International Conference on Rain Water Cistern Systems
USA - June 1982
1: History Of Cisterns
Lessons of History in
the Design and Acceptance of Rain Water Cistern Systems
University of Oklahoma, USA
Technology is the application of science to the resolution of a current problem.
There are several sub-classifications, such as intermediate technology, appropriate
technology, retrogressive technology. If one were to advocate the use of cisterns
today, it would be retrogressive technology because in early times-about 2000
B.C. - in the Middle East (Ancient and Medieval), typical middle class dwellings
stored rain water in cisterns; irrigation works were used as a domestic supply,
private bathing facilities for the wealthy, and sewage and solid wastes deposited
in streets and open spaces. During the 8th century, the Greeks (Olynthus) used
aqueducts of terra-cotta pipes; houses with bathrooms, cisterns, lavatories, and
a waste pipe running through the outside wall to the street; a central alley in
each block for drainage; and covered brick masonry drains.
Hippocrates advocated boiling water for disinfection and prevention of odors,
as did the Egyptians (47 B.C. Alexandria) where prominent families were provided
Thus, one can envision technology being applied and perfected, as required
by one's environment. This leads to the conclusion that the technology used is
also a function of socioeconomic conditions. Historically, most development has
been associated with socioeconomic growth. The concepts of technological growth
are shown in Table 1 and that of life style in Table 2. A third variable would
be time (Table 3).
Now one might reflect on these ideas, first as one's life style shifts from
hunting and fishing, to agriculture, industry and to mass production. One progresses
(if that's the word) from rural to urban life, increased services, ultimately
70 to 80% urbanization, 70 to 75% service employment and 3 to 5% in agriculture;
and develops progressively, resource strains, pollution and scarcities. Water
requirements escalate from 1 to 2 litres/person/day to 8000 litres/person/day
because of large irrigation and industrial components. Water service increase
needs in the home from 7 to 8 litres to 400 to 500 litres/day. Eighty to 90% of
the water used is contaminated, and needs treatment before recycling can occur.
Thus, in successive order, water requires treatment, then is discharged as sewage,
and finally is a reuse product.
Outlook on Ancient Cisterns
in Anatolia, Turkey
Ege University, Turkey
Evidence of human civilization in Anatolia goes back to millions of years:
remains of civilization date back to the VII millennium B.C.; those of water works
to the II millennium B.C. These ancient water works also included cisterns which
played a certain role in water supply throughout the entire history of our country
either as the only source or as an emergency water system.
Present day efforts in collecting rainfall precipitation directly into cisterns
is somewhat similar to the harnessing of solar energy. Almost one third of the
solar radiation reaching the earth's crust drives the hydrological cycle and thus
creates renewable fresh water and water power potential. Although actually only
one-fifth of the economically feasible hydroelectric potential is exploited, with
regard to spatial distributions of the water power potential and to time projections
of energy needs, man actually tried to directly exploit solar energy.
Similarly, the need for fresh water in areas of scarce surface water or groundwater
resources may be met by direct collection of precipitation and storage in cisterns.
Besides the opportunities lying in modern mathematical methods to deal with the
hydrological process involved, the physical application of this mode of water
supply is thousands of years old.
In this respect, Anatolia was the crossroads of civilizations and can perhaps
be considered as an open air museum of ancient water works, showing the greatest
richness and variety on earth.
During the seminar session concerning ancient hydraulic works of the XVII I.A.H.R.
Congress, nine contributions dealing with historical water works in Anatolia were
presented (I.A.H.R. 1977); the same subject was also part of the IXIII I.A.H.R.
Congress and included new contributions (Ozis et al. 1979). The author presented
a key paper at the opening of the sixth T.B.T.A.K. Science Congress (Ozis 1978),
a special bi national symposium held in Istanbul, Turkey (Braunschweig 1979).
It should be noted that the History of Hydraulic Engineering is offered as an
elective course in the Civil Engineering Faculty of Ege University.
So, like all ancient water works in Anatolia, cisterns too deserve special
interest. This paper is intended to provide a brief outlook on ancient cisterns
History of Yucatan Cisterns
University of Yucatan, Mexico
Instituto Regional de Antropologia e Historia, Mexico
Universidad Nacional Autonoma de Mexico, Mexico
The development of civilizations is always associated with sources of fresh
water - the more usual sources being natural rivers or lakes. In some cases, the
state of technical development permits the settlement of cities where only rain
water is available. The systems constructed to collect and store rain water are
historically the oldest hydraulic works. This system is practiced all over the
world under the same principles: a catchment area that collects rain water, a
transport system that conducts the collected water and a storage vessel where
the water remains until needed. The differences vary according to the type of
material, ecological/economic conditions and the state of the architecture or
design. Here is a brief presentation of the ways developed by the Yucatecans settled
in the Peninsula of Yucatan - the Mayas and modern inhabitants. The observations
and data were obtained from different studies and direct observations and measurements
of the authors. The presentation covers the beginning of the classical Maya period
(300 A.D.) to the present.
Present and Past Development
of Catchment Areas in the Mediterranean Coastal Desert of Egypt
Desert Institute, Egypt
The Mediterranean Coastal Desert of Egypt comprises a narrow zone having an
east-west length of about 1,000 km and a north-south width of about 20 km. This
coastal desert, located between the Cyrenaican Massif (+700 m) to the west and
the Negev-Lebanon Massif (+2 000 m) to the east, occupies a portion of the great
Sahara Desert of Africa and extends northward to the Mediterranean Sea (Fig. 1).
The climate of this coastal desert differs from the inland desert areas to the
south, and is characterized by winter rainfall of 150 to 300 mm frequent and comparatively
high periods of humidity, and small diurnal temperature variations.
This paper deals with the western portion of the coastal area, which is historically
known as the Mareotis District. The district extends westward to the Libyan border
and was once an area of prosperous cultivation. But by the 10th century, the area
gradually declined and changed into an almost desert tract. As discussed by Kassas
(1972), it is "unlikely that there have been major climatic changes during
the last 2000 years that could have caused the deterioration of this area."
Facts obtained from the work carried out in connection with the dating of groundwater
using carbon 14 techniques (Shata et al. 1962) support this conclusion and show
that the last rainy interval coincided with the "Late Wurme" some 7000
years before. The coastal area "must have depended for its cultivation on
dry farming that included methods of water management and conservation."
In this paper on the development of catchment areas, emphasis will be given
to the following tow methods used since Roman times in the Mediterranean Coastal
Desert area: (1) cisterns and (2) Karms or vineyards. Before describing the details
of such systems based on personal experiences and on information available in
the literature (Hume and Hughes 1921; De Cosson 1935; Shafie 1952; Paver and Pretorius
1954; Murray 1955; Kassas 1972), the physiographic features and the water resources
of the area will be discussed.
Rain Water Cistern Systems
for the Himalayan Region
Gupta & Vidya Sagar Katiyar
Central Soil and Water Conservation Research and Training Institute, India
The Himalaya receives very heavy to heavy rainfall during the monsoon months
of July to September. The annual rainfall varies from 900 to more than 2 000 mm
in the western Himalaya, and even more in the eastern Himalaya of Assam, the location
of Chirapunji, which means "always raining". During the monsoon months,
the region receives more than 80% of the total rainfall.
Most of the rainfall is lost as runoff into streams and rivers and causes problems
of flooding in the lower reaches of the rivers. Acute scarcity of potable water
is experienced in the region. Rural women are the worst sufferers because they
have to walk long distances to fetch drinking water from far-off streams and springs.
Due to heavy deforestation in the catchment areas, perennial springs supplying
potable water have dried. Rainwater cistern systems could easily meet drinking
water requirements in many areas, while in others, water could be harvested for
livestock and life-saving protective irrigation.
M. Crasta, Costantino A. Fasso, Francesco Patta and Giorgio Putzu
University of Cagliari, Italy
The island of Sardinia remained a Phoenician-Carthaginian colony for about
a millenium. The Phoenicians first began to settle on the island during the 9th
to 7th century B.C., founding several ports of call to carry out trade by sea.
Of these ports, Cagliari, Nora, Bithia and Tharros are evidence of the role that
the island's southern coast played in supporting the commercial routes of the
The types of rain water cisterns most commonly used in the period considered
here are the "bath-tub" and "flask" cisterns. Some examples
of large cisterns, which will be referred to as "cave" cisterns, have
also been discovered in Cagliari.
2: Rainfall Analysis
Stochastic Dynamic Models
for Rainfall Processes
Oklahoma State University, USA
University of Hawaii at Manoa, USA
In recent years, there has been a revival of interest in using rain water cistern
systems (RWCS) as a supplement to rural and urban residential water supply (Fok
et al. 1980; Fok, Murabayashi, and Fong 1979). The reasons for this have been
the increasing demand for water and the lack of adequate supply. Curtailment of
new urban developments and limits on new house-building permits because of water
shortages have been reported in many areas, such as Orange County, California
and all the counties o£ Hawaii. In addition, it may not be feasible in some
areas-the Hawaii Volcanoes National Park, for example - to install pipelines for
water supply (Wentworth 1959). Fok, Murabayashi, and Fong (1979) find that for
residential houses located in areas with an annual rainfall of about 508 mm (20
in.), RWCS's may be feasible and cost effective as their main or supplemental
source of water supply.
To properly design and operate a RWCS, it is necessary to understand the dynamic
and stochastic nature of rainfall processes. These processes evolve continuously
in time, thus suggesting models of differential equation form to describe their
characteristics. However, since rainfall data are often collected at a series
of discrete points in time, differential equation models can be directly used
to fit such data. The parameters of the estimated discrete model can then be used
to construct continuous time models if the data have been obtained through uniform
sampling of the continuous process. The details of such a procedure for modeling,
predicting, and simulating rainfall processes are explored in this paper.
Stochastic Model of
Daily Precipitation using the Time Series Methodology
University of Yucatan, Mexico
Universidad Nacional Autonoma de Mexico
The Yucatan Peninsula, situated in the eastern part of the Mexican Republic
(Fig. 1), has geological conditions that necessitate the proper management of
its water resources. The aquifer of this peninsula is of the calcareous type (Lesser
1976). Here, the limestone in the study area is covered in some places by just
a few centimeters of soil (Gaona, Gordillo, and Villasuso 1980). The area is relatively
flat, and there are no rivers and lakes. For this reason, groundwater and precipitation
are the only sources of water that can be considered.
In this region, the groundwater has a high content of carbonates and is frequently
contaminated by injections of municipal and industrial wastes that infiltrate
to the groundwater table. It is for this reason that we consider precipitation
as the most viable way to obtain potable water for human consumption. Although
rainfall catchment was a very common source of water in the past, the actual design
of an adequate system for catchment storage and the management of pluvial water
requires more scientific studies.
The first of these studies consists in the development of a statistical model
of rainfall by using historical data to plan the tank volume and their catchment
Presented here is the statistical analysis of the data and the way in which
it will be used to design the cistern, including the results.
The data consist of the daily rainfall-depth measurements corresponding to
the past twenty-five years from one of the forty meteorological stations that
exist in the Yucatan Peninsula-that which is situated in the city of Merida. A
microprocessor Radio-Shack TRS-80 model was used for the analysis, which was done
on a daily basis, to obtain results that can be used in other areas even though
it was not necessary for our purpose.
Estimation of Extreme
Point Rainfall Over Peninsular India
P.R. Rakhecha and A.K. Kularni,
Indian Institute of Tropical Meteorology
In November 1980, the United Nations launched International Drinking Water
and Sanitation Decade (1981-1990) to focus world-wide attention on providing safe
drinking water. In India there are still villages and towns in various parts of
the country where people have to carry water from long distances for their daily
use in spite of the fact that we have tremendous water resources which are replenished
year after year by rainfall during the monsoon months.
It has been estimated that the average annual rainfall of the contiguous Indian
area is about 117 cm of which about 76% is received during the four monsoon months
of June to September (Dhar, Rakhecha, and Kulkarni 1979). This much rainfall is
estimated to generate annually a surface flow on the order of 1 881 bil m3 (Murthy
1977). Apart from this, this country has groundwater resources which are on the
order of 350 mil m3.
Because the main goal of the International Drinking Water and Sanitation Decade
is to provide safe drinking water in sufficient quantity, an attempt has been
made in this study to find out what the maximum probable rainfall or the extreme
rainfall is that a station can get in the peninsular region of this country. This
information, would not only be useful in knowing the extreme amount of rainfall
that is physically possible over a station or a basin, but is also useful for
the safe design of hydraulic structures that may be constructed for conservation
of water in this region of India.
of Weekly Rainfall at Bahadrabad, India
National Institute of Hydrology , India
Mohan & S.S. Tiagi
U.P. Irrigation Research Institute, India
The state of Uttar Pradesh, which is extremely diverse in topography, climate
and vegetation, ranks fourth in area and first in population in India. Because
of the rapid growth in population, intensive urbanization and industrialization
is taking place in the basically agricultural areas in the foothill regions of
the Himalayas. Rainfall in this region occurs during the monsoon months of June
to October with most of it occurring July and August, with some rainfall during
the non-monsoon months. During the monsoon season, there is considerable variation
in rainfall in time and space. To provide information regarding expected levels
of rainfall at different time for planning drainage requirements, the analysis
of statistical characteristics of rainfall in the area is necessary.
The meteorological observatory at Bahadrabad, established in 1952, is situated
at 29°55.5' east latitude and 78°2.25' north longitude at an elevation
of 275 m above mean sea level. Its climatic observations are representative of
the foothill region of the Ganga-Yamuna interbasin. The observatory is equipped
with recording and non-recording types of rain gauges. The weekly rainfall for
1955 to 1980 for the monsoon season (1 June-1 November) has been used in the present
study. The maximum weekly rainfall of 395.7 mm during this period occurred in
the week of 3 to 9 August 1978.
for the Characterization of Rainfall Time Distribution
University of Quebec, Canada
Information on variations in rainfall time characteristics is always necessary
in various types of hydrologic studies concerning the planning, design and operation
of water resources systems.. Most previous research on the time distribution of
rainfall usually involved the study o temporal distributions of "rainfall
exteriors" characteristics, such as total event depth, total event duration
and time between events, but very few studies deal with the time distribution
of rainfall within each individual vent or the temporal pattern of each event.
The objective of this study is to provide basic information on the variability
of temporal patterns based on the probabilistic characteristics of an actual rainfall
record. Information concerning the nature of the temporal distribution of rainfall
within a rainfall event is usually presented as a mass curve of accumulated depth
as a function of time. The purpose here is to ascertain the probability distributions
of rainfall accumulated at the end each time unit within such a total rainfall
First, a general theoretical model will be proposed, and then a numerical application
will be presented by using a 32-year record of daily rainfall at Dorval Airport
on Montreal Island (Canada). In the numerical example, the daily precipitation
is selected because relatively long and reliable records are readily available
and such data are frequently sufficient for many practical problems. The model,
however, might be used for hourly rainfall (Nguyen and Rouselle 1981) and for
rainfall durations of one ay or longer.
Deterministic and Probabilistic
Processes of Weekly Rainfall
Ronald H.L. Fong, Edwin T. Murabayashi and Andrew Lo
University of Hawaii at Manoa, USA
In the design of rain water catchment cistern systems, the following design
variables are considered essential:
- Input (weekly rainfall)
- Catchment area (roof-top area)
- Storage capacity (cistern volume)
- Output (withdrawal/use).
Of these, the weekly rainfall is the only design variable that is uncontrollable
and unpredictable. Thus, to design an adequate water catchment cistern system,
the weekly rainfall must be estimated, using available statistical methods from
existing rainfall records. In this paper, the deterministic and probabilistic
processes of weekly rainfall data are discussed and presented for design purposes.
in Optimizing Rainwater Catchment Systems
Schiller & Brian Latham
University of Ottawa, Canada
Use of rainwater Collection
Systems in Canada
Rainwater collection systems (RWCS) have been widely used in Canada from the
time of the early settlers. The tradition was brought from Europe and fitted well
with the needs here. In the older farm areas, such as that around Ottawa, a cistern
was a common part of a farmhouse as it provided soft water for washing and bathing-
a necessity with natural soaps. Drinking water was obtained from a well or spring,
if available, because of the mineral content which "quenched" thirst.
Presently, RWCS's are still in use on farms in Ontario and on the prairies
of the west where groundwater may be saline and farmhouses are separated by great
distances. In many coastal areas, such as the Atlantic area of Nova Scotia, the
terrain is rocky with little or no soil cover. A central water system is difficult
and prohibitively expensive to install. However, coastal areas have high, consistent
rainfall and moderate temperatures which make a RWCS an attractive drinking water
Another area for use of RWCS's that may show great promise in the future is
the northern regions of Canada. During the warm season, RWCS's could provide safer
drinking water. Fully reliable, year-round systems would not be practical because
of the long freeze up during the winter period.
In all of these remote areas, a RWCS represents a least-cost option because
of the isolation of individual users, the unsuitable quality of groundwater or
the sheer unavailability of fresh water. Estimates o£ costs for setting
up a system will depend on many factors, but are reduced because of the nature
of Canadian houses. Much of what is required is already constructed in the house
and cannot be charged exclusively to the RWCS. Roofs are generally large and pitched
(to carry away the rain and snow). A sealed basement with poured concrete floor
and walls and plumbing is standard. Hence, one and possibly two walls are available
for use in tank construction. In areas without a central water system, a pump
and pressure tank are standard equipment and are not an additional cost due to
Hydrographs for Roof-Top
Runoff Under Varying Rainfall Conditions
Flood Control Dept. Gauhati, INDIA
University of Roorkee, INDIA
With increasing population, water supply systems may fail to satisfy the demand
for water. In arid and semiarid regions, especially, the source of water is often
depleted. Rain water collected from roof surfaces and utilized through cistern
systems can augment the usual domestic supply without large expenditures or energy
and can thus meet water shortages.
To design gutters and a cistern system, knowledge of the water surface profile
and flow hydrograph is necessary. The kinematics of flow over roof surfaces can
be determined from available studies of overland flow. Many investigators have
dealt with the problem of overland flow under uniform, excess rainfall either
by using the method of characteristics (Behlke 1957; Henderson 1964; Wooding 1965;
Morgali and Linsley 1965; Abbott 1966; Brakensiek 1966) or by solving the mass
balance equation by assuming a linear relationship between outflow and storage
(Horton 1938; Izzard 1944). Wooding (1965) has dealt with the problem of overland
flow under a constant, uniformly distributed rainfall of finite duration with
an analytical solution for a hydraulic model based on the method of characteristics
for flow over a plane, which is part of a V-shaped catchment. In reality, the
rainfall intensity is not uniform; instead, the distribution is skewed. The typical
time variant design of rainfall distribution patterns described by Rodda, Downing
and Law (1976) for a 10-year, 5-year and annual return frequencies are shown in
Figure 1. Water surface profiles and flow hydrographs for roof surfaces for such
design storms can be determined for different intervals of time by using the characteristics
3: Design, Cost, And Policy
Design Strategy for
Domestic Rainwater Systems in Australia
University of New England, Australia
Any closed rainwater supply system involving a sealed or almost impervious
catchment, a storage and a linked supply point may be characterized by some general
relationships regardless of the size of the system. This paper presents the results
from a simulation model of the operation of such water supply systems at four
locations in New South Wales, which are representative of the range of rainfall
regimes in Australia. The results are presented in the form of generalized design
graphs. Although this study refers particularly to Australia, the principles involved
are applicable to any rainwater supply system.
of Rain Water Cistern Systems as an Urban Water Supply Source
Kyoto University, Japan
New Japan Engineering Consultant Company, Japan
In the past, dam reservoirs were constructed to meet the increasing water supply
demand as a result of the growth in population and urbanization. In recent years,
however, social pressures and environmental controls have made it more difficult
to construct dam reservoirs; thus, a comprehensive water supply system has become
an increasingly important planning guide. With this in mind, we propose the integration
of rain water cistern systems into existing water supply systems.
In Japan, there are a few examples of rain water cistern systems that are limited
to the roof catchment and storage of rain on individual buildings or houses. Judging
from the scale effect and the operation and maintenance of this system, the collective
form seems to be more efficient and effective than small, individual rain water
cistern systems. As presented in this paper, the collective form of rain water
cistern systems relates to the expansion of roof catchment areas of many buildings
in the urban area. The assets of this sort of system are threefold: (1) a supplemental
source of potable water to the existing water supply system, (2) a means of diminishing
and utilizing storm runoff, and (3) a method of decreasing the amount of treatment
necessary for the combined sewer system.
Determining The Desirable
Storage Volume Of A Rain-Catchment Cistern System: A Stochastic Assessment
Leung & Yu-Si Fok
University of Hawaii at Manoa, USA
The four major design factors for rain-catchment cistern systems are rainfall,
catchment area, storage capacity and water demand. Of these, only rainfall is
uncontrollable by the system designer. In most cases, the size of the catchment
area or roof is largely predetermined for an existing structure. The initial basic
decision for the cistern owner is to determine the minimum storage capacity which
can satisfy the water demand. The minimum storage capacity can be easily determined
if given a set of deterministic rainfall for a fixed planning horizon. Most studies
(Fok et al. 1980; Wentworth 1959) used the worst rainfall occurrence for the design
of the storage capacity without looking into the impact of the stochastic nature
of rainfall on storage capacity design. The present study suggests using computer
simulation to determine the probability distribution of the minimum storage capacity
required. This will provide additional information to the cistern owner in deciding
on the necessary storage capacity. The historical rainfall pattern at the Manoa
Tunnel station on the island of Oahu was analyzed and used as a case study.
Optimal Catchment Design
by Marginal Analysis
The University of New, USA
Rainwater Catchment Design
In many regions, roofing and cisterns provide a simple hygienic household water
supply (Black and Popkin 1967; Bonilla 1967; Gillis 1967; McJunkin 1969; Ree 1976;
Roberts 1967; Wagner 1959; Watson 1915, pp, 278-279; Watt 1978; USPHS 1962). An
optimal allocation of resources for construction of such household rainwater catchment
systems may be determined from basic engineering principles. Computer simulation
may be used to investigate the effect of alternative combinations of rainfall,
catchment area, storage volume, and water use rate on the adequacy of supply.
Marginal economic analysis may be used to find that scale of facilities maximizing
net benefits. Optimal system design includes: (1) precipitation synthesis, (2)
water deficit calculations, (3) isodeficit curve construction, (4) isoquant analysis,
and (5) optimal scale identification.
Design And Calculation
Of Rainwater Collection Systems
West Java Rural Water Supply, Indonesia
Dry seasons occur even in monsoon areas. If there are no nearby wells or rivers,
people will walk long distances t o obtain water. A solution to this problem may
be the catchment of rain water-an ancient custom still practiced in many countries
in the world where rainfall is collected during the wet season t o use in the
dry season. The questions are (1) what should the volume be of such a rainwater
collection system and (2) how should such a collector be designed?
Application of Gould
Matrix Technique to Roof Water Storage
Queensland Institute of Technology, Australia
Gutteridge, Haskins & Davey, Australia
The dependence of many Australian homes on roof and tank rainwater collection
systems. has been discussed in detail by Perrens (1975), Perrens used a monthly
simulation model to relate roof area, storage capacity and demand to probability
of failure at Armidale in New South Wales. He drew economic comparisons between
extending the system capacity and buying water when the system failed to meet
the required demand.
Durham (1980) and Schiefelbein (1981) used the Gould matrix technique (McMahon
and Mein 1978) to determine probabilities of failure of a roof-tank system, rather
than to rely on critical period methods. These studies were initially made for
Brisbane and subsequently for a number of selected climatic zones within Queensland
as part of a continuing programme.
This paper covers some aspects of the work initiated by Durham (1980) and continued
by Schiefelbein (1981):
Assessment Of Rainwater
Catchment and Storage Systems on Majuro
A. Stephenson, Hiro Kurushina, & Stephen J. Winter
University of Guam, USA
This paper focuses on a discussion of freshwater supply systems in Micronesia.
Particular attention is paid to the conditions within a small Micronesian atoll
environment of the Marshall Islands, the village of Laura on Majuro atoll.
Initial fieldwork during July to August 1981 revealed that a paradox exists
between the abundant availability of fresh water as rain water and ground-water
on the one hand, and frequent shortages o£ fresh water, on the other. In
the course of earlier field research by Winter and Stephenson (1981) in the Eastern
Caroline Islands, Micronesia, the same paradoxical condition was found to exist.
We suggest that the paradox exists because of an inadequate management of water
supply and water storage systems in Micronesia. We further suggest that economic,
technical and social factors may be related to this phenomenon. The paper describes
the study area in the Marshalls, discusses local water supply and storage systems,
examines attitudes towards the use of groundwater versus rainwater catchment,
and attempts to explain why rain water is not utilized , more extensively than
it is. The paper concludes that, as water consumption is most likely to increase
along with modernization in Micronesia, government plans should provide for increased
Policy for a Rain Water Cistern System
Lo & Yu-Si Fok
University of Hawaii at Manoa, USA
Rain water cistern systems have long been a water supply source in many countries.
In some rural areas where municipal water is limited or unavailable, rain water
for domestic use is caught on roofs and stored in water tanks. To design an efficient
catchment system, adequate catchment area and cistern capacity in relation to
water demand are factors that have to be carefully selected and designed to suit
the rainfall pattern of the design area. If the average rainfall could be daily
obtained, only enough catchment and storage would be needed to satisfy respectively
the daily water demand and peak loads. However, there are many areas with frequent
droughts that can last for months. Severe water shortage problems emerge even
with extremely large catchment and storage. To alleviate such problems, the operating
rule of the catchment system must be modified. Appropriate water use reduction
imposed prior to the onset of dry weather may save enough water to last through
The following sections describe a linear and a non-linear reduction strategy,
and their performance is compared to the classical unadjusted operating policy.'
Conclusions are then drawn in relation to the proper form of rain water cistern
system operation policy.
Reliability of Roof
Runoff in Selected Areas of Indonesia
Meteorological and Geophysical Service, Indonesia
Institut Pertanian Bogor (Agricultural University), Indonesia
Indonesia, an archipelago of about 12,000 islands spread 4 000 km east-west
across the equator (Fig. 1), has a population approaching 160 million, with an
estimated $350 (1970) per capita gross domestic product, of which oil production
represents about 18% and agriculture about 32%. Approximately 65% of the population
lives on the island of Java (including the adjacent island of Madura), which has
an area of only 132 000 km2, or less than 7% of the total land area. Other densely
populated areas include Bali and Lombok, and the province of Lampung at the southern
tip of Sumatra. More than two-thirds of the population live in rural areas, generally
in villages or small towns, and engage principally in subsistence agriculture.
Rice is the main crop; others of importance are maize, cassava, soya beans, copra,
tea, coffee, rubber, palm oil and sugar.
The mean annual rainfall ranges from less than 1 000 mm in a few small areas
(e.g., Palu Valley, Saluwest) to over 4 000 mm in exposed coastal areas and parts
of Kalimantan and Irian Jaya. Estimates of mean annual rainfall and per capita
water availability for each of the main island groups are shown in Table 1.
The population is largely concentrated on islands with water resources below
the national average. This situation is aggravated by the seasonal pattern of
rainfall that is most marked in the southeastern islands of Indonesia: Timor,
Nusa Tenggara (Flores, Sumba, Sumbawa, Lombok, among others), Bali and Java, which
have a "dry" season from May/June until September/October. Rarely does
a month receive no rain at all, even in the dry season, except in Timor and the
lightly populated parts of Nusa Tenggara where the wet cultivation of rice is
only possible during the wet season and transition periods, unless advanced irrigation
is practiced. Elsewhere in Indonesia, rainfall has a less marked seasonal pattern,
and cropping throughout most of the year is possible in many areas (Oldeman, Las,
and Darwis 1979; Oldeman and Syarifuddin 1977). Surface water resources are consequently
more reliable in those areas than in Java and the islands to the southeast.
Rain generally occurs about 120 days per year, typically, as intense bursts.
Pan evaporation is relatively uniform-spatially and temporally-being about 1 500
Public water supply is reticulated only in the largest towns and cities of
Indonesia; elsewhere, the source of water is from streams or wells, or from stored
roof runoff. During the dry season, people walk several kilometres or more in
many parts of southeastern Indonesia to obtain water.
The Indonesian government is implementing a series of five-year development
plans. The current plan, REPELITA III, emphasizes the goal of equitable social
development as a result of the rapid growth in the value of exports (oil, timber,
tin, rubber), an expanding manufacturing sector, and improvements in agricultural
productivity. Transmigration from Java and Bali to the outer islands is being
encouraged, and a successful family planning program hopefully will limit the
population explosion. In line with the United Nations' International Drinking
Water and Sanitation Decade, Indonesia is promoting the improvement of water supplies
as a basic step toward better health and welfare. Many of these projects are small
in scale and geared to rural villages, where the majority of the population lives,
and to which special programs are directed. One such program involves UNICEF (a
UN agency concerned with the welfare of women and children) and the government
of Indonesia for selected regions, mainly the poorer and relatively dry areas
of Yogyakarta, Madura, East Java and Lombok.
Little in the way of hydrological studies has been done to support the current
program to increase the use of roof-runoff systems in villages. Instead, the approach
has been to improve access to potable water and to allow villages to determine
the safe yield from experience. The United Nations Educational and Cultural Organization
(Unesco) decided to support a hydrological study, financed from its regional component
of the International Hydrological Programme (IHP), to demonstrate technology transfer
and the methods of applying technology appropriate to the needs of a developing
country. This is consistent with the rational use and management of national water
resources emphasis in the later phases of the IHP, and extends and is consonant
to the synthesis of scientific knowledge, education and training of the International
Hydrological Decade and the first phase of the IHP.
Village water supply projects are being implemented at numerous sites throughout
the nation. This hydrologic network, which should cover a broad area, is based
on planning that recognizes the large gradients of mean annual rainfall in the
typical mountainous terrain of much of the highly populated areas.
A large quantity of daily and monthly rainfall data are available in Indonesia:
the Dutch colonists were pioneers in the collection and study of such data. There
are at present over 3000 sites (whose station density roughly approximates the
population) that regularly report daily rainfall to the national Meteorological
and Geophysical Service. By 1922, there were already 2800 stations with. five
or more years of data; by 1941, this had increased to 4400 stations. The Pacific
War, the disruption during the struggle for independence and the political turmoil
of the 1950s and the early 1960s reduced the number of stations making regular
climate or rainfall reports; however, this has been redressed in the last decade.
A computer has recently been installed to store and retrieve climatological data,
and monthly rainfall has been published in yearbooks for more than 80 years, However,
the shortage of trained personnel in the provinces, and especially outside the
cities, means that these data are hardly accessible to many potential users.
It was therefore decided to carry out a regional study based on the UNICEF-GoI
programme of village improvement. The techniques developed might then be applied
elsewhere in Indonesia and generally in Southeast Asia by using local data to
obtain relevant statistical relationships. The area selected for study is broadly
from Yogyakarta to Surabaya (parts of Central and East Java), the island of Madura,
the drier parts of the island of Bali, Lombok and all of Sumbawa, an area of about
50 000 km2 with a population of about 20 million.
Rain Water as a Water
Supply Source in Bermuda
Technical University of Nova Scotia, Canada
Any description of rain water supply systems in Bermuda must take into account
the geography and history of this small mid-Atlantic country.
The island of Bermuda is located at 32° north latitude, 65° west longitude,
917 km east of the North American coast. The "island" is actually a
. series of seven small islands, joined by bridges, that are the unsubmerged portion
of limestone deposits, approximately 100 m from the sea floor. The aeolean limestones,
laid down during glacial advances and retreats of the Pleistocene era, are loosely
cemented and extremely permeable. The rock is covered by a soil layer approximately
15 cm thick.
The island is 30 km long, with a mean width of approximately 1.5 km and.a maximum
width of 3 km. The total area is 53.1 km2. The elevation of most of the land mass
is less than 30 m above sea level, rising to a maximum of less than 100 m.
The climate is semitropical and frost free. Mean monthly temperatures approximate
20°C in winter and 30°C in summer. The average annual rainfall, based
on records since 1886, is 146.8 cm (Vatcher 1974); minimum and maximum 12-month
rainfalls are respectively 77.0 and 227.6 cm. Rainfall is fairly uniform during
the year, but onlthly average values for April through July are lower than the
One result of the high permeability of soil and rocks is the absence of freshwater
streams and lakes. Groundwater underlies 20% of the land area, in five lens. The
largest lens, with a mean thickness of 7.6 m, represents two thirds of the total
area. Brackish water (1-10% sea water) underlies another 23% of the island (Vatcher
Bermuda today is a self-governing British colony.
The island was uninhabited until its discover in 1503. It has been continuously
occupied since 1609, when it was settled by English colonists who also colonized
Massachusetts and Virginia in the United States.
The first Bermuda houses were similar to those in England, but construction
quickly adapted to indigenous materials of cedar and limestone. Native cedar was
in short supply as early as 1620, and stone buildings were encouraged, using cedar
for framing and trim. The native limestone, which can be cut with a saw and which
hardens on exposure to the atmosphere, was cut into blocks for walls. Roofs, supported
on cedar framing, were formed of overlapping limestone slates, 30.5 cm x 45.7
cm x approximately 3.8 cm. Limestone, burned in kilns, also provided the mortar
used to assemble both walls and roofs. This form of construction is basically
the same as that used today, except that concrete block walls have replaced limestone
in recent construction: in 1980, 95% of households lived in houses with outer
walls of limestone ("Bermuda stone") or cement block (Statistical Department
A unique feature of Bermuda roofs has been their role in water supply. Until
the 1930s, rain water provided the only source of potable water. Water was collected
on roofs, where wedge-shaped limestone "glides" were laid to form sloping
gutters on the roof surface, diverting rain water into vertical leaders and thence
into storage tanks.
Early storage tanks were rum puncheons or cisterns made of cedar. Others were
formed by excavation into rock and made tight with mortar. Prior to the 20th century,
tanks were located at the outside rear of dwellings, partly or entirely above
ground. Water was removed from tanks by bucket or hand pump and carried indoors.
In some later systems, hand pumps transferred water to elevated indoor storage
tanks. Current systems include storage tanks under buildings with electric pumps
and pneumatic tanks. Today, 96% of households are provided with piped indoor water
supplies (Statistical Department 1980).
Rain water was also collected from "artificial catches" created by
removing thin hillside soil and sealing the rock surface with mortar. Water from
large artificial catches continues to provide significant quantities of water,
e.g., an estimated 13.6 million l/yr from a catchment developed for a British
military installation, and 45.5 million l/yr from a catchment serving a major
hotel (Thomas 1980).
Roof water systems with adequate storage were not systematically encouraged
until the 20th century. Prior to adoption of current public health regulations
in 1951, storage capacities of 1400 to 22,000 l were common (previous public health
regulations required up to 6800 l per occupant, although 13,000 litres per occupant
were recommended), compared with typical storage today of 68,000.l.
Water was imported from North America during a five-year period from 1938 to
In 1932 a private company, Watlington Waterworks, began development of the
largest of the groundwater lenses, providing up to 3.5 million k/day of brackish
water for non-potable uses (primarily flushing) through a distribution system
serving the central part of the island. Part of this water fed a desalination
plant that provided potable water to several major tourist facilities. In 1979,
the Bermuda Public Works Department and Watlington Waterworks commenced a joint
venture aimed at rational development of the groundwater resource, involving new
wells in the central lens and delivery of potable water through. the Watlington
By the 1960s, desalination plants had been installed by several major hotels,
industry, and government. At present (June 1981) a government sea water distillation
plant is reaching the end of its useful life, and a brackish water reverse osmosis
plant is being brought on-line, by the Public Works Department.
Design And Calculation
Of Rainwater Collection Systems
West Java Rural, Indonesia
Dry seasons occur even in monsoon areas. If there are no nearby wells or rivers,
people will walk long distances to obtain water. A solution to this problem may
be the catchment of rain water-an ancient custom still practiced in many countries
in the world where rainfall is collected during the wet sea-. son to use in the
dry season. The questions are (1) what should the volume be of such a rainwater
collection system and (2) how should such a collector be designed?
This paper deals mainly with the first question: the calculation of the volume
of the rainwater collector.
H.M.C. Satijn (1979), who was a former project participant, analyzed the problem
and designed a computer simulation model of the rainwater collection system. Because
computers are not widely available, I was asked to review Satijn's work and to
develop a slide rule-calculation method that could be used by regional technicians.
Thus, a step-by-step method was designed to enable technicians to calculate the
volume of rainwater collectors by using available monthly rainfall data.
The results of the calculation are not sacrosanct because, first of all, the
variables of themselves vary widely, such as consumption or the water demand.
Thus, if 5 litres/person/day is the basis for calculating drinking water needs,
there is no way of knowing the actual use and the variation in conservation and
utilization. What must be borne in mind in the statistical calculation of rainwater
catchment systems is that its accuracy will depend on correct input. It is also
important to be realistic in using the statistical calculation method, rather
than concentrating on complicated statistical computations.
The vital question is "Who pays?" If the farmer (user) pays, he will
construct a 15-m3 collector and in the dry season will be conservative in using
his water while praying to Allah that rain will soon fall again. When the government
or an international organization pays, the designer might think of future users
and design a 20- or even 25-m3 collector.
The basic principle of this: method is the importance of calculating storage
to provide enough water of the period of the year when there is no rainfall or
when it is insufficient to meet water needs. In the following sections the step-by-step
method and the theoretical background of the method are presented, and the last
section includes some design criteria for the rainwater collection system.
Rain Water Collection
and Utilization at Tamil Nadu Agricultural University, Coimbatore, India
Tamil Nadu Agricultural University, India
"As free as the land, air and water" is an age-old expression, which
men have used for hundreds of years to signify the things that nature has bountifully
provided, as contrasted to the type of wealth that has a tangible value, usually
as a result of human efforts in reworking natural elements. But today the old
phrase is largely empty. It has lost most of its original significance and at
present water has become such a scarce resource that it is called "Liquid
Gold" in many parts of the world, especially in the Coimbatore District of
Tamil Nadu, India. It is needless to say that man simply cannot live without water.
He must have it to drink, to meet domestic needs, to raise crops and to cooperate
his manufacturing industries. And the demand for water is steadily increasing
as civilization becomes more and more industrialized.
The place of water in the agricultural and in the overall economy is clearly
established. It is indispensable to any form of life and action. It can be man's
greatest friend or one of his most destructive enemies. Under control, it performs
a host of vital tasks in addition to achieving its final and supreme purpose in
providing man with a resource necessary to life itself. Uncontrolled, it wreaks
havoc with floods and carries our most precious top soil out to sea.
Taking all these elements into account and in looking to the future to 2000
A.D. and beyond, we must carefully plan and harness every drop of available water
in the dry areas. If we should fail to act now, with intelligence and decision,
we would place our children in a position of deadly peril. There are several avenues
of approach and all of them must be explored and used to the fullest practicable
extent. One technique among these is water harvesting.
Rain Water as an Alternative
Source in Nova Scotia
Technical University of Nova Scotia, Canada
Nova an Alberta Corporation, Canada
The Canadian province of Nova Scotia includes a population of 856,600 persons
in an area of 52,840km2. Approximately one-half of this population is served by
municipal water distribution systems. Most of the remainder are served by private
wells. Groundwater in some parts of the province is inadequate in quantity, or
is made undesirable or completely unacceptable for domestic uses because of excessive
Arsenic and uranium have recently been added to a list of natural contaminants
that includes iron, manganese, and hardness. In one small municipality, 294 wells
were tested for arsenic. Arsenic concentrations exceeded 0.01 mg/l in water from
130 wells of which 51 had concentrations greater than 0.05 mg/l (Division of Public
Health Engineering 1979), compared with a recommended objective concentration
equal to or less than 0.005 mg/k and a maximum acceptable level of 0.05 mg/l (Health
and Welfare Canada 1978).
In another area, water in 101 of 299 wells tested for uranium contained an
excess of the maximum acceptable concentration of 0.02 mg/l, and water in a further
58 wells contained concentrations between 0.01 and 0.02 mg/l (Bower 1981).
For many years-, rain water collected on roofs has served as a complete or
a supplementary domestic water source in parts of Nova Scotia where water quantity
or quality is inadequate, but no documented evidence of roof water systems was
available. In 1977, the authors undertook an exploratory study of roof water use
in Nova Scotia. The study was initiated with a newspaper enquiry and followed
by a questionnaire, personal interviews, limited water quality analysis and analysis
of precipitation data.
Cost Analysis of Rain
Water Cistern Systems
& PingSun Leung
Univer ty o£ Hawaii at Manoa, USA
The economic feasibility of rain water cistern RWC) systems is an important
factor in its acceptance in the scheme of water resources planning and development.
A cost analysis of this water supply system is complex because socioeconomic conditions
vary in different countries. To present an unbiased cost analysis of a RWC system,
a case-by-case format is preferable and, if possible, a cost comparison with the
existing public water supply system should be also included. In general, RWC systems
are financed with private funds, and public water supply systems with public funds.
However, their costs to users may not differ too much. In addition, the cost of
labour is another factor that should be considered in the cost analysis. It is
this amount of labor that owners contribute to their own RWC systems that is difficult
to document as a cost item. Thus, these factors should be considered by the readers
of this paper.
Some Aspects of Roof
Water Collection in a Subtropical Region
Nanyang Technological Institute, Singapore
The ever-increasing demand for water is making man look towards different means
of conservation and new methods of abstracting water. The concept of collecting
and storing rain water, an age-old practice, could prove to be an encouraging
additional source that could very well enhance the limited and apparently dwindling
supply of water.
In a city-state like Singapore, there are competing demands for use of limited
land area and, with the added rapid economic grow and industrial development,
there is an even greater demand for water. Singapore lies 8° north of the
equator, has an average ambient temperature of 26°C and a population of 2.3
million. With the twin assets of 70% of the population living in high-rise flats
and an average annual rainfall of 2 230mm , it would appear to augur well for
the harnessing of roof water as a supplementary source of water.
Rain Water Cistern System
Impact on Institutional Policy
University of Hawaii at Manoa, USA
The adaptation of the rain water cistern system ill have a definite impact
on institutional policy. To promote the adaptation of this type of system, Fok
and Murabayashi (1979) indicated that, in water shortage areas, some incentive
measures-such as tax credits-would produce results and require a new institutional
Another impact is related to cistern water quality, which is a matter of concern
to many public health officials. Because the cistern catchment area could be polluted
by natural or artificial pollutants the rain water collected and stored in the
cisterns may not be fit for human consumption. Therefore, Fok (1980) reported
that in California a ruling as made that prohibited the use of roof-catchment
cistern water for drinking for other human consumption uses.
Because rain water cistern systems are considered structures, the safety of
these systems is another matter of concern. Thus, their impact on existing building
codes, which may not be applicable to cisterns imposes another impact on institutional
The impact of cistern systems on institutional policies and their acceptability
to users requires investigation. In this paper, examples of rain water cistern
system impacts on institutional policies are discussed and presented as suggestions
for further investigation and consideration.
4: Water Quality
Quality of the St. Thomas,
US. Virgin Islands Household Cistern Water Supplies
Lee & R. Anne Jones
Colorado State University, USA
A study was conducted in December 1972 to determine the characteristics of
individual household cistern water supplies locate on St. Thomas in the U.S. Virgin
Islands. Twelve cistern supplies as well as several other water sources, including
the domestic water supply for Charlotte Amalie, St. Thomas and several well water
supplies, were sampled. Measurements were made of specific conductance, alkalinity,
pH, Ca, Mg, Na, K, Cl S04, total P, N02, N03 NH4, organic N, F, Zn, Ca, Cd, Pb,
Cr, Ni, Fe, Mn an Hg. It was found that all of these contaminants' concentrations
were below U.S. EPA water quality criteria except for Hg, whose concentrations
exceeded the U.S. EPA regulations.
Individual household cistern water supplies did of appear to be contaminated
to a significant extent by materials of construction or painting of the rooftop
collection system. While the chemical characteristics of the cistern water supplies
were in general satisfactory in terms of drinking water quality, other studies
have shown that these systems tend to be contaminated with faecal coliforms and
that large amounts of decomposing organic materials, such as leaf litter, tend
to accumulate in the storage tank. A recommended maintenance program is presented,
which includes disinfection with chlorine, periodic removal of accumulated debris
from the bottom of he tank, and periodic sampling for measurement of sanitary
and chemical quality.
Effect of Acid Rain
Upon Cistern Water Quality
L. King & P.B. Bedient
Rice University, USA
As consumption of water increases, surface water supplies are unable to meet
the current demands and the receding groundwater table reflects the pressure placed
on groundwater reserves. One potential source of water is precipitation. The use
of rainfall catchment-cistern systems is not a new concept, but can be an old
approach to an emerging need. Cisterns superficially appear to be a simple means
to obtain water; however, cisterns require capital expense for the construction
of the system, system maintenance and a means of assuring cistern water quality.
Current and future use of cisterns requires an evaluation of precipitation quality
in addition to water, quality degradation in cisterns. This paper addresses the
impact of acid rain on cistern water quality.
Occurrence of Selected
Heavy Metals in Rural Roof-Catchment Cistern Systems
E. Sharpe & Edward S. Young
The Pennsylvania State University, USA
Roof-catchment cistern systems consist of a roof, usually the house roof, which
serves as an impervious catchment for precipitation, and a cistern to store the
collected water. The stored water is pumped from the cistern to points of use
within the house. Very little is known about the prevalence of this type of water
supply in the United States or the quality of drinking water obtained from such
systems. A recent paper by Kincaid (1979) cites Ohio Department of Health records
that reported a total of 67,000 cistern systems in the state of Ohio alone. A
company owned and operated by Mr. Kincaid specializes in providing service to
cistern owners in Ohio. The company handles approximately 800 requests for assistance
each year and provides specialized water treatment equipment to its customers.
Since mot of this equipment is designed to remove particulates and disinfect cistern
water, it may be concluded that these are important cistern water quality problems.
However, the relatively new phenomenon of acid rain (Cogbill and Likens 1974).
and the deposition of toxic metals such as lead (Lazrus et al. 1979; Hutchinson
1973) in roof-catchment cistern systems have not been previous investigated.
Roof-catchment cisterns are common in regions of the United States where groundwater
supplies are either unavailable or unusable. Cisterns are present in the coal
mining regions of Pennsylvania where ground water has been polluted by mining
and public water supplies are unavailable. Additional concentrations of these
systems occur where groundwater has not been successfully developed and surface
water sources are either polluted or nonexistent. The former case generally prevails
in rural areas of Clarion on and Indiana Counties, Pennsylvania and in much of
Although each cistern system was unique, most cisterns were constructed of
concrete or cinderblock coated with a waterproof cement-base sealant. Sixteen
of the 40 systems evaluated in 1980 incorporated sand and gravel filters to remove
particulates from incoming precipitation. In those systems with sand and gravel
filters, CaC03 may have also been added as the precipitation passed through the
A study was designed to survey water quality in roof-catchment cistern water
systems to determine the occurrences of the toxic metals, lead, cadmium and copper.
A related objective involved the evaluation of the corrosivity of the water being
collected and stored in roof-catchment water systems and its relationship to plumbing
type, cistern construction materials and water treatment devices.
A Water Quality Argument
For Rain Water Catchment Development In Belau
University of Guam, USA
Summary of Problem.
The quantity and quality of fresh water for human use has been a critical area
of development in the Republic of Belau, formerly Palau, in the Western Caroline
Islands. In an area which receives about 3 810 mm (150 in.) of rainfall per year,
development of water resources has lagged behind demand and use. The primary emphasis
for the last thirty years has been on the development of a centralized water system
utilizing the impoundment of surface water. Resulting water hours from an insufficient
quantity of water and delivery problems plus poor quality have limited the effectiveness
of the municipal system in meeting the needs of the consumer. Because of these
quantity and quality problems, rain water has been extensively utilized for human
consumption. Yet, there has been little organized effort to develop this resource
beyond a rudimentary level. Thus, rainwater catchments are often inadequate during
certain times of the year.
With increased growth and development and a need to be self-sufficient, a sound
water resources development policy that include rainwater catchment should be
considered for the Republic of Belau. The high quality of rainwater in this geographic
area should be an important actor in this choice.
Rain Water Cistern Utilization
In Selected Hamlets Of The Republic Of Belau, Western Caroline Islands
University of Hawaii, USA
An examination of water procurement through the use of rain water cisterns
should include not only rainfall data and the mechanical and the technical aspects
of catchment systems, such as their design r operation, but equally important
is the utilization of this water resource. The true test of the effectiveness
of a rain water cistern system rests with those persons who will utilize the contained
water supply. Fresh water usage is the result of deliberate human action and it
is not surprising to find that particular types of water, depending upon its source,
its quality, its quantity or availability, and its accessibility, have specific
The following report summarizes the more salient pints regarding rain water
catchment utilization based on a recent investigation o£ fresh water usage
in the Republic of Belau, formerly Palau. Entitled "An Investigation of Social
Aspects of Fresh Water Use in Selected Hamlets of Belau" (O'Meara, in press)
and conducted by the author, that study serves as the basis of this report. While
the aim of the previous study was (1) the identification and mapping of traditional,
historical, and modern freshwater sites and (2) the broader examination of freshwater
utilization, the information presented here concerns rain water cistern systems
and includes a description of historical and modern catchment systems, their utilization,
and their water quality.
Roof Catchments: The
Appropriate Safe Drinking Water Technology For Developing Countries
Ahmadu Bello University, Nigeria
Water is one of the major components in the structure of the human environment;
it comprises nine tenths of our body and coves three quarters of our world. However,
as much as water can, support and preserve life, it can also damage and destroy
it when this basic commodity is contaminated prior to consumption. There are various
sources of water contamination, but the most dangerous source is considered to
be human waste originating from sick people infected mainly with intestinal diseases,
like typhoid f ever and cholera, or from healthy carriers of these diseases. History,
in particular medieval history, has been recording numerous outbreaks of water-borne
diseases that wiped out whole communities.
Unfortunately, despite the remarkable technologic l achievements of our era,
dangerously contaminated water supplies still pose a serious threat for a large
portion of the world's population. Salas (1981) of the United Nations Fund for
Population Activities, has estimated the 1980 world's population at 4.4 billion.
According to recently released World Heath Organization (WHO) figures (World Water
1981), the number of people that lived without access to safe drinking water in
1980 has been estimated at 1,32 million, comprising 30% of the world's population
(the ratio is actually higher because the WHO figures did not include China).
Almost all these less privileged people resided in developing countries where
they comprised more than half of the population. In this respect, it has been
further conclude that mostly affected were the rural areas where an overwhelming
majority of developing countries people live.
These distressing environmental facts were among the main reasons leading to
the recently inaugurated International Drinking Water Supply and Sanitation Decade
(IDWSSD) 1981-1990 aimed at "providing safe water and proper sanitation for
all by the year 1990." It is universally hoped that this most human expectation
will come true but, meanwhile, together with the time consuming, large-scale water
resources development activities connected with the IDWSSD, it is essentially
important to embark as soon as possible on ways and means aimed at providing immediate,
though limited, solutions for the steadily growing safe drinking water problem
in the developing world. A large-scale development of roof catchment drinking
water supplies can be the appropriate answer for this problem due to the relatively
low costs of the method, but mainly because it provides an almost entirely safe,
raw drinking water supply that does not require costly and complicated purification
5: Current And Future Practices
Recent Initiatives in
Raintank Supply Systems for South Australia
Hoey & Stephen F. West
Engineering and Water Supply Department of South Australia
Much of Australia is arid and experiences a high evaporation rate (Fig. 1).
In these areas, lack of rainfall combined with high potential evaporation results
in a scarcity of surface water in the form of permanent lakes and streams.
With a population of 14 million concentrated in large coastal cities, domestic
water supply in Australia is most commonly provided by conventional reticulated
systems, which draw water from large surface storages or from groundwater.
Besides being a necessity in many country areas, rainwater tank/roof collection
systems have been and still are popular as adjuncts to urban water supplies in
Australian towns and cities. This is particularly so in areas where the quality
of aesthetic properties of the reticulated supply are poor. Adelaide, the capital
city of South Australia is one such city.
A large proportion of Adelaide's water supply is drawn from the River Murray,
a river beset with the problems familiar throughout, the world today, of rising
salinity levels, increasing nutrient loads, turbidity, and algal blooms. The Australian
media has for many years publicized the Murray's plight, with interest rising
dramatically in recent years as the result of widespread drought conditions.
The South Australian Government and the public are concerned about deteriorating
reticulated water quality, particularly that originating from the River Murray.
There is a growing awareness of the benefits of rainwater systems in terms of
water conservation and quality.
This paper discusses two recent government initiatives: a rainwater tank promotion
campaign, its aims, its strategy and its results; and research work undertaken
to gain a better understanding of raintank processes and demands, for incorporation
into improved computer models design d to predict the reliability of rainwater
tank/roof catchment systems.
Rural Rainwater Cistern
Design in Indonesia
Yayasan Dian Desa, Indonesia
Water is difficult to obtain in some areas, such as the region of Gunung Kidul,
which is located to the southeast of Yogyakart in Java. The main source of water
in this area is rainfall. During the dry season, villagers spend much time and
labor fetching water over great distances for domestic use.
In Yogyakarta, several ponds serve as catchment basins for rainfall that accumulates
during the rainy season. This water is used for drinking, cooking, bathing, washing
and also for livestock watering. Some of these ponds, which dry up during the
dry season, are several kilometres away from the people who use them. Under such
conditions, it is common for local inhabitants to search for water several kilometres
from their homes.
In the Gunung Kidul region, the water table is quite deep – up to 160
m (525 ft), thus making it difficult to hand dig wells o exploit the groundwater.
And because of poor economic conditions, local people traditionally catch rain
water in jugs as it flows from the roof.
It is especially true that Indonesians living in villages place great importance
on the joy and value of working together. This belief in solidarity is quite widespread
for, within the activities of day-to-day living, there is constant contact and
cooperation between neighbors. From this point of view, we believe that there
is much to gain if a rural program for constructing rainwater cisterns of ferrocement
and bamboo cement is encouraged especially in developing countries.
for Villages In West Java, Indonesia
Rural Water Supply West Java Project 0-9(a), Indonesia
The West Java Rural Water Supply Project is jointly sponsored by the governments
of Indonesia and The Netherlands. The International Water Supply Consultants IWACO
B.V. was appointed to provide consultant services, part of which included the
development of simple techniques for water supply systems and the transfer of
this information to the rural population so the villagers could construct their
own rainwater collection systems.
This paper presents the use of local building materials, the value of close
cooperation of local authorities and the rural population and how people can build
their own drinking-water system.
Effect of Rationing
on Reliability of Domestic Rainwater Systems
University of New England, Australia
In a companion paper, Perrens (1982) presented the elements of a simulation
model which has been used to study the main design parameters of rainwater supply
systems at four locations in Australia. For that study, the model was run assuming
that no rationing policy was opted when supplies were low. The results showed,
however, that for all but the areas of subtropical rainfall with a mean annual
greater than 1500 m, inadequate supply would-be available from all the roof areas
on a typical farm or "station" to allow a reasonable standard of living
for a family of four people. Under these circumstances, two strategies are commonly
- Overall reduction in the demand for rain water either by lowering expectations
or by seeking an alternative source of water to meet an element of the demand,
for the use of water from a farm dam for toilet flushing or, with minor treatment,
for clothes washing
- Acceptance of a short-term reduction in demand by accepting a rationing policy
which will increase the reliability of the supply for a given demand or, alternatively,
allow increased demand for the same reliability.
The problem of allocating the rainwater resource given certain practical constraints
on the physical elements of the system (storage size and catchment area) is one
which regularly faces many Australian homesteads. Rationing may therefore be seen
as an alternative to increasing the size of the physical components of the system.
To make rational decisions about rationing, the user will need to know:
- The rationing policy to apply (duration of rationing and reduction of demand)
- The effect of a particular policy on the reliability of the supply
- The frequency with which rationing will be imposed under a particular policy.
This paper presents some preliminary analysis of these factors which have received
very little attention to date.
Body (1968a, b) studied a range of rainwater supply systems in Australia and
examined the effect of rationing policy on the reliability of supply. His work
was never completed, however, and the results have not been made generally available.
Body adopted more complex rationing rules than those used in this study and examined
a three-stage rule requiring successive reductions of demand to 75, 50 and 25%
of full demand when particular storage levels were reached. The study took the
percentage of time that rationing could be accepted as one of the criteria for
design and examined the probability of achieving this. The study also examined
the variability of rationing with particular historic sequences of rainfall.
Like many engineering design tasks, the analysis can be made as complex as
desired. The main factor requiring judgement is the appropriate level of sophistication
required for the task in hand. In this apex, which is based on a study primarily
aimed at domestic rainwater system, one simple rationing rule has been examined.
Integrating Rain Water
Cisterns with Public Water Supply Systems
University of Hawaii at Manoa, USA
In recent years, many metropolitan centers have experienced water shortages,
due partly to droughts as well as rapid urbanization. The latter has resulted
in an oversubscription of existing water supplies. As a result, moratoriums on
building permits have been reported in Orange County (Los Angeles, California)
and in several counties in Hawaii. Developers in these areas were denied building
permits and told to develop their own water source before building permits could
be issued. As a result, many developers suffered losses in time, money, and business
Thus, it is evident that alternative water sources must be found to alleviate
water shortage problems in urban areas. Rain water-cistern systems are practical
alternative or supplemental water supply systems which have long been used prior
to the development of public water supply systems. During the 1977 California
drought, Monterey peninsula residents recycled their limited 50 gal/person/day
water rations to irrigate their gardens and lawns, and utilized rain cisterns
to supplement their recycled water. These emergency water management practices
reportedly reduced revenues to the water supply agencies, thus creating a financial
problem for the water supplier, Therefore, when a potential, alternative water
supply system is contemplated, related problems discussed in this paper should
be solved before the alternative is integrated into the existing water supply
Cistern Systems: The
Ingham & Charles Franklyn Kleine
Department of Water Resources, State of California, USA
The California drought of 1976-1977 focused attention on the limits of conventional
water supplies at the state and the local levels. Most of the rainfall occurs
in the northern. portion of the State, whereas the principal metropolitan developments
are in Southern California. To provide water supply for these developments and
for agriculture, largely in the San Joaquin Valley of Central California, the
State Water Project (SWP) was developed to collect water in reservoirs in Northern
California, and to transport this water to Southern California using pumping plants
and over 64.36 x 104 m (400 miles) of aqueduct. The system is currently supplying
about 60% of its contracted entitlements. As originally planned, the ultimate
development of the system would require construction of new reservoirs and canals
beyond those now constructed. In many developed areas of the state, natural surface
and groundwater sources are fully developed. The 1976-1977 drought reinforced
California's recognition that her water resources were limited; this; coupled
with increasing energy costs for pumping water to major urban areas and political
and environmental changes occurring in the last 10 years, encouraged the development
of statewide programs to expand existing conventional supplies by reclaiming municipal
waste waters and to promote conservation practices fox both urban and agricultural
water users. Sometimes these programs involved the investigation into the potential
for innovative development of water supplies, such as coastal fog recovery and
cistern technology. California's program to develop cistern systems is unique.
In this paper will be discussed the background, elements, and benefits of cistern
technology and California's program encouraging the development of these systems.
It is hoped that this program will serve as a model fox other states when they
plan their overall water development programs.
The technical discussion presented in this paper will address the State's residential
usage of water, the advantages of grey water as an alternative supply of landscape
irrigation water, and the typical elements of cistern systems used in California.
Attention will then be directed to reviewing the regulations and management of
cistern systems; California's tax incentive program for developing residential
cistern water supplies; and a program for implementing demonstration cisterns
for planners, engineers, health officials, and the general public. The paper will
close with a presentation of cistern benefits to the individual region and the
state; and hence, governments' responsibility to encourage this worthwhile technology.
6: Related Topics
System: New Perspectives in Soil and Water Management
Laboratorio Nacional de Engenharia Civil, Portugal
The basic idea presented in this paper is the combination of two very old techniques-
land cultivation in terraces and rainwater catchment in cisterns -to form a terrace-cistern
system whose potentialities are expected to exceed that of either technique by
Such a system can open new prospects for land and water management. In the
case of soil management, rainwater catchment for irrigation will make possible
the reclamation of waste land and/or the introduction of new crops with higher
yields. And for water management, a direct benefit will be the increase in the
available water resources as a result of the collection and utilization of runoff;
indirect benefits include the diminishing of soil erosion, and consequently, improving
the operation of reservoirs and channels.
One may ask in what circumstances the implementation of this system becomes
practicable from the technical and economic points of view. To throw light on
this question, the Laboratario Nacional de Engenharia Civil recently started the
research project reported here and which will require further research to solve
some of the problems. That such research is needed is beyond question. In some
of the most recent literature on water management, Cunha et al. (1980) concluded
that research is not only necessary but also urgent.
This paper is presented to the International Conference on Rain Water Cistern
Systems to profit mainly from any criticism and comments and to hopefully elicit
cooperation in the pilot studies and the work to be done.
Underground Pipes to
Recharge Rainwater Storage in Aquifers
Ishizaki, Fumio Yoshino & Akira Terakawa
Ministry of Construction, Japan
Rainwater cistern systems have high potentialities to supplement and thus reduce
the demands on public water supply systems if the storage tank cost can be made
more feasible. In general, the cost of water tanks is relatively high in comparison
to other components of the total rainwater cistern system. Thus, an underground
aquifer can be considered as one method to minimize the total. cost of rainwater
cistern systems if an aquifer, rather than a storage tank, can be used to store
rain water. Using underground pipes as an infiltration technique is a possible
Underground pipes, which are permeable and buried in the topsoil, are being
used for crop irrigation and also for drainage. They were recently found to be
also useful in the field of groundwater recharge (Ishizaki, Kitagawa, and Terakawa
1981). Because ordinary methods to recharge groundwater, such as well injection
and ponding, have common problems of clogging, considerable design and cost studies
will be necessary to maintain them as infiltration facilities (Ishizaki and Kitagawa
1981). Because of aerobic conditions, underground pipes used for irrigation have
little chance of clogging. Also, the cost of these pipes is relatively low because
of their simple structure. Thus, we discuss the possibility of using an underground
aquifer as the storage element and underground pipes as the catchment and conduit
for rainwater into the aquifer.
Rain Water Cistern Systems
East China Normal University, China
Rain catchment systems have long been used in China. People like to drink rain
water because it is cleaner than river or well water and does not have the bad
odor and taste of river or well water.
In the vast area south of the Yangtze where rainfall is abundant, rain water
cistern systems have been a common means of water supply in past years.
The method of collecting and storing rain water was rather simple. The most
available material that people used for making rain water gutters was mao bamboo,
which is very common in South China and has a thick stem, which can be hallowed
out and split into two halves for use as gutters. Since the introduction of tin
plate and galvanized iron, people have liked to use them instead of bamboo for
making gutter systems, although they are susceptible to rusting and are more expensive.
Earthenware, a traditional material used for making vessels in China, is also
available for making rain water cisterns. People use large earthenware vats as
storage cisterns. The vats have various sizes, but the largest one has a volume
of about one cubic meter. 'In appearance it is like a bowl, with an upper diameter
of about one meter or more Although earthenware is fragile, it is an ideal material
for a rain water cistern because it is less expensive and has no effect on water
In rural areas of China, an ordinary household usually has a small yard where
large earthen vats used as rain water cisterns are placed just under the gutter
systems to receive the rain water from above. When it -rains and the vats are
filled with water, wooden covers are put on them to avoid contamination and to
shut out the sunlight to prevent algae growths. No filtering process is needed,
but some alum as coagulant is generally added to remove the suspended solids.
The impurities on the bottom of the vat should be regularly cleared away. Because
mosquito larvae sometimes breed in the water, a goldfish is placed in the water
to feed on them.
In China, an average peasant may have a commodious house with a total roof
area of 50 to 100m2. As a catchment area, it is broad enough to receive
rain water for drinking, but still inadequate to provide water for other domestic
uses. Thus, river or well. water must be used for washing and other domestic uses.
Since the annual rainfall in subtropical and tropical areas of China generally
exceeds 1 000 mm, and in many regions over 1 500 mm, most of the domestic demand
for water can be very likely technically improved by using rain water cistern
systems with larger catchment areas.
In recent years, tap water has become an increasingly common source of water
in small cities and towns of China, while rain water cisterns have decreased.
However, people do not like chlorinated water for drinking because of its odor,
and some people still collect rain water for drinking.
Water Demand Analysis
for Agricultural Watersheds
Indian Institute of Technology Kharagpur, India
Agriculture cannot exist without water. And without the required quantity of
water, especially during critical periods, agriculture fails. If farmers cultivate
crops without a clear picture of the amount of water needed during the growth
period, two problems can occur: either crop damage because of a water shortage
or a decrease to some extent in net returns because of improper and underutilization
of the available water.
Farmers sometimes grow a single crop, paddy, for example, an their entire land
holding. If there is a shortage of water in such cases, it is possible to overcome
the problem by planting some other crops, such as wheat and pulses, in addition
to paddy during the same season without causing damage to the crops because of
a water shortage or diminishing the net returns. One means of increasing the per
capita income of farmers is the selection of the right combination of crops, whose
water demands remain well within the available water resources during a given
season and which result in maximum net return and which fulfil food-grain requirements
and yet remain within their investment potentialities. How and why water demand
analysis is used for agricultural watersheds are dealt in detail in this paper
and a water demand analysis case study is presented for small farmers.
Models for Storm Sewer Systems
University of Minnesota, USA
The traditional role of a sewer network has been primarily that of conveyance
of waste water and storm water. A common design criterion was to ensure an adequate
hydraulic capacity to convey a maximum design flow at a steady rate without surcharging
the sewer. The design objective and criterion of a sewer network have undergone
a fundamental change in recent years due to upgraded pollution control rules.
To meet these goals, it has become increasingly clear that a substantial saving
can be achieved by utilizing the in-line storage capacity of a sewer network.
Most existing sewer networks have enough capacity to store the entire runoff due
to a storm equal to or less than the one-year storm. The majority of storm runoffs
can thus be stored for future treatment if there are provisions for a suitable
control mechanism or some precautions against transient pressure.
A sewer network designed to store as well as convey storm water would undergo
changes in flow regimes following a large storm event. Typically, the flow would
initially be free surface flow and then begin to pressurize starting at the downstream
end of the sewer system. At this time there would be a combined flow regime consisting
of free surface flow and pressurized flow separated by one or more moving surge
fronts. The magnitude of such a surge may build up to a significant amount as
it moves upstream, and would generate severe water-hammer pressure upon collision
with an upstream boundary. Clearly, a steady state or a kinematic wave type model,
such as the SWMM model, is not suitable for a sewer network used as a storage-conveyance
system. A complete dynamic model capable of simulating unsteady mixed-flow is
This paper describes some experiences with two dynamic models: (1) the Priessmann-Cunge-Wagner
model and (2) the Song-Cardle-Leung model developed at the St. Anthony Falls Hydraulic
Flood Routing Through
A Series Of Detention Ponds
Liu & Johnny R. Barker
Lichliter/Jameson & Associates, Inc., USA
In recent years, storm water detention has become a more popular and acceptable
flood preventative measure used by planners in government agencies in the United
States. The main purpose of a detention pond is to attenuate the peak flow produced
upstream and to release only the maximum discharge which is equal to the existing
condition. Liu and Barker (1981) developed a computer program which routes a flood
hydrograph through a single storm water detention pond based on the effect on
downstream receiving waters in areas with relatively small relief or coastal zones.
The routing procedure becomes more complicated when a series of two or more detention
ponds is required because of physical or economical limitations.
The computer program for a flood hydrograph has been revised to route the flow
of flood waters through a series of two ponds by taking into account the variations
of headwater and tailwater discharged at each pond, as well as by balancing the
storage routing equation to determine the sizes of the ponds and their outlet
Rain and Waste Water
Reuse for Toilet Flushing: A Simulation Model
& S.A. Ferris
Trent Polytechnic, UK
The reuse of rain and domestic waste water for water closet flushing has an
effect on the water resources of a country: this conservation may have a particular
impact in areas where the carrier for the waste water is salt water or where the
potable water carrier is in short supply. In the United Kingdom, 30% of the, potable
water supplied to the domestic sector is used for the transportation of waste
water; however, the advantages of a reuse system are unlikely to be relevant here
because of the abundance of cheap potable water.
This paper considers two water closet [WC] supply systems: one is rain water
collected from the roof and the other combines rain and domestic waste water.
The stochastic nature of the rain and waste water time series have been simulated
using the Monte Carlo method. Subsequently, the operation o£ each system
is modelled to determine the percentage of WC water conserved per annum for a
range of tank capacities, roof area and family sizes.
Rain Water Cistern Systems
Universtiy of Indonesia
In Indonesia, villagers obtain their domestic water from springs, shallow wells,
rivers or lakes. The fast coastal. areas have brackish surface water, groundwater
and intermittent rivers. In such areas, rain water is collected from roofs for
From about three to four years ago, the Indonesian government has constructed,
with some financial aid from UNICEF, nearly a thousand rain water cistern (RWC)
systems in Gunung Kidul, Madura, Lombok and Nusa Tenggara. A program has been
established to train groups of villagers to build bamboo cement cisterns and to
construct roof gutters and other component structures. Unfortunately, the storage
capacity of the cisterns is not large enough to provide enough water for the very
long, dry season demands. H.R. Doelhomid, a University of Indonesia student, conducted
a study in which she presented nomograms for the volume of cisterns based on the
roof area and family size for the Gunung Kidul area.
In a large-scale, Dutch-aided program now underway in the north coast of West
Java, high quality and low quality cisterns of bricks, ferroconcrete, concrete
without reinforcement, bamboo cement and ijuk (palm fibre) cement are being constructed.
PDF of full document (13pp,
|Note: The IRCSA proceedings
section is still new and under active management, If you find any problems,
ommissions or corrections please contact
the administrator so we can put things right.