'Let not a drop of
water that falls from the sky flow into the sea.' These were the
words of Parakramabahu, a 13th century Sri Lankan monarch, who
constructed Parakrama Samudra or the Sea of Parakrama, a massive
rainwater harvesting reservoir which to this day irrigates vast
stretches of paddy fields in the Gal Oya district of Sri Lanka.
Rainwater harvesting is a technique of conservation wherein water is
harvested from roof and ground catchments and then safely stored and
treated as and when necessary. Archaeologists in Sri Lanka have
discovered a whole network of storage reservoirs, pools, artificial
streams and fountains in the north and central regions of the island
country. In fact, it has also been an integral part of the
irrigation system of the country.
A critical issue today is
the supply of adequate water and disposal of the excess to meet
society's needs and ensure equitable access throughout the year for
urban and rural populations, flora, fauna and other living forms. Thus,
it is important that rainwater be conserved, rather than left to flow
down the drains or flood fields and low-lying areas.
The pioneering National Policy on Rainwater Harvesting (RWH) was
introduced recently. It has been formulated by the RWH Secretariat
comprising Ministry of Urban Development and Water Supply, the National
Water Supply and Drainage Board and the Lanka Rain Water Harvesting
Forum (LRWHF). The policy had been under revision and discussion since
2004.
"Sri Lanka is the first country in the world to have a national policy
on rainwater harvesting," says Dinesh Guwardene, Minister of Urban
Development and Sacred Area Development. According to Tanuja Ariyananda,
Executive Director, LRWHF, the objectives of the new policy are in
keeping with the increasing costs of pipe-borne water supply, drainage,
flood control and soil conservation.
"The plan is to make rainwater harvesting mandatory. It will be
introduced in stages in all municipal and urban council areas within a
prescribed time period. It will initially cover certain categories of
buildings and development projects and will also be promoted intensively
in all council areas," elaborates Ariyananda.
The rationale for the policy is based on the fact that Sri Lanka today
has an annual rainfall volume of about 5,900 cubic metres from which the
annual discharge volume into the sea is about 1,400 cubic metres. It
also ranks high in the world in the annual renewable quantity of water
with two monsoons each year, explains Ariyanand. The rainfall volume,
annually, from both monsoons ranges between 750 and 6,000 mm across the
country. However, due to vagaries of the rain; improper land management
practices such as unrestrained filling up of low lands and restriction
of natural drainage paths; and due to insufficient storage mechanisms, a
substantial amount of rainwater flows into the sea.
Therefore, the policy aims to upgrade the status of rainwater from a
supplementary - which it is right now - to an optional source in all
rural-based water supply projects.
Rainwater harvesting has a number of benefits. Besides minimizing the
use of piped potable water for secondary purposes, it prevents depletion
of ground water and reduces water stress during droughts and lower
salinity intrusion.
It also reduces unproductive labor time and hazards, faced mainly by
women and children in fetching water across a distance. "In our water
and sanitation projects in Kalutara, where rain is plentiful almost the
whole year round, local women displayed a keen interest in rainwater
harvesting that would give them water in the house, instead of them
having to fetch it even from a few meters away. We are now planning to
get expertise from the RWH Forum," says Shirley Rodrigo, Executive
Director of Water and Sanitation Decade Service.
But one of the major hurdles that has to be overcome in making rainwater
harvesting popular is the traditional mindset that believes rainwater to
be impure and not suitable for drinking. "There are safeguards such as
using suitable roofing material to collect rainwater and collecting only
the rainwater that falls after the first shower," explains Lionel
Gunatilleke, a trustee of RWH forum.
Gunatilleke began rainwater harvesting as a hobby and successfully
implemented it even before the forum was launched. "As we live on high
ground, shortage of water used to become a serious problem during the
dry months of March and April. I had to transport gallons of water in my
car everyday. I was spending more than I could afford on car repairs. It
was out of sheer necessity that I started exploring the possibility of
rainwater harvesting. Now this experiment gives us water throughout the
year and also enough for my wife to indulge in gardening," he says.
Quoting scientific research on the use of rainwater, Ariyananda has a
word of caution, "There is one snag in using rainwater for drinking. It
lacks minerals and users must make sure that they add it in their food
if they depend totally on rainwater for drinking water."
Over the years, the LRWH Forum has conducted a number of workshops and
held exhibitions to spread awareness. It has also provided on-the-job
training to masons and given demonstrations in households on the
operation and maintenance of rainwater harvesting systems. Links have
been built, with both the government and the NGOs exchanging information
and communicating through awareness programmes, but there are still a
number of challenges that have to be met to optimize this abundant and
free gift of nature.
September 16,
2007
By arrangement with
WFS
Image under license with Gettyimages.com
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