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Roof top rainwater harvesting stored in a polythene lined earth retention tank. [Tajikistan]

Чамъоварии оби борон аз руи боми хона

technologies_1446 - Tajikistan

Completeness: 80%

1. General information

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

Key resource person(s)

SLM specialist:
SLM specialist:
Name of the institution(s) which facilitated the documentation/ evaluation of the Technology (if relevant)
Deutsche Welthungerhilfe (Welthungerhilfe) - Tajikistan
Name of the institution(s) which facilitated the documentation/ evaluation of the Technology (if relevant)
Pilot Program for Climate Resilience Tajikistan (PPCR Tajikistan) - Tajikistan

1.3 Conditions regarding the use of data documented through WOCAT

When were the data compiled (in the field)?


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


2. Description of the SLM Technology

2.1 Short description of the Technology

Definition of the Technology:

The use of an earth tank lined with a polyethylene sheet to retain rainwater collected from the roof of the house.

2.2 Detailed description of the Technology


An earth retention tank is a simple low cost structure that can be used to retain rain water from the rooftop. A hole is prepared and lined with a polyethylene sheet to prevent leakage. The top of the hole is covered with a metal lid for access. The roof of the house is fitted with a plastic guttering that captures the rainwater and funnels the water via a plastic pipe into the earth tank. The water in the earth tank then can be utilised for the irrigation of crops (especially during the hot dry summer months), sanitation, and potentially drinking water.

Purpose of the Technology: The population in Southern Tajikistan consists largely of subsistance farmers and are thus highly reliant upon their kitchen garden plots. As the population in the area continues to expand, the pressure on the land increases. The latter is already in a poor state, because it is becoming degraded through deforestation, overgrazing and general over exploitation. There is much precipitation during the rainy season from autumn until spring in Southern Tajikistan, but the scarcity of water from late spring to the end of autumn poses a problem with water shortages.
During the rainy season, a lot of water is lost as surface runoff, this water can be saved in a retention tank to be utilised during the dry season. It can be used to water crops to help increase yields as well as crop diversity and quality. The additional water can also be used for sanitation, drinking water and watering of livestock.

Establishment / maintenance activities and inputs: For the establishment of such a retention tank several steps are needed. In preparation, a rough estimation of the potential volume of harvested rainwater needs to be calculated. Thereafter, a location for the tank needs to be selected so that expenses are minimised and it is easy to access. The establishment of ponds near big trees is not recommended, because the polyethylene layer might be punctured by the roots.

Natural / human environment: The actual steps of constructing the tank involve:
(1) digging the pond, (2) plastering the inside walls with a fine soil and water mixture to smooth them, (3) lining the pond’s walls with double polyethylene layer, (4) connecting the inside polyethylene sheets with the pond coverage through a piece of cord, so that it can be taken out of the pond any time to be cleaned of sediments, (5) covering the pond with any available material such as a soil, water and straw mixture, reinforced by several poles, leaving an opening of 0.25 x 0.25m to extract water, (6) finally connecting the roof to the pond with a plastic pipe. To avoid dirty water flowing from the roof into the pond, the pipe should only be connected to the pond some time after the rainfall has started.

2.3 Photos of the Technology

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



Region/ State/ Province:

Khatlon province

Further specification of location:

Temurmalik, Baljuvon

2.6 Date of implementation

If precise year is not known, indicate approximate date:
  • less than 10 years ago (recently)

2.7 Introduction of the Technology

Specify how the Technology was introduced:
  • through projects/ external interventions
Comments (type of project, etc.):

The technology was developed through a Welthunger Hilfe Project and promotion in the local communities started in 2008.

3. Classification of the SLM Technology

3.1 Main purpose(s) of the Technology

  • improve production

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

Settlements, infrastructure

Settlements, infrastructure

  • Settlements, buildings

Kitchen garden


Major land use problems (compiler’s opinion): Inefficient natural resource management, which is mainly visual because people throw potential organic fertilisers away instead of spreading them on the fields. Incorrect ploughing techniques which leads to the acceleration of erosion, deforestation and waste of fuel materials in inefficient stoves and ovens. Overgrazing leading to pasture degradation.

Major land use problems (land users’ perception): lack of water

Constraints of settlement / urban

3.3 Further information about land use

Number of growing seasons per year:
  • 1

Longest growing period in days: 180Longest growing period from month to month: March - November

3.4 SLM group to which the Technology belongs

  • water harvesting

3.5 Spread of the Technology

Specify the spread of the Technology:
  • evenly spread over an area
If the Technology is evenly spread over an area, indicate approximate area covered:
  • 10-100 km2

3.6 SLM measures comprising the Technology

structural measures

structural measures

  • S5: Dams, pans, ponds

Main measures: structural measures

3.7 Main types of land degradation addressed by the Technology

water degradation

water degradation

  • Ha: aridification
  • Hs: change in quantity of surface water
  • Hp: decline of surface water quality

Main type of degradation addressed: Ha: aridification, Hs: change in quantity of surface water, Hp: decline of surface water quality

Main causes of degradation: soil management (Inproper land management), deforestation / removal of natural vegetation (incl. forest fires) (Cutting trees and shrubs), overgrazing, inputs and infrastructure: (roads, markets, distribution of water points, other, …) (poor water supply)

Secondary causes of degradation: population pressure (the population is increasing over time.), poverty / wealth (lack of funds)

3.8 Prevention, reduction, or restoration of land degradation

Specify the goal of the Technology with regard to land degradation:
  • reduce land degradation
  • restore/ rehabilitate severely degraded land

Main goals: rehabilitation / reclamation of denuded land

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

4. Technical specifications, implementation activities, inputs, and costs

4.1 Technical drawing of the Technology


Daler Domullojonov, 14, Giprozem str., Dushanbe, Tajikistan

4.2 Technical specifications/ explanations of technical drawing

Harvesting water from the household roof to an earth built retention pond with plastic sheet lining. The retention pond is covered with a removable metal plate for access.

Location: Davad village, Vatan jamoat, Temurmalik district,. Khatlon province, Tajikistan

Date: June 2009

Technical knowledge required for field staff / advisors: low (No special knowledge is needed for implementation)

Technical knowledge required for land users: moderate (Any farmer can implement, once they understand the basic concept.)

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

Dam/ pan/ pond
Depth of ditches/pits/dams (m): 3.5
Width of ditches/pits/dams (m): 1.2
Length of ditches/pits/dams (m): 1.2

Construction material (earth): digging in earth, plastering and cover

Construction material (wood): pole for cover

Construction material (other): polyethelene sheets, plastic pipe

Specification of dams/ pans/ ponds: Capacity 3.96m3

Catchment area: 72 m2m2

Beneficial area: 0.2h.am2

For water harvesting: the ratio between the area where the harvested water is applied and the total area from which water is collected is: 1:0.5

4.3 General information regarding the calculation of inputs and costs

other/ national currency (specify):


Indicate exchange rate from USD to local currency (if relevant): 1 USD =:


Indicate average wage cost of hired labour per day:


4.4 Establishment activities

Activity Type of measure Timing
1. Manual digging of pond;smoothing and plastering;covering pond Structural once in the beginning
2. polyethylene sheet and pipe procurement, preparation and placement; Structural once in the beginning

4.5 Costs and inputs needed for establishment

Specify input Unit Quantity Costs per Unit Total costs per input % of costs borne by land users
Labour Manual digging of pond Persons/day 2.0 30.0 60.0 100.0
Labour Placing sheet Persons/day 0.1 30.0 3.0 100.0
Construction material Wooden poles for pond poles 4.0 5.0 20.0 100.0
Construction material Earth tons 0.1 45.0 4.5 100.0
Construction material Polyethylene sheet square meters 10.0 2.3 23.0 50.0
Construction material Cord meter 20.0 0.025 0.5 50.0
Construction material Plastic pipe meter 5.0 2.0 10.0 100.0
Construction material Bucket pieces 1.0 4.5 4.5
Total costs for establishment of the Technology 125.5

Duration of establishment phase: 24 month(s)

4.6 Maintenance/ recurrent activities

Activity Type of measure Timing/ frequency
1. Cleaning of pond (washing out sediments) Structural once every year
2. Changing polyethylene sheet;covering Structural once every 2 years
3. Changing polyethylene sheet;covering Management once per 2 years

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

Specify input Unit Quantity Costs per Unit Total costs per input % of costs borne by land users
Labour Cleaning of pond (washing out sediments) Persons/day 0.1 45.0 4.5 100.0
Labour Changing polyethylene sheet (every 2 years) Persons/day 1.0 10.0 10.0 100.0
Construction material Polyethylene sheet square meters 10.0 2.3 23.0 100.0
Construction material Cord square meters 1.13 8.85 10.0 100.0
Construction material Earth tons 0.05 45.0 2.25 100.0
Total costs for maintenance of the Technology 49.75

The above costs were calculated for the building of one retention tank. One household could have several ponds in one kitchen garden.

4.8 Most important factors affecting the costs

Describe the most determinate factors affecting the costs:

The type of earth in Tajikistan is very good for making the retention ponds, the labour is provided by the land user, and the plastic pipes can be manufactured out of empty plastic bottles. The polythene sheet and cord have to be purchased from the shop.

5. Natural and human environment

5.1 Climate

Annual rainfall
  • < 250 mm
  • 251-500 mm
  • 501-750 mm
  • 751-1,000 mm
  • 1,001-1,500 mm
  • 1,501-2,000 mm
  • 2,001-3,000 mm
  • 3,001-4,000 mm
  • > 4,000 mm
Specifications/ comments on rainfall:

Average annual precipitation is 575 mm (according to data from the last 15 years), most of which falls between late autumn and spring time.

Agro-climatic zone
  • semi-arid

Thermal climate class: temperate. 3 months below 5 degrees, 7 months above 10 degrees

Continental conditions

5.2 Topography

Slopes on average:
  • flat (0-2%)
  • gentle (3-5%)
  • moderate (6-10%)
  • rolling (11-15%)
  • hilly (16-30%)
  • steep (31-60%)
  • very steep (>60%)
  • plateau/plains
  • ridges
  • mountain slopes
  • hill slopes
  • footslopes
  • valley floors
Altitudinal zone:
  • 0-100 m a.s.l.
  • 101-500 m a.s.l.
  • 501-1,000 m a.s.l.
  • 1,001-1,500 m a.s.l.
  • 1,501-2,000 m a.s.l.
  • 2,001-2,500 m a.s.l.
  • 2,501-3,000 m a.s.l.
  • 3,001-4,000 m a.s.l.
  • > 4,000 m a.s.l.
Comments and further specifications on topography:

Altitudinal zone: Mainly communities in this range

5.3 Soils

Soil depth on average:
  • very shallow (0-20 cm)
  • shallow (21-50 cm)
  • moderately deep (51-80 cm)
  • deep (81-120 cm)
  • very deep (> 120 cm)
Soil texture (topsoil):
  • fine/ heavy (clay)
Topsoil organic matter:
  • low (<1%)
If available, attach full soil description or specify the available information, e.g. soil type, soil PH/ acidity, Cation Exchange Capacity, nitrogen, salinity etc.

Soil fertility is medium and if it is not overused the fertility can be increased.

Topsoil organic matter: Usually locals collect cow dung and use it as fuel.

Soil drainage / infiltration is medium

Soil water storage capacity is medium because the loess material contains clay material

5.4 Water availability and quality

Ground water table:

5-50 m

Availability of surface water:

poor/ none

Water quality (untreated):

poor drinking water (treatment required)

Comments and further specifications on water quality and quantity:

Ground water table can also be below 50 m.

Availability of surface water is so poor du to deforestation the natural water balance is disturbed.

5.5 Biodiversity

Species diversity:
  • low

5.6 Characteristics of land users applying the Technology

Off-farm income:
  • 10-50% of all income
Relative level of wealth:
  • poor
Individuals or groups:
  • individual/ household
  • women
  • men
Indicate other relevant characteristics of the land users:

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

Population density: < 10 persons/km2

Annual population growth: 1% - 2%

100% of the land users are poor.

Off-farm income specification: In this example the farmer's son has migrated to Russia.

5.7 Average area of land owned or leased by land users applying the Technology

  • < 0.5 ha
  • 0.5-1 ha
  • 1-2 ha
  • 2-5 ha
  • 5-15 ha
  • 15-50 ha
  • 50-100 ha
  • 100-500 ha
  • 500-1,000 ha
  • 1,000-10,000 ha
  • > 10,000 ha
Is this considered small-, medium- or large-scale (referring to local context)?
  • small-scale

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

Land ownership:
  • state
  • individual, titled
Land use rights:
  • individual
Water use rights:
  • individual

5.9 Access to services and infrastructure

  • poor
  • moderate
  • good
  • poor
  • moderate
  • good
technical assistance:
  • poor
  • moderate
  • good
employment (e.g. off-farm):
  • poor
  • moderate
  • good
  • poor
  • moderate
  • good
  • poor
  • moderate
  • good
roads and transport:
  • poor
  • moderate
  • good
drinking water and sanitation:
  • poor
  • moderate
  • good
financial services:
  • poor
  • moderate
  • good

6. Impacts and concluding statements

6.1 On-site impacts the Technology has shown

Socio-economic impacts


crop production


fodder production


animal production

Water availability and quality

drinking water availability

Quantity before SLM:

120 litres

Quantity after SLM:

12000 litres

Comments/ specify:

Water storing capacity of household increased

irrigation water availability

Income and costs

farm income

Quantity before SLM:


Quantity after SLM:


Comments/ specify:

vegetables and greens are available for own consumption


Comments/ specify:

no need to carry water

Socio-cultural impacts

food security/ self-sufficiency


Livelihoods and human well-being


Ecological impacts

Water cycle/ runoff

water quantity

Comments/ specify:

more water available

harvesting/ collection of water

Comments/ specify:

more water available

surface runoff

Comments/ specify:

only in kitchen garden

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
Season Type of climatic change/ extreme How does the Technology cope with it?
annual temperature increase well

Climate-related extremes (disasters)

Meteorological disasters
How does the Technology cope with it?
local rainstorm well
local windstorm well
Climatological disasters
How does the Technology cope with it?
drought not well
Hydrological disasters
How does the Technology cope with it?
general (river) flood not well

Other climate-related consequences

Other climate-related consequences
How does the Technology cope with it?
reduced growing period well

To minimise the damage to the polyethylene waterproofing layers and, reduce evaporation rates, pond is covered. As the pond is dug into earth the temperature remains fairly stable. If precipitation decreases less water can be harvested.

6.4 Cost-benefit analysis

How do the benefits compare with the establishment costs (from land users’ perspective)?
Short-term returns:

very positive

How do the benefits compare with the maintenance/ recurrent costs (from land users' perspective)?
Short-term returns:

very positive


Before the implementation of this technology, one family would spend an avarage of $44.5 on one truck of water per month. A pond costs around $25 to build, and should provide families with around 4 months worth of water after the rainy season.

6.5 Adoption of the Technology

  • more than 50%
If available, quantify (no. of households and/ or area covered):

600 households (in an area of 10-100km^2)

Of all those who have adopted the Technology, how many have did so spontaneously, i.e. without receiving any material incentives/ payments?
  • 10-50%

58% of land user families have adopted the Technology with external material support

350 land user families have adopted the Technology with external material support

Comments on acceptance with external material support: In the initial stages of the project, they were provided with 50% of the costs of the polyethylene sheets and cord only.

42% of land user families have adopted the Technology without any external material support

250 land user families have adopted the Technology without any external material support

Comments on spontaneous adoption: After observing the benefits of the technology and the high cost benefit ratio, many people in the community and surrounding villages have replicated this technology themselves.

There is a strong trend towards spontaneous adoption of the Technology

6.7 Strengths/ advantages/ opportunities of the Technology

Strengths/ advantages/ opportunities in the land user’s view
Easy and quick to establish, and maintain.
Strengths/ advantages/ opportunities in the compiler’s or other key resource person’s view
It is a low cost technology and can be made from many locally available materials.

How can they be sustained / enhanced? To disseminate these ideas in areas with water scarcity through local Extension Service providers / NGOs or local inhabitants.
It reduces the time and effort to collect water and also the cost to buy water.

How can they be sustained / enhanced? Promotion of different water saving methods and technologies by interested and line departments.
More water available for gardening and household purposes
Increases access to water for drinking and sanitation purposes.

How can they be sustained / enhanced? Construction of larger and/or more tanks.
Provides water for irrigation during the hot dry months, therefore improving crop diversity and yields.

How can they be sustained / enhanced? Training and education on kitchen garden farming techniques to optimise the use of the extra water supply.

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

Weaknesses/ disadvantages/ risks in the land user’s view How can they be overcome?
The polyethylene only lasts for 2-4 years. To increase the number of layers or use a thicker polyethylene sheet
Weaknesses/ disadvantages/ risks in the compiler’s or other key resource person’s view How can they be overcome?
The plastic layers have a limited lifespan. To find thicker and more hardy materials, or apply multiple layers.
Th waterproof layer can easily be degraded by mice and large insects.

7. References and links

7.2 References to available publications

Title, author, year, ISBN:

Brochure - Converting drought prone areas into productive gardens! Low cost options to improve rainwater harvesting in Southern Tajikistan rain fed areas …. and beyond! 2009

Available from where? Costs?

Welthungerhilfe, Temurmalik office,

Title, author, year, ISBN:

Training film - Simple ways to improve management of kitchen gardens in Southern Tajikistan rain fed areas …. and beyond. 2009

Available from where? Costs?

Welthungerhilfe, Temurmalik office

Title, author, year, ISBN:

Welthungerhilfe project final narrative report (144-912) - 2010

Available from where? Costs?

Welthungerhilfe, Temurmalik office

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