Session FT 4.31
Ecological management and rainwater catchment systems
International Rainwater Catchment Systems Association (IRCSA)
Brazilian Rainwater Catchment and Management Association (ABCMAC)
In most urban areas, supplying adequate water to meet ever-increasing population water demand and to ensure equity access to water is the most urgent and significant challenges faced by most decision-makers. There are two solutions to satisfy sustainable freshwater management: (1) finding alternate or additional water resources using conventional centralized approaches, and (2) better utilizing the limited amount of water resources available in a more efficient way. To date, much attention has been given to the first option and only limited attention has been given to optimizing water management systems. Among the various alternative technologies to augment freshwater resources, rainwater harvesting and utilization is a decentralized, environmentally sound solution, which can avoid many environmental problems, often created using centralized, conventional, large-scale project approaches.
Rainwater harvesting, in its broadest sense, is a technology used for collecting and storing rainwater for human use from rooftops, land surfaces or rock catchments using simple techniques such as jars and pots as well as engineered techniques. Rainwater harvesting has been practiced for more than 4,000 years. It is an important water source in many areas with significant rainfall but lacking any kind of conventional, centralized supply system. It is also a good option in areas where good quality fresh surface water or groundwater is lacking. Appropriate application of rainwater harvesting technology is important for efficient utilization of rainwater.
- Rainwater harvesting can provide cheap, reliable and safe water supply for those without access to the modern water resources schemes. Although the supply quota is still low and there exist some quality problems but the quantity can meet the basic demand and water quality can be met by using simple device, such as a solar heater to boil water before drink.
- With water in the tank, farmers are able to change their production structure according to market need, thus greatly improving their income. Numerous greenhouses with simple structure now appear in the dry mountainside of Gansu, producing vegetables, flowers, herbs, tobacco, virus-free potato seeds, etc. Orchards also have been developed in the area after RWH project with big benefits.
- The RWH system can promote the ecology and environment construction. When the land productivity is enhanced, farmers give up those lands on the steep slope for cultivation and shift them to tree and grass planting. Development of husbandry as a result of structure change also promotes planting of grass land, which is important factor in improving the eco-system.
- P1MC and P1+2 programs go hand in hand with a big effort in community formation, education programs of children in the schools of SAB, advocacy in front of decision makers, etc. The communities make the water issue “their business” and not the business of the politicians or the big landowner and influence different governmental programs to get closer to the people, involving directly the population of SAB, using governmental funds for the well-being of the communities and not against the interests of the population.
- Rainwater harvesting is a decentralized solution, using indigenous resources, adopting traditional and acceptable technology, which is favorable to the user participation, requiring low initial input and running cost, and performing friendly to the environment. It is the sustainable way for the integrated development of social, economy and the environment conservation in the dry mountainous and semi-arid areas.
- Rainwater should play an important role in the surface and subsurface water in water resources management. It is reasonable and necessary to mainstream rainwater harvesting for meeting the Millennium Goal.
- The Government and the international funding organization should give the same emphasis to rainwater harvesting with the other kinds of water management. Especially when implementing the poverty alleviation project, RWH can play a very important role because water scarcity is often one of the root causes of poverty and many poor in the remote, mountainous areas cannot enjoy the modern water resources projects owing to geographic and economy reasons.
Orientations for action
- The GRIWAC would like to share its experiences on RWH with the developing countries: to technically assist the people to build the RWH systems for their survival and development. The Lanzhou International Rainwater Harvesting and Utilization Training Course welcomes those interested in this field to participate. GRIWAC also invites the international funding organization to support this training activity.
- The rural communities in Semi Arid Brazil are working hard to make their vision come true and hope that the Brazilian government will continue financing P1MC and definitely include P1+2 into its development projects. Also for other semi-arid regions of the world these experiences of community based rainwater harvesting in Semi-Arid Brazil could be examples, responding the challenge of integrated water management in both policy and practice.
- The local actions have illustrated the hard and soft technologies being used in the respective cases. The local experience should also form the basis for a recommendation for an international guideline on rainwater catchment systems.
Local Actions presented
Research, demonstration, training and extension on rainwater harvesting
Gansu Research Institute for Water Conservancy (GRIWAC)
This Local Action was conducted in the middle and eastern part of the Northwest Gansu province of China which is characterized by scarce rainfall and high evaporation, deep loess soil and serious soil erosion causing crisscrossed ravines and gullies. The surface and subsurface water are both lacking. The agriculture completely relied on the natural rain, which, however is unfavorably distributed both spatially and temporally. Millions of people could not have safe access to the water supply and has been suffered from thirsty for generations. People in the area had very low income and held a poor live. To address the problem the key issue is water and the only potential water source is Rain. Since 1988 to 1992, GRIWAC carried out the "Research, demonstration and extension on rainwater catchment and utilization in the semi-arid area". A total of 28 experiment sites were set up. Thousands of pilot projects were built to show the potential of rainwater harvesting (RWH), enabling 40,000 families got reliable and cheap water supply. In 1995, Based on the results of GRIWAC's work, the Gansu Provincial Government decided to carry out the "1-2-1" Rainwater Catchment Project aiming at supporting each rural family in the area where surface and subsurface water are not available to build one rainwater collection field with hardened surface, two storage tanks and one piece of irrigated land for courtyard economy. Within 1.5 years, the goals of the project were gained. Then in 1996, the government again initiated the RWH Irrigation project to enhance the rainfed agriculture production. In these two campaigns, GRIWAC has contributed in technical guidance, demonstration and training activities. With water farmers now grow many kinds of cash crops which greatly increase their income. When the land productivity was enhanced, farmers stopped land exploitation and shifted their slope land from cultivation to tree and grass planting, which greatly improves the eco-system in the area. Since 2003, the China Ministry of Commerce decided to support the GRIWAC to carry out the International Training Course for Rainwater Harvesting and Utilization each year. Since then, a total of 99 participants from Africa, Asia and South America attended the 45-day courses and learned much knowledge and experiences on RWH. The GRIWAC is now assisting Gigawa State of Nigeria to build the RWH systems. Some of them have already supplied water for those without safe water access in the past. The Saudi Arabian Ministry of Water Resources and Electricity will invite GRIWAC’s experts to give lectures on RWH for the local engineers and provide consultant service in building RWH pilot projects.
P1MC and P1+2, two Rainwater Harvesting Programs in the Brazilian Semiarid Tropics
Brazilian Rainwater Catchment and Management Association (ABCMAC)
This Local Action was conducted in the Semi-Arid Brazil (SAB) or so-called "drought stricken polygon" in the Northeastern part of the country. This region extends over almost one million square kilometers and inhabited by about 18 million people, half of them in the rural area. Until recent years, the rural population was periodically faced with droughts and not able to cope. Each year the people tilled the soil and planted corn hoping for sufficient rainfall. But regular rainfall often does not materialize and results in bad harvests.
This situation is changing now through awareness building: What are the real reasons of suffering from drought? How to be prepared for the next drought? The NGO IRPAA - Regional Institute for Appropriate Small-Scale Agriculture has focused on the above mentioned topics since 1990, in the same way as EMBRAPA – the Brazilian Governmental Agricultural Research Agency and later ABCMAC – The Brazilian Rainwater Catchment and Management Association. It was necessary to create the institutional base to make of the different isolated experiences in the SAB a political program. In 1999, organizations working in SAB gathered and founded the ASA Network, today made up of over 1000 grass-root organizations among them NGO’s, farmers’ unions, associations and cooperatives. First ASA launched a campaign with the slogan ‘No Family without Safe Drinking Water’ and elaborated the Program of 1 Million Cisterns (P1MC) to be executed by the civilian society in a decentralized manner (at the community, municipal, micro-region, state and regional levels). The program receives funding by governmental organizations and the private sector. The goal of the program is to supply safe and drought proof drinking water for 1 million rural households (five million people). At the end of 2005, more than 100,000 cisterns had been constructed and in some municipalities of SAB already all the rural households have their cisterns. P1MC was the kick-off for sustainable development of SAB, but other aspects such as food production, health, education, infra-structure, political organization, environmental protection, etc. are equally important to be considered. In the agricultural sector, therefore, P1MC is complemented now by the Program One Piece of Land and Two Types of Water (P1+2). P1+2 signifies that every rural family should own one piece of land (1), large enough to produce food and live in a sustainable way and two (2) types of water, one for human consumption and the other for food production. After guaranteeing drought-proof drinking water for one million households through P1MC, there remains to ensure water security for livestock raising and agriculture. Besides the use of green water conserving technologies such as contour tillage, vegetative soil protection and use of manure, other experiences are carried out that provide water supply for agriculture such as cisterns for supplemental irrigation of vegetable gardens, for poultry raising and beekeeping, shallow wells, rock cisterns for water for livestock, subsurface dams, rainwater catchments diverted from roads. The Bank of Brazil Foundation and Petrobras - the Brazilian Petrol Company are financing the initial phase of P1+2.