Every drop counts
Environmentally Sound Technologies (ESTs)
for urban and domestic water use efficiency
Presentation of key issues and tools
Every drop counts
presentation
Delft University of Technology
production of the presentation:
Dr. Aad F. Correlje, Faculty of Technology, Policy & Management
Dr. Ing. Thorsten Schuetze, Faculty of Architecture
Dr. Sybrand P. Tjallingii, Faculty of Architecture
Dr. Maki Ryu, Faculty of Architecture
UNEP DTIE IETC
coordination:
Vicente Santiago
every drop counts
Structure of the presentation
1. Introduction
2. Backgrounds of decision making
Policies, Criteria
3. Environmentally Sound Technologies
Storage, Supply, Use, Reuse & Recycling
4. Integrated options and cases
5. Questions for a specific case
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Objective and target group
objective •
•
target group •
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To support decision making about
Environmentally Sound Technologies (ESTs)
in urban and domestic water use.
A sourcebook that highlights essential
questions that have different answers in
different cases towards water use efficiency
Decision makers: participants in local
planning processes related to urban and
domestic water use
1. Introduction
Scope and focus
scope •
•
•
focus •
•
•
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Water use efficiency in urban and domestic
environments
Other water issues (e.g. flooding, drainage,
irrigation) only if relevant
Urban includes all concentrated settlements
Efficient use of ESTs
Efficient is: optimizing the balance between
demand and safe and sufficient supply
Efficient and fit : technologies that fit in with
sustainable perspectives for the local
situation
1. Introduction
Sourcebook, presentation and
WiseWater training module
sourcebook •
•
•
•
Backgrounds: policies, criteria
Relevant issues for analysis and discussion
A toolkit of environmentally sound technologies
Illustrative cases
presentation • Summary of the sourcebook
• Questions for decision making in your own case
WiseWater • Calculating the effects of water saving
technologies (ESTs) versus conventional
technologies
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1. Introduction
[Sourcebook
Chapter 2]
Policies and institutions
technology
economy
institutions
The challenge is to achieve an appropriate 'fit'
between the 'hard' technical and physical
characteristics, the economics of ESTs and the
institutional environment that facilitates their
selection, construction and operation.
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2. Backgrounds Policies
Decision-making in a complex
institutional actor network
The actors:
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• National, or regional governmental bodies.
• Local actors: agencies for water management,
municipalities, water supply corporations,
sewerage operators, public health policy
makers, housing corporations, project
developers, financing parties.
• Construction companies and equipment
suppliers.
• The users of the water systems, domestic
households in owned and rented houses, small
and medium size enterprises, and the citizens
living in the areas.
2. Backgrounds Policies
Policy, Rules and
Use
Introducing
ESTs:
Informal institutions,
customs, traditions, norms,
religion
What does it imply ?
Institutional environment
Formal rules of the game,
• Policies ?
property, water laws,
• Project development ?
bureaucracy
• Implementation ?
Governance
• Operation ?
All these activities have
to be considered in the
context of the four
layers of the
institutional framework.
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Embeddedness
Play of the game, contracting,
aligning governance structures
with transactions
Resource allocation
and development
Prices and quantities,
incentive management
2. Backgrounds Policies
National Water Policy
Policy
• The water cycle, requiring integrated water readdresses
sources management: surface water, groundmany
water, catchment-basin and land-use planning.
activities: • The environment as the source of water: water
collection control, augmentation, water quality
and pollution control.
• Principles for water use by the domestic
households, agriculture, industry, tourism, etc.
• Economic principles of water management: water
pricing, financing, the role of the private sector.
• Roles, responsibilities and authority of water
institutions: like federal and state institutions,
user engagement, basin organizations, etc.
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2. Backgrounds Policies
Local decision making
diagnosis
planning
Diagnosis as • Patterns of
a basis for
water supply
planning:
and sanitation
• Patterns of
operation
implementation
(sectoral)
water use
• Environmental aspects, ecosystem approach
• Institutional arrangements, legal framework
• Social and cultural factors
• Positions of stakeholders and interest groups
• Economics and the engagement of the private
sector
• Interaction with other infrastructures and
assets
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2. Backgrounds Policies
Problems in planning and
implementation
Plans that
fail:
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•
•
•
•
Technically inadequate plans, lack of ESTs.
Socially and culturally unacceptable plans.
Economically unfeasible plans.
Plans which make too great a demand on
available human resources.
• Plans that go counter to legal provisions.
• Plans that are blocked by other local
departments because of lack of coordination
and consultation.
• External factors such as poor public servant
morale or public resistance.
2. Backgrounds Policies
Operation, economic and
financial aspects
Issues:
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• Most beneficial use and exploitation, balancing
social and environmental requirements.
• Water has a value and water supply and
sanitation have a cost.
• Pricing and tariff arrangements.
• Budgetary resources, subsidies and tariff
revenue.
• The role of the private sector.
• Support towards the introduction of ESTs.
2. Backgrounds Policies
Risk, revenues and governance
Recommendations:
Innovation and change cannot go without risks.
• Identify the main areas of responsibility and
the risks associated. Shared understanding of
risks is the basis.
• Assign the responsibilities and risks to the
party best able to manage them.
• Bearing risk has a cost and the party bearing
the risk will likely demand something in return.
• A public regulator should secure the benefits
for society and the environment.
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2. Backgrounds Policies
Environmentally sound water
policies
Summary of • Sustainable water management, a vital aspect
of economic development in poor regions.
key issues:
• The economic value of water establishes
mechanisms that can enhance water efficiency.
Policies should create conditions for the poor to
have access to water.
• Public participation: practical experience of
what works and what does not. Planning is
learning.
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2. Backgrounds Policies
Environmentally sound water
policies (cont.)
Summary of • Gender issues are crucial in water management,
especially at the domestic level.
key issues:
• Expertise is crucial. Foreign advisers may play a
role but only local expertise can ensure that
policies meet local needs and local conditions.
• Ecosystem approach as a fundamental
component of Integrated Water Resource
Management (IWRM).
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2. Backgrounds Policies
[Sourcebook
Chapter 3]
Criteria for decisions
At the local decision level there is a need for
practical criteria that can guide ‘the actors’, those
who participate in the planning process.
Efficient is the best known criterion. An efficient
technology (EST) produces high results (sufficient
water for households, farming, industry, health)
with low efforts (money, time, resources, human
energy). Technologies can also be more or less
efficient in saving water. Calculating efficiency is
very helpful for making decisions.
But it is not the only criterion. The Bissau case
serves as an illustration:
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2. Backgrounds Criteria
The Bissau case
Like many cities in developing countries,
Bissau City (W.Africa) faces water and
sanitation problems in squatter areas. A
neighbourhood upgrading programme realises
new tap stands, new latrines and new
drainage gutters.
poor sanitation
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new watertaps
new pour-flush latrines
2. Backgrounds Criteria
Learning from a case
1. New taps not reliable (power failures). Thus
people turn to old wells that pose higher health
risks (latrines too close, clean rainwater
efficiently drained away).
 Plans for flows must fit together.
2. Improved drainage in neighborhoods leads to
erosion in the urban fringe.
 Plans for areas must fit together.
3. Construction work performed well but management and maintenance fail.
 Plans for actors must fit together.
 in addition to efficiency, there is a group of criteria called
fit. They have to be specified for flows and areas and actors.
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2. Backgrounds Criteria
Specifying ‘fit’ criteria for local plans
General criteria for sustainable plans
PLANET
(ecological)
sustainable is:
Specific criteria for
the local plan
FLOWS
 which flows?
choices made?
AREAS
 which areas?
- sound use
and
liveability
PEOPLE
(social)
(economic)
- participation
- fair sharing
- gender
How to make a
sustainable water
plan?
PROSPERITY
- profit and
development
guiding
principles
choices made?
ACTORS
 which actors,
choices made?
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guiding
models
2. Backgrounds Criteria
Working with ‘fit’ criteria
Analysis
• First, an analysis should provide the relevant
information: > Which flows ? (e.g. rainwater,
groundwater, drinking water, waste water,
solid waste, energy) > Which areas ? (e.g.
houses. yards, streets, neighbourhoods, urban
fringe) > Which actors? (e.g. women,
families, shopkeepers, agencies, NGOs).
Discussion
• Secondly, alternative plans (combinations of
technologies, policies and spatial plans) can
be discussed using general criteria for
sustainable plans and specific arguments from
the local context.
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2. Backgrounds Criteria
The planning cycle
EVALUATION
initiative
ORIENTATION
GUIDING PRINCIPLES
use
maintenance
starting
document
efficiency
realization
ANALYSIS
> flows
> areas
> actors
detailed
design
fit
strategic
plan
EXAMPLES
GUIDING MODELS
Fit and efficiency in the planning cycle
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2. Backgrounds Criteria
Criteria in the planning cycle
• The strategic stage of the planning cycle (from
initiative to strategic plan) focuses on
sharing the understanding of the problem,
sharing the general approach and sharing the
responsibility for solutions. ‘Fit’ criteria usually
dominate the process.
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2. Backgrounds Criteria
Criteria in the planning cycle
• The operational stage of the planning cycle
(from strategic plan to realization and use)
focuses on specifying concrete solutions,
specifying the funding, the contracts and the
organization of construction and maintenance.
‘Efficiency’ criteria usually dominate the
process.
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2. Backgrounds Criteria
Environmentally Sound Technologies
in the Urban Water Cycle
storage &
augmentation
reuse,recycle
& disposal
supply &
distribution
use &
saving
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3. ESTs Intro
[Sourcebook
Chapter 4.2]
Storage and augmentation ESTs
1. Ponds and Reservoirs
2. Artificial recharge of Groundwater
3. Water Tanks
4. Rainwater runoff in surface water
5. Rainwater runoff in groundwater
6. Rainwater runoff in tanks
7. Effluent in surface water
8. Effluent in ground water
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3. ESTs Storage
Ponds and reservoirs
Dams and reservoirs are a common
approach to storage of river water.
Big dams, however, do often cause
big unsolved problems and therefore
cannot be called environmentally
sound. Small dams with careful
consideration of ecological and social
impacts can do better. In permanent
rivers, under water beams are an
option. In ‘wadis’ sand dams are a
sound technology for the infiltration
of river water to the groundwater.
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3. ESTs Storage
Artificial recharge of ground water
Artificial recharge is appropriate for the
augmentation of groundwater in aquifers. It may
supplement the natural percolation. In seasonal
climates Aquifer Storage and Recovery practices
both the storage and the quality control that is
essential to maintain the
quality of groundwater
resources. Recharging can
take place from the surface
or directly into sub surface
layers.
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3. ESTs Storage
Rainwater harvesting ESTs
Rainwater runoff
from roofs is
stored in tanks to
be used inside
buildings.
Stormwater from streets and
parks can be infiltrated or
stored in ponds to provide water
for trees, gardens and parks.
Sand filters and constructed
wetlands can be used for quality
control.
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3. ESTs Storage
Storage of treated sewage
Effluent from sewage treatment plants can be
reused in surface waters as a source for urban
water supply. Quality control is crucial.
The use of effluent for
recharging groundwater is
possible. Soil Aquifer Treatment
technology prevents pollution by
pathogens, nutrients and other
contaminants.
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3. ESTs Storage
Priorities for storage solutions
In an integrated perspective, efficient and
sustainable storage and augmentation can best
be realized by decision makers if they follow this
sequence of options:
1. First, realize the full potential of treated
wastewater and rainwater options.
2. Then, use the potential of surface water
options.
3. And then, turn to aquifer based ESTs as a
third option.
Over-exploitation and pollution of aquifers
is a threat. Invisible impacts are hard to
restore.
every drop counts
3. ESTs Storage
[Sourcebook
Chapter 4.3]
Supply and distribution ESTs
1. Surface water abstraction
2. Groundwater abstraction
3. Water supply reservoirs (tanks)
4. Transfer of water
5. Single pipeline systems (one quality)
6. Dual pipeline systems (two qualities)
7. Water containers (bottles, tanks)
8. Centralised treatment systems
9. Point of use treatment systems
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3. ESTs Supply
Water pipe systems
Water supply networks are advanced
systems that require advanced
maintenance regimes. Leakage, due to
poor maintenance is a major problem.
Often more than 50% of the piped
water is lost. Capacity building and
fund availability for maintenance are
the first priorities.
Lowering night time pressure and
a system of metering and billing
water use above a basic level may
be helpful but are not a final
solution.
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3. ESTs Supply
Dual quality systems
A problem of central piped network supply, is the
use of drinking water quality for non drinking
purposes. In dual networks service water quality
has it’s own network. Wrong connections can be
avoided by different colours for different pipes.
Dual systems at the building level only, avoid city
networks.
Buildings should have a reliable
technical department for
maintenance and quality
control. Rainwater or treated
greywater can be used as
service water. Sizable tanks
can cope with fluctuations in
demand and supply.
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3. ESTs Supply
Wells, tanks and bottles
At the neighborhood level, improving the
quality and increasing the number of
traditional wells can be a good
environmentally sound technology.
In a situation of centrally collected
drinking water from rivers or groundwater
(boreholes), good quality water can be
delivered by trucks to static tanks,
from where people
can take water home
in bottles or small
containers.
every drop counts
3. ESTs Supply
Drinking water quality
Health requires good quality drinking water.
Centralized treatment systems can be
improved and extended.
If drinking water of
reliable quality is
not available,
proper treatment at
the user level is an
option.
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3. ESTs Supply
Priorities for supply solutions
Under an integrated water resource
management perspective, efficient and
sustainable supply and distribution can best be
realized by adapting priorities to decision-making
based on the existing situation:
1. In a traditional situation of wells, improving
this supply system has priority.
2. If this is difficult and there is an immediate
need, delivery by trucks is an option.
3. If there is a basis for financing and for
capacity building, piped water networks
become feasible. Their development should
go hand in hand with on-site systems for
supply of drinking water and service water.
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3. ESTs Supply
[Sourcebook
Chapter 4.4]
Use and saving ESTs
1. Waterless toilets (compost- and dry-)
2. Water saving toilets
3. Water saving urinals
4. Waterless urinals
5. Water saving taps
6. Water saving showerheads
7. Pressure reducers
8. Water saving household appliances
9. Economised water use: personal hygiene
10. Economised water use: cleaning & watering
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3. ESTs Use
Waterless toilets
Waterless toilets need neither water nor sewers.
They work on the basis of dehydration and
composting. The resulting compost can be
applied to the fields in urban agriculture. The
right degree of humidity is crucial. They are often
combined with urine separation. Vertical
ventilation pipes guarantee
odour free operation.
Compost toilets require
more space and need more
maintenance. Simple dry
toilets are easier to use and
cheaper. They need to be
emptied every week.
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3. ESTs Use
Water saving in households
Drinking, cleaning, bathing, washing, toilet
flushing. Combined water saving appliances lead
to 43% savings in liter per person per day.
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3. ESTs Use
Water saving in green spaces
Parks and gardens ask a lot of water, especially
in dry climates. Savings may result from
replacing piped water by rainwater or treated
wastewater.
The local government and
NGOs can also give a good
example demonstrating
how attractive green spaces
can be created with native
species adapted to dry
conditions.
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3. ESTs Use
Not only technology
The challenge is: “meeting increasing service
demands without increasing water supplies” (UN
-Habitat, Local Action for Global Goals, 2003).
This is not only a matter of technology but also
of life style, water squandering practices in
private and public buildings and in public open
space.
Change asks for a carrot and stick approach:
• tax incentives and levies, demonstration
projects
• rules, standards and enforcement
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3. ESTs Use
Priorities for use & saving
In an integrated water resource management
perspective, efficient and sustainable water use and
saving can best be realized by decision makers if
they combine strategies:
1. In new developments water saving
ESTs should become part of design and
planning strategies from the beginning. This
includes strategies for maintenance. 2. In
existing urban areas creating conditions is
crucial: financial incentives, technical
support, training of skilled labour, legal
support, new standards.
3. Demonstration projects can show the way in
a process of learning by doing.
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3. ESTs Use
[Sourcebook
Chapter 4.5]
Reuse, recycle & disposal ESTs
quality and treatment issues
1. Domestic rainwater use
2. On-site treatment of grey water
3. Constructed wetlands
4. On-site and near-site treatment of black
water and mixed sewage
5. Separating rainwater from sewer systems
6. Environmentally sound centralized sewage
treatment in developing countries
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3. ESTs Reuse
Rainwater quality and use
Roof-top rainwater only needs minor treatment
to make it safe for service water. For use as
drinking water, filtration and disinfection is
required. There should be no debris in the tanks
and no light. Quality control is a must.
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3. ESTs Reuse
Rainwater quality and use
Run-off rainwater from streets and open spaces
can be treated in wetland systems. Separating
rainwater from the sewers greatly improves the
city treatment plant’s performance.
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3. ESTs Reuse
Grey & black water treatment
Household based decentralised ESTs deserve
more attention. They create conditions for
reuse at the domestic level and save costs for
sewage systems.
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3. ESTs Reuse
Grey & black water treatment
Example for on-site
sewage treatment
Small scale aerobic (>compost) or anaerobic
technology (>methane + slurry) are feasible.
These innovative ESTs require careful and skilful
guidance. For example joint projects of users
with researchers and practitioners in a learning
by doing context.
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3. ESTs Reuse
Constructed wetlands
Stabilisation ponds and constructed wetlands are a
low-cost alternative for the treatment of domestic
wastewater. They provide water for irrigation in urban
agriculture and for watering green spaces.
Detention and retention ponds, lined up with reeds
and other wetland plants, perform well in purifying
run-off rainwater from quite streets. More polluted
water requires constructed wetlands designed for
horizontal or vertical flow,
filtering, adsorption and
uptake of nutrients.
Good design and maintenance
are vital.
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3. ESTs Reuse
Advanced primary treatment
Increasingly strict standards,
derived from the situation in
developed countries have made it
almost impossible to reuse
effluent and sewage sludge in
peri-urban agriculture. In
developing countries effluent
(from domestic wastewater
treatment) usually contains less
heavy metals and other toxic
substances and more pathogens.
Advanced Primary Treatment (APT) is a new technology that
combines primary (mechanical) treatment with filtration and
disinfection. This opens healthy and water efficient perspectives.
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3. ESTs Reuse
Priorities for reuse, recycling
& safe disposal
Under an integrated water resource management
perspective, the choice of reuse, recycling and safe
disposal options follows these priorities:
1. Pollution prevention goes first. Roof-top rainwater and water from wells should retain
drinking water quality.
2.
In urban situations with an existing piped
network, on-site rainwater and grey
water treatment for service water should
have priority in quality management strategy.
3. Reuse and recycle should have priority in
wastewater treatment both at a centralized and
decentralized level.
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3. ESTs Reuse
[Sourcebook
Chapter 5]
Integrated options and cases
EST-priorities for storage (and augmentation),
supply (and distribution), use (and saving) and
reuse & recycling (and safe disposal) have to be
integrated in locally ‘promising combinations’.
This integration depends on the potential of the
local situation (climate, hydrology, city-landscape)
‘Promising combinations’ also greatly depend on
institutional capacity and the development stage.
Five ‘guiding models’ illustrate these aspects. A
given decision situation may be close to one of
them. In a larger urban area, the guiding models
may guide the making of a zoning model for the
city, with specific strategies for each zone.
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4. Integration
Village model
development stage
Traditional simple systems, self organisation,
minor role for central government.
promising EST combinations:
storage
supply
use
reuse &
recycling
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Preferably ESTs based on groundwater, supported
by traditional rainwater based ESTs.
First option is water supply by wells. Residents
take water home in small containers. Demand is
usually < 30 liter per person per day.
First options for sanitation are dry toilets and
improved pit latrines to avoid groundwater
contamination.
Grey-water gardens or soil aquifer treatment for
waste water discharge. Compost for agriculture.
4. Integration
Squatter area model
development stage
Many new arrivals, short-term urgency and
possible roles of central relief organisations for
organising collective water and sanitation systems.
promising EST combinations:
storage
supply
use
reuse &
recycling
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Preferably ESTs based on groundwater or river.
Central supply by trucks to static tanks. Residents
take water home in small containers. Demand is
usually < 30 liter per person per day.
First trench latrines followed by improved pit
latrines and dry toilets to avoid groundwater
contamination.
Starting with simple soakaways for waste water.
Followed by grey-water treatment ESTs.
4. Integration
Urban village model
development stage
Squatter area (favela, bidonville) on a more
permanent basis. Increasing role of government
agencies and NGOs. Upgrading.
promising EST combinations:
storage ESTs based on groundwater, if feasible, small dam
reuse &
recycling
in river. Promotion of rainwater harvesting ESTs.
Piped water network that supplies collective tap
stands, Quality control by agency.
Introduction of dry toilets and compost collecting
system. Support for rainwater use in households.
Grey water treatment with irrigation and soil
aquifer treatment.
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4. Integration
supply
use
City model
development stage Existing medium to large cities,
important role for government agencies, few
collective and individual user based systems.
promising EST combinations:
storage Groundwater recharge, small dams in rivers. If big
supply
use
reuse &
recycling
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dam exists, alternatives reduce dependency.
Strong promotion of rainwater harvesting ESTs.
Full piped network. Priority for leakage control.
Promotion of water saving toilets and water saving
appliances. Water sensitive urban design to create
conditions for run-off use for watering parks and
gardens.
Improving centralised wastewater treatment.
Reuse of effluent and sludge in agriculture. Reuse
of treated wastewater in watering green spaces.
4. Integration
New town model
development stage
New development with a leading role for agencies,
NGOs and developers. Collective organisations and
individuals take over after construction.
promising EST combinations:
storage Groundwater or surface water based systems.
Building design regulations and legal frame
creates good conditions for rainwater harvesting.
supply Full piped network for drinking water. Collective
and individual systems for service water.
use Water saving and dry toilets, water saving
appliances. Water sensitive urban design for runoff use in green spaces.
reuse & Centralised and collective blackwater treatment.
recycling Building level grey water treatment (service
water). Constructed wetlands in urban design.
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4. Integration
Questions for a specific case
The sourcebook presents backgrounds (policies,
criteria), a toolkit of ESTs, and illustrative cases.
Moreover, the different chapters present
questions that can be used in the planning
process of a specific case. The model of the
planning cycle (slide 22., sourcebook 3.4) shows
the sequence of the questions in relation to the
steps in the strategic stage of planning.
In this way, the questions may structure a
workshop that generates alternative plans.
Wisewater is a supplementary tool for
calculating the water saving potential of ESTs in
the planning process.
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5. Questions
Workshop questions
• lessons from other local projects
• strenghts and weaknesses of this
EVALUATION
situation (SWOT)
initiative
ORIENTATION
efficiency
GUIDING PRINCIPLES
ANALYSIS
(sourcebook chapter 3.4)
• questions about ‘sustainable’
(sourcebook 3.3)
• questions about flows, areas and
actors
fit
strategic
plan
(sourcebook 4.2.2, 4.3.2, 4.4.2, 4.5.2)
EXAMPLES
GUIDING MODELS
• wich models come close?
(sourcebook 5.2.3)
• Which ESTs form a ‘promising
combination’ ?
(sourcebook 5.2.3, chapter 4)
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5. Questions
…every drop counts twice…
the joy and inspiration of planning with water
every drop counts