Contributions of Environmental Flows Science to River Conservation and Restoration

 Angela H. Arthington

Australian Rivers Institute, Griffith University Australia

   

10th Annual International Riversymposium & Environmental Flows Conference

Brisbane, September 2007

750 delegates from over 50 countries produced: Brisbane Declaration 2007 http://www.watercentre.org/news/declaration •   A new definition of e-flows •   7 e-flow principles •   9-point Global Action Agenda to protect rivers globally by maintaining or

restoring environmental flows

Environmental Flows – a new definition

 Environmental flows describe the quantity, timing and quality of water flows required to sustain freshwater and estuarine ecosystems and the human livelihoods and well-being that depend upon these systems

   

Brisbane Declaration 2007 International Environmental Flows Conference, Brisbane, September 2007 750 delegates from over 50 countries

Brisbane Declaration 2007 •   Freshwater and estuarine ecosystems have evolved with, and depend upon,

naturally variable flows of high-quality fresh water •   Flow alteration imperils freshwater and estuarine ecosystems  

Flaming  Gorge  Dam  1963  Lytle  &  Poff  (2004)    

Brisbane Declaration 2007 •   Greater attention to environmental flows must be exercised when

attempting to manage floods, water supplies, hydropower generation, navigation and recreation

•   Scientifically credible e-flow methodologies must quantify the variable – not just minimum – flows needed for each water body by explicitly linking environmental flows to specific ecological functions and social values

Scientifically credible e-flow methodologies

70% of global methods are based on: - hydrological rules, e.g. % of historical flow - hydraulic analysis, e.g. wetted perimeter - habitat modelling, e.g. PHABSIM (IFIM) Valuable contributions to habitat protection and restoration Significant new advances in habitat modelling, e.g. SEFA

SEFA: System for Environmental Flow Analysis Tom Payne, Bob Milhous, Ian Jowett http://sefa.co.nz/

SEFA contains: •   one and two dimensional habitat analysis •   habitat suitability criteria (e.g. fish) •   water temperature, dissolved oxygen modeling •   sediment analysis (deposition, flushing flows) •   riparian inundation modeling •   time series analysis of flows & aquatic habitat

Aquatic biodiversity and natural flow regimes

channel formhabitat complexitypatch disturbance

biotic diversity

Principle 1

Life history patterns • spawning• recruitment

Principle 2

lateral connectivitylongitudinal connectivity

Principle 3

natural regime discourages invasionsPrinciple 4

Time

Disc

harg

e

spates

seasonalitypredictability

reproductive triggers

variability

access to floodplains

dispersaltriggers

stable baseflowsdrought

Aquatic biodiversity and natural flow regimes

Bunn & Arthington (2002)

Connec'vity  

Life  history  

Channel  form  and  habitat  

Alien  and  invasive  species  

Floodplain Riparian Channel Fish

Monthly mean / median

flow

J F M A M J J A S O N D

Discharge  

(m3s-­‐1

)  

Holistic – Ecosystem E-flow Methods - 1991

2000

•   E-flows for riverine ecosystem from source to terminal waterbody, including:

- channel & habitat - algae - aquatic vegetation - invertebrates & fish - riparian vegetation - floodplain processes - fisheries

Hill et al. (1991)

Arthington et al. (1992)

Mapping ecological components to natural

hydrograph

Building Block Methodology – BBM Sth Africa - King & Louw (1998) Expert/Scientific Panels, FLOWS, Flow Events Method - Australia CAMS (Catchment Abstraction Management Strategies) UK Holistic-ecosystem applications: * River conservation * River restoration

Speed et al. (2011)  

J F M A M J J A S O N D

6

5

4

3

2

1

0

1 2

3

4

5

6

Natural annual flow pattern

Modified annual flow pattern

J F M A M J J A S O N D

6

5

4

3

2

1

0 1 2

3

4

5

6

Aver

age

Mon

thly

Dis

char

ge (1

06 x m

3 )

River Conservation - Maintain flow regime as near to natural as possible - Identify unacceptable thresholds of ecological change

River Restoration - Restore flow regime towards natural pattern - Identify ecological end points that can be achieved by flow restoration given constraints

Original annual flow pattern  

Modified annual flow pattern

Restored annual flow pattern  

Identifying unacceptable levels of ecological change

Unhealthy

Small Large

Ecosystem health response

Change in flow attribute

? Healthy Two frameworks:

DRIFT ELOHA

DRIFT – Downstream Response to Imposed Flow Transformation

Lesotho Highlands Water Project Objectives:

Export water to SA Hydro-electricity in Lesotho

Multi Phase project 6 Dams Delivery & transfer tunnels Infrastructure

Define scenarios of e-flows - rivers with proposed or

existing water infrastructure

Katse Dam

DRIFT Framework

   

Describe Aquatic Ecosystem & Hydrological relationships

Describe river use, health profiles & ID PAR

Develop predictive capacity for social impacts

Develop models to predict flow related changes

Identify possible future flow scenarios

Predict & rate biophysical consequences

Describe social consequences

Calculate compensation & mitigation

Output to decision maker

King et al. (2003)  Senqunyane River  

0

2

4

6

8

10

0 50 100 150Distance (m)

ΟΟ

Ο Ο Ο Ο Ο Ο Ο Ο Ο Ο ΟΟΟΟΟΟΟ

ΟΟΟΟΟΟΟΟΟ

ΟΟΟΟΟ ΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟ

ΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟ

ΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟ

ΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟ

ΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟ

ΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟΟ

������

������

������ ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ���

��� ��� ��� ������ ��� ��� ��� ���

��� ��� ��� ��� ��� ������ ��� ��� ��� ��� ��� ���

��� ��� ��� ��� ��� ��� ������ ��� ��� ��� ��� ��� ��� ���

��� ��� ��� ��� ��� ��� ��� ��� ������ ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ���

��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ������ ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ���

��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ������ ��� ��� ��� ��� ��� ��� ��� ��� ��� ��� ������

Δ Δ Δ Δ Δ Δ Δ

Δ Δ Δ Δ Δ Δ ΔΔΔΔΔΔΔΔΔ

ΔDΔΔΔΔΔΔΔΔΔ ΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔ

ΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔ

ΔΔΔΔΔΔΔΔΔΔΔ

ΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔ

ΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔ

ΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔΔ

0.0

0.1

1.0

5.0

0.0 0.1 1.0 10.0 100.0 1000.0

Discharge

Ο Maximum depth (m)

��� Mean velocity

Δ Wetted perimeter

(m.sec-1)

(m x 102)

(m3.sec-1)

1:21:51:10

1:20

0

1

2

3

20 30 40 50 60 70 80 90

Distance (m)

(i)

(iii)

(ii) (iv)

(v)

(I)

(II)

(III)

(IV)

(vi)

(a)

(b)

(c)

Ecological requirements

affected - reduction in low flows

Ecological requirements

affected - reduction in floods

Impacts on fishChange in health

Change in mortalities

Severity/ confidence

Social consecquence

DRIFT Fish: Predicting impacts of flow regime change on fish

Arthington et al. (2003)  

e.g.  MaloC  Minnow  Pseudobarbus  quathlambae        

DRIFT outputs •   Combined Integrity Score vs flow left in river

•   E-flow options tested against

development scenarios •   Social & financial implications of

development scenarios

•   Integrated Basin Flow Management (IBFM)

King & Brown (2010) -2

-1.8

-1.6

-1.4

-1.2

-1

-0.8

-0.6

-0.4

-0.2

0

0 50 100 150 200 (56%) 250 300 350 (99%) 400Total volume used (MCM)

(Percentage MAR in brackets)

Near natural

Significantly modified

Moderately modified

Highly significantly modified

Present River State = Near natural

DR

IFT

Inte

grity

Sco

reIn

tegr

ity S

core

Total flow left in river, % MAR  

DRIFT applications - Africa, SE Asia, South America Lesotho Highlands Water Project, 17 river systems & Lake Sibaya (South Africa) Lower Zambezi River & Delta (Mozambique) Mzingwane River (Zimbabwe) Okavango Basin (Angola, Namibia, Botswana) Neelum-Jhelum Basin, Poonch River (Pakistan) Lower Mekong River (SE Asia)

DRIFT recognised as a good practice E-Flows methodology by: World Bank, ADB, IFC, IUCN, OKACOM, and the South African, Tanzanian and Pakistan governments

King & Brown (2010)

Project - basin-scale regional e-flow assessment DRIFT - single dam to basin scale e-flows E-flows for river reaches based on expert prediction of ecological responses to flow alteration King & Brown (2010)

ELOHA - Ecological Limits of Hydrologic Alteration Regional-scale, multi-basin e-flows

e.g. bioregion, province E-flow ‘standards’ for many rivers based on analysis of existing or new ecological data, along gradients of flow alteration Arthington et al. (2006); Poff et al. (2010)

0

20000

40000

60000

80000

100000

120000

140000

0

500

1000

1500

2000

2500

3000

3500

4000

4500

5000

0

5000

10000

15000

20000

25000

30000

Classification of regional flow regimes into different types E-flows for each river type

Class A

Class C

Class B

Axis I

Axi

s II

1. Classification based on reference stream flow data

Health indicator 1

Departure from reference flow condition (flow variable X)

Health indicator 2

Mean and error for reference streams

Mean and error for reference streams

Dep

artu

re fr

om re

fere

nce

heal

th c

ondi

tion

1 2

3

4 5

1 2 3

4 5

è ç

è ç

4. Flow-response relationships for ecological health data from reference and flow-modified streams for each flow variable

Plots of ecological condition along flow alteration gradients for each flow metric / river type

Sustainable level of flow change

J L

Unsustainable level of flow change

Flow-ecology relationships: Arthington et al. (2012)

Inter-annual variability and predictability Seasonal timing Flood magnitude

Rate of rise & fall

Zero and low flow duration

Dis

char

ge

Flood duration

Flood frequency

white

-ve Total species richness, species per ha, Basal area late succession riparian species, No. regenerating species per ha vs CV daily flows

+ve l Density alien fish species vs no. zero flow days

-ve Aquatic plant cover vs flow to mobilise substrates, +ve response aquatic plant cover vs change in low spell duration

-ve Riparian species richness vs constancy and predictability

-ve Aquatic plant cover vs high spell duration

Mixed response Fish species richness vs change in CV daily flows

-ve Species richness density vs median daily flow, 10-year ARI

Step 1. Hydrologic Foundation SCIENTIFIC PROCESS

Monitoring

Acceptable Ecological Conditions

Societal

Values and Management Needs

Implementation

SOCIAL PROCESS

Adaptive Adjustments

Flow  AlteraCon-­‐Ecological    Response  RelaConships  

by  River  Type  

Stream Hydrologic Classification

Degree of Hydrologic Alteration

Hydrologic Alteration by River Type

Baseline  Hydrographs      

Developed  Hydrographs      

Ecological  Data    and  Indices      

Environmental    Flow  Standards  

Hydrologic  Model  and  Stream  Gauges  

Flow  -­‐  Ecology  Hypotheses  

Geomorphic Stratification

Step 4. Flow-Ecology Relationships

Step 3. Flow Alteration

Step 2. Stream Classification

ELOHA  ApplicaCons  -­‐  USA  ELOHA applications to e-flows at regional scale

ARI - Adverse Resource Impact

•   6 US states and 3 interstate river basins

A practical guide to environmental flows for policy and planning Kendy et al. (2012) www.conservationgateway.org

•   Mexico •   Colombia •   China •   European Union •   Australia

- northern rivers - SE Queensland - Murray-Darling Basin

Murray-Darling Basin >1 million km2, 4 states and ACT >77,000 km of rivers, creeks and watercourses, 30,000 wetlands Inflows 31,600 (6,700 -117,900) GL / year Water use audit 1995, water take capped Water Act 2007, M-D Basin Plan 2012 $AUD 9 billion for e-water purchases and improvements in water infrastructure (20% reduction in consumptive use) Geosciences Australia & MDBA (2008)

Basin-scale classification & mapping of ecological assets Bunn et al. (2014) http://www.finterest.com.au/wp-content/uploads/2015/03/Bunn-et-al.-2014-Ecological-reponses-synthesis-lo-res.pdf

Distribution of 14 riverine classes across the M-DB - large lowland rivers

to small headwater streams

Distribution of floodplain, wetland & lake classes across the M-DB

floodplain

wetland

lake  

wetland

lake  

Flow-ecology response models for different components of the flow regime - IPCC terminology (Mastrandrea et al. 2010)

Reversed seasonality of flows is likely to reduce recruitment of riparian trees and increase the risk of blackwater (low oxygen) events in-channel, if flood flows inundate floodplains rich in organic matter during summer (high confidence)

Artificially stable high flows in summer are likely to reduce the spawning and recruitment success for native fish (medium to high confidence)  

natural median monthly flow

1998 MDBC  

ELOHA Innovations New approaches to: Constructing hydrologic time series, flow regime & waterbody classification (Kennard et al. 2010; Olden et al. 2011; Mackay et al. 2014; Bunn et al. 2014) Modelling ecological roles of flow & effects of flow alteration Stakeholder engagement, inclusion of indigenous values & needs (Finn & Jackson 2011) Monitoring e-flow outcomes, identification of knowledge gaps, R&D priorities

ELOHA enables river managers to: •   deliver e-flows for rivers of distinctive flow regime type

•   minimise ecological impacts at most sensitive, high value waterbodies

•   prioritize river segments for flow regime restoration

at basin and regional scale •   envisage / predict how rivers may change under

different water infrastructure / management / climate scenarios Abel et al. (2007)

Looking to the future

•   Climates, flow regimes and freshwater ecosystems will change

•   E-flows are a vital tool for adaptation to climate & environmental change

•   E-flows science must generate deeper ecological

understanding to inform river flow management in changing environments

•   Monitoring e-flow outcomes is essential to inform

the e-flow scientists and managers of the future

Ecological states under shifting hydrological & geomorphic regimes

Auerbach et al. (2009)

 

University of California Press http://www.ucpress.edu/book.php?isbn=9780520273696 Inbooks.com www.inbooks.com.au Amazon.com http://www.amazon.com/Environmental-Flows-Saving-Rivers-Millennium/dp/0520273699 eBay  

Further light reading