Dr. Eloise KendyDirector, Environmental Flows Program

The Nature Conservancy

Dr. John S. Sanderson, TNC, Colorado

Dr. Julian D. Olden, University of Washington

Colin D. Apse, TNC, Northeastern States

Michele M. DePhilip, TNC, Pennsylvania

Jeanmarie A. Haney, TNC, Arizona

Rodney R. Knight, USGS, Tennessee

Dr. Julie K.H. Zimmerman, TNC, Maryland

International Environmental Water Allocations ConferencePort Elizabeth, South AfricaFebruary 25, 2009

APPLICATIONS OF THE ECOLOGICAL LIMITS OF HYDROLOGIC ALTERATION

(ELOHA) IN THE UNITED STATES

Step 1. Hydrologic Foundation

SCIENTIFIC PROCESS

Monitoring

AcceptableEcological Conditions

SocietalValues and

Management Needs

Implementation

SOCIAL PROCESS

Adaptive Adjustments

Flow Alteration-Ecological Response Relationships

by River Type

Stream Hydrologic

Classification

Degree of HydrologicAlteration

Hydrologic Alteration

by River Type

BaselineHydrographs

DevelopedHydrographs

Ecological Data and Indices

Environmental Flow Standards

Hydrologic Modeland Stream Gauges

Flow - EcologyHypotheses

Geomorphic Stratification

Step 4. Flow-Ecology Relationships

Step 3. Flow Alteration

Step 2. Stream Classification

Hydrologic Foundations

Michigan Water Withdrawal Assessment Tool

Texas Water Availability Model (WAM)

Virginia’s OASIS, HSPF

CALSIM, Sacramento Ecological Flows Tool

Colorado DSS, Watershed Flow Evaluation Tool

Massachusetts Sustainable Yield Estimator – Modified QPPQ

MassachusettsSustainable Yield Estimator

Step 1. Hydrologic Foundation

SCIENTIFIC PROCESS

Monitoring

AcceptableEcological Conditions

SocietalValues and

Management Needs

Implementation

SOCIAL PROCESS

Adaptive Adjustments

Flow Alteration-Ecological Response Relationships

by River Type

Stream Hydrologic

Classification

Degree of HydrologicAlteration

Hydrologic Alteration

by River Type

BaselineHydrographs

DevelopedHydrographs

Ecological Data and Indices

Environmental Flow Standards

Hydrologic Modeland Stream Gauges

Flow - EcologyHypotheses

Geomorphic Stratification

Step 4. Flow-Ecology Relationships

Step 3. Flow Alteration

Step 2. Stream Classification

River Classification

MICHIGAN, USA Seelbach et al

Hydrology-based

Define flow-ecology response curves for types of rivers

USGS Hydroecological Integrity Assessment

Process (HIP)

New Jersey, USA

Kennen et al (2007)

Flow Components

MAGNITUDE (3):

Average, High, Low

FREQUENCY (2):

High, Low

DURATION (2):

High, Low

TIMING (2):

High, Low

RATE OF CHANGE (1)

Step 1. Hydrologic Foundation

SCIENTIFIC PROCESS

Monitoring

AcceptableEcological Conditions

SocietalValues and

Management Needs

Implementation

SOCIAL PROCESS

Adaptive Adjustments

Flow Alteration-Ecological Response Relationships

by River Type

Stream Hydrologic

Classification

Degree of HydrologicAlteration

Hydrologic Alteration

by River Type

BaselineHydrographs

DevelopedHydrographs

Ecological Data and Indices

Environmental Flow Standards

Hydrologic Modeland Stream Gauges

Flow - EcologyHypotheses

Geomorphic Stratification

Step 4. Flow-Ecology Relationships

Step 3. Flow Alteration

Step 2. Stream Classification

Snohomish River basin, USA

Geomorphic Sub-Classification

Higgins et al (2003)

Snohomish River basin, USA

Geomorphic Sub-Classification

Higgins et al (2003)

Step 1. Hydrologic Foundation

SCIENTIFIC PROCESS

Monitoring

AcceptableEcological Conditions

SocietalValues and

Management Needs

Implementation

SOCIAL PROCESS

Adaptive Adjustments

Flow Alteration-Ecological Response Relationships

by River Type

Stream Hydrologic

Classification

Degree of HydrologicAlteration

Hydrologic Alteration

by River Type

BaselineHydrographs

DevelopedHydrographs

Ecological Data and Indices

Environmental Flow Standards

Hydrologic Modeland Stream Gauges

Flow - EcologyHypotheses

Geomorphic Stratification

Step 4. Flow-Ecology Relationships

Step 3. Flow Alteration

Step 2. Stream Classification

Fra

ser

Riv

er

Eng

elw

ood

Ran

ch S

yste

m

St.

Lou

is C

reek

Vas

que

z C

reek

Na

tive

Mai

n R

anch

Cre

ek

Elk

Cre

ek a

nd

Trib

utar

ies

Deg

ree

of

alte

rati

on

1-day minimum Extreme low flow duration 1-day maximum Small flood frequency Small flood duration Mean monthly flows

Natural

Minimal

Moderate

Strong

Diversion

Computing Hydrologic Alteration

Fraser River Basin, Colorado

Step 1. Hydrologic Foundation

SCIENTIFIC PROCESS

Monitoring

AcceptableEcological Conditions

SocietalValues and

Management Needs

Implementation

SOCIAL PROCESS

Adaptive Adjustments

Flow Alteration-Ecological Response Relationships

by River Type

Stream Hydrologic

Classification

Degree of HydrologicAlteration

Hydrologic Alteration

by River Type

BaselineHydrographs

DevelopedHydrographs

Ecological Data and Indices

Environmental Flow Standards

Hydrologic Modeland Stream Gauges

Flow - EcologyHypotheses

Geomorphic Stratification

Step 4. Flow-Ecology Relationships

Step 3. Flow Alteration

Step 2. Stream Classification

Verde RiverVerde River Flow-Ecology Hypotheses

Verde River basin, Arizona

Haney et al (2008)

Flow-Ecology Hypotheses – Verde River, Arizona

HYDROLOGIC VARIABLE

ECOLOGIC VARIABLE

SPECIES

Depth to water table Health/vigor Riparian vegetation, beaver, riparian birds

Relative abundance Goodding willow

Areal extent Marsh, wading birds

# of no-flow days/year

Abundance/diversity Aquatic invertebrates

Percent of average historic base flow

Population size Native fish and garter snake

Recruitment Spikedace

Response Fish species biomass and diversity

Predation Lowland leopard frogs

Step 1. Hydrologic Foundation

SCIENTIFIC PROCESS

Monitoring

AcceptableEcological Conditions

SocietalValues and

Management Needs

Implementation

SOCIAL PROCESS

Adaptive Adjustments

Flow Alteration-Ecological Response Relationships

by River Type

Stream Hydrologic

Classification

Degree of HydrologicAlteration

Hydrologic Alteration

by River Type

BaselineHydrographs

DevelopedHydrographs

Ecological Data and Indices

Environmental Flow Standards

Hydrologic Modeland Stream Gauges

Flow - EcologyHypotheses

Geomorphic Stratification

Step 4. Flow-Ecology Relationships

Step 3. Flow Alteration

Step 2. Stream Classification

3

3.5

4

4.5

5

0.05 0.20 0.35 0.50 0.65 0.80 0.95

Withdrawal Index

Hils

enho

ff B

iotic

Inde

x (H

BI)

25 mi2 basin100 mi2 basin500 mi2 basin1000 mi2 basin

Flow-Ecology Relationships

Ceilings and floors: Invertebrates, western United States

(Konrad et al, 2008)

Dependence on catchment size: Invertebrates, Pennsylvania (Apse

et al, 2008)

Step 1. Hydrologic Foundation

SCIENTIFIC PROCESS

Monitoring

AcceptableEcological Conditions

SocietalValues and

Management Needs

Implementation

SOCIAL PROCESS

Adaptive Adjustments

Flow Alteration-Ecological Response Relationships

by River Type

Stream Hydrologic

Classification

Degree of HydrologicAlteration

Hydrologic Alteration

by River Type

BaselineHydrographs

DevelopedHydrographs

Ecological Data and Indices

Environmental Flow Standards

Hydrologic Modeland Stream Gauges

Flow - EcologyHypotheses

Geomorphic Stratification

Step 4. Flow-Ecology Relationships

Step 3. Flow Alteration

Step 2. Stream Classification

CONNECTICUT

Class 1 – Natural

Class 2 – Near Natural

Class 3 – Ecologically Sufficient

Class 4 – Ecological Non-Attainment

MAINE

Class AA – Outstanding natural resource for preservation

Class A – Habitat for fish and other aquatic life is natural

Class B – Habitat for fish and other aquatic life is unimpaired

Class C – Habitat for fish and other aquatic life exists

Ecological Goal Classes

Connecticut River tributary

Penobscot River, Maine

Step 1. Hydrologic Foundation

SCIENTIFIC PROCESS

Monitoring

AcceptableEcological Conditions

SocietalValues and

Management Needs

Implementation

SOCIAL PROCESS

Adaptive Adjustments

Flow Alteration-Ecological Response Relationships

by River Type

Stream Hydrologic

Classification

Degree of HydrologicAlteration

Hydrologic Alteration

by River Type

BaselineHydrographs

DevelopedHydrographs

Ecological Data and Indices

Environmental Flow Standards

Hydrologic Modeland Stream Gauges

Flow - EcologyHypotheses

Geomorphic Stratification

Step 4. Flow-Ecology Relationships

Step 3. Flow Alteration

Step 2. Stream Classification

ImplementationMichigan Water Withdrawal Assessment

Tool1.0

0.9 -

0.8 -

0.7 -

0.6 -

0.5 -

0.4 -

0.3 -

0.2 -

0.1 -

0.0

Pro

port

ion

of i

niti

al f

ish

p

opu

latio

n m

etr

ic

Proportion of index flow removed

0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0

“Adverse resource impact”

EC

OLO

GIC

AL

CO

ND

ITIO

N

ENVIRONMENTAL FLOW STANDARD

Flow-ecology

relationship

0.97

0.26

Streams

Cold

Cool

Warm

Lg. RiversSm. Rivers

ColdTrans.

0

0.2

0.4

0.6

0.8

1

0 0.25 0.5 0.75 1

0

0.2

0.4

0.6

0.8

1

0 0.25 0.5 0.75 1

0

0.2

0.4

0.6

0.8

1

0 0.25 0.5 0.75 1

0

0.2

0.4

0.6

0.8

1

0 0.25 0.5 0.75 1

0

0.2

0.4

0.6

0.8

1

0 0.25 0.5 0.75 1

0

0.2

0.4

0.6

0.8

1

0 0.25 0.5 0.75 1

0

0.2

0.4

0.6

0.8

1

0 0.25 0.5 0.75 1

0

0.2

0.4

0.6

0.8

1

0 0.25 0.5 0.75 1

0

0.2

0.4

0.6

0.8

1

0 0.25 0.5 0.75 1

0

0.2

0.4

0.6

0.8

1

0 0.25 0.5 0.75 1

0

0.2

0.4

0.6

0.8

1

0 0.25 0.5 0.75 1

Proportion of index flow removed

Pro

po

rtio

n o

f in

itia

l fis

h p

op

ula

tio

n m

etri

c Source: Michigan Groundwater Conservation Advisory Council

ImplementationMichigan Water Withdrawal Assessment

Tool

Flow-Ecology Relationships

ELOHA ToolboxELOHA Home Partners Contact Us Case Studies Bibliography

Hydrologic Foundation River Types Flow Alteration Policy Implementation

Ecological Limits of Hydrologic Alteration (ELOHA) is a scientifically robust and flexible framework for assessing and managing environmental flows* across large regions, when lack of time and resources preclude evaluating individual rivers. ELOHA systematically translates understanding of the ecological ramifications of human-induced streamflow alterations from rivers that have been studied to rivers that have not, without requiring detailed site-specific information for each river.  In numerous case studies worldwide, water managers, policy makers, stakeholders, and scientists with diverse expertise are using ELOHA to accelerate the integration of environmental flows into regional water resource planning and management. 

ELOHA consists of the following steps, as illustrated in the framework flow chart (in English and Spanish):

Building a hydrologic foundation of daily streamflow hydrographs representing at least two conditions – baseline (pre-development) and present-day – for a single time period for every analysis point within the region Classifying river types according to hydrologic and other characteristics Computing flow alteration from baseline conditions at every analysis point Determining flow-ecology relationships that quantify biological responses to different degrees of hydrologic alteration for each river type, based on existing biological and related data and models. Implementing policies to maintain and restore environmental flows through a social process involving stakeholders and water managers informed by the flow-ecology relationships. The scientific basis for ELOHA was published in 2006 by an international group of river scientists (Arthington et al 2006).  Practical guidelines for its application have been developed by consensus of leading international environmental flow experts (Poff et al 2009).

Among the resources found on the ELOHA toolbox are:• 4-page ELOHA brochure in English, Spanish, and Vietnamese • PowerPoint with notes explaining ELOHA step-by-step, illustrated with examples from around the world• List of multidisciplinary expertise needed to carry out ELOHA (or any comprehensive environmental flow* assessment).• Case studies illustrating the various steps of ELOHA• ELOHA project database of cooperating agencies, costs, funding sources, timelines, and other attributes of selected ELOHA applications that are underway • Sample proposals from ELOHA projects that have been funded• Bibliography of useful reports and articles

* Environmental flows are the amount and timing of water flows required to maintain the species, functions, and resilience of freshwater ecosystems and the livelihoods of human communities that depend on those healthy ecosystems.

Welcome to the ELOHA Toolbox, an information resource to foster learning and communication about managing environmental flows over large regions

ELOHA framework

Building a Hydrologic Foundation

Classifying River Types

Computing Flow Alteration

Determining Flow-Ecology Relationships

Implementing Policy

Resources

• Get Started

Brochure in: English Spanish Vietnamese Flow Chart in: English Spanish

Journal Articles

PowerPoint

Expertise Needed

• Learn More

Case Studies

Project Database

Sample Proposals

Bibliography

Partners

Contact Us

Related Information

Global Environmental Flows Network

Instream Flow Council

Southern Instream Flow Network

Brisbane Declaration in: English Spanish

For further information:Dr. Eloise Kendy

Director, Environmental Flows ProgramThe Nature Conservancy

ekendy@tnc.org

http://conserveonline.org/workspaces/eloha

nutrient cycling