Technologies

River training dam [Tajikistan]

Дамбаи Обпартоб

technologies_698 - Tajikistan

Completeness: 84%

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)

land user:

Name of project which facilitated the documentation/ evaluation of the Technology (if relevant)
Book project: where people and their land are safer - A Compendium of Good Practices in Disaster Risk Reduction (DRR) (where people and their land are safer)
Name of the institution(s) which facilitated the documentation/ evaluation of the Technology (if relevant)
CARITAS (Switzerland) - Switzerland

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

1.4 Declaration on sustainability of the described Technology

Is the Technology described here problematic with regard to land degradation, so that it cannot be declared a sustainable land management technology?

No

2. Description of the SLM Technology

2.1 Short description of the Technology

Definition of the Technology:

The river training dam is a disaster mitigation structure protecting downstream areas from flash floods and mudflows. It consists of a channel dug and wire net gabions built to train the river and is hence cheap to establish and maintain. There is a substantial community contribution as labour is an important part of the input costs. The dam enables the rehabilitation of unproductive land in the downstream catchment areas, reduction of crop pests, increase in crop diversity and land productivity, and an overall improvement of livelihoods for downstream communities through reduced vulnerability to disasters.

2.2 Detailed description of the Technology

Description:

The river training dam is a disaster mitigation structure constructed in the middle zone of the watershed of Obishur (Southern Tajikistan), at 1400 metres above sea level. It is diverting the water from the river fan naturally flowing through Kulchashma village into a different direction and river outlet (Yakhsu river). The dike is a simple structure consisting of a 400m-long and 4m-high channel dug by bulldozer consolidated by a 60m-long and 3m-wide gabion protecting a sharp curve of the river. The material needed is limited to stones and wire net, and the construction as well as maintenance costs are hence low and don't need a too high amount of labour, provided by the communities as in-kind contribution. The structure is built to resist a pressure of up to 72 m3/sec. Given the annual frequency and strength of the local floods, the Kulchashma river training dam has an estimated life expectancy of 30 years. The land users proposed to establish the dam in order to protect the 250 households and 270 ha of land downstream being regularly affected by the floods. In particular, people, houses, roads and other infrastructure, crop and pasture land as well as animals and other assets were highly exposed to the risk of flood. The agricultural production, constituting the main part of people’s income was hindered by the regular occurrence of disasters. The establishment of the river training dam resulted in the rehabilitation of unproductive land in the river fan and its use as pasture and arable land which the community mainly uses for agroforestry. The occurrence of crop pests decreased, the crop diversity was increased, the crop and land productivity improved, thereby enhancing the land users’ food security and overall income. The dam also allowed vulnerable community members to access land and build houses. The construction of buildings behind the dam is however risky and communities tend to forget or ignore that a risk of failure of the dam persists, and that its life expectancy is limited. But first of all, the personal safety of the community members is now improved and they are happy to be able to sleep without the fear of regular floods.

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:

Tajikistan

Region/ State/ Province:

Khatlon Region, Muminabad District

Further specification of location:

Kulchashma Jamoat, Kulchashma village

Specify the spread of the Technology:
  • applied at specific points/ concentrated on a small area
Comments:

water diversion and drainage

2.6 Date of implementation

Indicate year of implementation:

2014

2.7 Introduction of the Technology

Specify how the Technology was introduced:
  • through land users' innovation
Comments (type of project, etc.):

The adoption of the technology was proposed by the land users.

3. Classification of the SLM Technology

3.1 Main purpose(s) of the Technology

  • improve production
  • reduce, prevent, restore land degradation
  • protect a watershed/ downstream areas – in combination with other Technologies
  • reduce risk of disasters
  • create beneficial economic impact

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

Grazing land

Grazing land

Extensive grazing:
  • Semi-nomadic pastoralism

3.4 Water supply

Water supply for the land on which the Technology is applied:
  • mixed rainfed-irrigated
Comments:

Irrigation - main irrigation channels also received water diverted by the dam.

3.5 SLM group to which the Technology belongs

  • water diversion and drainage

3.6 SLM measures comprising the Technology

structural measures

structural measures

  • S3: Graded ditches, channels, waterways
  • S5: Dams, pans, ponds

3.7 Main types of land degradation addressed by the Technology

soil erosion by water

soil erosion by water

  • Wt: loss of topsoil/ surface erosion
  • Wg: gully erosion/ gullying
  • Wr: riverbank erosion
  • Wo: offsite degradation effects
biological degradation

biological degradation

  • Bc: reduction of vegetation cover
  • Bh: loss of habitats
  • Bq: quantity/ biomass decline
  • Bl: loss of soil life
  • Bp: increase of pests/ diseases, loss of predators
water degradation

water degradation

  • Hs: change in quantity of surface water
  • Hp: decline of surface water quality
  • Hq: decline of groundwater quality
Comments:

Improvement of groundwater quality is not the focus of the project but the technology has an impact on this type of natural degradation process.

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
Comments:

Flood sediments are diverted by the dam and its accumulation in the lower zone of the watersheds is prevented, thereby allowing the rehabilitation of arable land downstream.

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

4.1 Technical drawing of the Technology

Technical specifications (related to technical drawing):

Specify how costs and inputs were calculated:

per Technology unit

Specify unit:

Dam
Specify dimensions of unit (if relevant):

400m-long dug channel and 60m-long gabion
Specify currency used for cost calculations:

USD

Author:

Sady Odinashoev

Date:

01/08/2013

4.2 General information regarding the calculation of inputs and costs

Specify how costs and inputs were calculated:
  • per Technology unit
Specify unit:

Dam

Specify dimensions of unit (if relevant):

400m-long dug channel and 60m-long gabion

Specify currency used for cost calculations:
  • USD

4.3 Establishment activities

Activity Timing (season)
1. 400m-long channel digging (bulldozer) August-October
2. Stone collection October (10 days)
3. Construction of gabions November (15 days)
Comments:

Establishment activities to be completed before the cold and snow/rain season.

4.4 Costs and inputs needed for establishment

Specify input Unit Quantity Costs per Unit Total costs per input % of costs borne by land users
Labour Construction of wire net gabions person-hours 1400.0 1.5 2100.0 100.0
Labour Bulldozer driving person-hours 150.0 1.5 225.0
Equipment Bulldozer rent day 15.0 63.0 945.0
Equipment Fuel for bulldozer litre 2250.0 1.35 3037.5
Equipment Diesel oil for bulldozer litre 68.0 2.13 144.84
Equipment Spindle oil for bulldozer litre 45.0 2.0 90.0
Construction material wire net (diametre 4mm) m2 625.0 1.6 1000.0
Construction material wire (diametre 3mm) kg 26.0 1.6 41.6
Other Gearbox oil for bulldozer litre 22.0 2.5 55.0
Other Solid oil for bulldozer litre 22.0 3.0 66.0
Other Gas for bulldozer litre 22.0 1.4 30.8
Total costs for establishment of the Technology 7735.74
Total costs for establishment of the Technology in USD 7735.74
If land user bore less than 100% of costs, indicate who covered the remaining costs:

Rent of bulldozer + bulldozer driving covered by local district government. All other costs covered by project.

Comments:

Cost-sharing for establishment and maintenance activities is agreed upon when determining the design and implementation of the dam as part of the project conditions.

4.5 Maintenance/ recurrent activities

Activity Timing/ frequency
1. Fixing of wire net gabions March, annually
Comments:

Maintenance activities to be conducted before peak rain/snowmelt/flood season.

4.6 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 Fixing wire net (by Self Help Group) hour 40.0 0.8 32.0 100.0
Construction material wire net kg 7.0 1.0 7.0 100.0
Total costs for maintenance of the Technology 39.0
Total costs for maintenance of the Technology in USD 39.0
Comments:

All maintenance costs covered by land users.

4.7 Most important factors affecting the costs

Describe the most determinate factors affecting the costs:

- Geography (steep hills to dig a diverting channel increases the establishment costs)
- Geology (quality/type of soil affects the time needed for digging)

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:

Varies very much from year to year.

Indicate the name of the reference meteorological station considered:

Muminabad meteo station (1200 m a.s.l.)

Agro-climatic zone
  • semi-arid

Average temperatures:
Spring:10-32°C
Summer: 20-35°C
Autumn: 10-32°C
Winter: -5-+5°C
Average yearly temperature: 11.1°C

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%)
Landforms:
  • 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.
Indicate if the Technology is specifically applied in:
  • concave situations

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):
  • coarse/ light (sandy)
  • medium (loamy, silty)
Soil texture (> 20 cm below surface):
  • coarse/ light (sandy)
  • medium (loamy, silty)
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.

On southern (sunny) side of the hills, loess type of soil. On northern (shady) side of the hills, humus type of soil

5.4 Water availability and quality

Ground water table:

> 50 m

Availability of surface water:

excess

Water quality (untreated):

good drinking water

Is water salinity a problem?

No

Is flooding of the area occurring?

Yes

Regularity:

episodically

Comments and further specifications on water quality and quantity:

Seasonal floods/high runoff in spring time, when heavy rain coincides with snowmelt.

5.5 Biodiversity

Species diversity:
  • medium
Habitat diversity:
  • medium

5.6 Characteristics of land users applying the Technology

Sedentary or nomadic:
  • Sedentary
Market orientation of production system:
  • subsistence (self-supply)
Off-farm income:
  • 10-50% of all income
Relative level of wealth:
  • average
Individuals or groups:
  • individual/ household
Level of mechanization:
  • manual work
  • mechanized/ motorized
Gender:
  • women
  • men
Age of land users:
  • youth
  • middle-aged

5.7 Average area of land used 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)?
  • medium-scale

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

Land ownership:
  • state
Land use rights:
  • leased
Water use rights:
  • communal (organized)

5.9 Access to services and infrastructure

health:
  • poor
  • moderate
  • good
education:
  • poor
  • moderate
  • good
technical assistance:
  • poor
  • moderate
  • good
employment (e.g. off-farm):
  • poor
  • moderate
  • good
markets:
  • poor
  • moderate
  • good
energy:
  • 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

Production

crop production

decreased
increased
Quantity before SLM:

No production

Quantity after SLM:

Self-use + surplus sold on market

Comments/ specify:

6000 kg onions/ ha

crop quality

decreased
increased
Comments/ specify:

35-40% increase

fodder production

decreased
increased
Comments/ specify:

On average 50% increase of fodder. Additionally, fodder crop seeds (lucerne) can be sold; increases land users' income.

fodder quality

decreased
increased

animal production

decreased
increased

risk of production failure

increased
decreased
Comments/ specify:

One of the main and most important impact

product diversity

decreased
increased

production area

decreased
increased
Comments/ specify:

25-30% increase in production area in lowlands (downstream) through rehabilitation of unproductive land which was previously regularly flooded and covered by sediments.

land management

hindered
simplified
Comments/ specify:

Trees newly planted are used for riverbed protection and fuelwood production

Water availability and quality

drinking water availability

decreased
increased
Comments/ specify:

Floods do not contaminate spring drinking waters with sediments

drinking water quality

decreased
increased

irrigation water availability

decreased
increased
Comments/ specify:

Irrigation channel not destroyed by annual floods anymore.

Income and costs

expenses on agricultural inputs

increased
decreased
Comments/ specify:

Pests decreased.

farm income

decreased
increased
Comments/ specify:

Through rehabilitation of unproductive land in river fan.

diversity of income sources

decreased
increased
Other socio-economic impacts

orchards

Socio-cultural impacts

food security/ self-sufficiency

reduced
improved
Comments/ specify:

Cultivation of wheat plots and vegetables for self-use and sale

health situation

worsened
improved

land use/ water rights

worsened
improved
Comments/ specify:

Previously unused land in the river fan is now registered as pasture land with a land certificate for the use of the community, and new houses where also built on this land.

recreational opportunities

reduced
improved

community institutions

weakened
strengthened
Comments/ specify:

Taxes can be collected with the registration and certification of pasture land and with the authorisation of house construction.

SLM/ land degradation knowledge

reduced
improved

situation of socially and economically disadvantaged groups

worsened
improved
Comments/ specify:

With dam constructed, economically disadvantaged people have space for building a house on the rehabilitated land.

Ecological impacts

Water cycle/ runoff

surface runoff

increased
decreased

excess water drainage

reduced
improved
Soil

soil cover

reduced
improved

soil loss

increased
decreased

soil accumulation

decreased
increased

nutrient cycling/ recharge

decreased
increased

soil organic matter/ below ground C

decreased
increased
Biodiversity: vegetation, animals

Vegetation cover

decreased
increased

plant diversity

decreased
increased

pest/ disease control

decreased
increased
Climate and disaster risk reduction

flood impacts

increased
decreased

landslides/ debris flows

increased
decreased

6.2 Off-site impacts the Technology has shown

reliable and stable stream flows in dry season

reduced
increased

downstream flooding

increased
reduced

downstream siltation

increased
decreased

damage on neighbours' fields

increased
reduced

damage on public/ private infrastructure

increased
reduced
Specify assessment of off-site impacts (measurements):

In the last three years no flood affected the downstream village. 330ha of land situated downstream of the dam has been rehabilitated, cleaned from big stones, and used fully as pasture. No sediment flood affected the use of this rehabilitated land.

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 increase or decrease How does the Technology cope with it?
annual rainfall increase well
seasonal rainfall spring increase well

Climate-related extremes (disasters)

Hydrological disasters
How does the Technology cope with it?
general (river) flood very well
flash flood very well

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

Comments:

From the land-user perspective, the benefit assessment of the establishment costs could only be done in relation to the land-users' contribution (i.e. 10% of establishment costs in cash or USD 600 , plus labour).
Because the dam was constructed less than 10 years ago, the long-terms returns cannot be assessed yet.

6.5 Adoption of the Technology

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

250 households and 270 ha covered, i.e. 50% of Kulchashma village's population.

Of all those who have adopted the Technology, how many did so spontaneously, i.e. without receiving any material incentives/ payments?
  • 0-10%
Comments:

This low percentage is explained by the fact that a structural measure like a dam construction is a big collective investment and can only be initiated as a group with coordination.

6.6 Adaptation

Has the Technology been modified recently to adapt to changing conditions?

No

6.7 Strengths/ advantages/ opportunities of the Technology

Strengths/ advantages/ opportunities in the land user’s view
The construction and maintenance of a river training dam prevents further land degradation caused by floods, allows the rehabilitation of unused land to create new pastures, and above all increases people's and livestock's safety.
Strengths/ advantages/ opportunities in the compiler’s or other key resource person’s view
General improvement of life quality, including life safety and opportunities to protect assets and improve livelihoods.

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?
None n/a
Weaknesses/ disadvantages/ risks in the compiler’s or other key resource person’s view How can they be overcome?
Downstream communities feel safe behind the dam and tend to ignore the risk of failure in extreme conditions (beyond the coping capacity of the dam). As a consequence, people build houses in places still at risk in the river fan. Strengthened governance (no authorisation of construction in the river fan/behind the dam in the risk zone).

7. References and links

7.1 Methods/ sources of information

  • interviews with land users

5 land users

  • interviews with SLM specialists/ experts

1

When were the data compiled (in the field)?

11/10/2016

Links and modules

Expand all Collapse all

Modules