WHAT ARE ENVIRONMENTAL FLOWS?
Background and rationale
Jay O’Keeffe
WWF Professor of Freshwater Ecosystems
UNESCO-IHE,
Delft, The Netherlands
PURPOSE OF THE NEXT DAY AND
A HALF
•
•
•
•
To introduce the concept of environmental flows
To describe some of the assessment methods
To identify different regional requirements
To discuss the role of WWF in promoting
environmental flows
Environmental flows workshop, 11-12th March
11th March, Morning
09:00
10:00
11:00
11.15
12.30
13.30
What are environmental flows? Background and rationale
Assessment methods for rivers
Tea/coffee
Policy, legislation and social context for environmental flows
Case study – Rio Conchos
Lunch
(O’Keeffe, McClain)
(O’Keeffe)
(v d Heydon, Ombara)
(Arias, Barajas)
11th March, Afternoon
15:00
16.00
16.15
16.45
17:30
Case studies – Mara River,Kafue River
Tea/coffee
Case study – Rio Grande
Discussion – the need for environmental flows in different
regions, appropriate methods and implementation
Close.
(Ombara, McClain, Leenen)
(Bardwell)
(O’Keeffe, facilitator)
12th March, Morning
09:00
11.15
11.30
12:30
Practical assessment: Small groups apply the BBM to a site on the Rio Conchos
Tea/coffee
Discussion: Identify priorities for implementing
environmental flows in different river basins.
Training needs and the role of WWF
(Pittock/Kuiper, facilitators)
Close
About 0.3 m3sec-1
WHAT ARE ENVIRONMENTAL
FLOWS?
The quality, quantity and distribution of water
required to maintain the components, functions
and processes of aquatic ecosystems on which
people depend.
The process of assessing an EWA will require a
societal judgement about the state in which an
ecosystem should be maintained.
The quality, quantity and distribution of water
required for any aquatic ecosystem will depend
on the environmental objectives set for that
system.
WHAT ARE ENVIRONMENTAL
FLOWS?
The quality, quantity and distribution of water
required to maintain the components, functions
and processes of aquatic ecosystems on which
people depend.
The process of assessing an EWA will require a
societal judgement about the state in which an
ecosystem should be maintained.
The quality, quantity and distribution of water
required for any aquatic ecosystem will depend
on the environmental objectives set for that
system.
Rivers
Groundwater
Water quantity
and quality
Wetlands
Estuaries
Lakes
COMMON MISCONCEPTIONS
Environmental flow allocation:
• is water wasted water on bugs and fish
• is water for “The Ecology” in competition with water
for “Beneficial Uses”
• costs a lot to implement
• is designed to maintain rivers in a natural condition
Environmental flows are all about balancing
sustainable use and protection of water resources
Very small gains
100
Economic
gain
Very
rapid
Increase
%
Large
gains
Environmental
degradation
Low env. costs
0
100
Last 30%
% MAR abstracted
0
First 30%
GOODS & SERVICES
COMMERCIAL
FOREST
MINING
WATER ABSTRACTION
CHANNEL MODIFICATION
HISTORICAL
WATER QUALITY
TEMPERATURE
IRRIGATION
SEASONAL CHANGES
SENSE OF
PLACE
MEDICAL
PLANTS
FLOOD
CONTROL
SUBSISTENCE
GOODS
RECREATION
& TOURISM
URBAN
WATER
SUPPLY
INDUSTRY
CULTURAL/
RELIGIOUS
ALIEN
PLANTS &
ANIMALS
SEWAGE
HEALTH
ISSUES
1O PRODUCTION
WATER RESOURCE CLASSIFICATION
Natural
Good
Fair
Protected
Good
Fair
Poor
Unacceptable
Questions that have to be answered to
provide realistic Environmental Water
Requirements:
“What was the system like?”
Reference Conditions
“What is it like now?”
Present Ecological State
“What condition would we like it to be in?”
Classification and Objectives
“What flows and water quality are necessary to make or keep
it as we would like it to be?”
Assessment of EWA
“How important is it?” (to achieve the
environmental objectives)
Ecological Importance and Sensitivity
“How much will it cost if the environmental
objectives are not met?”
Cost/benefit Analysis
“How can the required flows be provided?”
Implementation
“How will we know whether the objectives
are being achieved?”
Monitoring
How do you go about assessing
the water quantity necessary
for a river?
LOCAL SCALE PROCESSES
RIPARIAN ZONE
WETLANDS
VELOCITY
FLOODPLAIN
DEPTH
COVER
SEEPAGE
HYPORHEOS
WETTED PERIMETER
1° PROD & DECOMPOSITION
TEMPORAL VARIATION
SEDIMENTATION &
FLOOD
SCOURING
WET SEASON
VEGETATION
ENCROACHMENT
DRY SEASON
DROUGHT
A) RIVER FLOWING THROUGH A CONSERVATION AREA
F
L
O
W
Natural flows
Environmental flows
ONE YEAR
B) RIVER FLOWING THROUGH AN URBAN AREA
F
L
O
W
Natural flows
Environmental flows
ONE YEAR
C) A SPRING-FED RIVER (LESS VARIABLE FLOW)
F
L
O
W
Natural flows
Environmental flows
ONE YEAR
D) A TEMPORARY RIVER (NO FLOW IN THE DRY SEASON)
Natural flows
F
L
O
W
Environmental flows
ONE YEAR
GENERIC TYPES OF
ASSESSMENT
METHODOLOGY
•
•
•
•
•
•
•
•
Hydrology-based/Look-up table approaches
Extrapolation approach
Hydraulic rating methodologies
Habitat simulation methodologies
Holistic methodologies
“See what happens” method
“Upside down” instream flows approach
Burden of proof (Impairment of the public trust)
HYDRAULICS
Velocity, Depth,
Substrate
ECOLOGY
HYDROLOGY
Flows in m3/sec
The Engineer
Habitat types
Ecological processes
Indicator species
The Ecologist
Some Lessons:
Balance user and
environmental functions
Set environmental
objectives/limits
Learn to judge how far
water resources can be
used before those limits
are exceeded
Increase efficiency of water
supply and sanitation
Value ecosystem functions
For all three of these reports, go to ftp.ihe.nl.
The username and password are both ftpftp.
Open folder Jay and download the reports.
http://www.waterandnature.org/flowlaunch.html
http://www.rivers.gov.au/publicat/research.htm
Then click on:
Environmental water allocation: principles, policies and practices
King JM; Tharme R; De Villiers MS (2000)
Environmental flow assessments for rivers: Manual for the
building block methodology. TT131/00.
From:
The Water Research Commission,
Private Bag X03, 0031 Rietfontein,
Pretoria, South Africa
Contact Numbers:
Telephone: +27-12-330-0340
Fax: +27-12-331-2565
Wet Season
Dry Season
25
20
15
10
5
0
0
5
10
15
20
25
Hydrological Index
Figure 2
Flow requirements for drought years for all ecological
categories
30
3
( m
)
IFR 2 : SKIETDRIFT - 1.48 m /S
2
E le v a tio n
1.8
1.6
1.4
1.2
1
0.8
0.6
0.4
0.2
0
10
20
30
40
Chainage (m)
50
60
70
3
IFR 14 : Lower Buffalo 0.68 m /S
RDM protocols
1. INITIATE RDM STUDY
- STUDY AREA
- RDM LEVEL & COMPONENTS
- STUDY TEAM
Project
scope
RDM level
Rapid I, II, III
Intermediate
Comprehensive
?
Reserve Components
Rivers, Groundwater,
Estuaries, Wetlands
Cost/Confidence
analysis
System operation
2. DEFINE RESOURCE UNITS
Select IFR sites
3. DEFINE ECOLOGICAL
CATEGORIES (EC) AND
RECOMMEND
4. QUANTIFY ECOLOGICAL
WATER REQUIREMENT
(EWR) SCENARIOS
Geomorphological
zonation
EC Classification
Reference conditions
Present Ecological State
Trajectories of change
Ecological Importance and Sensitivity
Socio/Cultural Importance
Constraints
(EC specialist meeting)
Apply Process
(BBM, Stressor Response, DRIFT)
(IFR specialist meeting)
Ecoregions
Stakeholder Process
Capacity building
Empowering
Data Organisation
Collate existing data
Collect additional info
Analyse info
4. QUANTIFY ECOLOGICAL
WATER REQUIREMENT
(EWR) SCENARIOS
5. ECOLOGICAL
CONSEQUENCES OF
OPERATIONAL SCENARIOS
(quantity & quality)
YIELD CONSEQUENCES OF
RESERVE
Data Organisation
Collate existing data
Collect additional info
Analyse info
Apply Process
(BBM, Stressor Response, DRIFT)
(IFR specialist meeting)
Define operational
scenarios
Provide resource
economic consequences
Catchment
System Analysis
Integration BHN &
Reserve
components
Yield & stakeholder
requirements,
operational constraints
Stakeholder process
Scenario implications &
assessment
6. DWAF MANAGEMENT
CLASS DECISION MAKING
PROCESS
7. RESERVE SPECIFICAION
8. IMPLEMENTATION
DESIGN
IMPLEMENT &
MONITOR
Information on categories
other than Ecological, i.e.
domestic use, irrigation,
recreation etc
Ecospecs (ecological
component of RQO)
Implementation methods
and operating rules for
Reserve
RQO
Monitoring protocols
Monitoring DSS, Baseline,
Compliance monitoring