Water harvesting

This category contains 11 resources

Rooftop water collection, drip irrigation and plastic mulching in home garden conditions in drought prone areas of Cambodia

In Cambodia, drought can have different impacts: delay of rainfall onset in early wet season, erratic variations of rainfall onset, early ending of rains during wet season, and longer dry spell in July and August. This technology describes three different technologies and analyses the costs and benefits of their combined application: rooftop water harvesting, drip irrigation and plastic mulching in home garden conditions. As a result of the combined application of those good practices (GPOs), the resistance against drought is increased and a second cropping period is possible. The GPOs have been tested and validated in 19 Farms in the Kampong Speu (3) and Oddar Meanchey (16) Provinces in Cambodia.

Improved rainwater harvesting for fodder shrub production and livestock grazing: the Vallerani micro-catchment system in the Badia of Jordan

The Central and West Asia and North Africa (CWANA) region is characterized by a wide variability in rainfall and temperature. In these areas, evapotranspiration largely exceeds the amount of rainfall, leading to droughts with low forage production and water availability. The concurrent increase in human population with the growing demand for meat has led to increased grazing pressures on rangelands and the exhaustion of their potential productivity. The Badia in Jordan constitutes the largest part of the country. It encompasses approximately 72 thousand square kilometers, corresponding to 81 % of the total area of the country. Increased grazing pressure and cultivation of traditional and fragile grazing lands has led to severe degradation of the Badia rangelands. Since the main limiting factors to growth of plants in the Badia are low precipitation, and poor soil quality, the little precipitation water can be collected by establishing micro catchments on the rangelands. The Vallerani System is an intervention strategy for soil regeneration that integrates technology, traditional techniques and the application of good cultural practices adapted to the local reality, to restore big surfaces of degraded arid and semi-arid rangelands. Its application allows pasture improvement, reforestation and the establishment of agro-forestry sites, thus also enhancing the socio-economic development of the local communities affected. This practice explains the Vallerani System and highlights its benefits and limitations. The practical implementation of the system is described on the basis of an example of the Badia rangeland rehabilitation project, implemented by ICARDA within the first decade of the new millenium.

Construction of a hurricane-resistant small ruminant shelter, St. Lucia

Saint Lucia as an island in the southeast Caribbean basin lies within the hurricane belt. As such, the agriculture sector, among others, is highly affected by the impact of windstorms and hurricanes. In addition, the sector is also facing water shortages during the dry season (variable, but typically from January to April/May), lack of improved forage species for maximizing production and unavailability of improved housing for livestock. The construction of a hurricane-resistant small ruminant housing unit incorporates rain water harvesting and bio-security features, such as the construction of a footbath, a slatted wooden floor and concrete base beneath the pen to facilitate efficient manure handling and disposal. As a result, this technology ensures that small ruminant housing meet adequate construction and safety standards to reduce damage by hurricanes and windstorms and reduce the risk of infection and diseases among animals. Small ruminants are an important livelihood asset of farmers.

Rainwater harvesting for schools

Women and children are usually the main household collectors and users of water. Long walking distances from households to improved water sources make it difficult for them to access safe water. As a result, they resort to using inadequate and unsafe water sources such as unprotected self-dug wells and water holes, exposing themselves to diarrhea and other infectious water borne diseases. The water tanks ensure availability of safe water within communities, thus reducing the prevalence of infectious diseases such as diarrhea.

Mini ponds for resource poor households to provide supplementary irrigation during drought spells in rainfed areas of NW-Bangladesh

The drought-prone areas of western Bangladesh are characterized by high rainfall variability, with different types of seasonal droughts (initial, mid and terminal) posing regular threats to rice production. During monsoon season in wide areas of NW Bangladesh t. aman rice is cropped on rainfed basis. Risk management options need to include rainwater harvesting, recycling and conservation, essential to counteract seasonal drought spells, which are common also during monsoon season through supplemental irrigation. But huge amounts of the water available during high intensity rainfalls run-off unused, due to non-availability of proper water storage structures. The excavation and/or re-excavation of mini ponds is a simple but most feasible adaptation option, which can be realized with low investment, in particular in clayey soil. Adequate awareness of the utility of these structures must be raised at community level. Obstacles to the practice which is not yet widely spread in northwestern Bangladesh are most commonly the lack of investment capital and of organization among poor farmers.

Roof top rainwater harvesting – Concrete Tank

Roof top rainwater harvesting – Concrete Tank - The roof top rain water harvesting system using a concrete tank was designed to improve household access to water for irrigation of kitchen garden plots during the hot and dry summer months. A 16 cubic metre concrete tank situated in the shadow of the house constructed to retain rainwater that collects in the roof guttering. The purpose of the tank is to retain water to be used for drinking, sanitation and irrigation during the hot and dry summer months. The retained water allows for the irrigation of kitchen garden plots and more diverse crops, and hence should improve the livelihoods of households involved. There are three main elements to the construction of the rainwater harvesting system: - the construction of a metal gutter on wooden supports around the perimeter of the roof - the construction of a concrete pool in the shadow of the house; - the provision of a connection pipe between the gutter and the pool.

Water harvesting from concentrated runoff for irrigation purposes in Spain

Water harvesting from intermittent streams to nearby fields and terraces during runoff events. Water shortage is one of the most limiting factors for sustainable agriculture in large parts of SE-Spain. Part of the solution of this problem may come from the restoration of traditional water harvesting structures. This technology contains of a small earthen- or stone- built bund that diverts flood water from intermittent streams towards cultivated fields. The diverted water will temporarily flood the fields and provide the crops with water. Depending on the slope gradient and the amount of water to be harvested, the fields are organised as single terraces, or as a staircase of terraces. On fields with gradients above ~3%, terraces are necessary to reduce the gradient and to retain the floodwater as long as possible. Water is diverted from one terrace to the next through small spillways in the terrace. The spillways can best be fortified with stones to prevent bank gully formation. The extra input of surface water can double the yield. With these systems, water can be harvested up to 8 times per year, mostly in spring and autumn during high intensity rainfall events. The goal of this technology is to increase crop yield. In addition, these structures help to reduce the intensity of floods and reduce the damage caused by them by reducing runoff volume in intermittent streams.

Water conservation ponds in Nepal

During the pre-monsoon season, between March-and May, some areas in Nepal experience water shortage. On the other hand, during the monsoon, water excess causes regular floods and landslides. In this situation, activities such as agriculture or livestock, as well as the availability of drinking water and women’s workload are deeply affected. Guaranteeing water availability throughout the year is therefore essential to reduce the vulnerability of Nepalese farmers. Water conservation ponds prove strategic, storing water and replenishing groundwater reserves for the dry season and protecting hillsides from landslides during the rainy season. Conservation ponds are not a new practice in Nepal, as indigenous populations in the mid-hill region had used them in the past, but were lost due to the introduction of piped water supply. Currently, water conservation ponds are being reintroduced as a local adaptation strategy.

Labour saving technologies and practices: Roof water harvesting

This article contains roof water systems explanations, features of runoff collection and simple water filters. © Labour saving technologies and practices. FAO 2007

Conservation agriculture for smallholder farmers in dryland areas, Kenya

The Laikipia district, in the Rift Valley of Kenya, is located on the plateau north west of Mount Kenya. Due to its leeward position, the district is significantly dry, with aridity increasing from the slopes of the mountain to the dry lowlands. Inadequate rainfall and periods of drought have caused land degradation and soil erosion, affecting the productivity of agriculture and the livelihoods of smallholder farmers in these arid and semi arid areas. Two Farmer Field Schools established in the district introduced Conservation Agriculture principles and techniques which mitigated the impact of drought on farm production and on the environment.

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