed for the Sacramento/San Joaquin Delta

San Francisco Bay-Delta location

California Bay-Delta Restoration Program (CalFed)

Restore ecosystem health and improve water management in the Bay-Delta system

Increase reliability of water supplies

Improve water quality

Improve aquatic and terrestrial habitats

Strengthen levee system

At-risk species

Introduced species

Habitats Ecological processes

Aquatic toxicity

Large expanses of wetlands in C. Valley

Increase freely meandering rivers

Many river restoration actions

Harvestable species

How is it done?

• Process is long and complex, requiring extensive conceptual development and review, public input, negotiation between restoration agencies, regulatory agencies, indigenous peoples, and mainstream public stakeholders

• Expensive. Typically requires multi-year appropriations by legislatures or bond issues.

• Essentially experimental. Little secure theory about how to do it. Therefore confidence-building essential.

• Some trust and confidence established through a commitment to Adaptive Management, but this consensus-building methodology is also experimental and not yet well developed.

Who does it?

• Private developers, usually under regulation of urban development or re-licensing of power plants in small watersheds

• NGOs such as The Nature Conservancy in alliances with government agencies

• Federal government (e.g. US Bureau of Reclamation; US Army Corps of Engineers, NOAA Fisheries, US Fish & Wildlife Service)

• State agencies (e.g. Calif. Department of Water Resources, Calif. Department of Fish & Game)

Discussion with M.E.S.M. graduate responsible for wetlands restoration projects in S. California

• Strong argument among some environmental scientists and managers that

– “stream restoration is highly problematic”

– “restoration treats the symptoms not the causes”

– “streams can’t truly be restored”– “we engage in management practices that create attributes

that we care about, not restoration per se”

• So, why are we spending large sums of money doing it? 

• What are our goals? 

• Does it make sense to try to restore rivers?

• Can they be restored? 

• What does “restored” mean, i.e. what is our baseline?

• What are the benefits – habitat, ecosystem services, aesthetics?   

• What are our metrics to define and select restoration projects? 

• What are the “right” ones and the “right” circumstances? Why? 

More MESM…

Symptoms versus causes

• Invest in restoration with no end in sight to the degradation? 

• “most local govts. have adequate resource protection goals and policies in their General Plans” [Perhaps, but for sake of argument …..]

• But, local agencies need better data, tools, skills, and enforcement resources to implement the policies that already exist, and to better protect streams.

• E.g. If staff doesn’t know where the streams and wetlands exist in a county, they issue grading permits and building permits in them and on them. It happens all the time. 

• They “could” prevent the destruction/degradation of stream and wetland habitats in the first place.

More MESM ….

• Easier (and cheaper) to restore a riparian corridor by replacing non-native vegetation with native riparian habitat, than it would be to restore a straightened and channelized stream?  What are the implications? 

• Compare “restoring” the LA River (“too far gone”?) with funding restoration of rivers like the Santa Clara, that is relatively untouched? 

– What are the relative benefits? 

– What are the political, economic, and physical realities and constraints to those scenarios?