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)

Haramaya University (HU) - Ethiopia

1.3 Conditions regarding the use of data documented through WOCAT

When were the data compiled (in the field)?

02/05/2011

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:

Stone wall check dams are built across a gully to collect alluvial soil and hinder further gully erosion.

2.2 Detailed description of the Technology

Description:

During the 1980s stone walls and terraces were introduced in Ethiopia in order to combat soil erosion. The technology of stone walls or terraces is used to stabilize hills or to refill gullies also in Bati, Ethiopia. Stone walls can form a very strong check dam to rehabilitate gullies even several meters deep.

Purpose of the Technology: Although stone walls can be used for different purposes, this case study is focusing on stone walls used to combat gully erosion. Farmers in the Bati region often use stone walls to rehabilitate gullies if the material is easily accessible, otherwise they may search for alternatives.

Establishment / maintenance activities and inputs: Following procedure is undertaken to build a stone wall check dam: After breaking the stones in the source-area they are transported to the target-area either by hand, by camels or by donkeys, depending on the distance. After digging a foundation for the wall of approximately 30 cm depth, the gap between two rows of big stones 1 m apart is filled up with smaller stones and gravel. These actions are repeated until the desired height and width of the wall are reached

Natural / human environment: The case study site, Bati, lays in an semiarid climatic zone on 1600 m a.s.l. Rainfalls are erratic and the rain sum per year is between 500-1000 mm. The landscape is very hilly with rather steep slopes. As almost in all Ethiopia, the area has a high population density and growth. The agricultural sector is very dominant and lead by a lot of small scale farming with a lot of livestock and small plots of cropland.

2.3 Photos of the Technology

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

2.6 Date of implementation

If precise year is not known, indicate approximate date:

• 10-50 years ago

2.7 Introduction of the Technology

Specify how the Technology was introduced:

• through projects/ external interventions

Comments (type of project, etc.):

Soil and water conservation measures, including stone wall check dams, were mainly introduced to land users during the 1980s by the government. Sometimes the technology is not adequately performed though. In recent years the local Agricultural Office is teaching farmers how to correctly build soil and water conservation measures not only on a technology basis but to take care of an integrated watershed management.

3.1 Main purpose(s) of the Technology

• reduce, prevent, restore land degradation

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

Comments:

Major land use problems (compiler’s opinion): Deforestation, overgrazing, cultivation of erosion-sensitive areas or steep slopes.

Major land use problems (land users’ perception): Too much soil loss and land degradation, no vegetation cover and poor soil moisture.

Grazingland comments: Livestock is not fenced in. Children herd the animals and watch out that they do not browse through crop fields. In off-farming season crop residues are collected from the field and stored next to the field. Animals are allowed to eat the still remaining residues on the field. After that, the animals are fed by the collected crop residues.

Livestock is grazing on crop residues

Type of grazing system comments: Livestock is not fenced in. Children herd the animals and watch out that they do not browse through crop fields. In off-farming season crop residues are collected from the field and stored next to the field. Animals are allowed to eat the still remaining residues on the field. After that, the animals are fed by the collected crop residues.

3.3 Further information about land use

Water supply for the land on which the Technology is applied:

• mixed rainfed-irrigated

Comments:

Water supply: Also rainfed

Specify:

Longest growing period in days: 90 Longest growing period from month to month: June until September

Livestock density (if relevant):

> 100 LU /km2

3.4 SLM group to which the Technology belongs

• cross-slope measure

3.5 Spread of the Technology

Comments:

Total area covered by the SLM Technology is 0.6 m2.

Size of the case study watershed.

3.6 SLM measures comprising the Technology

Comments:

Main measures: structural measures

3.7 Main types of land degradation addressed by the Technology

Comments:

Main type of degradation addressed: Wg: gully erosion / gullying

Secondary types of degradation addressed: Wt: loss of topsoil / surface erosion

Main causes of degradation: deforestation / removal of natural vegetation (incl. forest fires) (Deforestation for the past 30 years.), over-exploitation of vegetation for domestic use (Wood collection for cooking and construction.), overgrazing (50% of the watershed area are cultivated - big grazing pressure on remaining land), other human induced causes (specify) (Cultivation of very steep slopes.), change of seasonal rainfall (Erratic rainfall.), Heavy / extreme rainfall (intensity/amounts) (If there is rain, it is intensive.), population pressure (High population pressure.), poverty / wealth (Poor facilities.)

Secondary causes of degradation: soil management (Poor soil management practices and lack of awareness.), crop management (annual, perennial, tree/shrub) (Annual cropping.), droughts (The research area is considered rather dry.), land tenure (If the land is rented, it is poorly managed.), inputs and infrastructure: (roads, markets, distribution of water points, other, …) (Poor access to fertilizer. Bad infrastructures.), education, access to knowledge and support services (Lack of awareness for soil degradation.), Low productivity of the land (As a consequence seeking for new/larger areas to increase production.)

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:

Secondary goals: mitigation / reduction of land degradation

4.1 Technical drawing of the Technology

4.2 Technical specifications/ explanations of technical drawing

Stone wall check dams as they can be found in the region of Bati. The approximately 1 m wide gap between two rows of larger stones is filled up with small stones or gravel. This is done for every new level of the wall until the wall reaches its final height. The first row of stones is placed in the top 30 cm of the ground and on each side the dam is entering the hill to some extent. After a wall has silted up, the height is increased by other rows of stones until desired dimension is reached. Walls up to 5 m can be found in the case study site.

Location: South-West of Bati. Bati Woreda, Amhara Region, Ethiopia

Date: 26.04.2011

Technical knowledge required for field staff / advisors: moderate (To teach the farmers how to perform an integrated watershed management.)

Technical knowledge required for land users: high (To build a robust check dam there is a lot of knowledge needed.)

Main technical functions: control of concentrated runoff: retain / trap, control of concentrated runoff: impede / retard, reduction of slope angle, reduction of slope length, increase / maintain water stored in soil, sediment retention / trapping, sediment harvesting

Secondary technical functions: water harvesting / increase water supply, improvement of water quality, buffering / filtering water

Retention/infiltration ditch/pit, sediment/sand trap
Depth of ditches/pits/dams (m): 6
Width of ditches/pits/dams (m): 10
Length of ditches/pits/dams (m): 1

If the original slope has changed as a result of the Technology, the slope today is: 0%

4.3 General information regarding the calculation of inputs and costs

other/ national currency (specify):

Ethiopian Birr

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

16.82

4.4 Establishment activities

	Activity	Type of measure	Timing
1.	Preparation of the stones (500 person days needed).	Structural	During dry season.
2.	Transportation of the stones (depending on the distance).	Structural	During dry season.
3.	Digging a foundation of 30 cm depth (165 person days needed).	Structural	During dry season.
4.	Building of the stone wall (500 person days needed).	Structural	During dry season.

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	Labour	ha	1.0	1165.0	1165.0	50.0
Equipment	Tools	ha	1.0	5.0	5.0	100.0
Total costs for establishment of the Technology					1170.0

4.6 Maintenance/ recurrent activities

	Activity	Type of measure	Timing/ frequency
1.	Prepare the stones (250 person days needed).	Structural	During dry season if needed.
2.	If dam is silted up, increasing the height by 0.5 m (250 person days needed)	Structural	Every year in dry season.

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	Labour	ha	1.0	500.0	500.0	50.0
Equipment	Tools	ha	1.0	5.0	5.0	100.0
Total costs for maintenance of the Technology					505.0

Comments:

Machinery/ tools: Shovel, digging hoe, iron rod.

Total costs of a hectare were calculated for a wall of 100 m length and 1 m of height every 20 m (500 m total wall) in the year 2011. Tool prices were estimated and labor costs were calculated with a daily wage of 1$.

4.8 Most important factors affecting the costs

Describe the most determinate factors affecting the costs:

Rough topology in the area, questionable availability of construction materials if they are not found nearby.

5.1 Climate

5.2 Topography

Comments and further specifications on topography:

Altitudinal zone: 1501-2000 m a.s.l. (The study site is located at 1600m a.s.l.)
Landforms: Hill slopes (ranked 1) and valley floors (ranked 2)
Slopes on average: Hilly (ranked 1), rolling (ranked 2) and steep (ranked 3)

5.3 Soils

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 depth on average: Very shallow (ranked 1) and shallow (ranked 2)
Soil textur: Coarse/light (ranked 1) and medium (ranked 2)
Soil fertility is low
Soil drainage/infiltration is poor
Soil water storage capacity is medium

5.4 Water availability and quality

Comments and further specifications on water quality and quantity:

Ground water table: Unknown
Availability of surface water is poor/none (Only during rainy season)
Water quality (untreated): Poor drinking water (treatment required, mostly groundwater)

5.5 Biodiversity

Comments and further specifications on biodiversity:

Relative to other parts of Ethiopia.

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: 100-200 persons/km2
Annual population growth: 6%
1% of the land users are rich (Adopt the most of SWC technologies).
19% of the land users are average wealthy.
89% of the land users are poor.
Off-farm income specification: Off-farm income has low importance.
Level of mechanization: Animal traction (Plowing by oxen, ranked 1) and manual labour (ranked 2)
Market orientation cropland: Subsistence
Market orientation grazing land: Goat/sheep are main meat source (in household or on market).

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

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

Land ownership:

• individual, titled

Water use rights:

• open access (unorganized)

5.9 Access to services and infrastructure

6.1 On-site impacts the Technology has shown

Socio-economic impacts

Production

Water availability and quality

Income and costs

Socio-cultural impacts

Ecological impacts

Water cycle/ runoff

Soil

Biodiversity: vegetation, animals

Climate and disaster risk reduction

6.2 Off-site impacts the Technology has shown

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	well

Hydrological disasters

	How does the Technology cope with it?
general (river) flood	well

Other climate-related consequences

Other climate-related consequences

	How does the Technology cope with it?
reduced growing period	well

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)?

Comments:

Big labour input for establishment. Also maintenance needs some work every year. But also high benefit by additional farming land gained due to the check dams.

6.5 Adoption of the Technology

Comments:

100% of land user families have adopted the Technology with external material support

Comments on acceptance with external material support: In the past 6 years the local Agricultural Office has supported farmers to treat their watersheds with SWC technologies based on a food for work programme. Today farmers build the structures on their own but seek support.

There is a moderate trend towards spontaneous adoption of the Technology

Comments on adoption trend: Most of the farmers build SWC technologies (includin stone check dams in gullies) because of the food for work programme

6.7 Strengths/ advantages/ opportunities of the Technology

Strengths/ advantages/ opportunities in the land user’s view
The stone check dams are conserving soil and moisture. How can they be sustained / enhanced? Maintain the dams.
Due to alluvial soil there is additional farming land and therefore increased productivity. How can they be sustained / enhanced? Take care of the walls as well of the surrounding area and the whole watershed.

Strengths/ advantages/ opportunities in the compiler’s or other key resource person’s view
Stone check dams are a quite durable structure. How can they be sustained / enhanced? Stability could be enhanced by additional technologies e.g. similar as gabbions or planting of trees/shrubs in front of the wall to reduce collapsing possibility.
The structure collects alluvial soil which can be plowed and used as new farming fields. How can they be sustained / enhanced? Structure maintenance is important. If the dam fails, the field is washed out as well.
The technology is widely used around the world (perhaps with local adaptations) and is therefore well documented. How can they be sustained / enhanced? Keep on with documentation and monitoring of limitations and potentials of stone check dams around the world.

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 Land users could not tell any disadvantages of the technology.	Could be an indicator that there is enough spare time to build and maintain structures during off-farming season.

Weaknesses/ disadvantages/ risks in the compiler’s or other key resource person’s view	How can they be overcome?
Large labour input at establishment and during maintenance period.	Possibly by machinery but it is very expensive.
During time of establishment/maintenance there is no time for farming activites. These activities can therefore be seen as hidden costs.	Perhaps a "professional" team that takes care of check dams and is payed for it.

7.2 References to available publications

Title, author, year, ISBN:

Bach S. (2012) Potentials and limitations of Jatropha curcas as a multipurpose crop for sustainable energy supply and soil and water conservation - a case study in Bati, Ethiopia, using the WOCAT approach. Unpublished master’s thesis, Centre for Development and Environment, University of Bern.