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

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

Scaling-up SLM practices by smallholder farmers (IFAD)

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

National Agricultural Research Organisation (NARO) - Uganda

1.3 Conditions regarding the use of data documented through WOCAT

When were the data compiled (in the field)?

17/10/2017

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

Comments:

The trenches constructed in these regions address the problem of soil conservation to act as flow barrier (restricting the flow velocity within the safe limit from soil erosion point of view) and facilitate water conservation.

2.1 Short description of the Technology

Definition of the Technology:

A contour trench and pit are an excavated ditch/pit along a uniform level across the slope of land in the top portion of catchment to trap runoff water.

2.2 Detailed description of the Technology

Description:

Water harvesting is the deliberate collection and storage of water that runs off on natural or manmade catchment areas. Catchment includes rooftops, compounds, rocky surface or hill slopes or artificially prepared impervious/ semi-pervious land surface. The amount of water harvested depends on the frequency and intensity of rainfall, catchment characteristics, water demands and how much runoff occurs. Contour trenches and pits are one of the oldest and most commonly used water management systems in the hilly areas of Mbale district. Contour trenches and pits are ditches dug along a hillside and run perpendicular to the flow of water. Their main objective is to slow down and attract runoff water which infiltrates into the soil which is used as soil moisture for crop cultivated after a rainfall event.These trenches and pits are constructed and maintained during the dry season. The size of the trenches is based on the slope and soil type. Bulabuli subcounty in Mbale district being a hilly area has trenches which are 5 metres long and 1 metre in width and depth. The materials needed in the construction of the trenches and pits are a hoe and spade. For maintenance they should be checked for build up soil, leaves and branches before the rainy season.The major advantages of rainwater harvesting are that it is simple, cheap, replicable, efficient, sustainable and adaptable and can be applied on any soil type and terrain. It can be implemented in small-scale, easily maintained and requires low investements which suites the rural community in Mbale district. Rainwater harvesting also has been shown an advantage as it reduces soil erosion, improves soil fertility and increases agricultural productivity as it reduces damage on the crops hence increases income and improves livelihood.

2.3 Photos of the Technology

2.4 Videos 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

Indicate year of implementation:

1989

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 land users' innovation

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
• create beneficial economic impact
• create beneficial social impact

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

3.3 Further information about land use

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

• mixed rainfed-irrigated

Comments:

Water is trapped from the streams flowing from the hills which is diverted into the farmlands

Number of growing seasons per year:

• 2

Specify:

Two rainy seasons between March to May and June to August or October

Livestock density (if relevant):

Cows and goats

3.4 SLM group to which the Technology belongs

• cross-slope measure
• water harvesting
• irrigation management (incl. water supply, drainage)

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:

• 100-1,000 km2

Comments:

Most of the farmers in Wanale sub county constructed the trenches and pits as a way to combat soil erosion since the area is hilly

3.6 SLM measures comprising the Technology

3.7 Main types of land degradation addressed by the Technology

3.8 Prevention, reduction, or restoration of land degradation

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

• prevent land degradation
• reduce land degradation

Comments:

The technology reduced further land degradation by controlled run off water hence soil and water conservation

4.1 Technical drawing of the Technology

4.2 Technical specifications/ explanations of technical drawing

Trenches of 5metres long and one metre in width and depth while the pits are 4metres deep and 5metres in diameter. The materials needed in the construction of the trenches and pits are a hoe and spade. Contour trenches are dug along a hillside and run perpendicular to the flow of water.

4.3 General information regarding the calculation of inputs and costs

Specify how costs and inputs were calculated:

• per Technology unit

other/ national currency (specify):

Ugandan Shilling

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

3600.0

4.4 Establishment activities

	Activity	Type of measure	Timing
1.	Plan according to the topography of the area	Structural	Before the on set of rains
2.	Purchase the materials need	Structural	Before the on set of rains
3.	Measure and indicate	Structural	Before the on set of rains
4.	Construction of the Trenches and pits	Structural	Before the on set of rains

Comments:

The establishment activities are done during the 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	Man Power	Trenches	58.0	4000.0	232000.0
Equipment	Handhoe	piece	3.0	10000.0	30000.0
Equipment	Spade	piece	3.0	15000.0	45000.0
Total costs for establishment of the Technology					307000.0

Comments:

The land user bore all the costs since it was self innovative.

4.6 Maintenance/ recurrent activities

	Activity	Type of measure	Timing/ frequency
1.	Excavation of soil and other sediments from the trenches	Management	Annually before on set of rains

Comments:

Once the trenches and pits are constructed, the land user is only left with digging out the soil that has build up in the trenches.

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	Trenches	58.0	1500.0	87000.0
Equipment	Handhoe	pieces	2.0	10000.0	20000.0
Equipment	Spade	Pieces	2.0	15000.0	30000.0
Total costs for maintenance of the Technology					137000.0

If land user bore less than 100% of costs, indicate who covered the remaining costs:

The land user bore all the costs

Comments:

The maintenance costs are lower since less labour is need to maintain the structures. The land user doesn't have to buy the equipments again since they had been purchased at the beginning during the construction of the trenches.

4.8 Most important factors affecting the costs

Describe the most determinate factors affecting the costs:

Labour

5.1 Climate

5.2 Topography

Comments and further specifications on topography:

Wanale hills is standing at the height of 6,864 ft

5.3 Soils

5.4 Water availability and quality

Is water salinity a problem?

Yes

Specify:

There' s soil erosion in the hilly areas of Wanale which pollutes the water sources in low land areas

Is flooding of the area occurring?

No

Comments and further specifications on water quality and quantity:

There's high adaptation of contour trenches in the area

5.5 Biodiversity

Comments and further specifications on biodiversity:

Most of the land is arable land and less occupied with natural forests

5.6 Characteristics of land users applying the Technology

Indicate other relevant characteristics of the land users:

The land user is highly educated (University Level)

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

Land use rights:

• individual

Water use rights:

• individual

5.9 Access to services and infrastructure

6.1 On-site impacts the Technology has shown

Socio-economic impacts

Production

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

Comments regarding impact assessment:

Contour trenches are mainly dug to control soil erosion which slow down and trap run off water which infiltrates into the soil.

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	very well
annual rainfall		decrease	very well
seasonal rainfall	wet/ rainy season	decrease	very well

Climate-related extremes (disasters)

Hydrological disasters

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

Other climate-related consequences

Other climate-related consequences

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

The trenches maintained after two rainy seasons and readily available cheap labour hence low maintenance cost.

6.5 Adoption of the Technology

• more than 50%

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

• 90-100%

Comments:

Landowners have knowledge about the advantages of trenches and there’s readily cheap labour. Availability of Farmer groups in the area hence collective knowledge sharing.

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
Reduces soil erosion
Improves agricultural productivity through infiltration of the water collected in the trenches and pits
water can be used for irrigation and spraying after rains

Strengths/ advantages/ opportunities in the compiler’s or other key resource person’s view
Prevents pollutants from draining into the low land water bodies
Reduces salinity of ground water

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?
Trenches silt up and need regular maintenance	Regular maintenance
Accidents may occur through drawning	Controlled movement of children
The trenches and pits are habitats for mosquitoes

Weaknesses/ disadvantages/ risks in the compiler’s or other key resource person’s view	How can they be overcome?
Increases land fragmentation since these trenches divide the land into small pieces of land

7.1 Methods/ sources of information

7.2 References to available publications

Title, author, year, ISBN:

Importance of Continuous Contour Trenches (CCT) in Maharashtra by Nitin Bajirao Borse M.V.P.Samaj’s (2016) Arts, Science and Commerce College, Ozar (MIG) Affiliated to SP Pune University

Available from where? Costs?

https://www.researchgate.net/publication/308666186_Importance_of_Continuous_Contour_Trenches_CCT_in_Maharashtra

7.3 Links to relevant information which is available online

Title/ description:

Soil and water conservation Trenches

URL:

https://ecoursesonline.icar.gov.in/mod/page/view.php?id=2197

Title/ description:

Infiltration Trenches (water Absorption Trenches)

URL:

http://www.catchmentguidelines.org.mw/en/technical-guidelines/water-harvesting-and-storage/infiltration/infiltration-trenches-water-absorption-trenches

Title/ description:

Water Portal / Rainwater Harvesting / Groundwater recharge / Contour trenches

URL:

http://akvopedia.org/wiki/Water_Portal_/_Rainwater_Harvesting_/_Groundwater_recharge_/_Contour_trenches