1.2 Detalles de contacto de las personas de referencia e instituciones involucradas en la evaluación y la documentación de la Tecnología

Nombre del proyecto que financió la documentación/ evaluación de la Tecnología (si fuera relevante)

DESIRE (EU-DES!RE)

Nombre del proyecto que financió la documentación/ evaluación de la Tecnología (si fuera relevante)

Book project: Water Harvesting – Guidelines to Good Practice (Water Harvesting)

Nombre de la(s) institución(es) que facilitaron la documentación/ evaluación de la Tecnología (si fuera relevante)

University of Botswana (University of Botswana) - Botswana

1.3 Condiciones referidas al uso de datos documentados mediante WOCAT

¿Cuándo se compilaron los datos (en el campo)?

03/06/2011

El compilador y la/s persona(s) de referencia claves aceptan las condiciones acerca del uso de los datos documentados mediante WOCAT:

Sí

1.4 Declaración de la sostenibilidad de la Tecnología descrita

¿La Tecnología aquí descrita resulta problemática en relación a la degradación de la tierra, de tal forma que no puede considerársela una tecnología sostenible para el manejo de la tierra?

No

2.1 Breve descripción de la Tecnología

Definición de la Tecnología:

Roof rainwater catchment system using galvanised iron roof material, feeding underground water tank.

2.2 Descripción detallada de la Tecnología

Descripción:

A roof of galvanised iron (corrugated iron) with the dimensions 7 x 6m is constructed on a support of gum poles (see photos). The roof catches the rain. The rain water flows over the roof into pipes at the rear end of the roof (sloping side) into an underground conical water tank. The tank is made of bricks and mortar. The underground tank serves two key roles: i) it stores water for use during the dry spells or times of no rain; and ii) the tank keeps the water cool in this hot environment. The technology is most preferred for so-called ‘lands’ areas, to provide household drinking water. On average, these lands are distant from water sources (e.g. 2-15 km). Other benefits of storing rainwater include less pressure on natural water ponds, but this would be a secondary concern

Water is critical for human consumption and needed around the home. The cool water is effective in quenching the thirst; it reduces labour time to collect water thus freeing time to concentrate on other farm activities. The water is mainly for household drinking and household chores like washing. Some is used as drinking water for chickens and for the animals used for draught power (e.g. donkeys during ploughing). The units are for use by individual farmers and thus restricted to individual households. The owner or the farmer has exclusive rights to the use of the water. Some farmers indicated that, in times of no rain, or before the first rains, they collect water from the village in drums, and pour it into this underground water tank, thus using it as a reservoir. They especially like the persistent coolness of water stored in the underground tank.

The technology is for rainwater collection in four villages. Rainwater that flows over the roof is collected, for example, on galvanised iron roofs. The water then runs through gutters and a pipe to the underground water tank. To build the underground tank, the ground is excavated, to about 2m deep and about 3m wide. Within this hole, a drum-like feature is built with concrete bricks and mortar. After the wall of the tank is complete, it is then lined with mortar from the inside, and the base is also lined to form the completed tank. It is then sealed at over most of the surface leaving an opening with a lid. This opening is large enough for a man to enter for occasional cleaning of the groundwater tank. Thus the system comprises a roof, for collecting rainwater, and an underground tank for storing it.

The environment is semi-arid and seasonal rainfall dominates during the summer months of October to April. People depend on nearby boreholes for water in the lands areas or have to travel to the village (about 2-5km away on average, but can be up to 15km) to fetch water. Most boreholes are either privately owned or communal and water is rationed to about two drums per week or even fortnightly. Most of the borehole water in the area is brackish. Thus roof rainwater (which is fresh) acts as the preferred alternative source of water. The underground tank, once full, is equivalent to 110 drums. Most normal rain events fill the tank, and the water remains in use till the next rainy season, which was found to be the case at all four pilot sites visited. Thus the rainwater catchments systems offer water security in the lands areas; water of very good drinking quality (sweet taste, cooler).

2.3 Fotografías de la Tecnología

2.5 País/ región/ lugares donde la Tecnología fue aplicada y que se hallan comprendidos por esta evaluación

2.6 Fecha de la implementación

Si no se conoce el año preciso, indique la fecha aproximada:

• 10-50 años atrás

2.7 Introducción de la Tecnología

Especifique cómo se introdujo la Tecnología:

• mediante proyectos/ intervenciones externas

Comentarios (tipo de proyecto, etc.):

This is an ALDEP (arable lands development project) which is specifically for arable lands areas, to ascertain water provision and it started in the 1980-1990s, then up to mid 2008.

3.1 Propósito(s) principal(es) de la Tecnología MST

• reducir el riesgo de desastres naturales

3.2 Tipo(s) actuales de uso de la tierra donde se aplica la Tecnología

Comentarios:

Major land use problems (compiler’s opinion): The water harvesting system is critical in a semi-arid environment, where water shortages are common. To augment water supplies, storage is needed especially in arable land areas where there are no coordinated water distributions like standpipes, as is the case in villages. People at the lands eke a living out of the arable fields, and assured water availability enables families to remain longer close to the fields for essential crop management, hence increased yields.
Major land use problems (land users’ perception): Water shortage and poor water quality.
Type of cropping system and major crops comments: Very little in a way of cash crops as the production system is subsistence based.
Type of grazing system comments: Free range grazing
Constraints of settlement / urban: piped water is cheap

3.3 Información adicional sobre el uso de tierras

Provisión de agua para la tierra donde se aplica la Tecnología:

• de secano

Comentarios:

Water supply: rainfed, rainfed

Número de temporadas de cultivo por año:

• 1

Especifique:

Longest growing period in days: 197, Longest growing period from month to month: Oct - Mar

Densidad del ganado (si fuese relevante):

1-10 LU /km2

3.4 Grupo MST al que pertenece la Tecnología

• cosecha de agua

3.5 Difusión de la Tecnología

Comentarios:

Total area covered by the SLM Technology is 0.01 m2.
This is a roof rainwater catchment system which is about 7m by 6m = 42 m2. The collection tank has a capacity of 10 000 litres.

3.6 Medidas MST que componen la Tecnología

3.7 Principales tipos de degradación del suelo encarados con la Tecnología

Comentarios:

Main causes of degradation: droughts (Reduced water/moisture due to droughts), land tenure (livelihoods depending on fragile ecosystem)
Secondary causes of degradation: overgrazing (high stocking rates in dry areas), population pressure, poverty / wealth (limited access to water and saline water)

3.8 Prevención, reducción o restauración de la degradación del suelo

Especifique la meta de la Tecnología con relación a la degradación de la tierra:

• reducir la degradación del suelo

4.1 Dibujo técnico de la Tecnología

4.2 Especificaciones técnicas/ explicaciones del dibujo técnico

The top lid of the underground tank:
Rain water falls onto the corrugated roof surface, which usually measures 7 x 6m. This water flows down into the gutters, then down through the pipe into an underground water storage tank (built from concrete blocks which are lined with a coating of mortar, or mortar is applied to wire mesh. Most storage tanks, when full, have a capacity of about 110 drums (a drum holds 200 litres). Without this system, a farmer usually only has about 2 drums per week.

Technical knowledge required for field staff / advisors: moderate (Easy strycture or system to explain)
Technical knowledge required for land users: low (Needs professional builder to construct, but easy to run)
Main technical functions: water harvesting / increase water supply
Secondary technical functions: is used as open storage for farm equipment, offers shade against the heat, as well as temporary shelter

Structural measure: Roof rainwater system (roof)
Width of ditches/pits/dams (m): 6
Length of ditches/pits/dams (m): 7

Structural measure: Tank specifications (conical)
Depth of ditches/pits/dams (m): 2.7
Width of ditches/pits/dams (m): 1.75
Length of ditches/pits/dams (m): 3.5

Construction material (earth): To mix with cement
Construction material (wood): gum poles, rafters for supporting iron roof
Construction material (concrete): To build tank foundation
Construction material (other): iron
Lateral gradient along the structure: 5%
Specification of dams/ pans/ ponds: Capacity 10m3
Catchment area: 42m2
Beneficial area: 5m2

4.3 Información general sobre el cálculo de insumos y costos

otra / moneda nacional (especifique):

Pula

Indique la tasa de cambio de USD a la moneda local (si fuese relevante): 1 USD =:

8,0

4.4 Actividades de establecimiento

	Actividad	Tipo de medida	Momento
1.	Digging pit	Estructurales
2.	Transporting sand, cement and concrete blocks	Estructurales
3.	Construction	Estructurales

4.5 Costos e insumos necesarios para el establecimiento

	Especifique insumo	Unidad	Cantidad	Costos por unidad	Costos totales por insumo	% de los costos cubiertos por los usuarios de las tierras
Mano de obra	labour	ha	1,0	12,5	12,5	100,0
Mano de obra	labour by gov (8 person days)	ha	1,0	500,0	500,0
Material de construcción	sand, cement, concrete block	ha	1,0	1500,0	1500,0	100,0
Costos totales para establecer la Tecnología					2012,5

Comentarios:

Duration of establishment phase: 1 month(s)

4.6 Actividades de establecimiento/ recurrentes

	Actividad	Tipo de medida	Momento/ frequencia
1.	Cleaning roof	Estructurales	once a year, before onset of rains
2.	Cleaning storage tank	Estructurales	once a year, before onset of rains

4.7 Costos e insumos necesarios para actividades de mantenimiento/ recurrentes (por año)

	Especifique insumo	Unidad	Cantidad	Costos por unidad	Costos totales por insumo	% de los costos cubiertos por los usuarios de las tierras
Mano de obra	labour	ha	1,0	12,5	12,5	100,0
Indique los costos totales para mantenecer la Tecnología					12,5

Comentarios:

Machinery/ tools: Stock bricks, corrugated iron sheets, meshwire, gutters, wire nails. No machinery, just broom and bucket to collect sediment and dispose of it.
Prices of construction material for the roof rainwater system, fitted with the underground water storage system. All prices and exchange rates were calculated for 29 September 2008. The government subsidy was such that, men pay 30% of all costs, while women pay 20%. The 20-30% could be paid through labour (i.e. digging the pit, transporting sand and cement and serving as a labour hand during construction. Thus if the farmer offers labour, then he does not pay anything. The costs are calculated with labour input and its price or the local wage.

4.8 Factores más determinantes que afectan los costos:

Describa los factores más determinantes que afectan los costos:

Cost of building materials, specifically iron sheets, timber, bricks, concrete and the professional builder from the government.

5.1 Clima

5.2 Topografía

5.3 Suelos

5.4 Disponibilidad y calidad de agua

5.5 Biodiversidad

5.6 Las características de los usuarios de la tierra que aplican la Tecnología

Indique otras características relevantes de los usuarios de las tierras:

Land users applying the Technology are mainly disadvantaged land users
Population density: < 10 persons/km2
Annual population growth: 2% - 3%
10% of the land users are very rich and own 50% of the land (rich cattle barons).
60% of the land users are average wealthy and own 30% of the land (most inhabitants).
30% of the land users are poor and own 20% of the land (subsistence farmers).
Off-farm income specification: Saves labour time to fetch water. Very limited off-farm income opportunities for everyone, including non-adopters of the technology

5.7 Área promedio de la tierra que pertenece a o es arrendada por usuarios de tierra que aplican la Tecnología

5.8 Tenencia de tierra, uso de tierra y derechos de uso de agua

Tenencia de tierra:

• comunitaria/ aldea
• individual, sin título

Derechos de uso de tierra:

• acceso abierto (no organizado)
• individual

Derechos de uso de agua:

• comunitarios (organizado)
• individual

Comentarios:

Communal grazing and individual land ownership for ploughing. Water availed through communal boreholes in lands and cattle posts, but with individual standpipes in villages. Open access to surface water resources for livestock e.g. pans after rains. Dual grazing rights problem, whereby private ranchers graze in the commons, but the opposite not possible.

5.9 Acceso a servicios e infraestructura

6.1 Impactos in situ demostrados por la Tecnología

Impactos socioeconómicos

Producción

Disponibilidad y calidad de agua

Ingreso y costos

Impactos socioculturales

Impactos ecológicos

Ciclo de agua/ escurrimiento de sedimento

Reducción de riesgos de desastres y riesgos climáticos

6.2 Impactos fuera del sitio demostrados por la Tecnología

6.3 Exposición y sensibilidad de la Tecnología al cambio climático gradual y a extremos relacionados al clima/ desastres (desde la percepción de los usuarios de tierras)

Cambio climático gradual

Cambio climático gradual

	Estación	tipo de cambios climáticos/ climas extremos	¿Cómo es que la tecnología soporta esto?
temperatura anual		incrementó	bien

Extremos (desastres) relacionados al clima

Desastres climatológicos:

	¿Cómo es que la tecnología soporta esto?
tormenta de lluvia local	bien

Desastres climatológicos

	¿Cómo es que la tecnología soporta esto?
sequía	no muy bien

Desastres hidrológicos

	¿Cómo es que la tecnología soporta esto?
inundación general (río)	bien

Otras consecuencias relacionadas al clima

Otras consecuencias relacionadas al clima

	¿Cómo es que la tecnología soporta esto?
periodo reducido de crecimiento	bien

Comentarios:

The roof area is such that, some limited amounts of rain do fill or add some water into the storage tank

6.4 Análisis costo-beneficio

¿Cómo se comparan los beneficios con los costos de establecimiento (desde la perspectiva de los usuarios de tierra)?

¿Cómo se comparan los beneficios con los costos de mantenimiento/ recurrentes (desde la perspectiva de los usuarios de tierra)?

Comentarios:

Very costly to set up, if no government aid. It is however, very good for long term water provision.

6.5 Adopción de la Tecnología

Comentarios:

1% of land user families have adopted the Technology with external material support
1 land user families have adopted the Technology with external material support
There is one such structure per village in Boteti sub-district - and they are all demonstration schemes. There was no public uptake following demonstration, as government subsidy changed and was later stopped.
It is too costly e.g. building materials, hiring of professional builder and cement to set up in lands areas.
There is no trend towards spontaneous adoption of the Technology
High capital or start-up costs. The area has low income groups who get water from communal boreholes, while rich cattle owners obtain water from their private boreholes, and hence desalination is favoured rather than rainwater systems.

6.7 Fuerzas/ ventajas/ oportunidades de la Tecnología

Fuerzas/ ventajas/ oportunidades desde la perspectiva del usuario de la tierra
Useful as shelter or storage

Fuerzas/ ventajas/ oportunidades desde la perspectiva del compilador o de otra persona de referencia clave
Provides cool water in hot summers
Provides water in lands areas, where it is most needed
Farmers appreciate the good water quality and clean system annually
It has low maintenance costs, it is easy to use

6.8 Debilidades/ desventajas/ riesgos de la Tecnología y formas de sobreponerse a ellos

Debilidades/ desventajas/ riesgos desde la perspectiva del usuario de la tierra	¿Cómo sobreponerse a ellas?
Costly to set up, due to price of building materials	Government subsidies, priviate sector, NGOs
Fear that their land would be taken away by the government after financial assistance	Education about subsidies to allay fears

Debilidades/ desventajas/ riesgos desde la perspectiva del compilador o de otra persona de referencia clave	¿Cómo sobreponerse a ellas?
Costly to set up	subsidies by government, NGOs, private sector
Seen as dependent on rains, thus fails during droughts	research, information dissemination to stakeholders
Water quality issues (concerns)	education on keeping storage clean and boiling water for human consumption

7.1 Métodos/ fuentes de información

7.2 Vínculos a las publicaciones disponibles

Título, autor, año, ISBN:

Ministry of Agriculture Headquarters, Department of Crop Production, Engineering Division, Water Development Section,

¿Dónde se halla disponible? ¿Costo?

P/Bag 003, Gaborone,

Título, autor, año, ISBN:

en.wikepedia.org/wiki/rainwater-harvesting

¿Dónde se halla disponible? ¿Costo?

website

Título, autor, año, ISBN:

www.harvesth2O.com

¿Dónde se halla disponible? ¿Costo?

website

Título, autor, año, ISBN:

www.rainwaterharvesting.org/index.htm

¿Dónde se halla disponible? ¿Costo?

website

Título, autor, año, ISBN:

www.rainwaterharvesting.co.uk

¿Dónde se halla disponible? ¿Costo?

website

Título, autor, año, ISBN:

cgwb.gov.in/Ground Water/roof-top.htm

¿Dónde se halla disponible? ¿Costo?

website