Feature

WHEN IT RAINS, IT POURS
Harvesting water as a conservation technique
by Christmas B. de Guzman

Dr. Murli M. Sharma, scientist from ICRISAT, lectures on rainwater harvesting during the BAR Seminar Series.

In this country, we have so much rain that every year we see flooded cities and towns featured on TV news reports. Yet there are times when we turn on our faucet and find out we don't have a drop of water.

The Philippine archipelago, made up of 7,107 islands, is located in southeastern Asia, between the Philippine Sea and the South China Sea, east of Vietnam. It has a population of 91,077,287 and an adult literacy rate of 92.6 percent. Only about 85 percent has access to safe drinking water, the remaining 15 percent, which constitutes the 40 percent who are under the line of poverty, does not.

Admittedly, water is a scarce resource in the tropics. It is a fact that our country, the Philippines, has a clearly defined rainy or wet season in which there is much precipitation in the form of rain. Since we do not have an efficient water management system, this rainwater is typically “wasted” by its flowing into underground sewers (and maybe even flooding) while during summer there is a shortage of water.

An environment-friendly system that would be beneficial in the Philippines is the rainwater harvesting system. Such a system has the objective of collecting and storing rainwater for domestic uses at a later time. This is particularly useful in lowering water bills during times of water shortage. It also lowers the volume of rainwater that passes through sewage systems, while also reaping the environmental advantages of efficient water use.

Additionally, community-based rainwater harvesting - the paradigm of the past - has in it as much significance as it ever offered before. Studies revealed that those which had undertaken rainwater harvesting in earlier years had no drinking water problem and even had some water to irrigate their crops.

Dr. Sharma’s house featuring the rainwater harvesting system that he developed.

The mechanism to harvest rainwater is easy and doable in every independent house and some high-rise buildings as well. It starts with rainwater being collected from the hard surface of a flat or slanted roof. The rainwater is, in turn, stored in an underground reservoir. The harvested water can be drawn manually or by using an electric pump.

This basically was the idea presented by Dr. Murli M. Sharma, a scientist from the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT) based in India, during a seminar series at the Bureau of Agricultural Research (BAR) on 13 June 2008.

BAR Assistant Director Teodoro S. Solsoloy, in his opening speech during the seminar series, said that rainwater harvesting has been practiced in arid and semi-arid areas, and has provided drinking water, domestic water, water for livestock, water for small irrigation and a way to replenish ground water levels.

Presently, China and Brazil practice rooftop rainwater harvesting for use for all the purposes aforementioned. Gansu province in China and semi-arid northeast Brazil have the largest ongoing rooftop rainwater harvesting projects.

Dr. Sharma said, the government's water supply system in India meets only a part of the household requirement while the remaining part is addressed by water from dug wells, bore wells, or purchases from uncertain sources. The latter poses an important concern, specifically on the quality of water and the delivery system.

In the Philippines, a water crisis is already a reality and a nightmare among 15 percent of families that do not have access to safe drinking water. Twenty-eight percent of them also do not have sanitary toilets. As a consequence, waterborne illness is a major cause of infections, or worse, prolonged diseases.

Rainwater management and conservation, Dr. Sharma emphasized, is a solution to unabated population growth coupled with high demand for dependable and safe water supply. As suggested, every household needs to become part of the rainwater conservation system. Developing reliable sources of water is technically difficult, time-consuming, often not environmentally sound and may not be efficient. In relation, assistance from the government may have some limitations.

Rainwater harvesting system has several salient features such as: 1) high quality crystal clear water; 2) absence of chemical treatment; 3) minor maintenance, no running cost; 4) easy in design and construction; and 5) sustainability.

People generally need water for everyday living – for drinking, cooking, laundrying, bathing, etc. Justifiably, water quality and water quantity affect our living. Through rainwater harvesting system, water can be conserved and wisely utilized. Water indeed is life; rightfully so, no water means no life on earth.