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)

EEZA-CSIC (EEZA-CSIC) - España

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

Consejería de Agricultura y Agua Murcia (CARM) - España

1.3 Condiciones referidas al uso de datos documentados mediante WOCAT

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

12/06/2008

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

Sí

2.1 Breve descripción de la Tecnología

Definición de la Tecnología:

Water harvesting from intermittent streams towards nearby fields and terraces during runoff events.

2.2 Descripción detallada de la Tecnología

Descripción:

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. Many of these structures were widely used in SE-Spain already during Arab and Roman times, and are also widespread in N-Africa and the Middle East. However, nowadays in Spain many of them are abandoned and forgotten. Here, we describe the technology of a small earthen- or stone- built bund that diverts flood water from intermittent streams towards cultivated fields with almond orchards and/or cereals. 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 almond yield. The use of these water harvesting structures is only possible under certain environmental and topographic conditions. The cultivated fields should be at a relatively short distance from an intermittent stream (<~50m), and the stream should have a sufficiently large upstream contributing area to provide significant amounts of runoff water during rainfall events. With these systems, water can be harvested up to 8 times per year, mostly in spring and autumn during high intensity rainfall events. A well designed Boquera system may provide up to 550 mm of additional water, in areas with an average annual rainfall of 300 m.

Purpose of the Technology: 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.

Establishment / maintenance activities and inputs: Water harvesting requires the identification of a suitable location for the construction of a diversion structure. This requires assessment of expected water inflow, which can usually be based on simple field observation during rainfall events and based on local knowledge of land users. It is, however, important to consider whether there are activities upstream that possibly affect the water quality (e.g. farm animals) and to assess the implications the water harvesting might have downstream. Permission is required from the water authorities to construct any type of water harvesting structure. Such structures are built by creating a small bund (<1m height) in the centre or to the side of a stream. Depending on the size, the bund can be built with a shovel or a tractor. The water harvesting structure will require control and some maintenance after each important runoff event. When strengthened with concrete, maintenance will be reduced to approximately once every 5 years.

Natural / human environment: Soils are mostly of shallow to medium depth (20-60 cm), and slopes are gentle to moderate (5-15%). The climate is semi-arid with a mean annual rainfall around 300 mm. Droughts, centred in summer commonly last for more than 4-5 months. Annual potential evapotranspiration rates larger than 1000 mm are common.

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:

• hace más de 50 años atrás (tradicional)

2.7 Introducción de la Tecnología

Especifique cómo se introdujo la Tecnología:

• como parte de un sistema tradicional (> 50 años)

Comentarios (tipo de proyecto, etc.):

Most of the water harvesting structures are already much older than 50 years and originate even from Roman or Arab times.

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

Comentarios:

Major land use problems (compiler’s opinion): There is a lack of water for irrigation of crops limiting the crop types that can be planted as well as the crop yield of dryland farming. A lack of water availability seriously limits the production potential of the soil and results in a low vegetation/crop cover. The relatively high soil erosion rates cause various off-site related problems (i.e. flooding, reservoir siltation) and on-site problems (i.e. gully formation and loss of soil depth).

Major land use problems (land users’ perception): Lack of water for irrigation of crops limiting the crop types that can be planted as well as the crop yield of dryland farming.

Livestock is grazing on crop residues

3.3 Información adicional sobre el uso de tierras

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

• de secano

Número de temporadas de cultivo por año:

• 1

Especifique:

Longest growing period in days: 220Longest growing period from month to month: november until June

3.4 Grupo MST al que pertenece la Tecnología

• cosecha de agua

3.5 Difusión de la Tecnología

Especifique la difusión de la Tecnología:

• distribuida parejamente sobre un área

Si la tecnología se halla difundida homogéneamente en un área, indique el área aproximada que cubre:

• < 0.1 km2 (10 ha)

Comentarios:

The exact area is not known. Traditionally the technology was common throughout the province of Murcia and the district of the upper Guadalentin, now most are abandoned and destroyed.

3.6 Medidas MST que componen la Tecnología

Comentarios:

Main measures: structural measures

3.7 Principales tipos de degradación del suelo encarados con la Tecnología

Comentarios:

Main type of degradation addressed: Ha: aridification

Secondary types of degradation addressed: Wo: offsite degradation effects

Main causes of degradation: droughts (Dry periods and dry years require higher water availability)

Secondary causes of degradation: crop management (annual, perennial, tree/shrub) (Large areas without a protective vegetation cover cause increased runoff and erosion rates and facilitat flash floods), over abstraction / excessive withdrawal of water (for irrigation, industry, etc.) (Over-abstraction leads to a lowering of the water table. Therefore additional aquifer abstraction is not allowed by water authority.), Heavy / extreme rainfall (intensity/amounts) (Extreme rainfall causes flash floods with high water losses and low effectiveness for crop production.)

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:

• prevenir la degradación del suelo
• reducir la degradación del suelo

Comentarios:

Main goals: prevention of land degradation, mitigation / reduction of land degradation

4.1 Dibujo técnico de la Tecnología

4.2 Especificaciones técnicas/ explicaciones del dibujo técnico

Sketch of a water harvesting structure consisting of an earthen- or stone- built dyke that diverts water into cultivated fields. Several terraces are present in the fields in order to reduce slope gradient and retain water longer within the fields to allow maximum infiltration. Depending on the expected inflow of water several spillways can be made per terrace to prevent excessive concentration of flow in each spillway.

Technical knowledge required for field staff / advisors: moderate (Selection of the proper location and assessment of up- and downstream linkages.)

Technical knowledge required for land users: low (Practical implementation of the water harvesting structure does not require a high level of knowledge)

Main technical functions: control of concentrated runoff: retain / trap, control of concentrated runoff: impede / retard, control of concentrated runoff: drain / divert, increase of infiltration, water harvesting / increase water supply

Secondary technical functions: increase of groundwater level / recharge of groundwater, water spreading

Spillway
Spacing between structures (m): 50
Depth of ditches/pits/dams (m): 0.5
Width of ditches/pits/dams (m): 1-3

Structural measure: water harvest dyke
Depth of ditches/pits/dams (m): <1
Width of ditches/pits/dams (m): <2
Length of ditches/pits/dams (m): <50

Construction material (earth): Soil from the stream banks is used to built the dyke and provide an opening into the cultivated fiel

Construction material (stone): Stones are used to fortify the dyke and spillways against the impact of flow.

Construction material (concrete): Potentially concrete is used to fortify the dyke and spillways against the impact of flow.

Specification of dams/ pans/ ponds: Capacity 5m3

Catchment area: >0.5km2m2

Beneficial area: 1-2 ham2

Slope of dam wall inside: 100%;
Slope of dam wall outside: 100%

Dimensions of spillways: 1-3m wide and <50 cm deep

4.3 Información general sobre el cálculo de insumos y costos

otra / moneda nacional (especifique):

EURO

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

0,63

4.4 Actividades de establecimiento

	Actividad	Tipo de medida	Momento
1.	Construction of a dyke (dam)	Estructurales	summer or winter

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	5 meter dyke	1,0	150,0	150,0	100,0
Equipo	Machine use	5 meter dyke	1,0	350,0	350,0	100,0
Material de construcción	Concrete	5 meter dyke	1,0	400,0	400,0	100,0
Costos totales para establecer la Tecnología					900,0

Comentarios:

Duration of establishment phase: 1 month(s)

4.6 Actividades de establecimiento/ recurrentes

	Actividad	Tipo de medida	Momento/ frequencia
1.	restoration of the dyke	Estructurales	once in 5 yr (after important events)

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	5 meter dyke	1,0	4,0	4,0	100,0
Equipo	Machine use	5 meter dyke	1,0	12,0	12,0	100,0
Material de construcción	Concrete	5 meter dyke	1,0	25,0	25,0	100,0
Indique los costos totales para mantenecer la Tecnología					41,0

Comentarios:

Machinery/ tools: For construction and maintenance of the dyke tractor or small bulldozer is required.

The costs were indicated assuming a length of the bund dimensions of 5*1*1 metres. Maintenance is required once every 5 years, so yearly costs are the total costs divided by 5 (Prices are for spring 2008).

4.8 Factores más determinantes que afectan los costos:

Describa los factores más determinantes que afectan los costos:

Labour costs and price of concrete are the most determinate factors affecting the costs.

5.1 Clima

5.2 Topografía

Indique si la Tecnología se aplica específicamente en:

• situaciones cóncavas

Comentarios y especificaciones adicionales sobre topografía :

Landforms: Valley floors (mostly concave slope section)

5.3 Suelos

5.4 Disponibilidad y calidad de agua

Comentarios y especificaciones adicionales sobre calidad y cantidad de agua:

Ground water table: >50m (There is a lowering of groundwater table due to overexploitation for irrigation purposes)
Availability of surface water: Poor/none. Sporadically excess when there are flash floods during extreme rainfall events
Water quality (untreated) For agricultural use only (irrigation)(groundwater)

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 common / average land users
Difference in the involvement of women and men: Traditionally most agriculture is done by men in this region.
Population density: 10-50 persons/km2
Annual population growth: < 0.5%
15% of the land users are rich and own 20% of the land.
80% of the land users are average wealthy and own 75% of the land.
5% of the land users are poor and own 5% of the land.
Off-farm income specification: There is no difference in the ones who apply the technology and those who don’t. Most farmers do have an off-farm income for example from hunting, work in a factory, or office.

Market orientation: Commercial/market or mixed (subsistence and commercial)(some farmers are weekend or hobby farmers and not market oriented)

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:

• estado
• individual, con título

Derechos de uso de tierra:

• comunitarios (organizado)
• individual

Derechos de uso de agua:

• comunitarios (organizado)
• individual

Comentarios:

Most land is privately owned. The streams are not privately owned. Therefore permits are required to construct a water harvesting structure. Some shrubland or forest is state property. Water rights are provided and controlled by the Water authority of the Segura river basin (CHS).

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

Suelo

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	no muy bien
tormenta de viento	bien

Desastres climatológicos

	¿Cómo es que la tecnología soporta esto?
sequía	bien

Desastres hidrológicos

	¿Cómo es que la tecnología soporta esto?
inundación general (río)	no muy 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 crop type is sensitive to changes in water availability under the semi arid conditions.

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:

Implementation of the technology is relatively expensive. Once installed, maintenance is not expensive and pays off because of higher productivity.

6.5 Adopción de la Tecnología

De todos quienes adoptaron la Tecnología, ¿cuántos lo hicieron espontáneamente, es decir, sin recibir incentivos/ pagos materiales?

• 90-100%

Comentarios:

100% of land user families have adopted the Technology without any external material support

There is no trend towards spontaneous adoption of the Technology

Comments on adoption trend: Much of this knowledge is forgotten and not applied or maintained anymore.

6.7 Fuerzas/ ventajas/ oportunidades de la Tecnología

Fuerzas/ ventajas/ oportunidades desde la perspectiva del usuario de la tierra
The extra input of free water allows higher crop productivity.

Fuerzas/ ventajas/ oportunidades desde la perspectiva del compilador o de otra persona de referencia clave
This technology is very effective at increasing water available for crop production and so increasing crop yield and farm income How can they be sustained / enhanced? Temporarily store the harvested water in a cistern to be used for irrigation using drip irrigation when most needed.
The technology takes advantage of floodwater that is otherwise lost because of the erratic character and short duration of flow How can they be sustained / enhanced? Finding the optimal location for the water harvesting structures using a modelling approach

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?
Farmers consider it relatively expensive to implement and there is no guarantee for water as this depends on the rainfall events.	Subsidies might help to install these structures where feasible. Therefore, good assessments of expected water inflow volumes are required before construction

Debilidades/ desventajas/ riesgos desde la perspectiva del compilador o de otra persona de referencia clave	¿Cómo sobreponerse a ellas?
The implementation costs are relatively high when the bunds are made of concrete	Use of cheap materials that are freely available (stones from the fields). However, it is important to make the structure as resistant as possible against flood events.
The water provided by these techniques is mostly interesting for small- and medium- scale rainfed farming. Intensively irrigated farming requires more water and a guarantee for water independently of flood events	Intensively irrigated farming might use this technology as an additional source of water and may store the harvested water in a cistern for use when needed.

7.2 Vínculos a las publicaciones disponibles

Título, autor, año, ISBN:

rot, E., van Wesemael, B., Benet, A.S. and House, M.A., 2008. Water harvesting potential in function of hillslope characteristics: A case study from the Sierra de Gador Journal of Arid Environments 72(7):1213-1231

¿Dónde se halla disponible? ¿Costo?

Internet

Título, autor, año, ISBN:

Giráldez, J.V., Ayuso, J.L., Garcia, A., López, J.G. and Roldán, J., 1988. Water harvesting strategies in the semiarid climate of southeastern Spain. Agricultural Water Management, 14(1-4): 253-263.

¿Dónde se halla disponible? ¿Costo?

Internet

Título, autor, año, ISBN:

Hooke, J.M. and Mant, J.M., 2002. Floodwater use and management strategies in valleys of southeast Spain. Land Degradation & Development, 13(2): 165-175.

¿Dónde se halla disponible? ¿Costo?

Internet

Título, autor, año, ISBN:

López-Gálvez, J. and Losada, A., 1998. EVOLUCIÓN DE TÉCNICAS DE RIEGO EN EL SUDESTE DE ESPAÑA. Ingeniería del Agua, 5(3): 41-50.

¿Dónde se halla disponible? ¿Costo?

Internet

Título, autor, año, ISBN:

Nasri, S., Albergel, J., Cudennec, C. and Berndtsson, R., 2004. Hydrological processes in macrocatchment water harvestingin the arid region of Tunisia: the traditional system of tabias. Hydrological Sciences-Journal, 49(2): 261-272.

¿Dónde se halla disponible? ¿Costo?

Internet

Título, autor, año, ISBN:

van Wesemael, B., et al., 1998. Collection and storage of runoff from hillslopes in a semi-arid environment: geomorphic and hydrologic aspects of the aljibe system in Almeria (Spain). Journal of Arid Environments 40(1):1-14

¿Dónde se halla disponible? ¿Costo?

Internet

Título, autor, año, ISBN:

Greenpeace, 2007. El negocio del agua en la cuenca del Segura, Greenpeace.

¿Dónde se halla disponible? ¿Costo?

www.greenpeace.es