United Nations
Commission on Sustainable Development

Background Paper

                                EXPERT GROUP MEETING



                                 27 - 30 January 1998

                                  Harare, Zimbabwe




                                   Paper No. 18

                                  Prepared for the
                       Department of Economic and Social Affairs
                                   United Nations



         Current ideas regarding Integrated Water Resources
         Management (IWRM) recognize the limitations of supply
         driven water management approaches. Within IWRM, ecosystems
         are seen as important users that need water for their
         maintenance. Although they are seen as important users
         their role as providers of water resources and other goods
         and services is paid little attention to. However,
         ecosystems such as head waters, forests, wetlands,
         floodplains, riparian zones and coastal areas provide
         regulation, habitats, resources and information to
         human society and regulate water resources. 

         An Ecosystem Based Management Approach is
         presented that secures the water resources and
         maintains ecosystem functioning and
         consequently services and goods ecosystems
         provide. This approach aims to meet human
         requirements for the use of freshwater, whilst
         maintaining hydrological and biological
         processes and biodiversity that are essential
         for the functioning of ecosystems, the
         sustainable use of water resources and the
         maintenance of services and goods provided by
         ecosystems. The implementation of this
         approach is based on four principles: a)
         improving the assessment of water resources
         and ecosystem functions, b) strengthening the
         capacities to manage water resources at
         different levels, c) improving communication
         through establishing partnerships and, d)
         adapting policy and planning to included an
         equitable sharing of costs and benefits and
         wise use practices. The Ecosystem Based
         Management Approach is recommended as the most
         appropriate strategy to meet current and
         future water demands in a sustainable way.

1. Introduction

The direct economic value of water as a resource, for domestic use,
agriculture and industry, and the economic value of the most obvious
goods that it provides, such as fish, are appreciated world wide.
Consequently, freshwater management strategies have typically been
geared to the maintenance of supplies of water and these tangible
goods.  Until th 1980s, the approaches taken to secure the
availability of water and goods were mostly sub-sector based and
tailored according to supply driven principles with little
consideration of competition for scarce resources between different
users. The Integrated Water Resources Management (IWRM) approach
that is advocated most recently has recognised the limitation of
this approach. In response, it specifically considers the
interactions between all components of water resources and water
resource users, and is mainly inter-sectoral and demand driven.
There is a growing consensus that the IWRM approach could provide
a way out of the gridlock that currently faces water resources
management and could also have the potential for developing
strategies for sustainable water resources management (NEDA, 1997;
GWP, 1997).

Within the current ideas of IWRM, ecosystems are seen as important
water users that for their maintenance need water that cannot be
used for other purposes. The use of water resources to maintain
freshwater ecosystems includes e.g. the use of water to maintain
wetlands, the use of water to maintain minimal river flows, and the
use of water to maintain seasonal inundations. Although ecosystems
have now been recognised as important users of water, little
attention has been given to their vital role as providers and
regulators of water resources. In addition, little consideration has
been given to the other services and goods ecosystems provide, such
as flood regulation, biodiversity conservation, fish and firewood.
However, it is of fundamental importance to the longer
term availability and sustainable management of water
resources that the maintenance of ecosystems and the
strengthening of their role as providers of services and
goods is recognised (Laanbrock et al., 1996).

In this paper the relationship between the functioning of freshwater
ecosystems and the services and goods they provide will be discussed
to substantiate and exemplify this. Based on these considerations,
an Ecosystem Based Management Approach is presented that harnesses
the functioning of ecosystems and the sustainable management of
resources, services and goods they provide. The approach is based
on four components: monitoring resources, strengthening capacities,
improving communication, and adapting the planning process and
policy. These components will be discussed in more detail. Finally,
recommendations considering the valuation of functions and services
provided by ecosystems and the actions required to improve the
monitoring of these functions will be given.

2     Functions and values of water based ecosystems

2.1   The traditional approach to water management

People need water to drink, grow and prepare food and provide power
for domestic and industrial use.  These are the direct or obvious
uses of water, and policy makers are traditionally driven to manage
water to provide people with water for these purposes.  In view of
the unprecedented rise in human population (from 2.8 billion in 1955
to 5.3 billion in 1990), and the prediction that by 2025 as many as
1,100 million people will suffer severe water stress (Engleman and
LeRoy, 1993; Falkenmark, 1989), it is not surprising that
governments and water resource managers constantly seek to maximise
the volume of water available for direct use.
Consequently, traditional management plans for water resources
divert water from original stores and pathways to new stores and
pathways that supply it to people for direct use. Groundwater is
extracted from stores in aquifers. Artificial dams and reservoirs
are created to hold water in convenient locations to supply large
populations with power and water. River channels are dredged,
straightened, isolated from their floodplains and wetlands, forests
are removed from river catchments in efforts to speed water across
the landscape to points of consumption. In some cases water is
channelled so efficiently for direct use that rivers run dry before
they reach the sea.

In view of society■s need for water for basic goods provided through
agriculture, industry and domestic services, and the highly
successful attempts to channel water to meet that demand, the idea
that water should be used to support ecosystems rather than
withdrawn to support people, may be seen as extravagant and
wasteful. Allowing rainfall to "run away" into underground aquifers,
be absorbed by soil or taken up and released into the atmosphere by
forests, might appear as bad management of the water resource.
Indeed as holders and consumers of water, the landscape and plants
and animals can appear as direct competitors with people for water
use.  However, although it is true that ecosystems may lock up
water, for example in wetlands or aquifers, and plants and animals
consume water which can not then be used for direct use by people,
■expending■ water in this way may per unit volume, provide greater
benefits to people than those provided by directly using it for
agriculture, industry or domestic use.  How can allocating water to
the ■environment■ provide benefits to people?  How can society weigh
these benefits against those provided through agriculture, industry
or domestic use? How can society decide on a strategy of allocation
that will obtain the maximum benefits for the maximum number of
people over the maximum period of time?

The first step is to appreciate the "hidden" benefits provided to
people by the environment which requires water for its support. In
holding or consuming the water, ecosystems maintain hydrological and
biological processes which determine how the environment functions.
How the environment functions determines which services the
environment provides to people. To explain what these processes,
services and goods are, we will describe how water is ■used■ by
ecosystems and what benefits the environment provides to people in
return, both in terms of water resources and services and goods.

2.2 Ecosystems as providers of water resources and key-functions

Water forms an essential element for sustaining life on earth. As
water travels from moutains to the sea, proportions are used along
the way to support the various ecosystems and maintain their
functioning. In return for this expenditure of water, the
hydrological and biological processes of the ecosystem enable the
ecosystems to provide several functions to people both throughout
the catchment and globally.  Ecosystem functions are defined as ■the
capacity of natural processes and components of natural or semi-
natural systems to provide services and goods that satisfy human
needs (directly or indirectly) (De Groot 1992). Generally, ecosystem
functions are grouped into four cateregories (after De Groot 1992):
regulation functions, habitat functions, production functions and
informations functions.

Ecosystems as providers of regulation

Ecosystems function both as regulators of water quantity and water
quality. Several types of ecosystems are known to act as
hydrological buffers, absorbing water to prevent flooding and
releasing it in times of drought. Providing this service increases
the quantity of water and protects downstream communities from flood
and drought. For example, cloud forests in La Tigra National Park
(Honduras) sustain a well-regulated, high quality water flow
throughout the year, yielding over 40% of the water supply of  the
capital city (Acreman and Lahmann, 1995). 
In a slightly different way, wetland ecosystems are able to reduce
rates of water flow and store water above the surrounding water
table (for example in a raised bog). The vegetation and hydrology
enables the wetland ecosystem to function as a ■sponge■ and provide
the services of flood prevention and water storage. The value of
these services may be considerable. Often technical alternatives to
regulate the quantity of flow are much more expensive. New York
City, for example, spends only 10% of the costs of building water
treatment facilities (US$7 billion) to ensure its water supply
through the protection of the biological and hydrological processes
of the upper parts of the catchment on which the water supply is
depending (Abramovitz, 1997). 
Ecosystems also regulate the quantity of water resources through
taking up water and releasing it into the atmosphere.  rain forest
tree, for example, can pump 2.5 million gallons of water into the
atmosphere during its lifetime (Ehrlich and Ehrlich, 1992) of which
most is recycled and not lost from the forest. In the Amazon
rainforest, 50% of rainfall is derived from local evaporation. After
forest cover is removed an area can become hotter and drier because
water is no longer cycled between plants and the atmosphere.  This
can lead to a positive feedback cycle of desertification, with an
increasing loss of local water resources (Gash et al, 1996). 

Results of computer simulations have confirmed these feedbacks play
an important role in determining local climate. A global circulation
simulation model predicted that if the Amazon tropical forest and
savannah was replaced with pasture land, the climatic consequences
would included a weakened hydrological cycle, less precipitation (-
26%) and evaporation and an increase in surface temperate due to
changes in albedo and roughness (Shukla et al, 1990; Lean and
Warrilow, 1989). Similarly, modeling the removal of natural
vegetation in the Sahelian region of Africa predicts that rainfall
would be reduced by 22% between June and August and the rainy season
would be delayed by half a month (Xue and Shukla, 1993). These two
examples show that forest ecosystems function as water recycling
systems. In return for the water they use, they provide the service
of regulating both local and global climate and maintaining local
water resources.

Ecosystems not only regulate the quantity of water flow but also
regulate the quality of the flowing water. On sloping ground, for
example, vegetation anchors soil and prevents it from being washed
into the water course where it would cause siltation and
nutrification and reduce light penetration. This would reduce water
quality, the health of aquatic ecosystems and the suitability of the
water for aquaculture and other uses.  The physical structure of
water courses and the organisms that inhabit it also regulate water
quality. For example, waterfalls, rapids and aquatic vegetation
oxygenate the water, and river banks, river beds and vegetation trap
sediment. These hydrological and biological processes enable the
water course to function as a water purification unit providing
fresh water.

Freshwater wetland ecosystems are also known as important water
quality regulators.  Within these systems toxins and excessive
nutrients are removed from the water both by processes of
decomposition and uptake by vegetation (Baker and Maltby, 1995). As
wetlands hold water for long periods of time, decomposition
processes and vegetation are given enough time to remove nutrients
and toxins from the water. For example, vegetation found in the
Melaleuca wetlands in SE Asia reduces the acidity of polluted water
and removes toxic metal ions making the water suitable again for the
irrigation of rice (Ni et al., 1997).  In this way, the combination
of hydrological and biological processes allows wetlands to function
as filtration and purification systems and to provide the service
of water purification.

Coastal wetlands systems, such as saltmarshes and mangroves, also
function as buffers and regulators of water quality (Koch et al.,
1992). These systems provide a physical and hydrological buffer
between marine and freshwater, while their vegetation removes
sediment and nutrients from the freshwater before it flows into the
sea. This process allows the coastal wetland to function as a final
freshwater filter, providing the service of protecting coastal
marine resources, such as coral reefs or seagrass beds from sediment
deposition. Coastal wetland vegetation absorbs the energy of winds
and waves from the sea, a process that enables the wetland to
function as a barrier against saltwater intrusion, marine floods,
erosion and wind damage and provide the service of protecting
coastal land resources. In recognition of the protective function
of the mangrove forest of the uncleared Sundarbans forest of
Bangladesh and India, the Bangladesh government have planted and
replanted mangroves to protect embankments and new land (Saenger et
al., 1983).

Ecosystems as providers of habitats

Floodplains, wetlands, river courses and headwaters of catchments
are important for the regulation of water resources. Sustaining the
functioning of these ecosystems to keep them providing the
regulation service requires the maintenance of many biological
processes. These processes are often extremely complex and depend
on the maintenance of these areas as habitats for many species of
plants, fish, birds and others animals. For example, wetlands in
semi-arid and arid areas are known as prime areas for biodiversity
conservation and as important nursery and feeding areas for many
aquatic and terrestrial migratory species. Wetlands are particularly
important for aquatic species whose young require low water flow
rates. Consequently wetland ecosystems can provide the service of
maintaining fish and shrimp fisheries.

River courses are also important habitats. The vegetation, banks and
bottom of wild water courses provide shelter and food for a large
variety of animals. In contrast to wetlands, water courses function
as habitat for animals that require fast flowing oxygen rich water,
and consequently provide the service of maintaining fisheries.
Together, freshwater ecosystems support important biodiversity,
including over 10,000 species of fish and over 4,000 of amphibians
described sofar (McAllister et al., 1997; WCMC, 1992).

Coastal wetlands are also important providers of habitats. They
provide food and shelter for marine animals that require freshwater
conditions for part of their life-cycle.  Consequently, coastal
wetlands function as habitat for o.a. crabs, oysters and shrimp, and
provide the service of supporting fisheries based on these goods.
For example, 90% of the fish harvest of the gulf of Mexico, worth
US$700 million per year, consists of species which are dependent
upon the mangroves and coastal wetlands of the region at some stage
in their life cycle (Dugan, 1990).

Ecosystems as providers of resources

Many water based ecosystems provide large quantities of water, food
and energy for direct human consumption, agriculture, fisheries,
watering livestock, industry and energy production. Water supply in
many rural areas within or near wetlands depend largely on water
extracted from shallow boreholes. The aquifer these boreholes tap
is often recharged directly from the extensive wetland. 

Harvesting wetland ecosystem goods while respecting the production
rate and the regenerative capacity of each species can generate
great benefits to human society. One of the most important products
of wetland ecosystems is fish. In many areas the fishing industry
related to wetland ecosystems forms a fundamental pilar of the local
and national economy. Direct harvest of forest resources of many
wetlands and floodplains yields a number of important products,
ranging from fuelwood, timber and bark to resins and medicines which
are common non-wood ■minor■ forest products (Dugan, 1990). Wildlife
rich wetlands also provide important commercial products such as
meat, skins, eggs and honey. Wetland and floodplain ecosystems often
contain substantial grasslands and forests that are grazed by
livestock and are important to pastoral communities. Leaves,
grasses, and seed pods are amongst the prime resources these systems
provide to these communities.  Wetlands also contain a large genetic
reservoir for certain plant species, fish and other animals. For
example, wild rice continues to be an important resource of new
genetic material used in developing disease resistance and other
desirable traits.

The importance of ecosystems as providers of many resources is very
often underestimated or neglected.  However maintaining their role
as providers of resources is of fundamental importance for the
sustainable development of human societies.

Ecosystems as providers of information 

Water based ecosystems provide many opportunities for recreation,
aesthetic experience and reflection. Recreational uses include
fishing, sport hunting, birdwatching, photography, and water sports.
The economic value of these can be considerable.  For example in
Canada the value of wetland recreation was estimated in 1981 to
exceed US$ 3.9 billion (Dugan, 1990). Maintaining the wetlands and
capitalizing on these uses can be a valuable alternative to more
disruptive uses and degradation of these ecosystems. They are
important repositors and stores of palaeontological information.
Under anaerobic conditions biological material such as pollen, and
diatoms and even human bodies can be preserved in peats and lake

It is up to society to decide how to allocate water to maximise the
benefits it provides to society as a whole. The problem is to decide
how much water should be used for the maintenance of ecosystems to
provide environmental goods and maintain elemental services and how
much water should be used to support agriculture, industry and
domestic services to provide basic goods. Obviously, the value that
society places on these alternative goods and services will
determine the pattern of allocation. It is important therefore that
the costs and benefits to society of allocating water to maintain
ecosystems and to support agriculture, industry and domestic uses
is well understood.

Techniques are now available to estimate the economic value of
specific biomes. Barbier et al. (1996), for example, have produced
guidelines for the economic valuation of wetland goods and services.
Costanza, et al. (1997) have attempted to calculate the economic
value of 17 ecosystem services for 16 biomes. They used these
estimates to determine a value of US$ 16-54 trillion per year (with
an average of US$33 trillion per year) for the value of the entire
biosphere. This is almost twice the global national product total
of US$18 trillion.

2.3 Negative effects of current water development practices

Management plans for water systems that focus solely on maximising
the quantity of water available for direct use typically only
consider costs and benefits of the project in these terms. For
example, the economic costs of labour and technology set against the
economic benefits of increased agricultural productivity or supply
of power. Diverting water from one pathway to another means that new
benefits from the water resource will replace old benefits. Society
needs to be sure that the new benefits are greater than those
provided by the water in its old pathway. It is essential that
societies can consider both the economic and the social and cultural
benefits of alternative allocation strategies and their
sustainability for future generations. If these considerations are
not made societies risk making less than the best use of their water
The economic benefits of using water to support fisheries,
agriculture and fuel wood in wetlands may be many times greater than
using it for intensive irrigation. However, these benefits may be
overlooked in water resource management plans, as in the case of the
construction of Tiga and Challowa Gorge dams on the Hadejia River
in Northern Nigeria. The dams reduced inundation of the Hadejia-
Nguru floodplains. Inundation is necessary to recharge the
groundwater which supplies well-water downstream and to some 100,000
people in the Komodugu-Yobe basin (Hollis et al., 1993). In respect
of the importance of this and other functions of the wetland, the
Nigerian authorities are making test releases of water from the
reservoirs to augment flooding of the wetlands (Acreman, 1994).

The social and cultural costs and benefits people receive from
different water allocation patterns are often less visible than
economic ones. Consequently the chief aim of hydrological management
has been to speed up economic development. In recent years the
construction of major dams is seen as a key component of this
strategy.  Dams store water when river flows are high and release
it when needed to supply power and irrigation to urban populations
and industry. In many parts of the world, dams have stimulated
economic growth and permitted intensification of agriculture,
increased yields.

However, in many cases dams have hastened removal or conversion of
riverine forests and other floodplain and wetland habitats and also
replaced the natural cycle of floods and low flows with a more
constant flow pattern related to electricity or irrigation demand.
These changes in water flow can lead to changes in the way
ecosystems dependent on that flow function, which in turn impacts
on societies dependent on these ecosystems. For example, two dams
were built in the Senegal River valley in 1986/7: the Diama dam near
the river mouth and the Manantali dam in the headwaters. The Diama
dam inhibits saltwater intrusion into the river to allow its use for
irrigation and regulating water levels to facilitate transport. The
Manantali dam was built to generate hydro-electric power and to
regulate flows in the river. In addition, embankments were
constructed along both banks of the river to prevent inundation. The
engineering works had many effects on the environment, some of which
created social problems in terms of increased health risk and loss
of productivity in agriculture and fisheries. The character of the
vegetation in the Djoudj National Park, adjacent to the river,
changed significantly as the dry season saline water intrusion into
the river was replaced by a regime of continuous freshwater. This
led to increased survival of snails and mosquitoes which carry
diseases. Before 1987 neither rift valley fever (a mosquito-borne
viral disease) nor human intestinal schistosomiasis (an aquatic
snail-borne worm parasite disease) had been recorded in West Africa.
Following construction of the Diama dam, 200 deaths from rift valley
fever were recorded and an 80% abortion rate among sheep and goats. 
In 1988, there was a 2% prevalence rate of schistosomiasis, by 1989
this had risen to 72%.  In addition, there was a 90% drop in the
productivity of the fisheries of the Senegal delta which relied on
inputs of freshwater from upstream (Verhoef, 1996).

Cultural costs of construction of the same dams include the loss
from society of traditional cultures adapted to the dynamics of the
Senegal River valleys floodplains.  Diversion of water from the
floodplains prevented the recharge of nutrient levels and
groundwater stores achieved by the previous regular flooding. Of
80,000ha of traditional grazing lands, only 4,000ha could still
support vegetation for grazing cattle. The society that had adapted
to the floodplains seasonal cycle were forced to abandon its
culture, and the knowledge base of that culture lost to society.

More recent thinking has tried to develop traditional approaches to
water management which have evolved over many years, often in
sympathy with the environment rather than against it. Flood
recession agriculture is a prime example, where flooding is seen as
a positive process, bringing fresh soil, nutrients, water and fish
to the floodplain. Floating rice is often grown during inundation
of African floodplains, and arable crops are planted in the wet soil
as the flood waters recede. Some soil moisture persists to the dry
season and provides essential grazing for migrant herds. Throughout
west Asia, much water is stored in alluvial cones at the base of
steep impermeable slopes. This has been exploited traditionally by
the excavation of tunnels, called kareses, from the alluvium
downslope towards the villages or agricultural land, with vertical
shafts every few hundred metres to provide water abstraction points.
Rather than develop this sustainable technique, many of the kareses
have now fallen into disrepair and replaced by boreholes directly
into deeper aquifers powered by electric pumps, which have permitted
over exploitation of the groundwater.

1.Maintaining ecosystem functioning using an ecosystem approach.

3.1 Maintaining ecosystem functioning 

As described above, the goods and services provided by an ecosystem
depend on how it functions. How it functions depends on what
hydrological and biological processes occur within it. Which
processes are performed depend upon which physical chemical and
biological components make up the system. These include the quantity
and type of plants, animals, microbes, soil and minerals. The
components that make up the system are dependent to a large degree
on the quantity and the quality and water moving in and out of the
system. This dependency originates mainly from sediment and
nutrients brought in by water entering an ecosystem, which bring
food for animals and maintains soil fertility for plants.

To maintain the functions and services of an ecosystem, both the key
components, and the quantity and quality of water flowing through
the ecosystem needs to be conserved.  For example, the vegetation
of "Melaleuca" forest in SE Asia will only be able to reduce the
acidity of water if the flow of water in and out of the ecosystem
is slow enough to give the process time to work. Similarly the
papyrus swamps in Uganda absorb sewage discharged from Kampala and
purify water supplies, but a certain quantity of water is required
within the ecosystem to allow the biological processes to take
place. The National Sewerage and Water Corporation recognises this
need and is ensuring enough water is allocated to the swamps to
maintain their functioning (Dugan, 1990).

Degradation of ecosystem components other than water also often
leads to changes in the ability of ecosystems to function and
provide services that benefit water resources. For example, forest
clearance has had a great effect on the water purifying service of
the North Selangor Peat Swamp forest (Khan, 1996). The 75,000
hectare swamp once performed the functions of water storage and
water purification, and provided one of the largest rice schemes in
Malaysia which borders it with the services of flood protection and
provision of high water quality. In recent years the forests have
been cleared for agriculture and tin mining.  The trees are no
longer present to retain soil, sediment, water and toxins.
Consequently, the swamp no longer provides the services to the rice
scheme.  It is forecast that further clearance would result in
significant water quality problems in the rice fields.

If society wishes to continue to benefit from the services an
ecosystem provides, it must ensure that both the key components of
the ecosystem, and the quantity and quality of water resources
within the ecosystem are maintained. Society also needs to consider
all the ecological, economic, social, cultural and political costs
and benefits of alternative management options. The fundamental
question is - How can societies decide how to manage water resources
and maintain key functions provided by ecosystems and balance the
need to support agriculture, industry, domestic use, and natural
goods and services? The only sustainable method is for the
stakeholders in the water resource to choose which benefits they
most want to receive from the water resource, and create a
management plan that provides these benefits. To make an informed
choice all stakeholders of the water resource need to appreciate
both the benefits water can provide through supporting agriculture,
industry and domestic life, and through supporting ecosystem
processes, functions and services. Stakeholders also need to
understand the choice of management actions available to maintain
those benefits, and the consequences the management actions would
have for alternative benefits.

3.2 What is an Ecosystem Based Management Approach?

An Ecosystem Based Management Approach approach aims to meet human
requirements for the use of freshwater, whilst maintaining the
biological diversity, hydrological and ecological processes
necessary to sustain the composition, structure and function of the
ecosystems that support human communities. It is a holistic approach
that considers all the relevant and identifiable (ecological and
economic, social, cultural and political) costs and benefits of
alternative management options to all stakeholders, and ensures that
the plan which is adopted is that which is most acceptable to all

3.3 Spatial and temporal scales of management

The appropriate spatial scale at which to apply ecosystem based
management depends upon the relative importance of the components
in the system, the scale of natural disturbances (e.g., fires,
landslides, floods), pertinent biological processes (e.g. disease,
foraging, reproduction) and dispersal characteristics and
capabilities of the component populations. The fundamental unit for
water-related management issues is normally the drainage basin, as
this demarcates a hydrological system, in which components and
processes are linked by water movement. Deforestation of headwater
catchments can, for example, affect water yield and frequency of
flooding downstream. Hence the term integrated river basin
management has developed as a broad concept which takes a holistic
approach at this scale. However, frequently the underlying aquifer
does not coincide exactly with the surface river basin. Thus, where
groundwater plays a significant role, a group of basins overlying
an aquifer may constitute the appropriate unit of water resource
Defining the temporal scales of an ecosystem based management,
short, intermediate and long term considerations need to be taken
into account. Many of today■s practices only consider short and at
best intermediate term availability en reliability of water
resources. Little attention is paid to the long term sustainability
of current practices. For example, mining of non-renewable
groundwater resources, that is unsustainable in the long term, is
practised in many dryland areas. Another example is the pollution
of infiltrated water that will percolate to groundwater at larger
time scales (100 - 10,000 years). The long term unsustainability
makes these practices inappropriate from many perspectives (National
Researach Council, 1997).
An Ecosystem Based Management Approach especially takes into account
the long term sustainability of practices. Although some options may
be more appropriate from a short time frame perspective, the
approach considers practises ■wise■ when they are sustainable and
thus both meet current and future demands and support ecosystems to
provide services and goods at the longer term.

3.4   Recognizing the importance of an Ecosystem Based Management Approach

The importance of an Ecosystem Based Management Approach is being
recognised, not just by the scientific and conservation community,
but also by international environmental instruments. For example,
the Convention on Biological Diversity is in the advanced stages of
formulating a work programme on inland water systems that recognises
the importance of adopting an ecosystem-based approach to achieve
the conservation and sustainable use of the biological diversity of
inland waters and the fair and equitable sharing of the benefits
these provide (UNEP 1997). Consequently the Secretariat of the CBD
is seeking to develop a ■modus operandi■ to assist Parties to the
CBD to implement an ecosystem based approach internationally,
regionally and locally.

In general, ecosystem management is still far from being
successfully implemented. The rate at which it is implemented, and
the success of that implementation depends largely on how well
international environmental instruments work together to advise
their often shared Parties. In view of the interdependency of
biological diversity and sustainable development it is particularly
essential that the Commission on Sustainable Development and the
Convention of Biological Diversity work together. Both are currently
considering the thematic area of fresh or inland water resources.
By joining with the CBD in advising Parties to adopt an ecosystem
approach as a Strategic approach for the sustainable management of
freshwater resources, the Parties of the CSD and the CBD will
continue to benefit from the close co-operation between the
Commission and Convention.

4. Implementing an ecosystem-based approach to the management
   freshwater resources

The importance of an ecosystem approach is beginning to be accepted.
International instruments are beginning to advise that countries
adopt it, but what advice is available to Countries on how to
implement an ecosystem-based approach to the management of
freshwater resources? Most of the questions that we can anticipate
countries asking fall into four categories. What are the extent of
the water resources and what ecosystem functions do they support? 
How can we achieve the capacity to design and implement an ecosystem
based management plan for water resources? How can the various
stakeholders in society communicate, and reach agreement over the
design and implementation of development projects? Is policy and
planning sufficiently based on a sufficiently diverse disciplinary
ground to support implementation of ecosystem based approaches to
the management of water resources? To ensure that we can answer
these questions we need to assess what is known, identify gaps in
the available information, and set about filling those gaps so that
high quality is advice is available to countries on demand.
4.1 Assessment of water resources and functions and values of

Monitoring of water resources

Effective management of resources can only be achieved if decisions
are based on sound information. Even in developed countries, where
there is a dense network of rainfall and river flow measurement
stations, the amount of water resources data is still limited and
considerable funds are being invested to develop methods of resource
assessment for un-gauged rivers. Furthermore, hydrological data on
slow flowing or static water bodies and terrestrial ecosystems are
very rare (Acreman and Hollis, 1996). It is therefore extremely
difficult at present to quantify the water resource used and
provided by many ecosystems.    We are still largely ignorant of
precisely how these ecosystems function in transforming hydrological
inputs into ecological, environmental and human goods and services.

With a projected increasing pressure on water resources there is a
large need to increase the monitoring of hydrological properties of
catchments. As part of water resource planning and management the
movement through and storage within key ecosystems must be
quantified to enable their crucial hydrological functions to be
assessed and used effectively. Water quantity measurement should
include rainfall, river flows, infiltration to grasslands,
interception and recycling of water within forests, storage of
floodwater, recharge of groundwater (within wetlands),  and extend
of annual flooding. Water quality measurements should include levels
of acidity, nutrients (nitrate, phosphate), pesticides, ammonia,
BOD, oxygen and heavy metals. Re-vitilising excisting measurement
networks and establishing new networks should be encouraged to
support these tasks.

Monitoring and valuing key-functions of ecosystems

Besides monitoring hydrological aspects, a sound ecosystem based
management needs to monitor the functions, services and goods that
ecosystems provide. In addition to one-off assessments of the
hydrological functions of ecosystems for planning purposes, data
collection must be continued through periodic monitoring to ensure
that the function continues and is not degraded. The frequency of
recording depends upon the variable being measured and the hydrology
of the river basin. 

To ensure a cost effective assessment of functions, indicators of
the performance of functions need to be developed. Currently these
indicators are being established for monitoring biodiversity but
these need to be expanded to include other functions of freshwater
To be able to select between different management options within a
IWRM approach, resources and functions provided by ecosystems need
to be economically valued. A recent valuation of environmental
services and goods provided by the world ecosystems has estimated
these to be US$ 4.5 billion (Costanza et al., 1997). Economic values
of ecosystems can be evaluated against economic benefits from
outputs under changed conditions. Decision makers will then be able
to base their decision on a balanced judgement of economic costs and
benefits of projected developments.

4.2 Strengthening capacities 

Transferring appropriate technology to local water managers and
regional planners

Current planning practices are often aimed at the implementation of
new technologies to improve water resources use. However, often
local knowledge and practices need not to be replaced or adjusted.
Therefore planners should consider both traditional and modern
technologies in the design and implementation of water projects. To
ensure balanced implementation of appropriate technologies,
capacities need to be build at the various levels ranging from the
regional planner to the individual stakeholder (Borrini Feyerabend
and Buchan, 1997; OECD, 1996). Whatever the level, institutions need
well-informed members who have an appreciation of the wide range of
issues facing water resource allocation.  Training is an essential
element, but training needs to vary with the type of institution. 
Professional technical advisors require formal training courses, for
example, on water resource planning and wetland management, whilst
local community representatives may be best trained with involvement
in local activities, such as participatory rural appraisal or
through visits to demonstration projects.

Furthermore, local circumstances should help determine the choice
of appropriate technology. Important in this respect is the change
to demand based management. To change demands appropriate
technologies and new methods for water conservation, recycling, and
maintenance or restoration of water quality need to be pursued. An
example of this is the development of non-water based sanitation
systems for arid and semi-arid areas. Selected technologies need to
be promoted through the use of on-farm trials, farmer-to-farmer and
women-to-women contacts, radio-programmes, posters etc. aiming at
a replication of successful initiatives.

Integration of management and development planning

The management of water resources takes place at many different
levels in society ranging from the individual farmer to communities,
districts and national water authorities. Most planning of
development occurs mainly outside the affected area at district or
national level both by national institutes and consultancy firms.
To change current practices communities should be involved in the
design and implementation of development projects (Borrini
Feyerabend and Buchan, 1997). Collaborative management agreements
between governments and local communities should be encouraged.
Under these agreements, communities assume responsibility for sound
management of local agro-ecosystems including their biodiversity in
return for the right to use water and involvement in river basin
management and planning. The design, implementation and evaluation
of water projects should benefit more from community participation.
To ensure community involvement in planning, a change in
institutions will be needed in many places. To facilitate this
change an assessment of current decision making strategies, internal
communication structures and organisational capacities of the
institutions involved can be a valuable first action.

Development of strategies for conflict resolution

With the rise in demands for the many uses of limited water
resources, conflicts concerning quantity, quality and allocation
will increase. Water related conflicts arise at levels ranging from
communities and districts to countries and regions. As freshwater
becomes more scarce, users and other stakeholders must reach a
consensus on individual needs, negotiate on solutions and
collaborate on long term conservation of water resources and
biodiversity. Involvement of all interested parties is essential in
the process of conflict resolution. 

Currently there is a need for strengthening the capacities for
conflict management at different levels (community, district,
national, international) (Borrini Feyerabend and Buchan, 1997). At
local, district and national levels, independent water commissions
should have the authority to arbitrate and adjudicate between water
users and should ensure equitable distribution of water-use rights.
Distribution patterns should support the long term conservation of
water resources and ecosystem functions, services and goods for
future generations. At the national and multilateral level
agreements on shared water resources should be negotiated. These
should encompass the current and future rights and responsibilities
of users of upstream and downstream surface water resources and
renewable and non-renewable groundwater resources.

4.3 Improving communication through establishing partnerships

Using multidisciplinary teams to ensure coherence in planning and

Traditional sector based planning and management is characterised
by a lack of co-ordinating the allocation of limited resources to
different users and harnessing the role of ecosystems as providers
of many services and goods. Important reasons for these are the
dominance of a single discipline in the supply-based planning and
management process and the underestimation of the many functions and
values of ecosystems. To ensure improved planning and management,
scientific and technical coherence should be advocated by the
involvement of multidisciplinary teams. These teams are to be
established at local, regional, national and international levels
and be aimed at communicating different perspectives on water
resources and building consensus on the conservation of water
resources and the maintenance of ecosystem functioning as the bases
for sustainable development.

Establishing inter-sectoral teams for development of policy and
planning tools 

Current initiatives on IWRM are encountering many new challenges for
which traditional sub-sector based solution are often inadequate.
The new problems are often less of a technical nature rather then
relate to the handling of a broad range of information sources, the
integration and synthesis of this information, reaching agreement
on facts, alternatives and solutions, the communication of the
synthesised information to a wide range of stakeholders and the
transformation of this information into adequate policies. To ensure
development of adequate policies and planning tools that support the
conservation of water resources and ecosystem functioning, inter-
sectoral teams need to be established. Within these teams, local
user groups should be represented to ensure both their input into
the planning process and the communication of outputs to individual

Setting-up multi-stakeholder teams for programme definition and co-

Local communities are the key-actors in the management of agro-
ecosystems and water resources as a part of these. An effective
communication with the local communities is required to learn from
their experiences and to integrate their views and aspirations into
development and management plans. Only with the involvement of local
groups plans and policies will be supported and adhered to and a
successful implementation be possible. Therefore, a considerable
effort should be put in organising local communities in resource
user groups with special attention to the formation of women groups
given their specific relation and responsibilities in water
resources utilisation and conservation. Empowerment of these user
groups through their representation in multi-stakeholder teams is
essential for the success of these initiatives. The multi-
stakeholder teams ensure that meaningful contacts will be
established amongst stakeholders and between stakeholders and
governmental organisations. The advantage will be that the views of
the various stakeholders can be better communicated to policy and
decision makers while development and management options can be more
easily communicated back to communities.

4.4 Adapting policy and planning 

Including environmental and economic costs, and sharing of costs and

Inappropriate water use can lead to considerable environmental and
economic costs. A loss of functions, services and goods through
decreased water inputs into aquatic ecosystems can lead to a sharp
decline of profits from these areas. Including the environmental and
economic costs of reduced flows into these ecosystems and other
inappropriate water uses into planning and policy making should be
promoted to improve the environmental and economic efficiency of
water use. Looking into the subsidies on water and especially their
negative effects on both economy and ecosystems could be a valuable
action within this realm.

Furthermore, large changes are expected in many areas in the amount
and distribution of domestic water use due to changes in lifestyle
and increased urbanisation. The impact on environment and rural
water use of these changes could be vast, given the need for more
water and infrastructure for storage and delivery. Changes in
lifestyle and population size and distribution should be
incorporated into water resources plans and policies. These should
be aimed at safeguarding the maintenance of equitable sharing of
water resources and the costs and benefits involved.

Promoting wise use, best practices and use of appropriate technology

Within a IWRM framework different options are available for the
allocation of water resources to the various users. The selection
of best IWRM practices should be based on a sustainable pattern of
water use, promote wise use of water resources and safeguard the
fundamental role of ecosystems as providers of clean water. Specific
attention should be given to supply to and use of renewable and non-
renewable groundwater resources.

To promote best ecosystem based management practices in planning,
management and water use, regional and on-site operational
guidelines need to be disseminated. These guidelines need to be
substantiated with regional examples of best practices from case
studies that exemplify development options that achieve water
management goals, but preserve functioning of freshwater ecosystems. 
Examples of these include the use of wetlands to improve water
quality and the utilisation of floodplains for flood damage control.

To facilitate the change to demand driven IWRM, environmentally
appropriate technologies need to be promoted. Whilst technology has
clearly brought benefits to many people, to be sustainable it must
be appropriate in terms of the ability of local people to maintain
the system and appropriate for the environment, as far as possible
working in sympathy with it, rather than just against it. Examples
of these technologies include non-water based sanitation systems,
many forms of traditional rain fed agriculture, indigenous water and
soil conservation techniques and riparian zone management.

Restoring ecosystem functioning to degraded freshwater ecosystems

Degraded  river channels and wetlands are characterised by a loss
of structure and functions they formerly fulfilled. Restoration of
freshwater ecosystems has only began in recent years and experience
is still limited. For river channel restoration the rehabilitation
of water quality, flow regime and habitat structure are principal
components. Successful restoration of drained wetlands is not merely
to obstruct installed drainage but includes damming, flooding or
"irrigating" affected areas. A complex seasonal regime may be
required to rehabilitate the original ecosystem.

Restoration of degraded freshwater ecosystems should been seen as
an ultimate solution to combat the loss of structure and function.
Preference is given to pro-active actions that aim at sustaining
these structures and functions. The economic justification of
restoration can often be found in the much higher economic output
of restored freshwater ecosystems compared to e.g. outputs from
large scale irrigation schemes if all products are properly costed
(Acreman, 1994).

5. Recommendations for further work

It is clear that healthy ecosystems can provide beneficial
hydrological functions to assist with water management.
Consequently, maintaining the functioning of these freshwater
ecosystems is a key element in the sustainable management of water

We recommend that:

1.    An Ecosystem Based Management Approach is adopted as the most
      appropriate strategy to meet current and future water demands
      and the economic, social and cultural requirements of society
      in a sustainable way.
2.    Initiatives are supported that improve the assessment of water
      resources and functions and values of ecosystems. This
      involves quantifying the water requirements of ecosystems and
      determining the ecological, environmental, economic, health,
      social and cultural benefits of the functions provided by
3.    Research is undertaken to understand ecosystem functioning
      more fully with the aim of developing rapid and easy to apply
      methods for functional assessment of ecosystems and the
      quantification of their water needs.
4.    Capacities are build at various levels to ensure a balanced
      implementation of appropriate technologies. This involves
      development of training tailored to the requirements at the
      various levels and on-site development of new techniques
      related to water use and management through ■learning-by-

5.    Communities are highly involved in the development,
      implementation and evaluation of water recources management
      schemes through an adequate representation within the various
      institutions. This requires a considerable change in decision
      making strategies, internal communication and organisational
      capacities of these institutions and improving capacities to
      resolve conflicts at the various levels.
6.    Partnerships are established that support the development of
      coherence between planning and management of water resources.
      The establishment of inter-sectoral teams to develop policy
      and planning tools and multi-stakeholder teams for programme
      definition, co-ordination, implementation and evaluation are
      essential elements for this.
7.    Analysis of ecosystem functioning, their water requirements
      and the services and goods they provide are adopted as a key
      elements of water resource planning and management. This
      requires a further development of tools such as impact
      assessments and valuation of ecosystems functions.
8.    Social, economic and legal incentives, subsides and policies
      are analysed on their possible negative effects on both the
      environment and economies and are either adjusted or further
      developed and implemented to maintain ecosystem functioning
      and the sustainable development of societies.


The authors would like to thank E. Maltby and J-Y. Pirot for their
contribution towards producing this document.


Abramovitz, J.N., 1997. Valuing Nature■s Services. In: State of the
World. A worldwatch Institute Report on Progress Toward a
Sustainable Society. Worldwatch Institute, Washington DC, p. 96-114.

Acreman, M., 1994. The role of artificial flooding in the integrated
development of river basins in Africa. In: C. Kirby and W.R. White
(Eds). Integrated River Basin Development. John Wiley and Sons,
Chichester (UK), p. 35-44.

Acreman, M.C. and Hollis, G.E. (Eds), 1996. Water management and
wetlands in sub-Saharan Africa. IUCN, Gland (Switzerland), 249 pp.

Acreman, M.C. and Lahman, E. (Eds), 1995. Managing Water Resources.
Parks 5(2), special issue, 56 pp.

Baker, C.J. and Maltby, E., 1995. Nitrate removal by river marginal
wetlands:factors affecting the provision of a suitable
denitrification environment. In: Hughes, J. M. R. and Heathwaite,
A.L. (Eds). Hydrology and hydrochemistry of British wetlands, John
Wiley and Sons, Chichester (UK), p. 291-313.

Barbier, E.B., Acreman, M.C. and Knowler, D., 1996. Economic
valuation of wetlands: a guide for policy makers and planners.
Ramsar Convention Bureau, Gland (Switzerland), 127 pp.

Borrini Feyerabend, G. and Buchan, D. (Eds.), 1997. Beyond fences.
Seeking social sustainability in conservation. Volume 1: A process
companion. IUCN, Gland (Switzerland), 129 pp.

Costanza, R. et al., 1997. The value of the world's ecosystem
services and natural capital. Nature, 387: 253-260.

De Groot, R.S., 1992. Fuctions of nature. Evaluation of nature in
environmental planning, management and decision making. Wolters
Noordhoff, Deventer (The Netherlands), 315 pp.

Dugan, P.J., 1990. Wetland Conservation: A review of current issues
and required action. IUCN, Gland (Switzerland), 95 pp.

Ehrlich, P.R. and Ehrlich, A.H., 1992.The value of biodiversity.
Ambio, 21(3): 219-226.

Engleman, R. and LeRoy, P., 1993. Sustaining water - population and
the future of renewable water supplies. Population Action
International, Washington D.C. (USA).

Falkenmark, M., 1989. The massive water scarcity now threatening
Africa: why isn't it being addressed. Ambio, 18(2): 112-118.

Gash, J.H.C., Nobre, C.A. Roberts, J.M. and Victoria, R.L. (Eds),
1996. Amazonia deforestation and climate. John Wiley and Sons,
Chichester (UK), 611 pp.

GWP, 1997. Documents and Proceedings of the Special GWP-TAC Meeting.
Copenhagen, October 1997.

Hollis, G.E., Penson, S.J., Thompson, J.R. and Sule, A.R., 1993. The
Hadejia-Nguru wetlands: Environment, economy and sustainable
development of a Sahelian Floodplain Wetland. IUCN, Gland
(Switzerland), 244 pp.

Khan, N. 1995. Protection of the North Selangor Peat Swamp Forest,
Malaysia. Parks, 5(2): 24-31.

Koch, M.S., Maltby, E., Oliver, G.A. and Bakker, S.A., 1992. Factors
controlling denitrification dates of tidal mudflats and fringing
salt marshes in south-west England. Estuarine, Coastal and Shelf
Science, 34: 471-485.

Laanbroek, H.J., Maltby E., Whitehead, P., Faafeng, B. and Barth,
H., 1996. Wetland and aquatic ecosystem research science plan.
European Commission, Brussels (Belgium), p. 26-27.

Lean, J, and Warrilow, D., 1989. Simulation of the regional impact
of Amazon deforestation. Nature, 342: 411-413.

McAllister, D.E., Hamilton, A.L. and Harvey,B., 1997. Global
freshwater biodiversity: Striving for the integrity of freshwater
ecosystems. Sea Wind, 11(3), special issue.

WCMC, 1992. Global biodiversity. Status of the Earth■s living
resources. Chapman and Hall, London (UK), 585 pp.

NEDA, 1997. Water for the future: Integrated Water Resources
Management. Policy Priorities for Netherlands Development
Assistance. Netherlands Development Assistance, Den Hague, 54 pp.

Ni, D.V., Maltby, E., To Phuc Tuong, Safford, R. J. and Vo-Tong
Xuan. 1997. The role of Melaleuca in tropical wetland soils. In:
Samuel, C., Safford, L. and Weir, A. (Eds.). Book of abstracts of
5th Symposium on the biogeochemistry of wetlands. Royal Holloway
University of London, London (UK), in press.

National Research Council, 1997. Valuing ground water - Economic
concepts and approaches. Prepared by: Committee on valuing ground
water. Water science and Technology board, Commission on
Geosciences, Environment and Resources. National Academy Press,
Washington DC. 

OECD, 1996. Capacity development in environment. Proceedings of the
IIED/OECD workshop, Rome, 4-6 December 1996, 301 pp.

Saenger P., Hegerl, E. J., and Davie, J.D.S., 1983. Global status
of mangrove ecosystems. IUCN-WWF, Gland (Switzerland), 

Shukla, J., Nobre, C. and Sellers, P., 1990. Amazon deforestation
and climate change. Science, 247, 1322-1325.

UNEP, 1997. Report of the Third Meeting of the Subsidiary Body on
Scientific, Technical and Technological Advice UNEP/CBD/COP/4/2.

Verhoef, H. 1996. Health aspects of Sahelian floodplain development.
In: Acreman, M.C. and Hollis, G.E. (Eds) Water management and
wetlands in sub-Saharan Africa. IUCN, Gland, (Switzerland), p. 35-

Xue, Y and Shukla, J., 1993. The influence of land surface
properties on Sahel climate. Part 1, Desertfication.

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