Marina Robles, Emma Näslund-Hadley,

María Clara Ramos, and Juan Roberto Paredes

Module 5

Sustainable
Water
Management
Rise Up Against Climate Change!
A school-centered educational initiative
of the Inter-American Development Bank
 A school-centered edu-
cational initiative of the
Inter-American Develop-
ment Bank

Elaborated by Maria Robles, Emma Näslund-Hadley,

María Clara Ramos, and Juan Roberto Paredes.
Editor: Steven Kennedy.
Design and illustration: Sebastián Sanabria.
Copyright © 2015 Inter-American Development Bank. This work is licensed under a Creative
Commons IGO 3.0 Attribution-NonCommercial-NoDerivatives (CC-IGO BY-NC-ND 3.0 IGO) Modules in the Toolkit
license (http://creativecommons.org/licenses/by-nc-nd/3.0/igo/legalcode) and may be
reproduced with attribution to the IDB and for any non-commercial purpose. No derivative work Module 1 What Is Climate Change?
is allowed.
Any dispute related to the use of the works of the IDB that cannot be settled amicably shall Module 2 Motivating the School Community to Rise
be submitted to arbitration pursuant to the UNCITRAL rules. The use of the IDB’s name for
any purpose other than for attribution, and the use of IDB’s logo shall be subject to a separate Up against Climate Change
written license agreement between the IDB and the user and is not authorized as part of this
CC-IGO license. Module 3 Environmentally Friendly School
Infrastructure
Note that link provided above includes additional terms and conditions of the license.
Module 4 Energy Savings, Efficient Use, and
The opinions expressed in this publication are those of the authors and do not necessarily
reflect the views of the Inter-American Development Bank, its Board of Directors, or the Alternative Technologies
countries they represent.
Module 5 Sustainable Water Management
Module 6 Comprehensive Solid Waste Management
Module 7 School Green Areas
Cataloging-in-Publication data provided by the
Inter-American Development Bank Module 8 Selecting and Using Sustainable Materials
Felipe Herrera Library
Module 9 Managing Risk in the School
Sustainable water management / Marina Robles, Emma Näslund-Hadley,
María Clara Ramos, Juan Roberto Paredes.
p. cm.
Includes bibliographic references.
1. Water—Management—Latin America.  2. Climatic changes—Latin America.  3. Sustainable
development—Latin America.  4. Sanitation—Latin America.  I. Robles, Marina. II. Näslund-
Hadley, Emma.  III. Ramos, María Clara‫‏‬.  IV. Paredes, Juan Roberto.  V. Inter-American
Development Bank. Education Division. 
IDB-BR-167
2015
 Contents of module 5
Identifying the • Adopt alternative
problem technologies
»» Dry toilets
Making a change
in your school »» Artificial wetlands
and biofilters
Diagnosis »» Permeable paving
• The water cycle in the »» Collecting rainwater
school from roofs
• School water use: habits Monitoring and
and perceptions evaluating progress
• Conditions of the
school’s hydraulic system Tips for finding
financial support
Recommendations
• Decrease water Bibliography
consumption
»» Small technical
changes
»» New habits and
behaviors
Even though there is plenty of water on earth, not
all of it is suitable for consumption. One out of
every five people does not have access to safe
drinking water, and 40 percent of the planet’s
population lacks basic sanitation systems.

1
 Identifying
the problem of water—not all of this liquid is available for human consumption.
Have you ever wondered where the water you drink comes from, where Ninety-seven percent of the earth’s water is salt water, 2 percent of it is
it goes after you use it, or how people survive when water is not avail- frozen, and only 1 percent flows as fresh water under or over ground.
able or easily accessible?

Water is almost as old as the planet. Despite the fact that the earth
looks blue-green from a distance—evidence of its abundant volumes

Figure 1. The world’s water

Of the world's fresh water

75 %
of planet earth is
70is ice% 29 %
is groundwater

covered in water
of that 75%:
1% enters watersheds in the form
of rivers and lakes

97.5 %
is ocean
2.5 %
is fresh water
70 %
for irrigation
20 %
for industry
10 %
for domestic use

Source: www.unwater.org.

2 2
 Fresh water
Water resources are also unevenly distributed—abundant in some
places and lacking in others. About 1 billion people worldwide must
travel great distances daily to obtain it. In Latin America, despite

available worldwide
considerable improvements in recent decades, almost 10 percent of
the population (approximately 60 million people) still lack household
access to this vital resource (Adler, Carmona, and Bojalil, 2008).

Figure 2. Fresh water available worldwide

Freshwater
Fresh availability, cubic
water availability, cubic meters
metersper
perperson
personand perper
and year, 20072007
year,
Scarcity
Scarcity
Stress
Stress
Vulnerability
Vulnerability
Source: www.un.org.
0 1,000
1,000 1,700
1,700 2,500
2,500 6,000
6,000 15,000
15,000 70,000 684,000
70,000 684,000 Data
Data not available
not avalible

3
 Box 1. To live comfortably a person needs at least 20 liters of water a day;
this totals 7,300 liters per person per year. Unfortunately, many do
Our not have access to this amount because of environmental condi-
water needs tions, lack of infrastructure, and poor water quality (that is, unfit for
human consumption)

Population with access

to good-quality water
>> 80%
80 % 20%-40%
20 % - 40%
60 % - 80%
60%-80% 0 % - 20%
0%-20%
40 % - 60%
40%-60% No Data
No data

Source: www.unwater.org.

4
 There is a strong link between ecosystems and the water cycle. High Inequality is clearly evident in global levels of access to and consump-
rates of deforestation and the contamination of seas, lakes, and rivers tion of water. While some people barely have access to 20 liters per
(due to inadequate sewage and industrial sanitation) leave certain day (the minimum needed for basic needs), others consume over 400
regions particularly vulnerable to the scarcity and pollution of water liters. Should we consider this a result of ignorance, or apathy—or a
(figure 3). combination of both?

Natural purification
Figure 3. The water cycle
Natural purification
Solar
heat

Solar Water
Water in atmosphere
Heat
Sublimation
Sublimation
Water
Water in
in ice
ice
and snow
and snow
Condensation
Condensation

Vapor
Precipitation
transformation
transformation

Water runoff
into rivers
Wellspring
Wellspring

Evaporation Evaporation
Lake
Lake

Water in
oceans Infiltration
Infiltration
Infiltration

Subterranean wáter
Subterranean water courses
courses
Infiltration
Infiltration
5
 Many people waste large volumes of water while washing their cars or Population growth, human apathy, the widely held belief that water is
sidewalks or while showering. This misuse probably results from hav- an unrestricted renewable resource, increased costs of supply (since
ing misunderstood the water cycle and assuming water to be a renew- we have to go continually farther and deeper to get it), pollution prob-
able and unlimited natural resource. Although safe water is available to lems, lack of sanitation systems and technologies, and the intensifica-
these people at present—even as other people suffer scarcity—it will tion of droughts and floods (caused by climate change) have all further
not necessarily always be so. exacerbated the problem of water scarcity.

This problem is enormous; although your school cannot solve it alone,

your intervention can make a big difference. First, you can change the
perception that water is an unlimited resource and emphasize that
supplying water involves using energy for drilling wells, transporting the
water, and purifying it. Second, your school can serve as an example of
a responsible user. Solutions are available to any group willing to work
together to adopt alternative forms of retrieving water, allow it to infil-
trate the subsoil, and handle it more effectively.

6
 1,000 liters of water to produce a liter of milk
2,500 liters of water to produce 500 gms of cheese
840 liters of water to produce a coffee jar
1,700 liters of water to produce 500 gms of rice
1,830 liters of water to produce 300 gms of a piece of lamb

Figure 4. How much water does it take to manufacture a product?

VIRTUAL WATER
Virtual water
An An 1 cup of 750 ml 500 gr 500 gr
Apple Orange Tea Corn Rice
70 50 750 450 1,700
One 500 ml A pack 300 gr
500 gr
Egg Bread Beer Fries Piece of
Lamb
200 650 150 185 1,830
500 gr 300 gr Bottle Jar
300 gr
Chicken Wheat Beef Wine Coffe
1,170 500 4,500 720 840
300 gr 1 litro 500 gr
Pork Milk Cheese
Liters of water to produce
1,440 1,000 2,500
Source: Virtual Water 2007 (http://virtualwater.eu/).
Note: Poster based on Hoekstra and Chapagain, 2007. Designed by Timm Kekeritz.

7
 Making a change Diagnosis
in your school Preparing a general diagnosis of water conditions in the school in-
volves at least three steps:
If a school is using water as if it were an unlimited resource, it must • Outline the route that water follows in the school: consider
change that mindset. This can be accomplished by making necessary where it comes from, the path it takes, and where it goes
adjustments to the curriculum and by teacher (and student) example. when it leaves.
Smart use of water is vital to transforming the traditional school into an • Identify how water is used and regarded by the school
environmentally friendly space. community.
Transforming and improving water utilization in schools is not as diffi- • Evaluate the school’s current hydraulic facilities.
cult as you may imagine. Once a group makes up its mind, much can
be accomplished through consistent action. The first step in establish-
ing a water management program is to identify and analyze existing
conditions, including the water habits and perceptions of the school
community and the state of the school’s water supply and sanitation
infrastructure.

Next, steps can be taken to reduce water consumption, either through

adoption of new habits and customs by the school population or the in-
corporation of small changes and new technologies that improve water
use and allow its infiltration to underground aquifers.

8
The water cycle
in the school
Understanding how the school obtains, uses, and disposes of water By addressing these considerations, you will be able to ascertain
are the first tasks of the diagnostic exercise. In most schools, water whether the school is actively generating problems for the ecosys-
distribution systems will either be hidden beneath building foundations tem, either in how it accesses water resources or how it disposes
or hard for the inexperienced eye to observe. Take advantage of your of water.
students’ and teachers’ interest and resources, your communities’
water services offices, and the senior school staff responsible for the As part of this first exercise, it may be useful to draw a sketch or
schoolyards, restrooms, and gardens. Tour the school facilities together map of your school in addition to listing information in a format
to determine the path of water at the school. similar to the example provided in table 1.

9
 Table 1. Analyzing where the school’s water comes from and where it ends up
Topic or question Answer Comments
Origin of the water supply The Lerma-Cutzamala Basin and Magdalena Contre- Both the basin and the river are heavily overused. In
ras River fact, deeper wells are being built each year. The basin
system is very far from town, so water transportation
costs are very high.

Each year, the communities adjacent to the basin hold

demonstrations asking officials to stop supplying the
town with water because they themselves experience
serious scarcity problems.

Costs incurred by the town to pro- More people are without access to water each year.
vide the water supply Many communities hold meetings and protest march-
es demanding increased supply.
Cost of water to the community per
cubic meter or per liter
Water supply problems in the school
School’s drinking water supply and A complex network supplies water to restrooms, the It can be useful to find out how old the school’s water
drainage and runoff systems kitchen, laboratories, sports facilities, and other areas. systems are, as well as the frequency of their break-
(The water comes from the town’s water supply.) down and regular maintenance.

It is supplied by tankers and trucks that bring water in If toilets use drinking water, consider making the
containers to fill the school tanks. small adjustments necessary to use gray water(water
from sinks or showers).
The school has its own water well.

10
Table 1. Analyzing where the school’s water comes from and where it ends up, continued
Water consumption at the school In cubic meters or liters
(over a given period of time)
Economic cost

School population total (students, teachers, and other employees)

Uses of drinking water at the school Drinking
(may be estimated in percentages or in liters, Restroom cleaning
if you are able to calculate it) General school cleaning
Garden irrigation
Washing backyards and sidewalks
Washing cars
Washing tools
Washing kitchen and dining room utensils
Bodies of water close to the school (lagoon, lake, wetland, river, dam, ocean, others)
Where is the water used at the school At a drainage system in town, a river or stream nearby, a local treatment
disposed of? plant, a treatment plant of the school, and so on.
Where does the water used at school Once it goes down the drain, it is treated and dumped on a nearby It is important to keep in mind
finally end up? beach. (Without any treatment it ends up in a lagoon, from which the that, as in all natural systems,
area gets its water supply.) water is part of a cycle. Every-
thing we do to this cycle (good
or bad) will later affect us.

11
 Figure 5. Water’s journey

Drainage
Drainage Drinking water
Drinking water
School water use: community
habits and perceptions
P The most significant legacy your school leaves is the education it offers
to students and the rest of the community. Educating people in intelli-
gent, sustainable water use is of paramount importance.

As you examine current water use and envision future improvements,

members of the school community may be invited to share their ideas
and viewpoints. This exchange could be conducted in a classroom.
Teachers and students should be encouraged to include an activity of
this kind in their curricular or extracurricular activities. You may also
carry out a small survey or interview to collect answers, discuss them
with the group, and share them with the school community.

You may choose to conduct both a written survey and classroom dis-
cussions. In tables 2 and 3, we offer guides for both exercises. Once
they are completed, you can collect all the information, illustrate it in
a way that makes it easy to understand, and share it with the school
community. The next step will be to motivate community members to
participate in the initiative.

(Note: The exchange of ideas can take place over a one-hour session;
if more time is needed, several short sessions are more effective than
one single long one. Moreover, if the community you are bringing to-
gether does not see plans taking shape over the short term, they may
become discouraged. Take initial steps before preparing a comprehen-
sive plan.)

12
 Table 2. Ideas for a classroom exchange on water use
Meeting objective:
Find out the views of the school community (students, parents, teachers, Meeting location
and so on) on the water problem. Develop ideas to improve the and date
school community’s water utilization performance.

Schedule Discussion questions and Initial presenter or pre- Required materials and general Comments
subjects senter in charge ideas
8:00 AM Present meeting objective Initiative leader Meeting objectives and agenda Appoint one or two rapporteurs for the
to 8:05 and agenda should be typed, presented on process, who will record what is said
AM a board or blackboard in front and agreed on.
of the classroom, or projected
digitally.
8:05 AM Do you believe the school Invite a guest speaker to offer an over-
to 8:45 adds to the community’s view of the topic in the community or the
AM or the world’s water prob- world, then open up the discussion.
lems? Why?
Start with a round of open sharing and
Do you believe that the close with a brief talk given by a guest.
school has a water-related
problem (supply, quality,
cost, and so on)? What are
the school’s main water
problems?
8:45 AM What can the school com- Provide examples of what other Record agreements and a list of volun-
to 9:00 munity do to improve the schools, local or international, teers who want to take part in initiating
AM school’s water utilization have done. specific proposals.
performance?

13
 Table 3. Sample survey: the school community’s views on the water problem
Parent
Name: School role: Teacher Associated
Student school grade
Staff
Other
What river, ecosystem, or basin Name? Don’t know
supplies the school’s water?

What is the town’s main water-related problem? Shortage

Poor quality
Pollution
Wastefulness
Other (specify)

Do you think the school handles its water in an envi- None

ronmentally harmful way? What harm is caused?
Contamination—sewage or other
Waste from consumption
Waste due to poor facilities and leaks
Do you think the school can make adjustments to improve its management of water? YES NO
If yes, continue to the next questions. If no, ask why and go to the last question.

14
Table 3. Sample survey: the school community’s views on the water problem, continued
What are Agree on new ways to decrease consumption
they?
Fix leaks
Use rain water collectors
Reuse gray and sewage water
Create a means to treat gray and sewage water
Others
Would you be willing to participate in initiatives or actions like these? YES NO
If yes, continue with the following questions. If no, go to the last question.
In what way? Exercise care in my consumption
Detect and fix leaks
Seek advice on using a collector, biofilter, or other alternative technology
Get support from educational or governmental institutions
Gather materials
Convince other colleagues to participate in a project like this
Others
If no, answer the following question.
What might encourage you to participate in actions such as these?

15
 Condition of the school’s hydraulic facilities
The first step is to identify the school’s hydraulic facilities (restrooms, have formed large areas of moisture (because of their location deep
swimming pool, showers, drinking water dispensers, dishwashers, within walls or floors) will be evident. Others will be more difficult to
washbasins, and so on), and the location and distribution of drinking identify, including small leaks in toilets or very slow seepage from un-
water networks, drainage, and wastewater. derground piping. Such leaks may be few but steady.

To determine whether facilities are working properly, it is essential to Before consulting a specialist, conduct your own audit. Recommenda-
audit leaks. You can do this through a class activity with students. With tions on how to proceed and how to record, systematize, and solve the
a map and record sheet, inspect all hydraulic facilities. Initially, only problems discovered are as follows.
surface leaks (such as dripping faucets and showers) or those that

Figure 6. Storing and using rainwater

Storage tank
Storage tank
Pipe
Piperainwater
rainwater
harvesting
harvesting
Potable
PotableWater
water
supply
Supply
Greenwater
Green watersupply
supply

Drain
Drain

Fire hose
Fire hose

Storage tank tank Control

Control
Storage
box
Box

16
 Figure 7. Examples of various types of water meters

Water meters
Water meters

m3

m3 9
0
1

8 2

0 7 3
9 1 0
9 1 6 4
5
8 2 8 2

7 3
7 3
0 6 4
9 1 6 4 5
5
8 2
7 3
6 4
5

Home use
Home use Hydrant pits
Hydrant pits
9
m3

0
1

8 2

7 3
0
9 1 6 4
5
8 2
7 3
6 4
5

Compoundpressure
Compoud pressure valve
valve
For wells
For

m3
• Once you locate the water meter, locate the flow indicator.
0
9
0
1
Usually this is a red triangular pointer or narrow needle—
like that on a watch dial. When water is flowing, the indica-
9 1
8 2
8 2 7 3
0
7 3 9 1 6 4

tor moves visibly.

4 5
6
5 8 2
7 3
6 4
5

• Close all the stopcocks in the school’s water system, in-

cluding those in tanks and cisterns, and observe the flow
Industrial
Industrial use
use indicator. If it continues to move, you have leaks. You can
gauge their size by how fast the needle is moving.

17
 Figure 8. Sources of water waste

Toilet
Toilet

Taps
Taps

Shower
Shower
Simple
Simple
water
water
harvest
harvest

• Once a leak is detected, you must determine whether its

source is inside the building or between the building and
municipal supply. Look for the shutoff valve to the building’s
Pipes
Pipes hydraulic facility and close it; if the meter stops, the leak
is inside the building, and you must carefully inspect each
item that uses water (toilets, taps, and so on). If the meter
is still moving, the leak is outside the building; you should
then look for wet spots, areas where more grass has grown
or that are greener than their surroundings, drainage runoff,
and so on.
• In case you do not detect the source of the problem, call a
specialist or consult the local water authority in your com-
munity.

18
Recommendations
A diagnosis of your school’s water resources and usage patterns can
Many of the recommended actions depend on the school’s spatial,
economic, and human resources. While some actions require special-
be used to: ized help and costly technologies, others are very easy to implement at
• Learn about and raise awareness of the availability and low cost. Yet, much of the work to improve the way we use water has
quality of the water in your town and school. to emerge from our own efforts, intent, and desire to succeed.
• Plan and design, along with school authorities, a gradual Developing a savings plan depends on the aspirations and resources
change of the school’s water-management technologies. of each group and school. Following a format like the one proposed in
• Design a comprehensive water-saving and environmentally table 4 can help; other ideas may emerge at your group meetings to
sound water-management program for the enrich, modify, or supplement it.
school community.
A plan usually has better results when made in a group. Convene a
planning session with members of the school community—include
parents, students, teachers, administrative and maintenance
staff, and others. Begin by presenting an overview of
their insights into the problem, and discuss how
their suggestions could improve the school’s
environmental performance
and student learning.

19
Table 4. Preparing a plan to save water and improve water management at the school
Those responsible
Actions required to implement Results for carrying out or
Problem Potential causes Solution
solution expected coordinating the plan

Water leaks in Equipment is old or in Comprehensive Make a schoolwide schedule to fix leaks. Reduction of Coordinated by the gym
the restrooms. poor condition. diagnosis of leakage and teacher with support from
leaks. Request support from a plumber to guide the consumption. parents.
work.
Change faucets Participation by students in
and washers. Purchase materials. the entire process.

Waste of water Students, teachers, and Campaign for Prepare posters. Decrease Coordinated by the
in the kitchen, workers. responsible water consumption. students’ association.
restrooms, and use. Include the topic in the curriculum for all
laboratories. grades. Raise the school
community’s
Assign teams (of teachers and students) to awareness about
monitor the ways in which water is used. the value of water.

Lack of Inadequate time taken to Appoint either a Find volunteers interested in the topic. Increase knowledge Coordinated by the science
knowledge investigate. member of the about the topic. teacher with the support of
about alternative administrative Integrate the subject into the school administrative staff.
technologies. Lack of informative staff to curriculum, then plan and carry out a Options for water
material on the subject. investigate or a research project with students. use in the school. Parents and students
group of students to lend support to the
(as part of research.
classwork).
Lack of financial Insufficient budget Investigate Quote cost to make technical improvements Organize financial Coordinated by the
resources to allocated to schools for possible support in school. support to carry out parents’ association, with
make repairs or system maintenance programs a plan or program the participation of the
modifications and adaptation to new to develop Obtain advice for the project planned. of technical school’s teachers and
to the water environmental conditions. alternative improvement in administrators.
system. forms of water Contact potential sources of financial support the school’s water
Others. management. and check requirements for support. management.

20
Decrease water consumption
Options for reducing water consumption range from technical inter- Small technical changes
ventions to behavioral change. The following tips can help you create
• Solve leakage problems by replacing old washers, changing
a water-saving plan in the school community. Even though this activity
or repairing small parts, or replacing whole sections of pip-
can be initiated and promoted by anyone in the community, experience
ing. For small problems, you can ask the assistance of com-
has shown that excellent results are obtained when the plan is de-
munity members or parents who know about plumbing and
signed and coordinated by student groups and associations.
have the required tools. If the school conditions allow it, you
can get help from a certified technician. The economic and
Emphasize the plan’s objectives at your meetings and classes. Put up
water savings you will achieve will be worth it, as a dripping
posters depicting your goals and your achievements.
tap can waste up to 30 liters of water a day!
• Place a couple of plastic bottles (of 1 or 2 liters each) filled
with sand, stones, or water inside the toilet tank if you have
high-capacity toilet tanks (greater than 10 liters and usually
built before 1999). By running tests to find the minimum
amount of water the toilet needs to work perfectly, you can
save up to 4 liters per flush. If your school has the budget,
you could consider new equipment or dual flush valves,
which can be adapted to any type of toilet (figure 9). Users
of these valves can choose how much water to use when
flushing—whether three liters for urine or six liters for solid
waste.
• Place water-saving devices on taps or showers. Search
for local organizations and institutions that can advise you
on water-saving products. If you are unable to locate any,
browse the Internet—many can be purchased and shipped
to you.

21
 Figure 9. Dual flush valves

• Change conventional 16-liter toilets to

small 6-liter ones.
• Build dry toilets, also known as compost-
ing toilets.
• Put containers and tanks in place to
collect rainwater for use in garden sprin-
klers or in bathrooms. Cover these con-
tainers with a fine mesh to prevent the
breeding of mosquitoes.
Dualflush
Dual flushvalve
valve
• Install water-saving faucets in the sink,
if possible. There are several different
kinds—from the most sophisticated that
automatically cut off water flow after a
given time period, to those with a small
lever at the faucet’s center to adjust
overall pressure (figure 10).

Figure 10. A type of water-saving faucet

Water-Saving
Water-saving
faucet
Faucet

Pressure
Pressure Time
TIme Censor
Sensor

22
New habits and behaviors Adopt alternative technologies
• Establish new ways to save water, and create posters con- There is a wide range of techniques and technologies to improve the
taining this information to educate the school community. way we use water—both drinking water and wastewater (gray and
The most simple ways to achieve significant water savings sewage water). Some of them (such as diffusers or low-consumption
include: toilets) will only help you save water, while others capture rainwater. Yet
- Shutting the tap while washing hands or brushing others treat and make wastewater reusable. These tools range from
teeth. sophisticated and high-cost products to replicas of natural ecosystems
- Turning off the shower while soaping up. If the school that are simple to build and maintain and much more economical.
offers shower facilities for athletes or workers, em-
phasize their role in this water-saving practice. As you read below, you will find some of the alternative techniques
- Watering gardens or filling containers in the afternoon available to schools, and recommendations for further reading. In some
or evening (to prevent loss by evaporation) and de- cases, you will need to rely on an expert or a person with experience
creasing the frequency of watering. and knowledge from your immediate school community or locale. Basic
- Not using toilets as trash cans. requirements for success are available space and the will to work hard.
• Eliminate or reduce the use of cleaning products with in-
gredients toxic to the ecosystem. Use organic soaps and When this work is performed as a component of a school project in-
detergents that have no phosphates and, without violating volving teachers and parents as volunteers, not only is water manage-
any hygiene rules, use natural cleaners such as white vine- ment provided, but the cohesion of the school community and social
gar for cleaning glass. networks is also strengthened.

Dry toilets
Although building dry toilets is not possible in all situations, they can
be an excellent option in rural schools with yards, areas where water is
scarce, and communities with no access to town drainage networks.

Dry toilets offer several advantages: they do not use water, do not
require a sewer system, do not pollute bodies of water (because the
organic material first breaks down in the decomposition chambers),
can produce compost, and are easy to build and maintain.
A dry toilet essentially separates solid waste from liquid. Solid waste
accumulates in a treatment chamber consisting of a tank, where it is
broken down slowly and eventually transformed to compost.

23
 Artificial wetlands and biofilters There are two types of wastewater treatment devices—those that use
Artificial wetlands replicate the action of sewage treatment plants surface flow and those that use subsurface flow. In the first instance,
and the aquatic ecosystems known as wetlands (which include lakes, water flows on the surface and is exposed to the environment; in the
lagoons, rivers, marshes, estuaries, swamps, and so on). The role second, water flows underground. The second option produces no bad
that these ecosystems play in the world is crucial: they are import- smells, does not foster mosquitoes, and is easy to maintain. It is also
ant retainers of carbon dioxide (CO2) and they generate oxygen (O2). the best option for a school because of the safety it affords: students
Moreover, they protect many diverse creatures, serve as shock absorb- are not tempted to play in the water. Just as with dry toilets, the con-
ers against the impact of natural phenomena such as cyclones and struction of biofilters is a great opportunity for rural schools.
storms, and help filter and clean water.
Figure 11. An artificial wetland

Tope de agua Wetland

WETLAND
plants
PLANTS

PEA
Pea RecycleMOUND
RECYCLE mound
GRAVEL
gravel with2 2INCHES
WITH inches OF
of
largeMULCH
LARGE mulch
PEA
Pea GRAVEL
gravel
2
11

Water level
INFLOW
Inflow
OUT FLOW
Length
LENGTHof IN Outflow
LARGE
Large flow
screened DIRECTION OF FLOW
SCREENED
river gravel
RIVER GRAVEL
24
 Building a wetland calls for certain space and soil constraints:
• Wetlands require roughly 3 square meters (m2) for ev-
ery 10 users, which means that a school of 100 people
would require 30m2 of biogarden or artificial wetland.
• Soil that is impermeable or exposed to very high rainfall
is not suitable for wetlands. Consult an expert to assess
soil conditions.

Figure 12. Covered or underground or subsurface wetland

Top of berm
Riprap
TOP OF BERM
RIPRAP
Sandy,
clay loam
Sandy,
Water level
clay loam
TOP OF WATER
Liner Liner
LINER LINER Outflow
Inflow
INV IN INV OUT
Length of flow
LENGTH IN
DIRECTION OF FLOW
25
 Permeable paving
The waterproofing of most current buildings requires rain water to
flow into drainage systems, which prevents it from contributing to the
loque, adopasto, and so on. Any construction material warehouse will
underground aquifers. If your school has or needs to have covered soil
give you more information.
spaces, build them with permeable paving. This allows water to pass
through. This material creates a yard in areas that have to be covered
Moreover, you have to take precautions to ensure that the permeable
with soil (useful for a play area, park, or sports court) or are used for
paving is a genuinely environmentally friendly option. If the area is used
vehicle transit, while allowing water to filter into the subsoil.
as a parking area as well as a patio, drippings of oil, gasoline, and oth-
er car-related liquids could contaminate the water by seeping into the
Some kinds of permeable paving must be installed by specialists; there
garden or water table. You must guard against this. Finally, permeable
are also options that anyone with basic building knowledge can install.
paving cannot withstand high-density traffic or heavy vehicles.
Each region has its own name for such materials: cobblestone, adob-

Figure 13. Permeable paving

Allows
Allows
evaporation
evaporation
Lets
Allowssow grass
for grass
and plants
and plants
Allows the
Allows the
passageofof
passage
Permeable
Permeable
water
water paving
paving
Cobble
Cobble

Bed
Bed Seat
seat

Underground
Underground
drainage forfor
drainage
soils with low Seat gravel
Gravel bed
Granular
Granular
soils with low
absorbency base
base
absorbency

26
Collecting rainwater from roofs The catchment, or collection, of rainwater is not a new practice. In
many countries, especially in urban areas where water can become
During the rainy season, it is estimated that over 80 percent of the scarce, people collect water for irrigation, housecleaning, and
water flowing in drainage areas is rainwater that could be collected drinking. Most collection systems are simple containers placed at the
and used. end of gutters to collect the water that runs off roofs.

Figure 14. Rainwater collection system

Rainwater Collection system

Rainwater collection System
Rainwater colec-
Rainwater Green water supply
Rainwater
collection pipes colection pipes
tion pipes
Rainwater
Rainwater Rainwater filter
Rainwater filter
overflow drain
overflow drain
Control box
Control Drinking
Drinking water tap
Outside
Outside box Mains water water tap
taptap
Mains water
supply pipes
supply pipes

27
 This simple and useful educational practice can decrease the pressure - A simple plan involves installing gutters on the roofs
exerted on the area’s water resources and make more gardening and directing the water toward garden areas that
projects possible. need more moisture.
- A complex plan can be as elaborate as the uses
Rainwater collection can be performed through these steps: to which you would like to devote the water. If you
• An analysis of conditions at the school during the rainy sea- want to use rainwater for irrigation or toilets, include
son: Where does the rain on the roof flow? Are there gutters an area for collection, piping, filtering, storage, and
to collect it? Are roofs in good condition? Is there space in distribution. If you also want to use it for human
the schoolyard to place large containers for collection? consumption, you must have a treatment plant to
ensure the health of those who drink it.
• An analysis of the school’s financial status to decide wheth-
er to develop a simple or complex plan to collect rainwater,
based on planned water use (figure 15):

Figure 15. Rainwater harvesting techniques

Water Water
harvest for irrigation WaterWater
harvest for human
Simple
Simplewater
water harvest
harvest harvest for
and sanitation
harvest for
consumption
irrigation and sanitation human consumption
area
area ofof area
areaofof areaareaofof
collection
collection collection
collection collection
collection

filters
Filters

filters
filters
treatment
treatment
drain
Drain
irrigation
irrigation storage
storage distribution
distribution storage
storage

forforirrigation
irrigation
andandsanitation
sanitary

Source: Adapted from Water Use and Conservation Bureau, A Waterwise Guide to Rainwater
Harvesting (New Mexico Office of the State Engineer); www.ose.state.nm.us/.
28
Monitoring and
evaluating progress
The first indication that your plan is progressing well is the water bill.
Log such bill amounts monthly or as frequently as they arrive at the
school.

If the school does not get water bills, you can keep a record of water
meter readings. This will allow you to see how much you have spent
every month and to adjust your plan accordingly.

If your consumption remains very high despite your campaigns and

new technologies and techniques, you may have persistent major
leaks. If so, audit the leaks.

One indicator that your plan is functioning well is a reduction in the

presence of toxic cleaning products—which ensures that the water
that you are sending down the drain or to a wetland contains no highly
toxic pollutants.

Finally, monitor interest in participating in the project. Regularly ask

participants about their experiences with the program. Ask what they
would change, and what new interventions they would like to promote.

29
 Tips for finding
financial support
An important part of the research involves visiting the offices
responsible for managing the water system in your hometown and
asking for information (that is not possible to collect through your
diagnosis) and training. These professionals can explain to you how
the water system works in your town and region. Many of these
institutions provide training in environmental education that might be
of great help to the school staff.

These offices may also offer advice on possible funding that enables
you to initiate projects and improve water management at your
school. In many parts of the world, such institutions have initiated
technology replacement programs for restrooms and other re-
source-saving devices.

30
 Bibliography
• ACEPESA (Asociación Centroamericana para la Economía, la • National Institute of Ecology, INE Portal on Sustainable Housing.
Salud y el Ambiente). 2010. Manual para la Construcción y 2010. “In the Bathroom.” http://vivienda.ine.gob.mx/index.php/
Mantenimiento de Biojardineras. II Edición. San José, Costa agua/usos-en-el-hogar/en-el-bano.
Rica: ACEPESA. http://www.scribd.com/. Recommendations • Pervious Concrete Pavement. “An Overview.” http://www.pervi-
and guidelines for the construction of artificial wetlands for ouspavement.org/.
wastewater treatment.
• SACM (Sistema de Aguas de la Ciudad de México). “Catalog of Water
• Adler, Ilán, Gabriela Carmona, and José Antonio Bojalil. 2008. Saving Products and Devices, Alternatives for the Efficient and Ra-
Manual de Captación de Aguas de Lluvia Para Centros Ur- tional Use of Water in the City of Mexico.” http://www.sacm.df.gob.
banos. UNEP and the International Renewable Resources mx. Provides a list of numerous water-saving devices that are already
Institute. http://www.pnuma.org. available on the market, and their features.
• Capital Regional District (of British Columbia, Canada). “Per- • SASI Group (University of Sheffield) and Mark Newman (University of
meable Pavement.” http://www.crd.bc.ca. Michigan). 2003. “Water for Domestic Use.” http://www.worldmapper.
• EPA (United States Environmental Protection Agency). 1993. org UNATSABAR (Technical Support Unit for Rural Sanitation),
“Subsurface Flow Constructed Wetlands for Waste Water Pan American Center for Sanitation Engineering and Environ-
Treatment, A Technology Assessment.” http://water.epa.gov. mental Sciences, Division of Health and the Environment, Pan
Recommendations and guidelines for the construction of arti- American Health Organization—Regional Office of the World
ficial wetlands for wastewater treatment. Health Organization. 2001. “Guide to Rainwater Catchment De-
sign.” http://www.aguasinfronteras.org.
• Fundación Agua Tuya. 2008. Manual de Construcción:
ECOSAN, Baños Ecológicos Secos. Cochabamba, Bolivia: • UNATSABAR. 2001. “Rainwater Collection Design Guide.” http://
Fundación Agua Tuya. http://www.aguatuya.watsan.net. Rec- www.aguasinfronteras.org UNDP (United Nations Development Pro-
ommendations and guidelines for building dry toilets. gramme). 2006. Human Development Report 2006. New York: UNDP.
• Guía de los baños secos. “Global Dry Toilet.” Club of Finland, • Urbanarbolismo. 2008. “Using Permeable Pavements.” http://
Tampere, Finlandia. http://www.drytoilet.org. Recommenda- www.urbanarbolismo.es.
tions and guidelines for building dry toilets. • Water Use and Conservation Bureau. A Waterwise Guide to Rain-
• Hoekstra, A. Y., and A. K. Chapagain. 2007. “Water Footprints water Harvesting. New Mexico Office of the State Engineer—
of Nations: Water Use by People as a Function of Their Con- USA. http://www.ose.state.nm.us/
sumption Pattern.” Water Resources Management 21(1): • World Bank Group, Depweb. “Access to Drinking Water.” http://
35–48. www.worldbank.org

31
 Module 5
Sustainable Water Management
Marina Robles, Emma Näslund-Hadley, María Clara
Ramos, and Juan Roberto Paredes

2015

Rise Up Against Climate Change!

A school-centered educational initiative
of the Inter-American Development Bank