International Conference on Rain Water Cistern Systems
"Rainwater Catchment for Future Generations"
Keelung, Taiwan, R.O.C. - August 1991
1: Keynote Papers
Progress Of International
Conference On Rain Water Cistern Systems
University of Hawaii at Manoa, U.S.A.
As the subject-conference-series has been progressed to the 5th conference,
it is very appropriate to document the back-ground, the birth and highlights of
each conference for the benefit of the future development of this conference series.
This paper is based on an invited keynote paper presented at the 2nd conference
which has not been, published. The development and highlights of subsequent conferences
have. been included in this paper. In addition, the initiation and establishment
of the International Rainwater Catchment Systems Association (IRCSA) are also
included. This paper is intended to put important events of each conference in
the record. The request of past conference participants to contribute their own
experience in this conference series has also been made.
Progresses Of The U.N.
Water Decade And Rainwater Catchment Systems
University of Hawaii at Manoa, U.S.A.
Taiwan Ocean University, Keelung, Taiwan
According to a report by UNDP in December, 1989 (The progresses of the United
Nations' International Drinking Water Supply and Sanitation Decade 1981-1990,)
on the water decade, there are about 55% targeted population in-developing countries
has received :safe drinking water supply while only 17% of. Those received sanitation
disposal of their waste. This paper has made an assessment of factors that affects
this imbalanced of development drinking water supply and sanitation during the
U.N. water decade. In addition, possible approaches that may be used to fulfill
the U.N. Water Decade's objectives are also presented. In the process of the assessment,
progresses of rainwater catchment systems have examined. The Thailand Jar Rain
Water Catchment Program is cited as an outstanding drinking water supply program
which should be recommended to the U.N. Water Decade decision makers and planners
The Contribution of
Rainwater Catchment Systems to the International Drinking Water Supply and Sanitation
Decade : Lessons from Thailand
University of Kent, U.K.
Compared to the lofty goals set for the IDWSS Decade in the late 1970's, the
achievements in many developing countries seem disappointing. The Decade did,
nevertheless, coincide with a period of renewed interest in Rainwater Catchment
Systems (RWCS) technology and the implementation of many millions of tanks world-wide
made a significant contribution to improving both access and quality of domestic
water supplies for tens of millions of people. Although, during the last decade,
thousands of individual community projects around the globe have recognized the
potential for RWCS operating in tandem with other water supply technologies for
meeting their water supply needs; only one national government, that of Thailand,
has wholeheartedly taken the technology on board. Since the mid-1980's, Thailand
has actively promoted and supported RWCS through the Thai Jar Programme and has
incorporated it into its water supply provision plans at local, regional and national
.levels. The result. of this was the construction of around 10 million 1-2m3
jars and hundreds of thousands of 6-12m3 rainwater tanks by the end of the Decade
and Thailand becoming one of the few countries to even approach the IDWSS Decade
targets for rural water supply provision.
Despite its unprecedented scale and success, the rapid implementation of the
Thai jar programme encountered a variety of problems. These provide useful lessons
for others and are examined. in this paper. They include:
- The importance of conducting health and hygiene education campaigns associated
with the operation and maintenance of the RWCS before and during their implementation,
- The need for awareness about the adverse affects caused by the rapid commercialization
of tank/jar construction and implementation on their effective operation and maintenance.
- The importance of research and of communicating the findings of such research
widely and rapidly, particularly aspects relating to potential design problems
or health hazards related to rainwater supplies.
2: Catchment Water Quality Regulation
The Bacterial Content
Of Cistern Waters In Hawaii
Fujioka, Steven G. Inserra, Robert D. Chinn
University y of Hawaii, USA
The drinking water quality of 15 cistern systems in Honolulu, and 3 cistern
systems on another island (H waif) in the State ofHawaii was evaluated. These
cistern waters an be expected to meet turbidity, chloride, nitrate and pH levels
established by USEPA for drinking water. However, the bacterial (total heterotrophic
fecal coliform, E. coli, fecal streptococci) c oncentrations in these cistern
waters usually exceeded drinking water standards. Low levels of. C. perfringens
and salmonella bacteria were also recovered from :some cistern reservoir tanks.
Higher concentrations of bacteria were' recovered from cistern reservoir tanks
than from household faucet sources. The cisterns in Hawaii are susceptible to
contamination by indicator bacteria via multiple sources an cannot be expected
to meet bacterial drinking water standards. e recommend that the portion of water
to be used for drinking be disinfected and standards specifically for cistern
waters based on fecal coliform or E'.coli be established.
Improving Cistern Water
University of the Virgin Islands, U.S.A.
As cistern water systems become increasingly popular around the world, it is
important that adequate attention be given to maintaining and improving cistern
water quality. Periodic water testing, to at least determine the presence of coliforms,
should be initiated in those areas where cistern water is used for drinking purposes.
A number of relatively simple techniques are discussed in this paper, which will
assist in improving cistern water quality. These include roof maintenance and
removal of overhanging vegetation, installation of screens and first-flush devices,
ultraviolet radiation, exposure to sunlight and the use of silver compounds in
small quantities. The specific choice of a disinfection method depends upon the
personnel and other resources available-in any given area or region.
Rainwater Quality: Pathogens
And Heavy Metals
Khon Kaen University, Thailand
The quality of rainwater samples collected from collecting system (roof and
gutter), storage containers (both outdoor and indoor) were evaluated both bacteriologically,
using indicator organisms and pathogen isolation, and chemically by analysing
heavy metal concentrations. The source of bacteriological contamination was investigated
employing the ratio of fecal coliform to fecal streptococci (FC:FS). Information
on saitary practices was also investigated.
Approximately 60-91 %, 34-78 %, 43-78 %, and 10-33 % of samples collected from
collecting system and storage containers did not meet the drinking water quality
standard expressed in terms of total bacterial count, total coliform, fecal colliform,
and E.Coli, respectively. About 79-84 % of samples collected from roof and gutter
had FC:FS ratios of less than 1, indicating the source of contamination was animal.
While about 39 % and 47 % of samples collected from in-house containers had FC:FS
ratios of less than 1 and greater than 4 respectively, which indicated the contaminating
sources were both animal and human.°The contamination induced by human was
mainly caused by unsanitary practices on water handling and usage of the villagers.
Pathogenic contamination was found approximately 1.1 % of samples collected,from
such sampling points. The pathogens identified were Salmonella gr.E. and gr.C,
V. parahaemolyticus, and Aromonas. The heavy metals analysed in this study included
Cd, Cr, Pb Cu, Fe, Mn and Zn. Most of the heavy metal concentrations taken from
various sampling points compared favorably with WHO drinking water standards with
two exceptions, Mn and Zn. However, Mn and Zn are considered to affect the asdthetic
quality of drinking water only and were therefore not significant to health.
The findings from this study indicate that any health risk evolving from the
consumption of stored rainwater would be due to bacteriological contamination
rather than heavy metal contamination.
Qualite Des Eaux Des
Citernes De Captage Wea De Pluie Au Sahel
C. Tandia, Or. C. S. To
CREPA, Burkina Faso
Despite its existence for several centuries, the development of rainwater roof
catchment system faces great difficulties in African countries. particularly in
the Sahel. Obstacles for its expansion include the scepticism and uncertainty
of local populations concerning the safety of rainwater when store for long time.
In order to promote this technology in African co ntries, CREPA and CIEH have
established a program for construction of rainwater c tern systems throughout
Ouagadougou in Burkina Faso. Also, CREPA has extended his program to include all
other countries which are members of the Centre through demonstration projects.
At the samr time, CREPA examines regularly the water quality during conservation.
According to WHO standards, rainwater stored is drinkable Sometime , pollution
due to animals is noticed. But, the lack of organic matters in stored rainwater
precludes the growth of micro-organisms
In conclusion, when well constructed, the rainwater cistern system can be an
alternate source of water supply.
Microbial Levels in
Cistern Systems: Acceptable or Unacceptable
Environmental Protection Agency, USA
The acceptance of cistern systems as a source of potable water and as a possible
source for non-domestic use is dependent upon the quality maintained within the
entire system. Microbial levels measured within a cistern system are reliable
indicators of water quality and of deteriorations that may give rise to offensive
odors and tastes. The number of microorganisms commonly found within most contemporary
cistern systems is usually lower than surrounding surface waters but these microbial
levels may still be unacceptable for many alternative uses. Our laboratory is
studying the bacterial populations growing and residing within cistern systems.
During periods of rainfall collection and heavy usage, the microbial populations
of single-chamber cistern systems do not decrease significantly during subsequent
storage (self-purify). The storage of rain water in cistern systems may actually.be
conducive to the growth of certain bacterial strains in numbers beyond those found
in natural water sources. Our studies have shown that certain types of maintenance
of individual, single-chamber catchment systems may actually increase the levels
of certain microbial strains when compared to similar systems receiving no.treatment
at all. More work is required to identify those parameters necessary for the proper
storage and maintenance of high quality cistern water.
3: Catchment and Storage System Designs
Proposal For Disseminating
Ferrocement Rainwater Tank Technology In The Province Of Capiz The Philippines
International Development Research Centre (Canada), Singapore
Nanyang Technological University, Singapore
Ferrocement has been used as the sole building material in the, construction
of 30 rainwater cisterns which constitute the pilot project for introducing rainwater
catchment systems in the Province of Capiz. These tanks which were built in three
localized areas have been successfully tested for their structural stability and
their use has been found to be socially acceptable. The main objectives of the
current proposal are to disseminate the acquired ferrocement technology to communities
throughout Capiz and to extend the number of, tanks by a further 540. Selected
members of the target communities will be trained and communication materials
will be designed, tested and produced to support the dissemination activities.
A revolving fund w:.ll provide loans to families who want to build tanks but do
not have the resources to purchase the construction material required. Health
education and communication organization elements will also be built into the
project activities to ensure that the ferrocement tanks will have the desired
impact in improving the health of the communities and that the technology is fully
adopted through a participatory approach by members of various communities.
And Its Application In Taiwan
Ministry of Economic Affairs, Department of Water Resources R.O.C.
Yeh, Jeffery, Tseng
Taiwan Provincial Water Conserancy Bureau R.O.C.
in Taiwan, with unevenly distributed abundant annual rainfall and the steep
slope of rivers rushing the rain water flow in rapid speed to the sea, fabridam
is highly regarded as one of the best suit for storage and diversion of rain water
because of its elastic characters of anti-wearing and compaction resistance.
If properly designed using precast method in mesium or small size of canal,
fabridam may perhaps be widely and applicably adopted, for its effective (unique)
function of auto-operation which will save more labour cost and fit for economical
considerations. The Following papers is a brief description on fabridam engineering
proposed to be discussing.
Hong-Lo Transbasin Rainwater
Harvesting Works For The Cheng-Kung Reservoir In Penghu
Council of Agriculture, R.O.C.
The Penghu Pescadores located in the west of Taiwan Proper are scarce in' water.
The annual precipitation is only about 1,000 mm which is much less than the measured
evaporation of 1,800 mm. The water supply there entirely relies on the surface
runoff and groundwater. In the dry year, the domestic water supply entirely depends
on the groundwater even up to 100% as most of the reservoirs dry up.
Due to lack of geological and meteorological data, hydrologic analysis was
extremely; difficult for planning reservoirs especially in the early stage of
development. At present, there are five surface-water reservoirs and one underground
reservoir with a total effective capacity of 3.9 million cubic meters, of which
the Chengkung Reservoir with a capacity of 1.04 million cubic meters, is selected
This paper is to review the hydrologic analysis of the Chengkung Reservoir
and to illustrate its transbasin rainwater harvesting system which was completed
in the recent year. It is emphasized that continued efforts on collection of geological
and hydrological data are to be made for application of the improved methodology
in hydrological analysis for planning cisterns on the water-scarcity off-shore
Solar Electricity in
Rain Water Cistern System
Ide Takashi Yoshida & Akira Higuchi
Yoshida Iron-work Co., Ltd.
Water is the origin of life and precious resources to us. For the purpose of
getting water, communities were composed, farming managed, and manufacturing done.
And stable supply of water has helped progress of agricultural techniques, development
of industrial economy, and improvement and conversion of industrial structures.
In order to get water resources, we can make the following statements.
- River water
- Water from lakes, marshes, and reservoirs
- Rain water
- Water from underground and spring
- Reutilization of water
- Replacing sea water to fresh water, etc.
In order to get water resources in the isolated islands and the top of depth
of mountains, utilization of rain water and spring water is easy and economical.
We had investigated and studied to get and stabilize the supply of rain water
at the isolated islands of Tokai district in Japan. Besides we devised an apparatus
by solar energy .(not by commercial energy) available for the isolated islands.
The outline is following:
- Quantity and quality of rain water
- Collecting works of rain water
- Solar cells and pump facilities
- Water supply apparatus
Investigation Into Feasibility
Of Usage For Domestic Use Of Collected Rain Water From Open Areas In Urban Regions
Shimizu Corporation, Japan
The purpose of this study is to examine the feasibility of collecting rain
water for reuse not only from roofs, but also open areas, such as park and public
lands. I examined the recovery rate and quality of collected rain water through
the use of permeable test pieces representing several types of ground compositions.
The results are as follows:
- The recovery rate of collected rain water ranges from 40-70% of the total
rainfall during the course of one year and these values depend upon the compositions
of the test pieces.
- The quality of collected rain water from non-fertilized test pieces satisfies
the Japanese flush water requirements for toilets, and it can be used for a wide
variety of purposes, including sprinkler systems.
- The collected rain water from fertilized test pieces contains a high concentration
of organic and inorganic substances during the first stages., so its reuse must
be restricted to plant cultivation.
However, during the last stages, its quality is almost equal to that of non-fertilized
test pieces, so it could be used for a wide variety of purposes.
Modernization Of Rain
Water Cistern System In Tokyo, Japan
Tsukuba University, Japan
Generally speaking, Japanese islands are plentiful in annual precipitation
about 1,600 mm in average, however, annual precipitation is different from place
to place and from time to time. Small islands located in the southern part of
Tokyo such as Izu islands and Ogasawara islands, there are primitive rain water
cistern such as Toshima, Shikine-jima, Hachijo-jima and Aogashima.
However, Tokyo Metropolitan area are modernized in' architectures, cultures
and so on especially after the World War II. Many tall buildings are characterized
and low with large roofs buildings such as Shin-Kokugi-Kan, Tokyo Dome and etc.
I would like to explain about the water resources for miscellaneous uses to
collect the low and large roofs buildings with the modernized rain water cistern
systems in Tokyo.
Ground Tanks In Urban
Or Rural Settings; The Answer To Water Crisis.
Development of Environmental System, Inc., Philippines
The Philippines is a tropical country situated approximately between latitudes
5° and 20°, north of the equator and longitudes 117° and 126°.
This island is annually visited by an average of 30 typhoons dumping an average
of 2500 mm of r ins. This large amount of rainfall, however, is not evenly distributed
throughout the year thus causing long periods of wet and dry months
Analyses of the annual distribution of rainfall shows that during the period
from January to June, the rainfall is about 31% of the annual average while from
July to December tuber, the rainfall is about 69% of the annual average.
It is to the problem of water crisis brought about by the long dry, spell that.
the use of around tanks is addressed. It can be concluded that rain water recovery
through the use of ground tanks is an economical method which can be utilized
in urban as well as rural water supply systems. Furthermore, ground tanks will
also help in minimizing the flooding problem accompanying intense rainfall.
Store and Utilization
of Rainwater with Tameike Cistern System at Rural Areas in Northeast Thailand
and Isao Minami
Kyoto University, Japan
In northeast Thailand, 10 tameikes, designed to store rainwater which is catched
at paddyfield, were constructed at two villages where they often suffer from,
drought damage under rainfed condition. Field data on the ability of tameike pond
t conserve rainwater and the possibility of the rainwater utilization for agricultural
production were collected.
It was shown that rainwater was efficiently catched and stored with tameike
system in rainfed farming areas. Every pond was filled with rainwater flowed from
paddyfields during wet season and the rainwater could be conserved even under
dry season condition. The stored rainwater seems to have the ability not only
to alleviate drought damage but also of desalinization.
Rice cultivation has not 'been affected y dry spell caused by erratic rainfall
because the stored rainwater could decrease the damage. In addition, horticultural
crops rowing and fish raising were promoted owing to the available water all seasons.
Although the benefits areas of the' rainwater for these crops or fish cultivation
were confined, 'the amount of their productions was enough to meet self-sufficiency.
In some cases their products seem to have a potential to increase income.
These suggests that tameike system is an effective measure which develops rural
life in small scale with utilization of rainwater in rainfed areas. This system
is more adaptable to improve the subsistence agriculture. The avoidance of the
drought and increased the agro-aquaculture due to the stored rain water may increase
the standard of living in the village.
Extending the Limits
of Rubber Dam (Sumigate) Technology
Tsuji, Ichiro Maruyama, Haruhiko Matsuoka, Kazutoyo Yamada & Katsuya Sakaguchi
Sumitomo Electric Industries, Japan
Sumigate is a inflatable and deflatable rubberized fabric+dam (rubber dam),
Which consists of, a rubberized fabric tube, operation equipments and pipings.
It is inflated by air or water and used for various applications, such as, irrigation,
water supply, tidal barrier; etc. because of its many features, namely reliable
deflation, easy and quick installation, low cost, excellent durability, and easy
operation and maintenance. We have installed about 1200 rubber dams (most less
than 3 m high) for mainly irrigation since 1966.
We developed materials for higher rubber dam full automatic operation., system
actuated by solar battery, and special cushioning technique and have installed
the 5m high experimental rubber dam in 1982 in cooperation with the New 'Energy
Foundation and the Electric Power Development Co.
After ten (10) years observation since the installation, it has no damage and
it has become clear that our large Sumigate is operating effectively as an diversion
dam even in the upriver:
Moreover as the number of rubber dams increased, their: reliability was revaluated
through practical demonstration. In 1990 the Japanese Ministry of Constriction
has. installed the first actual use high dam(Inou river: 4.71 m H * 24 m L) for
irrigation and tidal barrier, exceeding the construction regulations, that prohibited
the use of higher rubber dams than 3 m high dams, and the Electric Power Development
Co. starts to install the highest dam (Kurotani river: 6 m H * 34.5 m L) for small
hydropower diversion dam this year.
This paper describes the current status and future potential of the inflatable
rubber dam in Japan through the development procedure of a higher rubber dam.
Storage of Rainwater
and Snow-water in Southeast Coastal Districts of China and Scattering Purification
Treatment of Drinking Water
Hangzhou University, China
On the premise that the evaluation is made on the utility value of rainwater
and snow-water used as drinking water by residents in the southeast coastal districts
of China, this paper illustrates the purification treatment of drinking water
which the residents there carry on in their scattering households.
4: Hydrological Data and Analysis
Test Of Watershed Acidification
Models Responses To Rainfall Intensity
Department of Agricultural Engineering, National Taiwan University
Mathematical models are useful in improving our understand- ing of various
processes and predicting the response in freshwater chemistry to changes in the
deposition. A general weakness in models of the effects of acid deposition is
that the models have not been tested sufficiently against observation. An alternative
way to assess the applicability of models is to perform hypothesis test. Consequently,
a hypothsis--increasing rainfall intensity will increase outflow hydrogen concentration--was
tested with two well known watershed acidification models, the ILWAS and Birkenes
The ILWAS models confirms the hypothesis, while the Birkenes model does not
produce the same conclusion. This is probably due to the simplicity of the hydrologic
submodel of the Birkenes model and its assumption of constancy of the cation exchange
capacity. The result of test the ILWAS model for the hypothsis show that it is
a useful tool in the investigation of watershed acidification. This process-oriented
model provides the essential insight to make predictive assessment of the effect
of surface and subsurface water acidification under different loading.
Application The Bayesian
Approach To Hydrologic Sampling Theory For The Cho-Shut River In Taiwan
National Taiwan Ocean University, R.O.C.
The principal aim of this article is to study the Bayesian approach applied
to the statistical distribution of the annual maximum flow of the Cho-Shui river
in Taiwan. An important result obtained from investigation is the without and
with prior information to the Cho-Shui river, the posterior distributions are
respectively N(3.721,0.100) and N(3.055,0.081).
Envelope Curves for
Extreme Flood Events in SW Iran
Mohammad Hossein Borhan
Research Institute of Forests and Rangelands, Iran
Fars Water Authority, Iran
Water shortage in dry areas is the most limiting factor in their growth, even
in their existence. Many civilization have vanished because their water resources
had exhausted. Preparation of the systems which harness and conserve floodwaters
in unusual rainfall events is one way to replenish the badly depleted aquifers,
as well as to produce and preserve food, feed, fiber and fuel for the lean years.
Prediction of the runoff potential of watersheds in extreme events is a rather
conservative method for estimation of the size of floodwater spreading systems
and artificial recharge facilities. However, long time, continuous hydrological
data required to base the pred:.ctions on are lacking for most of the desert watersheds
in Iran. Therefore, it is necessary to resort to empiricism for prediction of
runoff events. Development of envelope curves for regions with a few gauged watersheds
facilitates reasonable estimation of the maximum probable peaks for ungauged basins
in the same area.
A total of 36 data points of the deluge of Dec. 1986 were used to derive envelope
curves for the Mond, Helleh, Zohreh and Shiraz basins. Euation of the form Q=C+B/A,
in which Q is the peak flow in ls-1 km-2, A is the area of the basin in km2 and
C and B are constants, best describe the overall performance of the basins. However,
other equation farms might better match some individual watersheds in the region.
A Coupled Model Of Overland
Flow, Soil Water Variation And Groundwater Regime In North-China Semi-Arid Plain
Loo and Dei-sun Lu
Shanghai Tongji University, China
Rain water, soil water and groundwater are interconnected as an intrinsic system.
Differential equations of water movement for individual unit of the system have
been solved separately but linked together by regarding their common interfaces,
namely the surface- water/soil-water and the soil-water/ground-water, as internal
boundary conditions. The soil water variation is a controlling factor in transmitting
rain water into groundwater, an one dimensional equation for soil water variation
is then solved first using finite analysis method with a prescribed initial soil
water content above a variable groundwater level during either precipitation or
evaporation. If the precipitation intensity is higher than the soil infiltration
rate, a depth-averaged two dimensional solution for the overland flow is approximated
by a power series method to see if both the duration and the depth of ponding
water are suitable for crop growth, or otherwise a three dimensional groundwater
regime due to adjusting the pumping scheme for the agricultural and/or the municipal
use is calculated by boundary element method in order to make an optimal management
of the water circulation. Such a computational process is repeated until minimizing
the water-logging, preventing the soil salinity and balancing the water resource
are reached to an expected situation.
For the North-China semi-arid plain, model studies show that the optimal groundwater
depth for an excess.rain season is about 3.5 m at the up-plain, but 5.0 m at the
down-plain area, especially, near the shore line, the groundwater level must further
be lowered owing to both the slow infiltration rate of the fine soil and the existence
of saline water unable for plant growth.
Characteristics Of Maximum
Daily,Rainfall On Vietnam And It's Influence On Soil Erosion
Van Tuan, Le Van Lan
Hanoi University, Vietnam
Vietnam is the Tropical country, so its rainfall is high and its periods of
sunlight are long. It's rainfall, especially, daily rainfall is the main cause
of the flood and soil erosion. Studies of maximum daily rainfall serve as a base
estimate flood and soil erosion.
This article expresses the results of the studies undertaken for many years
about rainfall and soil erosion all over Vietnam Consisting of more then 1000
rainfall station with ten years data and data of 40 erosion tanks at Tay Nguyen-central
part of Vietnam and at Vinh Phu province. Also this article mentions the following
- The causes of flood Rain in Vietnam
- Characteristics of an annual Rainfall and maximum daily Rainfall, it's spatial-duration
- Methods for calculating the maximum daily Rainfall.
- Influence of Rainfall on soil erosion and methods of soil erosion estimation
based on maximum daily Rainfall data. Characteristics of maximum daily rainfall
on Vietnam and it's influence on soil erosion
The main causes of flood Rain in Vietnam, Vietnam is the Tropical monsoon country,
so that it's rainfall is very high. Many Researchers (5,6,7,9) show two main factors
that cause flood Rain in Vietnam. They are:
- The action of world air masses (General circulation of air masses and
5: Cistern Management and Operation Guidelines
of Rain Water Catchment
University of New Mexico, USA
Rain water catchment has four engineering aspects: design, implementation,
construction and operation. Routine design matches capacity with demand. Improvements
in financial and educational infrastructure further the regional-scale implementation.
Material and technique development make construction more appropriate. The weak
link in the engineering process is that of operation, managing the catchment to
Dynamic programming, a tool long used in reservoir operational studies, reveals
how a catchment can be managed (when to draw,, when to conserve) to minimize the
penalties associated with water shortage. Penalties can be defined in arbitrary
terms, relatively or absolutely. Demands can be historic or synthetic, with or
without trend, seasonality or random fluctuation. Rainfall can be likewise actual
or synthetic. As a deductive tool, dynamic programming reveals the optimal mode
of catchment operation for any, scenario of supply and demand. As an inductive
agent, the analyst may reduce that knowledge to rules for real-time decision making.
A New Mexico catchment system is dynamically evaluated. A seven year rainfall
record is employed with logistic, exponential and unit price penalty schedules.
Development of Guidelines
for Rainwater Cistern Systems in Nova Scotia
S. Scott, Donald H. Waller
University of Nova Scotia.
Rainwater cistern systems have been in use in Nova Scotia for more than 50
years as an acceptable alternative drinking water source where groundwater supplies
are inadequate or are contaminated by gypsum, arsenic, uranium, iron and manganese,
road salt, or sea water intrusion. In recognition of its importance, the Nova
Scotia Department of Health published guidelines in 1982 for system construction
and operation. The source material for this document originated from outside the
province and for the most part was not directly applicable to the region. For
this reason, research was initiated by the Centre for Water Resources Studies
at the Technical University of Nova Scotia and later conducted jointly by the
Centre and the Nova Scotia Department of Health on Nova Scotian systems to develop
more comprehensive guidelines with the local climate in mind. This paper discusses
the various components of a rainwater cistern system and presents recommendations
for system design and system operation and maintenance in Nova Scotia.
Water Operation On Tameike
In Toban Region In Japan: A Rain Water Catchment System
Ishikawa agricultural college Japan
Kyoto university, Japan
Toban region has been irrigated mainly by tameikes which are operated mostly
intensively. The rules of operation have been formed by farmers experience for
hundreds of year. They are reasonable and instructive. So the author had investigated
about the tameike operation in the Toban irrigation area for several years and
got the following results.
1) Tameikes are classified into four types by their function, mother-ike, daughter-ike,
independent-ike and collecting-ike. They compose a water system combining the
function of each type of ike. Features of the system are much related to the topography.
For example, in the flat belt, a close combination between mother-ike and daughter-ike
Is obviously seen. In the mountainous belt, each independent-ike irrigates its
own area independently. And each collecting-ike exclusively supplies its daughter-ikes.
In the middle belt, the characteristics of both flat and mountainous belt are
2) A standard storage level is set at each tameike. Usually, it is decided
at a level of half to one-third of its full depth. When the storage of daughter-ike
decreases to this level before the middle of September, the mother-ike supplies
her during the night, from 20 to 6 o'clock in the next morning.
3) A ditch-tender selected among farmers exclusively operates the tameike and
distributes the water to each plot of field systematically. His standard working
time is usually 12 hours a day, from 6 to 18 o'clock. When it rains, he stops
release of tameike to conserve its storage.
Optimization Of Ground
Catchments To Maximize Rain Water Collection In South Africa
About 40% of South Africa suffers semi-arid id to arid conditions with annual
rain varying up to 200 mm. People staying in these areas are largely served by
ground water through bore holes for their water needs. Typically the water is
rich in dissolved iron or has an unacceptably high content of salt. The settlements
in these areas, as is often the case, are sparsely distributed making it costly
to import water. This means that the next practical and appropriate source to
develop is rain water which is at the moment only exploited limitedly.
The importance of rain water as an alternative source have already been well
documented elsewhere (e.g. Waller 1989) and will hence been assumed in this paper.
In the past the development of rain water catchment systems in South Africa
has centred largely in the optimization of roof catchment Systems. Significant
breakthroughs have been realized in work on water storage tanks. However, little
has been done to explore the potential for ground catchment systems.,
This paper reports on work done by the Division of Water Technology (CSIR)
to evaluate ground catchments that have been treated with four locally available
materials viz a tar product, paraffin wax graded sand and gravel and gravel covered
sheeting. To date the gravel-covered sheeting method. ha shown the greatest promise
for use because the catchment plots are easy to prepare, the media affordable
and most importantly deliver a reasonably good quality water.
Optimal Cistern Size
For Hydroponic Greenhouse Operation
University of Guam Mangilao, USA
University of Hawaii USA
Hydroponic farms are starting to be adopted in the American Pacific Island
for a variety of reasons. There are currently hydroponic operations in Hawaii,
American Samoa, Guam and the Marshall Islands. Many of these operations use cistern
stored rainwater, because of a lark of reliable water supplies, or because of
the quality of available water supplies is unsuitable for hydroponic culture.
Many of these sites are prone to periodic droughts. Thus, sizing. the cistern
is of vital importance to the economic viability of the operation. The cost of
construction of an oversized cistern is an unnecessary expense, while the construction
of an inadequate cistern exposes the operation to a higher risk of a loss of crops.
This paper develops a simple methodology for the optimal sizing of cisterns
given the rainfall history of the site, the water use of the hydroponic system
and the costs of construction. Specific examples are developed for Guam and the
6: Socioeconomic Aspects and Cost Analysis
Economics of Flood Irrigated
Cereal Hay Production
& Esmail Rahbar
Research Institute of Forests and Rangelands, Iran
Insufficient rainfall makes dry-farming an undependable method of food and
feed production in many parts of Iran. Moreover, groundwater (GW) mining for irrigation
of crop is threatening the very existence of the desert dwellers. Therefore, augmentation
and conservation of GW for later, wise utilization holds the key to the prosperity
of the future generations. Flood-water spreading (FWS) is a very easy and economical
means of crop production in the arid and semi-arid areas
Flood irrigation of wheat and hay in the e Joonegan County, Mamassani (mean
annual precipitation, MAP- 579mm) in 500 ha of rainfed wheatfields during the
1980-81 growing season resulted in substantial gains in grain and hay production.
The grain yield on a 40 ha tract ranged 1214-1685 kg ha-1. The highest grain yield
in control farms was 700 kg ha-1. T'he forage yield ranged from 1500 kg hasup-1
for Medicago scutellata Mill. to 300 k ha-1 for Trifolium alexand it num L. Improved
yield for wheat of up o 3200 kg ha-1 have been reported of up to 4300 kg ha-1,
and for medic of up to 3200 kg ha-1 have been reported for more recent years.
Disregarding the extra benefits accrued through artificial recharge (AR) and flood
mitigation (FM), the benefit to cost ratio (C) was 5.1.
A 650 ha FWS system was constructed in the e SE corner of the Gareh Bygone
Plain (MAP=150mm) for barley reduction. The grain yield of individual farms ranged
700-2000 kg ha.-1 with the mean of 1400 kg ha-l in the 1984-85 crop season. The
highest grain yield of control plots was 700 kg ha-1, Disregarding the extra benefits
accrued through Area of GW,. FM, and forage production in the fallow period, the
BCR compounded yearly at 15% for 10 years was 2.2. Should the real cost of irrigated
grain and hay production be considered, the BCR would be larger than the reported
Opportunities For Rainwater
Cistern Systems In Rural Economic Development
Lee Ping Sun Leung Yu-Si Fok
Univ. of Hawaii, USA
National Taiwan Ocean University Taiwan, ROC.
Lack of sufficient supplies of safe drinking water plagues the development
of rural communities. Selecting an appropriate system to supplement freshwater
supplies depends on economic, social, and institutional components of the community.
Rain water cistern systems are recognized as an effective, alternative means for
providing safe drinking water to rural areas worldwide. Rural rainwater cistern
systems are generally government initiated. Successful implementation, however,
requires both community acceptance and community cooperation in the construction
and use of the new systems. This paper examines the relationship between rural
water supply systems and stages of economic development, and suggests opportunities
for implementing rainwater cistern systems to meet rural development goals in
A Method Of Economic
Appraisal Of Rain Water Cistern Systems As Applied To High-Rise Buildings
Nanyang, Technological University, Singapore
The revival of Rain Water Cistern Systems (RWCS) and their adaptability for
application in high-rise buildings are of relatively recent origin. A p::ime mover
for acceptance of RWCS in high-rise buildings by both society and any water authority
is to establish the economic viability of such systems. In this paper, the capital,and
operating costs fcr an RWCS in high-rise buildings are considered. The benefits
are limited to savings in water utilized and the deferring of capital-intensive
schemes due to this saving. The methodology used for the latter is the "Unit
Cost of Leakage" approach. A typical case study is costed in the Singapore
context to establish the net benefits that can be reaped by adopting such RWCS
in high-rise buildings.
Derivation Of Some Opportunity
Cost Analysis Solutions For Economically Optimal Tank And Catchment Sizes In Rainwater
Collection System Design
Tulungan sa Tubigan Foundation, Inc, Philippines
I. For Constant Catchment
Assuming an RWCS with known catchment area A, constant and known demand D,
and operating under known rainfall pattern and rainfall-runoff relation:
Situations, And Cost Optimization Of Rainwater Harvesting Systems
The benefits of rainwater harvesting from house roofs for domestic water supply
are: the rainwater supply is next to the users house; it is compatible with the
approach of "user participation" and "local resources" technology;
its technical simplicity; it promotes water conservation; schemes are suitable
for construction in stages and in conditions of uncertain initial data on water
use; no land requirements; and, operation and maintenance are simple. Favourable
situations for the development of rainwater harvesting systems are: dispersed
settlements; existing house roofs; and high average rainfall (reduced catchment
area required) and little seasonal or annual variability in rainfall (reduced
storage volumes required) result in relatively low total costs. The cost of rainwater
harvesting systems can be optimized through appropriate planning, design and construction
of roof catchments, storage techniques, storage size, use of water. Costs can
be saved by the use of unreinforced storage tanks, durable tanks and by planning
storage into construction of new buildings.
Costs And Benefits
University of Science and Technology
In this paper, it is argued that rainwater as an important alternative source
of community water supply cannot only be viewed in terms of cost justification
but also in terms of such unquantifiable benefit: as time savings and improved
hygiene. An attempt has been made to provide guidelines for cost calculations
of rainwater harvesting projects, bearing in mind that when resource constraints
are applied to the selection of an appropriate community water supply technology,
it may turn out that improvement of traditional sources is the only feasible option.
Gravity Fed Water Catchment Schemes In Kenya “Following A New Approach”
Canadian Hunger Foundation,
In 1982, the Canadian Hunger Foundation (CHF) carried out a study of village
water projects in Kenya to find out why they had such a high failure rate. Many
of the projects studied had received donations from development agencies or NGOs
which were used for the purchase and installation of materials. Ho ever, without
a sound institutional framework, water would flow only for a short time much to
the bewilderment of the donor, who would of understand why the project had 'failed'.
The result would frequently be an evaluation seeking technical flaws that excludes
'an assessment of the institutional aspects. Repairs or modifications would then
be carried out for the technical flaws, but water would still not flow continuously.
Eventually, the donor would be come disillusioned and finally resign from the
The symptoms of institutional inadequacy were found to be
- Poor Management skills
- Little or no organisational structure
- Lack of maintenance skills
- Absence of a sound financial plan of regular income and of administrative
- Absence of a sense of ownership of the water project by the community
- Ignorance of the skills and resources required to run a water project
- A 'charity' relationship between funding partner and the community groups
It was clear that the institutional requirements of village water projects
had not received enough attention. All parties concerned had grossly underestimated
what is required f r such projects to be successful and self-sustaining. It was
apparent that a new approach was required. Thus the CHF embarked on the development
of a new approach and used it to support a number of projects. In the case of
the first CHF assisted project, the CHF commenced in 1984 and withdrew in 1987.
By 1989, the group had a healthy bank balance, expanded their project by 100%
and had built their own offices. It now serves as a model for other project development
all over Kenya. It is the NGO which participated in the community's project not
the other way round.
7: Agricultural Uses of Cistern Water
Diversion Project In Penghu Area
Chien, Cheng-Nan Tsay, J a -Chyun Wang
Water Conservancy Bureau (TPWCB, Taiwan, R.O.C.
Penghu Archipelago is located in southeast part of Taiwan Strait. The average
annual rainfall is 1,'013 mm which is no more than one half of that in Taiwan
Area. In addition, evaporation is as high as nearly 1.8 times of its average ,annual
rainfall. Since there are no high mountain and forestry in the area, most of the
rainfall either infiltrates or runs off to the sea immediately. The supply of
fresh water is in great shortage all year round for Penghu area. To solve the
problem, the utilization efficiency of rainfall should be promoted. Cheng-Kung
reservoir has usually failed to' be filled up owing to insufficient inflow. In
order to increase the inflow, an interception wall and conveying channel were
built near Hung-Lou village to divert the runoff from adjacent watershed to the
reservoir. As a result, the annual water supply has increased 20 %.
Rainwater, Water Table
And Soil Moisture In A Hillslope
Oliveira Leite & Antonio Cadima Zevallos
Cacao Research Centre, Brazil.
The objective of this work was to stud y the relationships between the rainfall,
the water table and the soil moisture regimen in a hillslope planted with cacao.
These parameters were measured daily during 270 days.
The water table was observed in a set o 5 wells located in a contour line of
the hillside. Beside the middle well two sets of tensiometers were installed at
15, 30, 60, 90 and 135 cm depths. Also, the soil composition, density of aggregates
and moisture equivalent were measured. It was found that, horizontally, the soil
profile can be divided into three zones: the op zone (from 15 to 30 cm depth),
not submissive to the water table rise under rainy conditions. This zone presents
an average soil moisture content of 0.48 (cm3/cm3). In the middle zone (30.- 90
cm), the average moisture content ranges from 0,50 to 0,55 f the water table.
is below or above 4m depth, respectively, and th bottom zone, below 90 cm, is
more submissive to that saturation although its moisture content is not statically
different than o the upper zone. The peculiarity of the middle zone, which is
composed of B21 and B22 horizons, is associated with its high clay content. Also
this zone represents a water reservoir to the cacao' tree. In general, the results
suggested that the water table height, associated with the rainfall conditions,
controls the moisture content in the whole soil profile. However at the 30 - 90
cm depth, the transpiration flow of the cacao tree may also play an important
role in the soil moisture regimen.
Scientific Method of
Kanat's Artificial Recharge, With Examples of the Efficiency of the Methods Describe
Chamran University, Iran
In this research different methods causing kanat's artificial recharge are
identified classified, and introduced. The results of their application have been
described in Iran. These methods consist of five ways of surface recharge and
three ways of underground recharge of aquifers. The five surface recharge methods
as follow: construction of vast artificial pool with specific artificial pond;
storage of water in the area above the mother well; Construction of earth dams
at the floodway s around kanats; The expansion of the vegetation of soil and making
the strips along the tarekar of kanats. Three methods of artificial groundwater
are artificial recharge by well, by joining the deep wells and kanats and lowering
the ground water level. Based n the local research among the eight different methods
presented for the artificial recharge of kanats, the construction of recharge
well is recognized to be the cheapest and the easiest of all and is recommended
as an effective method for increasing kanats discharges.
8: Irrigation and Uses of Water
For Future Generations; Small Reservoir Irrigation Scheme In The Philippines
N. De Guzman
National Irrigation Administration, Philippines
The Philippine Archipelago, a country of 61 million inhabitants lies entirely
within the humid tropics between latitudes 5° and 20°N longitudes 117°
and 127°. Micro climate within the islands are largely influenced by altitude.
(most islands have narrow coastal plains surrounding mountain ranges with height
from 500 - 2,900 m) and the direction of prevailing air stream. the latter influences
seasonal variation in climate, in particular the rainfall distribution pattern.
Annual rainfall is from 1,500 to 4,200 mm. In most lowland areas average rainfall
is generally adequate for a single crop in the rainy (wet)season. However, rainfall
is often not evenly distributed and dry spells frequently necessitate supplementary
water supplies. Unfortunately, the country lies in an area recognized. as having
the greatest frequency of tropical typhoons in the world. Between 1948 and 1988
an average of tropical typhoons were recorded annually mostly in the months of
June to December, with the highest monthly frequencies (more than three) in July,
August and September.
Water resources development in the Philippines for irrigation, power, domestic
water supply, and industrial purposes involves a variety of types, from simple
diversion to huge reservoirs, to shallow wells, to deepwells, and to rainwater
conservation through storage.
This paper presents a case study of rainwater cistern system or rainwater catchment
for irrigation, flood control and soil and water conservation for future generations.
Rain Water Catchment
Ponds For Irrigation In Taoyuan And Shihnen Districts Taiwan
Hu & Ching-Ho Ku
Council of Agriculture, Executive Yuan, ROC
Both the Taoyuan and Shihmen Canals take water from the Shihmen Dam to irrigate
farm lands amounting to 37,00 h .in the Taoyuan and Hsinchu counties of northern
Taiwan. According he definite plan of the Shihmen Dam Project and the actual irrigatio
operation, the dam can only provides a portion or about 50%-60% f the total amount
of irrigation water, and the rest .s to be supplied by the regulation of irrigation
farm ponds and the flow catch d by local diversion weirs. The topographic conditions
and soil types in these areas are generally suitable for farm pond construction
an operation. Totally 686 farm ponds with capacity of 45,160,000m ere constructed
as rain water catchment facitities and have Dean operated by the Irrigation Associations
(IA)for irrigation for a long time.
Recently, owing to the Environmental and socio-economic changes, the farm land
has decreased because f industrialization and urbanization. Review on the capacity
o he farm ponds was, therefore, considered necessary so as to keep ac with the
reduction of irrigation area. A mathematical model based on the theory of linear
programming has been studied for review ing and planning to determine the necessary
capacity of the farm ponds. By computer manipulation of the linear programming,
the results appeared that the farm ponds still play a very important role for
irrigation in this area. If the farm ponds provide 35% or r.10 more of the irrigation
water, the total capacity of the farm ponds s hould be reduced by reducing the
farm lands. As the result of the s tudy, the purpose of effective utilization
of land and water resources in Shihmen Dam service area can be realized.
The Merits Of Smoothing
Irrigation Furrows To Improve The Uniformity And Reduce The Total Application
Of Irrigation Water
Agriculture Head Office of Eastern Aearbaijan, Iran
The infiltration rate changes with time. It is a fairly high value when the
soil is first wetted, then it quickly decreases to a much smaller, but stable,
rate known as the basic infiltration rate. There are many factors which will change
the initial part of the infiltration curve, the two major factors are the soil
moisture content before irrigating and the surface roughness. Smoothing the roughness
in a furrow acts to speed up the furrow advance and the recession so that for
a given' inflow time the opportunity time remains nearly constant. The accumulated
infiltration is a function of the opportunity time and the infiltration rate curve
for the particular soil. The uniformity of the water which is infiltrated into
a soil is dependent on the uniformity of the opportunity time along the length
of the furrow being irrigated.
The data reported were collected during the third irrigation in a field planted
to corn on a silty loam soil in Eastern Nabras. Two basic ditching treatments,
using a conventional ditcher and using a Hawkins ditcher, were each compared with
and without an additional smoothing operation.
Smoothing the furrows increased the uniformity coefficients for the opportunity
times along the furrow in both ditching methods. No test of significance was conducted
on the data due to the lack of replications.
Reducing the roughness coefficient by smoothing the furrows speeded up the
furrow stream advance which would have allowed a shorter set time, thereby reducing
the total application of water. The objective of applying 2 inches of water could
have been achieved if the well had been shut off: sooner. This would not have
adversely affected the uniformity of water application.
9: Alternative Uses of Cistern Water
Water Cistern Systems
National Taiwan Ocean University, Keelung, Republic of China.
University of Hawaii at Manoa, U.S.A.
Rain water cistern systems can serve multiobjectives. Although they are traditionally
used for domestic water supply, however they have been used for other purposes.
From an economic view point, if a rain water cistern system (RWCS) can serve multiobjective
uses, it could afford a higher initial and operation/maintenance costs. Therefore,
planners of rain water cistern systems should seek multiobjective uses to enhance
the feasibility of their applicability. Examples of :cain water cister systems
multiobjective uses are presented in this paper, Readers are encouraged to report
their experience related to this subject.
The Water Harvesting/Aquaculture
Bocek Kyung H. Yoo & Bryan L. Duncan
Auburn University, Alabama, U.S.A.
The Water Harvesting/Aquaculture Project ( P): was a five-year project funded
by the U.S. Agency for International Development (USAID). The principal goal was
to "improve the quality of rural life in selected developing countries through
the introduction of improved technology in ways that would balance local capacity
for development with total community needs and potentials."
WHAP involved collaboration with six private and voluntary organizations (PVO's)
in 41 countries during: h project period. The project provided technical training
and assistance on water harvesting and aquaculture technology to field staff working
with local organizations, communities and individuals. Training participants acquired
background knowledge. o- :make. preliminary project designs and assessments. Technical
ass -stance was provided to those who initiated projects but lacked the kills
and knowledge necessary to go beyond preplanning and site assessment.
The paper provides overview of WRAP, and discusses the water harvesting concept
and authors' experiences u d r arid and semi-arid conditions.
Using Farm Pond in Southwestern Taiwan
P.W. Yuan, Y.H. & Wan; Y.
Taiwan provincial soil and water conservation Bureau
Farm ponds are primarily designed and constructed for storing rain water and
providing water supply for the township of Tos-cheng, Yu-Ching, and Nan-Hua in
Taiwan county. Te-Liao, and Yen-Tsoinkaohsiung county where water shortage is
a serious problem. In the past 20 years, from 1970 to 1990, a -total f 58 farm
ponds were constructed with a total volume of 2,745,200 Using farm ponds to collect
rainwater is an unique feature in Southwestern Taiwan.
Rivers and streams in Taiwan are short and steep. Water flows swiftly to the
ocean. Although the rainfall is abundant, water supply in Taiwan is limited. The
average annual rainfall on the island is about 2,510 mm with large spatial variability.
Rainwater is a valuable water resource in mudstone are areas with unavailable
groundwater resource and insufficient surface water source Since 1965, the Taiwan
Procincial Soil and Water Conservation Bureau initiated a policy to construct
a lot of farm ponds for storing rain water and supplying water to satisfy people's
domestic needs, agriculture and livestock raising. The cost for a pond construction
is higher than tap water. However, it is necessary to improve people's living
environment, and to upgrade a production. Farm ponds can also control gully erosion
and landslide in mudstone areas.
A lot of effort have been spent in conducting reconnaissance survey, planning
and design of earth embankment and farm ponds using impermeable mudstone materials
So for, no dam failure has been reported. When farm pond is filled with sediments,
the sludge has to be dredged out. The sludge has been used o cultivate crops such
as dates and guava to increase farmer’s income. This technology has been
transferred to local governments to assist in planning and design of more farm
ponds and rainwater cats en systems.
Water Use Problems In
Mudstone Areas Of Southwestern Taiwan
J. F. Hsi.ao
& C. H. Wu
Taiwan Provincial Soil Conservation Bureau , Taiwan
The hilly areas of southwestern Taiwan is dominated by mudstone. Under normal
conditions, these areas have adequate but unevenly distributed rainfall. Many
small gullies are found on steep slopes. Mudstone soils are usually shallow and
impermeable. Even with abundan, rainfall at times, water shortag problems often
occur during dry seasons due to poor water holding capacity. The agricultural
water use in these areas is characterized by growing first crop of rice in river
valley' and flatland d using rainfed. The field-collected rainwater is used to
grow a se and crop of rice from June to October. In recent years, increasing number
of farm ponds has been constructed to provide^ water for hill lope orchard farming.
Besides irrigation and pest control, purposes the collected water has been used
domestically. This paper briefly introduces this water utilization method and
its use in a natur al setting.
Rain Water Catchment
System In Hydraulic Experimental Station
Kyoto University, Japan
Gifu University, Japan
We has developed the rain water resources ya tameike (pond) in the laboratory
of water use engineering , Kyoto University. Though we needed much water for the
new laboratory of water use engineering at the remote location from Maizuru city,
Kyoto Prefecture, the water was not enough to operate hydraulic experiment for
45 students and for researches of water use engineering. After several Years from
the construction of new laboratory, though the Maizuru city had constructed new
domestic water line with bigger diameter in this area in 1980, the water fee -consumed
by hydraulic experiment in the laboratory was very expensive: one'. Then we had
introduced the facilities with rain water collection pipe line in underground
and a tameike in our experiment station The major items of facilities are as follows.
- dimensions of rain water catchment system total area of laboratory 2.5 ha
- watershed area of tameike 1.0 ha
- rain water collection pipe line in underground side ditch of paved road 150m
long an 6 meters width
- under ground drain pipe 250m
Design Of Coastal Fresh
Water Pond For Optimum Use Of Water Resources
C Eng-Kung Univ, Taiwan
Fifth Division, Industrial Development- Bureau, Taiwan
An idea of constructing a coastal fresh water pond system for reclaimed area
is reported. This pond utilizes.. a dividing channel, initially designed to isolate
the reclaimed l and from the nearby urban area, as the fresh water reservoir.
The completed fresh water pond system is composed of (1) Linkage, conveyance and
bypass (2) Monitoring & control, MACS and., (3) pond storage, CFPW systems.
System design requirement for the pond and consideration are listed.
The MACS is planned to be fully automatic: and performed in both predictive
and real-time modes. The linkage system uses two by-pass channels and retain most
of the current environmental issues. The pond is designed to have overall storage
of 21, x106 M3 and capable for industrial water supply of two months. The overall
system is being evaluated in an experimental-station:
The Use Of Rain Water
For W.C. Flushing In The U.K.
& A Jay
Nottingham Polytechnic United Kingdom
The general problem concerns the use of rain water for w.c flushing. In the
past there has been no financial incentive for U.K. customers to conserve water
because charges were not based upon the volume used. During the next: decade the
me tering of domestic supplies is to be introduced and water conse rvation devices
are likely to become financially viable. The integ ration of rain water w.c. flushing
cisterns into U.K. dwellings and their economic feasibility is evaluated. Finally
the reactions of water suppliers, housebuilders and consumers in the U.K. t his
method of water conservation are presented and discussed.
A Simple Weir for Economical
Research Institute of Forests and Rangelands, Iran.
Diversion dams or weirs sometimes constitute the most expensive and troublesome
structures in the design and construction of floodwater spreading (FWS) systems.
Many plan for construction of potentially viable FWS systems have bee cancelled
in the feasibility stage studies because, on occasions, the expenses involved
in the design and construction o a single weir or diversion dam far outweigh the
cost of the rest of the project. Thus, justification of the entire project hinges
on designing a workable structure at a low cost. Gabion provides a useful material
for construction of simple, inexpensive weirs which could be fitted into many
designs, and may be. built by unskilled laborers.
Fifteen pieces of 3 0 x 4 0 m, 3 mm diameter galvanized wire netting were used.
to construct a.0.60 m high on a 28.0 m wide ephemeral river on a debris cone to
diver up to 5m3 s-l of floodwater to a 25 ha FWS system in the Gareh Bygone Plain
in, southern Iran. The costs were at least 136 times lower than building a hydraulically
efficient, concrete structure having the same capacity.
Although the intake structure behind the weir located on the inside of the
river bend, and at a 9° angle to it, no detectable deposition of sediments
has--taken-place at this point during 6 years of operation. These hydraulic anomalies
deserve further attention.
The Catchment Rain Water
System Used as Supplemental Water Sources of Cities and Towns
Institute of Environmental Health & Engineering
Catchment rain water used as domestic water has a long history in many areas
of china. That is not only major water source in short water areas, but also important
supplemental water source in which far from water sources or bad water quality.
With consumption increasing rapidly, water resource is deficient day by day. Catchment
rain water for additional water sources is more and more paid attention to.
10: Country Reports and Future Outlooks
Experience In Rainwater
University of Dar es Salaam
This paper discusses a wide range of experiences onpractical aspects of rainwater
harvesting in Tanzania. The discussion covers the prospects and difficulties experienced
in aspects such as the cost of rainwater cistern systems, the rainwater quality,.
the adequacy of rainwater supply and the feasibility of rainwater cistern system
in both urban and rural areas in Tanzania. In most of rainwater cistern systems,
the quality of rainwater was found to vary widely largely due to the design and
construction of the storage tanks, the consumers user habits and flushing system
for first rains. The quality was generally found to be insufficient for full domestic
use in most of the rainwater cistern systems and the availability of alternative
sources of water was found to influence the rainwater consumers' habits
Water Of Island In Japan
Kyoto University, Japan
Shimane University, Japan
So far the water situation of small islands far from main land of Japan was
especially very serious. The water had been developed from rainfall by several
traditional methods. But there was no enough studies on suitable apparatus and
facility to store that rainfall. Then many islands were very strict in water utilization.
Lately Japan government had issued big budget to improve this water shortage in
remote islands, and they had developed the water of remote islands introducing
various technology and engineering methods.
We would like to show the comparison between old situation and present situation
of water resources of remote islands.
Rainfall distribution of island in Japan has big difference between north part
and south part. But most serious part is the islands in Seto Inland Sea. Then
we had performed field survey on water situation on this area. The smallest island
was Uwoshima island and the most developed island was Nakajima island.
(old situation of water in islands)
- Rain water cisterns were used on inconvenient parts of islands
- People has clustered in flat: places along seashore
- People has been endured serious shortage of water
- Ground water had been developed, but sometimes salt water was contained.
(present situation of water in islands after development by government)
- Ground water was developed by wells and pipe line system were introduced.
Utilization Of Rain
Water For Domestic Activities In Thaibinh And Nghetinh Provinces In Vietnam
Van Tuan & Le Van Lanh
Hanoi University, Vietnam
I. Physical geological
characteries of Nghetinh and Thaibinh provinces in relation with the water supply.
1. Physical geological conditions of Thaibinh province. - Geological position:
Thaibinh is one of the provinces situated near by the sea in Bacbo plain (fig
1). Three sides of it are large rivers: Red River, Luoc River making natural border
between Thaibinh and Haihung at the North and Thaibinh and Hanamninh at the South.
Its Eastern side faces Biendong sea.
The area of this province is 1495 Km2. Population is about 1,539,500 people
with a density of 1022 people/Km2.
Topography of Thaibinh
It is a province in the plain in the Red River estuary. It's Topograph is out
by the rivers and streams outside as well as inside: Red River, Luoc River (outside),
Trady, Hoa Rivers (inside) and a lot of ponds marshland, lakes. Density of rivers
is about 0.25 Km/Km2.
The area of all lakes and marshland is 11044 ha and the lenght of canels is
over 45 Km. It's has over 50 Km coast line. It means that salinity intrusion into
the land goes throughout the province. So salinity takes place nearly everywhere
of the province.
Thaibinh is one of coastal provinces in the tropical and mosoon zone. It's
rainfall is rather high. It often happens together with storms. The rainy season
costs for 6 months (May to October) and the rest six months belong to the dry
Systems For Drinking Water Supply In China
Inst. of Environmental Health & Engineering, CAPM, China
The Office of National Patriotic Health Campaign Committee, China
Rainwater has been harvested and used for domestic water supply in area lacking
good alternative water sources, especially in loess plateau of the northwest China.
There the rainwater harvesting system in general;, consists of ground catchment
area, collecting drain, silt trap, sedimentation tank, screen and water cellar.
The initial cost for 20 m3 storage volume was equivalent to U.S. Dollar 35
that could be afforded by a farm family in general. In China, rainwater cistern
systems have been mainly used for domestic water supply in rural areas where groundwater
is unfit for human consumption, such as bitter brine water in Northwest plateau
or surface water is heavy polluted with wastewater discharged from the village
enterprises in Southeast coast. The cost of purification for facilities, maintenance
and operation would be extremely high due to the advanced treatment: processes
have to be applied for those water sources. Rainwater has been, therefore, harvested
and used popularly for domestic water supply in areas lacking good alternative
water sources especially in loess plateau of the Northwest, where annual rainfall
is pretty low, only 316mm,and its 64% is concentrated, between July and September
each year. There the groundwater either containing a great number of minerals,
is too bitter to drink, or too deep to withdraw, otherwise, surface water is very
seldom and too far to transport, more than 10 km from the water source to the
consumers. The deep wells with the high lift pump have been, on trial built in
some areas, but it ceased because too high cost to operate in comparison with
very low output for drinking water supply. Seeing that, more than 0.2 million
Rain Water Harvesting
Systems In Southern Africa
University of Natal, South Africa
Poor water supplies and sanitation services continue to be critical problems
in the less developed rural areas of southern Africa despite considerable effort
to improve and expand access. It is widely recognized that safe, easily available
water supplies provided in a form acceptable to the communities concerned are
essential for rural development.
Most rural communities depend on local sources of water which are available
naturally - river water, open wells and springs - and these are frequently polluted.
Not nearly enough use is made of rain water collection systems.
This paper describes the research and development work conducted on rain water
harvesting systems in southern Africa in recent years. A case study is referred
to for the purpose of illustrating the approach being used to meet the water needs
of communities in some less developed rural areas for domestic as well as agricultural
use, with particular reference to the introduction of simple, cost effective rain
water harvesting technologies. The approach emphasizes the need for attention
to be given to community involvement, through appropriate institutional arrangements,
in choosing suitable technologies.
The Necessity And Scope
Of Rainwater Harvest In Bangladesh.
Bangladesh Agricultural University, Bangladesh
Bangladesh is a tropical country influenced by Monsoon climate. The average
annual rainfall is about 2300 mm. But more than 80% of that rainfall occurs during
a short period (May-August) resulting in huge runoff volume and subsequent floods.
On the other hand, during the dry season (Nov. - Feb.), there is almost no or
very little-rainfall resulting in too much shortage of water with subsequent severe
draught conditions. Due to this two extreme and opposite conditions prevailing
in Bangladesh the total economy of the country is suffered tremendously
In this paper, with respect to taking care of this two extreme situations to
some possible extend, the necessity and scope of rain water harvest in Bangladesh
has been discussed and suggested some strategies.
Malian Experience In
Rain Water Cistern Systems
Groupe de Recherches et d'Applications Techniques (GRAT), BAMAKO/MALI
Water needs, supplies and uses constitute a compound subject in Mali. The appropriateness
between water needs and resources Varies throughout the year. The rain season
(2 - 4 months long) undergoes serious climatic disturbances these last two decades.
People do not have enough access to water, because there is not enough systems
(wells, reservoirs, pumps) to make the most of the potential water supply and
the situation becomes more complex with the nature of the persons who support
all the water supply charge. Whatever the reason, water shortage is especially
prevalent in rural areas.
In this complex water supply system, the surety technology is not necessarily
the one which occurs more water at less cost, but which occurs water at a specific
moment in a specific place. It is the case of rain water cistern and catchment
systems, which exempt women from supply duties at the moment when they have heavy
The rain water cistern and catchment systems used in Mali depend on the geoclimatic
factors of the different regions, the nature of the needs to satisfy (domestic,
agricultural) and the way of life of the people (settlement).
According to the nature of the need, there are individual and collective implemented
systems. Some of the systems are widely used in many areas and the others are
known only in a small part. The importance of the rain water cistern and catchment
systems is well known in Mali.
Traditional and modern techniques have been presented and the constraints and
limits analysed for more wide application and efficiency use.
Rain Water Cisterns
- A New Approach To Supplement The Rural Water Supply System In Sri Lanka
De Silva Ariyabandu
Agrarian Research. and Training Institute, Sri Lanka:
The envisaged target for the IDWSS decade in Sri Lanka was to construct 16,000
tube wells to provide adequate safe drinking water for the rural population. However,
due to the unsettled situation in the country coupled with lack of funding have
resulted in a shortfall of 4000 tube wells by the end of the decade. It is.hoped
that the target could be achieved by 1995 if funding is granted by the Government
of Sri Lanka and International donors to cover the spiralling cost.of constructing
This paper proposes a novel approach to supplement the shortfall in the tube
well programme by introducing rainwater catchment through roof run-off. Having
an annual rainfall of more than 1000mm in the dry zone, Sri Lanka's potential
for success in this approach seems positive. This approach, if proves to be a
success would. save time of the peasants otherwise used in fetching drinking Water.
from distant places. The time thus saved could be utilized , in .more productive
occupations like paddy coutivation or animal husbandry. Collection of rain water.will
be either in jars (2-3m3) or in small tanks. which ever the cheapest and preferable
in the area. Approximately, it is estimated that cost of a jar of 2m3 is 3% of
the cost of constructing a tube wall. At the existing cost estimates even if the.
state gives a jar free of cost to every beneficiary household in a tube well community,
the state can save upto 30%.of cost of constructing: a tube well. With a drinking-water
requirement of 5 liters per day per person a jar can supply drinking: water for
60 days for a family of five. With an additional jar a family can store sufficient
drinking water for almost half the year. " The implementation of the project
will seriously take note of the social aspects of drinking water specially from
roof run-off. Project anticipates. to conduct classes to women in the community.
to educate them and eliminate any myth about' drinking water off roof catchments
and having, safe drinking water. The men will be. trained in, for
Rain Water Conservation
Department of Agriculture, Zambia.
The Aim of the paper is to assess the need of rain water conservation for Agricultural
purposes in Zambia. The paper also looks at the means and ways of rain water harvesting
in the Country.
Rain water in Zambia is wholly restricted to the rainy season which is between
the months of October and April.
The Eastern and Southern Parts of the Country are most of the year dry with
very few perrenial rivers. This has affected Agricultural Development. Hence the
other objective. of the paper is to examine the drought relief programme introduced
in these areas. The paper also looks at whether or not Dam construction which
forms a major portion of the programme has been effective. The paper analysis
other ways of rain water conservation if they could be good alternatives to the
Utilization Of Rain
Water In Tanzania
Ministry of Water, Energy and Minerals, Tanzania
Rain water has been in use in Tanzania for ages, but not as a significant source
of rural or urban water supply. Being a poor developing country, it is faced with
,a number of problems which renders services like water supply difficult to achieve
This paper looks at roof top rain water harvesting as a relatively cheap and
appropriate technology that can either solve water scarcity problems or at least
reduce them in Tanzania. It traces the historical background of rain water harvesting
in Tanzania and points out why the method has or hasn't been adapted in different
parts of the country. It looks at the present situation in Tanzania as pertaining
to the availability of water for various uses, both in the rural and urban areas.
It further highlights on the research efforts being currently undertaken in the
country in the area of rain water catchment. The paper attempts to justify the
need of popularising the utilization of rain water in Tanzania, in order to supplement
the conventional waiter supply endeavours by the government.
Finally, the paper points out the problems that have rendered the technology
unpopular in some parts of the country and why it is not widespread as a major
Rainwater Cistern Its
Uses In Nepal - Problems, Prospects And Promotion
Peace Corps Nepal
Experience of construction of few rain water cisterns in Nepal shows that the
approach could be a viable water supply system in the country. The system has
more relevance in settlements in ridges, spurs, river terraces and generally water
critical pockets at different climatic zones. Of the several factors, cost of
the storage tank appears to be the major constraint in the way of wider uses of
the system. In order to make it attractive, storage system need to be built at
lesser cost, when the system would be more affordable. Prototype of a tan}, that
used plastic lining has been developed and is being installed in field situations,
whose performances need to be evaluated. For wider promotion of the system, an
action oriented approach is being pursued. The feed backs would be useful in further
promotion of the rain water cistern system in the country.
Hafirs In Sudan
Ministry of Health, Sudan
The HAFIR is an underground :reservoir designed for storing rain water carried
by streams and used for domestic water supply and for agricultural purposes in
rural areas in the Sudan.
Hafirs are usually constructed where there is enough rainfall and where there
is no underground water.
It is usually big enough to cater for the needs of the villagers and their
live-stock for a whole season.
The Hafir is surrounded by earthen embankments and protected by barbed wire
fencing from animals.
The shape of the Hafir is like a trunkated frustum of a pyramid. The average
capacity of a Hafir varies from 15,000 to 250,000 m3.
There are different types of Hafirs e.g.:
- Conventional HAFIRS
- Lined HAFIRS
- Overground storage HAFIRS
Maintenance of HAFIRS depends on:
- Removal of slit
- Cleaning of water pipes
- Cleaning of canals-stilling bowels, inlets and outlets.
- Compaction of eroded embankment.
Rain Water Harvesting
In Sarawak And Brunei: Progress Of Its Implementation As Part Of The Rural Water
University of Brunei
Piped water supply to homes definitely has a better coverage in Brunei Darussalam
than in neighbouring Sarawak. Nevertheless in some isolated villages where no
reticulated system exists and where shortages from natural streams during dry
spells occur, rain water harvesting has been introduced. In Sarawak the problem
of developing rural water supply is much more difficult as the population is widely
scattered in the coastal swampy plains and the interior. In the coastal plains
concerted efforts have been made by the government to introduce rain water cistern
systems as a viable means of potable water supply to the more than 500 village
settlements of varying sizes. This paper examines the rain water harvesting plan
in Brunei Darussalam and in particular Sarawak, and the extent of success of its
implementation to date.
Rainwater Cistern System
In Malaysia Reconsidered
University Kebangsaan Malaysia
Ministry of Health Malaysia
It has been almost a decade since an attempt was made to examine the policy
and practice of rainwater cistern system (RWCS) in Malaysia. The main aim of this
paper is therefore to review the development of RWCS over the past decade and
consider its future prospect. This is especially in view of the massive rural
water supply programme undertaken by the government particularly during the second
half of the decade.
It has to be mentioned at the outset that RWCS in Malaysia is essentially a
rural water supply system. There has been no attempt on the part of any agency
related to water supply to introduce the system in an urban environment and: attempts
by private individuals to utilize this source of supply can be said to be minimal.
The urban areas has been entirely dependent on the potable system provided by
the various waiver supply agencies and the folly of this over-dependence has been
clearly demonstrated by the recent failure of the Malacca water supply system.
Other than private efforts which are largely uncoordinated, the only programme
on RWCS in the rural area is under the purview of the Ministry of Health. However,
to quite an extent it could also be said that the RWCS programme of the Ministry
of Health at the State levels is largely uncoordinated, This is illustrated by
the absence of any clear-;:guideline on programme implementation at the policy
as well as technical level.
As Supplemental Source For The Traditional And Modern Water Supplies For Forming
Families In Malawi.
Meteorological Department, Malawi
Rainwater harvesting simply means collecting rain water in some suitable reservoirs.
To achieve this simple phenomenon a systematic process has to be followed.
This involves provision of an ideal surface area, referred: to as catchment-area
` and the receiving tank or reservoir referred to as cistern.
The family rainwater harvesting system is expected to provide water for all
their needs, drinking, cooking -washing, irrigation etc. But there are several
limiting factors that regulate the volume of water collected. The natural factors
are the potential- annual rainfall and the duration of the dry season. The adjustable
factors are the collection surface (roof) area or catchment area and the cistern
capacity. The most important limiting factor is the FUND.
The Nakuru C.P.K. Rainwater
International Rainwater Catchment Systems Association - National Representative
The above programme started in 1984 with a goal of introducing sustainable
affordable, replicable and acceptable water supply projects within 6'1/2 administrative
districts which are Nakuru, Nyandarua, Narok, Baringo, Samburu, Kericho and part
of Laikipia. During this period of 6 years a number of target groups have been
identified and mobilized. To date the programme has over 150 active groups made
up of 90% women who are also responsible for their group management. Total number
of tanks constructed are over 3,0.00 and sizes:: vary from 500 gallons capacity
to 30,000 gallons. This. means over 3`0,000 people and hundreds of cattle have
safe water supplies at their homes'. Challenges have been in areas of research,
documentation, quality monitoring and promotion of rainwater catchment system
in other areas other than domestic, such as agriculture. The programme with assistance
from UNICEF hosted first IRCSA workshop which attracted over 55 participants from
over 20 organization including 4 ministries. There were also participants from
Botswana and Tanzania.
11: Technical Short Papers
Effect of Vegetation
Cover on Rain Water Harvesting
Ferdowsi university of mashhad, Iran
Vegetation influences the run oft cycle through different processes, such as
evapotranspiration, interception, and reducing flow velocity._ In an investigation,
the effect of vegetation management on water yield of three small watershed was
studied. Management included burning and hand removal of all vegetation cover.
Rainfall and collected run off were measured for each of the precipitation. The
result show that both type of management increase harvested water compare to control
watershed. However the effect of burning was more significant.
Rain -Water Harvesting
- The Constraints
Irrigation Department, Sri Lanka
Water resource exploitation for human; needs has grown: by, leaps and bounds
in the last two decades. Nearly all the suitable sites for storage dams and river
diversions have been utilized and ground water 'extracted regardless of consequences
as in Bangkok
Water for all by the year 2000 still remains an ideal, Rivers that were once
perennial now become, raging torrents that convey their runoffs in the form of
flash flooding.. As forests are reduced by deforestation and catchments urbanised
the need to harvest rain before it reaches the dry streams beds or fall into polluted
rivers becomes of paramount importance.
Runoff areas: in catchments continue to diminish and are replaced by concrete
paving or bitumen. covered roads or asbestos or tiled roofs. Rainfall runoff from
such artificial catchments can be collected in cisterns. above ground or in tanks
below Preserving the rain close to where it fell avoids contamination that occurs
with surface runoff : Percolation and. evaporation loss °is reduced: But rainfall
in urban areas has its drawbacks when atmospheric pollution sulphur dioxide and
carbon dioxide from vehicular traffic; coal fired power stations or industrial
flue gases can convert the composition of rain to acid rain is very real.
Collection of rain in cisterns also could attract growth 'of organisms and
larvae that could promote diseases like malaria, filaria, dengue and Japanese
encephalitis, if such water is consumed without boiling. Water -stored in. underground-
cistern could be contaminated by leakage from septic tanks. in the proximity adding
nitrates and phosphorous Cisterns take up space in high value urban areas.
Population growth the world over has mushroomed to such extents that efforts
made by countries to supply their basic requirements of water for drinking;. for
'irrigation and for power production can hardly copy with.
is Semi-arid , and Arid Eastern. Africa
ASAL Consultants Ltd. Kenya.
In semi-arid and arid Africa there are several methods of harvesting rainwater
as water supply for people, livestock, crops and :forestry. The method depends
mainly on the features of the landscape and on the amount of labour and founds
Water Harvesting Practises
in North-east Iran (an overview)
Ferdowsi University, Iran
Water harvesting is a process of collecting and storing water from an area
that has been treated or covered to increase precipitation runoff. The collected
water is stored in a suitable container for domestic use or it is used for agricultural
purposes. The latter in normally :referred to as runoff farming and is used to
provide water for the growing crops
Much of the early history of rainwater harvesting has its origin in Europe.
The Romans achieved considerable control of runoff by building structures to modify
the outflow of lakes. Runoff vas collected for the primary purpose of running
watermills, forming fish ponds or for recreational purposes. Rain water harvesting
techniques for agriculture were extensively practised throughout a vast region
of North America, South America, North Africa, Middle East, China and India. This
technique was flourished in Negev desert during the days of Roman Empire, when
the Roman trade mute to the East passed through the area
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