1.2 Contact details of resource persons and institutions involved in the assessment and documentation of the Technology

Name of the institution(s) which facilitated the documentation/ evaluation of the Technology (if relevant)

Name of the institution(s) which facilitated the documentation/ evaluation of the Technology (if relevant)

1.3 Conditions regarding the use of data documented through WOCAT

The compiler and key resource person(s) accept the conditions regarding the use of data documented through WOCAT:

Yes

2.1 Short description of the Technology

Definition of the Technology:

Cisterns are reservoirs used for storing rainfall and runoff water for multiple purposes: drinking, animal watering and supplemental irrigation.

2.2 Detailed description of the Technology

Description:

Cisterns were traditionally used to provide drinking water. In the cistern system, runoff water is collected and stored in stone-faced underground cisterns, of various sizes, called majel (private reservoirs) and fesquia (communal reservoirs). Basically, a cistern is a hole dug in the ground and lined with a gypsum or concrete coating, in order to avoid vertical and lateral infiltration. Each unit consists of three main parts: the impluvium, the sediment settlement basin, and the storage reservoir. The impluvium is a sloping piece of land delimited by a diversion channel (hammala).

Purpose of the Technology: It is estimated that a tank with a capacity of 35 m3 can meet the annual water needs of a family and its livestock (Ennabli, 1993).

Establishment / maintenance activities and inputs: In flat areas, where it is possible also to exploit floods via a diversion dyke, one also finds artificially paved runoff areas. A small basin before the entrance of the cistern allows the sedimentation of runoff loads. This improves the stored water quality and reduces maintenance costs. Big cisterns have, in addition to the storage compartment, a pumping reservoir from which water is drawn (Ouessar, 2007).

Natural / human environment: Small private and communal cisterns (5 to 200 m3) and big cisterns (up to 70,000 m3), mainly built during the Roman and Arab-Muslim eras, can be found throughout the water-deficient zone south of the 400-mm isohyet .

2.3 Photos of the Technology

2.5 Country/ region/ locations where the Technology has been applied and which are covered by this assessment

Country:

Tunisia

Region/ State/ Province:

Medenine

Further specification of location:

Medenine nord

Specify the spread of the Technology:

• evenly spread over an area

If precise area is not known, indicate approximate area covered:

• 10-100 km2

Map

×

2.6 Date of implementation

If precise year is not known, indicate approximate date:

• more than 50 years ago (traditional)

2.7 Introduction of the Technology

Specify how the Technology was introduced:

• as part of a traditional system (> 50 years)

3.2 Current land use type(s) where the Technology is applied

Land use mixed within the same land unit:

Yes

Specify mixed land use (crops/ grazing/ trees):

• Agroforestry

Cropland

Number of growing seasons per year:

• 1

Specify:

Longest growing period in days: 180Longest growing period from month to month: Oct - Apr

Grazing land

Other

Comments:

Major land use problems (compiler’s opinion): Runoff loss

Major land use problems (land users’ perception): Water loss

3.5 SLM group to which the Technology belongs

• water harvesting

3.6 SLM measures comprising the Technology

structural measures

• S11: Others

Comments:

Main measures: structural measures

3.7 Main types of land degradation addressed by the Technology

water degradation

• Ha: aridification

Comments:

Main type of degradation addressed: Ha: aridification

Main causes of degradation: droughts

3.8 Prevention, reduction, or restoration of land degradation

Specify the goal of the Technology with regard to land degradation:

• reduce land degradation

Comments:

Main goals: mitigation / reduction of land degradation

4.1 Technical drawing of the Technology

Technical specifications (related to technical drawing):

Components of the cistern system.

south east Tunisia

Date: January 2009

Technical knowledge required for field staff / advisors: low

Technical knowledge required for land users: low

Main technical functions: water harvesting / increase water supply

Structural measure: Reservoir
Depth of ditches/pits/dams (m): 4-10
Width of ditches/pits/dams (m): 2-4

Construction material (stone): Stone

Construction material (concrete): coating

For water harvesting: the ratio between the area where the harvested water is applied and the total area from which water is collected is: 1:4

Author:

Ouessar M., Medenine, tunisia

4.2 General information regarding the calculation of inputs and costs

other/ national currency (specify):

TND

If relevant, indicate exchange rate from USD to local currency (e.g. 1 USD = 79.9 Brazilian Real): 1 USD =:

1.3

4.3 Establishment activities

4.4 Costs and inputs needed for establishment

Comments:

Duration of establishment phase: 1 month(s)

4.5 Maintenance/ recurrent activities

4.6 Costs and inputs needed for maintenance/ recurrent activities (per year)

5.1 Climate

5.2 Topography

5.4 Water availability and quality

5.6 Characteristics of land users applying the Technology

Indicate other relevant characteristics of the land users:

Land users applying the Technology are mainly common / average land users

Population density: 10-50 persons/km2

Annual population growth: 0.5% - 1%

10% of the land users are rich and own 15% of the land.
70% of the land users are average wealthy and own 75% of the land.
20% of the land users are poor and own 10% of the land.

5.7 Average area of land used by land users applying the Technology

5.8 Land ownership, land use rights, and water use rights

Land ownership:

• communal/ village
• individual, titled

Land use rights:

• communal (organized)
• individual

Water use rights:

• communal (organized)
• individual

5.9 Access to services and infrastructure

6.1 On-site impacts the Technology has shown

Socio-economic impacts

Production

Water availability and quality

Socio-cultural impacts

Ecological impacts

Water cycle/ runoff

Soil

Climate and disaster risk reduction

6.3 Exposure and sensitivity of the Technology to gradual climate change and climate-related extremes/ disasters (as perceived by land users)

Gradual climate change

Gradual climate change

Climate-related extremes (disasters)

Meteorological disasters

Climatological disasters

Hydrological disasters

Other climate-related consequences

Other climate-related consequences

6.4 Cost-benefit analysis

How do the benefits compare with the establishment costs (from land users’ perspective)?

How do the benefits compare with the maintenance/ recurrent costs (from land users' perspective)?

6.5 Adoption of the Technology

Comments:

30% of land user families have adopted the Technology with external material support

70% of land user families have adopted the Technology without any external material support

There is a moderate trend towards spontaneous adoption of the Technology

6.7 Strengths/ advantages/ opportunities of the Technology

6.8 Weaknesses/ disadvantages/ risks of the Technology and ways of overcoming them

7.1 Methods/ sources of information

7.2 References to available publications

Title, author, year, ISBN:

Ben Mechlia, N., Ouessar, M. 2004. Water harvesting systems in Tunisia. In: Oweis, T., Hachum, A., Bruggeman, A. (eds). Indigenous water harvesting in West Asia and North Africa, , ICARDA, Aleppo, Syria, pp: 21-41.

Available from where? Costs?

IRA, ICARDA

Title, author, year, ISBN:

Chahbani, B. 2004. Technical innovations to optimize water harvesting, conservation and use for a sustainable development of rainfed agriculture in arid zones. Options Méditerranéennes, 60: 73-78.

Available from where? Costs?

IRA, CIHEAM

Title, author, year, ISBN:

El Amami, S. 1984. Les aménagements hydrauliques traditionnels en Tunisie. Centre de Recherche en Génie Rural (CRGR), Tunis, Tunisia. 69 pp.

Available from where? Costs?

IRA, CRGER

Title, author, year, ISBN:

Ennabli, N. 1993. Les aménagements hydrauliques et hydro-agricoles en Tunisie. Imprimerie Officielle de la République Tunisienne, Tunis, 255 pp.

Available from where? Costs?

IRA, INAT

Title, author, year, ISBN:

Ouessar M. 2007. Hydrological impacts of rainwater harvesting in wadi Oum Zessar watershed (Southern Tunisia). Ph.D. thesis, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium, 154 pp.

Available from where? Costs?

IRA