MANILA, Philippines – Now that the rainy season is here, the public is encouraged to “harvest” and make use of rainwater – either for flushing the toilet, watering plants, or even as drinking water.
The technology of catching rain is not new but has been practiced by ancient civilizations.
“The technique usually found in Asia and Africa arose from practices employed by ancient civilizations within these regions and still serves as a major source of drinking water supply in rural areas,” stated a report obtained by The STAR from the Department of Agriculture-Philippine Rice Research Institute (DA-PhilRice).
Rainwater harvesting has three components, namely the catchment area, the collection device and the conveyance system.
Benefits of rainwater harvesting (RWH) technologies include increase in agricultural productivity, enhanced household food security and additional income and savings (for instance, using rainwater, which is free, instead of water from the faucet for cleaning comfort rooms or for garden use).
The importance of RWH was further emphasized in another PhilRice report, authored by Dr. Leocadio Sebastian, Dr. Rolando Cruz, Jovino de Dios, Jaime Manalo IV, and Marc Mariano which said: “Asia receives 22 percent of the world’s precipitation. “However, it is home to 53 percent of the world’s population, which means that competition for water is very high.”
PhilRice reported that RWH started in the Philippines in 1989 with assistance from the International Development Research Center (IDRC) of Canada.
About 500 tanks made of wire-framed ferrocement were built with capacities varying from two to 10 cubic meters.
“Income-generating activities in Capiz prompted the implementation of RWH in the Philippines,” the PhilRice report stated.
Under the system, a participant was lent $200 payable in three years. The amount covered the tank, as well as income-generating activities like swine-raising and others.
This way, direct subsidies are avoided, unlike the case of financing rural water supplies.
In the farming sector, rainwater harvesting has been practiced in some communities through the small farm reservoir (SFR) system or small water-impounding project (SWIP).
In India, according to PhilRice, communities have revived and created new water harvesting systems such as checkdams, johads (traditional earthen dams), and other structures to harvest rain.
In Kenya, locals use tanks, ponds, and small dams to collect rainwater.
“Just like the diversion dams in the Philippines, they (Kenyans) have placed concrete tanks near their natural springs. Some placed pipes to direct water both to individual and collective users,” PhilRice said, adding that there are also simple techniques of catching rain using pots and jars.
“The pressure on rural water supplies, as well as deteriorating water quality in surface reservoirs already constructed, constrain the ability of communities to meet the demand for freshwater from traditional sources, and present an opportunity for augmentation of water supplies using this (RWH) technology,” stated the PhilRice report.