Technologies

Percolation pits [Uganda]

Ebyina

technologies_619 - Uganda

Completeness: 90%

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:

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)
Tear Fund Switzerland (Tear Fund 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:

Ja

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?

Geen

Comments:

So far, where this technology has been applied, the water runoff has been reduced, water retention increased and soils trapped

1.5 Reference to Questionnaire(s) on SLM Approaches (documented using WOCAT)

Catchment Based Integrated Water Resources Management
approaches

Catchment Based Integrated Water Resources Management [Uganda]

Catchment based integrated water resources management is a process which promotes the coordinated development and management of water, land and related resources in order to maximise economic and social welfare in an equitable manner without compromising the sustainability of vital eco systems

  • Compiler: Philip Tibenderana

2. Description of the SLM Technology

2.1 Short description of the Technology

Definition of the Technology:

A percolation pit is an excavation in the ground in the pathway of water runoff to intercept the flow of the water and thereby reduce erosion and destruction of crops, settlements and other infrastructure downstream

2.2 Detailed description of the Technology

Description:

The technology is applied in already existing degraded farmlands, which are individually owned. An average farm size is less than half an acre.

A typical percolation pit is 2m wide, 2m long and 1m deep planted with a hedge row on its lower side

This technology reduces the speed of water running down the slope during a downpour and traps the water and soil that is being washed thereby reducing soil erosion and increasing water retention

Areas which are prone to degradation by erosion are identified and later, the farmers are trained on benefits of this technology, how to construct the pit and how to maintain them by periodic de-silting and planting grasses and shrubs on the lower side

This technology helps maintain the good top soil, which would have otherwise been washed down the water course into the valley and increases water retention.

The land users like this technology because their soil is not lost by erosion. In addition it is localized, not like a conservation channel which runs along the whole contour. Percolation pits consume less land because they are located in an already existing waterway. What land users don’t like about this technology is that it has a huge sediment load and requires frequent de-silting

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:

Uganda

Region/ State/ Province:

South Western Region

Further specification of location:

Rubaya Sub County, Kabale District

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

The technology is localised to water runoff courses which are susceptible to erosion

2.6 Date of implementation

Indicate year of implementation:

2015

2.7 Introduction of the Technology

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

The technology was introduced under the Integrated Water Resources Management Project to support farmers to maximise land productivity

3. Classification of the SLM Technology

3.1 Main purpose(s) of the Technology

  • improve production
  • reduce, prevent, restore land degradation
  • conserve ecosystem
  • protect a watershed/ downstream areas – in combination with other Technologies
  • reduce risk of disasters
  • adapt to climate change/ extremes and its impacts
  • mitigate climate change and its impacts
  • create beneficial economic impact
  • create beneficial social impact

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

Land use mixed within the same land unit:

Ja

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

Cropland

Cropland

Number of growing seasons per year:
  • 2
Specify:

September to January and March to June

Grazing land

Grazing land

Mines, extractive industries

Mines, extractive industries

3.4 Water supply

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

3.5 SLM group to which the Technology belongs

  • water harvesting
  • water diversion and drainage
  • ground water management

3.6 SLM measures comprising the Technology

vegetative measures

vegetative measures

  • V1: Tree and shrub cover
  • V2: Grasses and perennial herbaceous plants
structural measures

structural measures

  • S3: Graded ditches, channels, waterways

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
  • Wm: mass movements/ landslides

3.8 Prevention, reduction, or restoration of land degradation

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

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

4.1 Technical drawing of the Technology

Technical specifications (related to technical drawing):

Dimensions indicated on drawing above

Author:

Kigezi Diocese Water and Sanitation Programme

Date:

12/12/2016

4.2 General information regarding the calculation of inputs and costs

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

Per pit

Specify dimensions of unit (if relevant):

4 cubic meters

Specify currency used for cost calculations:
  • USD
If relevant, indicate exchange rate from USD to local currency (e.g. 1 USD = 79.9 Brazilian Real): 1 USD =:

3300.0

Indicate average wage cost of hired labour per day:

USD 2.12

4.3 Establishment activities

Activity Timing (season)
1. Excavation of the percolation pit During the dry season
2. Planting hedge rows Onset of rains

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 Excavation of pit person days 4.0 2.12 8.48 100.0
Equipment Forked hoes (1 piece can excavate 50 pits) pieces 0.02 4.55 0.09
Equipment Pick axes (1 piece can excavate 50 pits) pieces 0.02 4.55 0.09
Equipment Spades (1 piece can be used on 50 pits) pieces 0.02 4.55 0.09
Plant material Starria grass (1 sack for 5 pits) per pit 1.0 1.21 1.21
Total costs for establishment of the Technology 9.96
If land user bore less than 100% of costs, indicate who covered the remaining costs:

Kigezi Diocese Water and Sanitation Programme

Comments:

The land users excavate the pis themselves but the tools are beyond the financial capacity of the land user hence the need for subsidy

4.5 Maintenance/ recurrent activities

Activity Timing/ frequency
1. De-silting the pits When half full
2. Maintenance of the hedge rows by triming and replanting empty spaces Continous

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 Desilting the pits when half full person days 1.0 2.12 2.12 100.0
Labour Trimming of hedge rows (on 25 pits per day) person days 0.04 2.12 0.08
Total costs for maintenance of the Technology 2.2
If land user bore less than 100% of costs, indicate who covered the remaining costs:

N/A

Comments:

The initial investment of the equipment is adequate for maintenance at least for some years

4.7 Most important factors affecting the costs

Describe the most determinate factors affecting the costs:

The costs have been calculated basing on depth of top soil of 51 – 80cm. When the depth of the top soil is shallow, then the costs of breaking the underlying sub-surface layers, which are usually rock, are much higher. Also during the rainy season, the soil is more workable

The costs of maintenance will be less where the rest of the landscape also has other percolation pits, conservation channels, good vegetative cover and where the hill slope is gentle.

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
Specify average annual rainfall (if known), in mm:

1200.00

Specifications/ comments on rainfall:

Bi-modal rainfall pattern with long rainy season from September to December then March to May

Indicate the name of the reference meteorological station considered:

Kabale District Meterological Department

Agro-climatic zone
  • sub-humid

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:
  • not relevant

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):
  • medium (loamy, silty)
Soil texture (> 20 cm below surface):
  • medium (loamy, silty)
Topsoil organic matter:
  • medium (1-3%)

5.4 Water availability and quality

Ground water table:

> 50 m

Availability of surface water:

good

Water quality (untreated):

poor drinking water (treatment required)

Is water salinity a problem?

Geen

Is flooding of the area occurring?

Ja

Regularity:

episodically

Comments and further specifications on water quality and quantity:

Water quantity and quality is dependent on human activities and rainfall patterns.

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)
  • mixed (subsistence/ commercial)
Off-farm income:
  • less than 10% of all income
Relative level of wealth:
  • poor
Individuals or groups:
  • individual/ household
Level of mechanization:
  • manual work
Gender:
  • 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)?
  • small-scale

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

Land ownership:
  • individual, not titled
Land use rights:
  • individual
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
Comments/ specify:

The impacts are visible even after the first crop

crop quality

decreased
increased

fodder production

decreased
increased

fodder quality

decreased
increased

risk of production failure

increased
decreased

product diversity

decreased
increased

production area

decreased
increased

land management

hindered
simplified
Income and costs

expenses on agricultural inputs

increased
decreased

farm income

decreased
increased

diversity of income sources

decreased
increased

workload

increased
decreased

Socio-cultural impacts

food security/ self-sufficiency

reduced
improved
Comments/ specify:

It is expected to improve in the long term

health situation

worsened
improved

community institutions

weakened
strengthened

SLM/ land degradation knowledge

reduced
improved

conflict mitigation

worsened
improved

Ecological impacts

Water cycle/ runoff

surface runoff

increased
decreased

groundwater table/ aquifer

lowered
recharge
Comments/ specify:

Recharge is hoped to increase in the long term as more farmers adapt the technology

Soil

soil moisture

decreased
increased

soil cover

reduced
improved

soil loss

increased
decreased

soil accumulation

decreased
increased

soil organic matter/ below ground C

decreased
increased
Comments/ specify:

By use of manure

Climate and disaster risk reduction

flood impacts

increased
decreased
Comments/ specify:

Flooding in the valley bottoms due to runoff reduces significantly

6.2 Off-site impacts the Technology has shown

water availability

decreased
increased
Comments/ specify:

As more people adopt the technology this is expected to increase

downstream flooding

increased
reduced

damage on neighbours' fields

increased
reduced
Comments/ specify:

The runoff which causes damage is trapped in the percolation pits

damage on public/ private infrastructure

increased
reduced
Comments/ specify:

Especially on roads and water systems

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 temperature increase not known
seasonal temperature wet/ rainy season increase not known
seasonal temperature dry season increase not known
annual rainfall decrease not known
seasonal rainfall wet/ rainy season decrease not known

Climate-related extremes (disasters)

Meteorological disasters
How does the Technology cope with it?
local rainstorm well
local thunderstorm well
local hailstorm well
Climatological disasters
How does the Technology cope with it?
land fire well
Hydrological disasters
How does the Technology cope with it?
general (river) flood very well
flash flood very well
landslide well

6.4 Cost-benefit analysis

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

positive

Long-term returns:

very positive

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

positive

Long-term returns:

very positive

6.5 Adoption of the Technology

  • single cases/ experimental
Of all those who have adopted the Technology, how many did so spontaneously, i.e. without receiving any material incentives/ payments?
  • 91-100%
Comments:

The adoption rate of this technology is gradual as people keep appreciating the benefits

6.6 Adaptation

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

Geen

6.7 Strengths/ advantages/ opportunities of the Technology

Strengths/ advantages/ opportunities in the land user’s view
It controls soil loss from the land users gardens
It provides silt which is spread in their garden
Hedge rows are used as fodder and as mulching material
The conserved water is used to benefit the plants in the same garden
Strengths/ advantages/ opportunities in the compiler’s or other key resource person’s view
The percolation pits prevent development of gullies
It improves water percolation in the soil which increases soil moisture content and increases ground water recharge
They prevent silt deposition in the valley bottoms and siltation of water bodies
It is a simple technology which uses simple hand tools

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?
This technology requires a lot of hard labour The land users were encouraged to form small groups which work together to ease the work and share knowledge and skill
Weaknesses/ disadvantages/ risks in the compiler’s or other key resource person’s view How can they be overcome?
This technology is dependent on land users continued efforts in de-silting it. When this is not done the technology fails Land users are encouraged to periodically de-silt the pits
The effectiveness of this technology is dependent on the compliance of other land users in the landscape. For example if it is done downhill and not uphill, then the pits will be overwhelmed by the volume of the soil and water runoff All community members were sensitised on the importance and effectiveness of this technology and existing by-laws will foster members uphill to practice the technology. The benefits of the technology will encourage other land users to adopt it
The process of maintaining and rolling out this technology requires engagement of many stakeholders Management structures, which are well linked with government structures, have been set up and trained at various levels to manage the process of maintaining and rolling out the technology

7. References and links

7.1 Methods/ sources of information

  • field visits, field surveys

Observation field visits to percolation pit sites

  • interviews with land users

Focus group discussion with 18 land users

  • interviews with SLM specialists/ experts

Programme implementation team

  • compilation from reports and other existing documentation

Programme progress reports

When were the data compiled (in the field)?

07/09/2016

7.2 References to available publications

Title, author, year, ISBN:

Kigezi Diocese Water and Sanitation Programme, IWRM Annual Report (April 2015 - March 2016)

Available from where? Costs?

www.kigezi-watsan.ug

Title, author, year, ISBN:

IWRM Pilot report 2013

Available from where? Costs?

www.kigezi-watsan.ug

7.3 Links to relevant online information

Title/ description:

Test pits

URL:

http://gamarch.co.uk/?page_id=966

Title/ description:

Percolation test pits

URL:

http://www.mfkelly.ie/percolation_tests.asp

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