Technologies

Deepening the channels supplying water to lakes and ponds [Mali]

Creation: 09/24/2014 5:03 p.m.
Update: 05/28/2019 2:22 p.m.
Compiler: Dieter Nill
Editor: –
Reviewers: Deborah Niggli, Alexandra Gavilano

Surcreusement des canaux d’alimentation en eau des lacs et des mares (French)

technologies_1635 - Mali

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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:

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SLM specialist:

Coulibaly Bakary Sékou

IFAD

Mali

SLM specialist:

Nadio Mamadou

National Coordinator for IFAD In- Country Programmes

Mali

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

Manual of Good Practices in Small Scale Irrigation in the Sahel (GIZ ) {'additional_translations': {}, 'value': 611, 'label': 'Name of the institution(s) which facilitated the documentation/ evaluation of the Technology (if relevant)', 'text': 'Deutsche Gesellschaft für Internationale Zusammenarbeit (GIZ) GmbH (GIZ) - Germany', 'template': 'raw'}

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?

2. Description of the SLM Technology

2.1 Short description of the Technology

Definition of the Technology:

The deepening of the channels has made it possible to control pond and lake recharge, optimise yields and crop growing, and increase the area under cultivation.

2.2 Detailed description of the Technology

Description:

The water for the lakes and ponds in the lakeland area (‘zone lacustre’) alongside the Niger River is supplied when the Niger is in spate by means of a system of natural channels. As the water height of the annual flood wave of the Niger has decreased, some lakes and ponds receive little water. The disadvantages of this natural system are: the loss of harvests due to the flooding of fields before the crops have time to mature, and the rapid retreat of waters that inhibits the capillary effect across large areas.
In relation to the building of control structures and the deepening of channels supplying water to ponds and lakes, the projects main objectives are to: restore water supplies to the lakes and ponds previously fed by the Niger River; regularise water supplies to the ponds and lakes; increase the area under cultivation; restart the growing of flood recession crops and other activities in the areas around ponds and lakes; restore the environment and biodiversity around ponds and lakes; raise the water table around the ponds and lakes.

The deepening of the channels has made it possible to recharge lake and pond basins. It is the reason why we are now seeing the resumption of farming, market gardening, animal husbandry and fishing around the lakes and ponds. By building control structures and large dykes it is possible to control pond and lake recharge, optimise yields and crop growing, and increase the area under cultivation. There is a diversification of production and incomes through the farming of small family units and market gardening plots in the lake and pond areas. The installation of bridge crossings with causeways running across marshlands have helped to open up the area and, as such, facilitate the transport of farm produce, the provisioning of local communities and the circulation of road traffic. The development of the dual road/ferry scheme (the Saraféré-Niafunké road and 40-tonne motor ferry) has revived an economic and human activity that was dying out due to extremely high levels of male outmigration, which left women running households and highly vulnerable.

The stages of initiating, planning and implementing works and installations are based on the studies (soil, topographical and socio-economic) carried out by a consultancy and private company recruited through a tender process to deliver the works according to a well-defined timetable. An oversight and control office undertakes the monitoring and control of works quality and the meeting of agreed deadlines.
In principle, works are carried out during low-water periods when most of the floodplains are dry. The swampy nature of the area makes any intervention in the rainy season impossible. Furthermore, the planning of activities must respect the constraints imposed by nature. The Dabi installation on Lake Takadji is a good example of the application of technical standards.
The application and modus operandi of this good practice involve the following: the water inlets for the lake and pond basins alongside the Niger River are reopened by deepening the feeder channels; the high waters of the Niger River feed the ponds and lakes; water supply is controlled using a cement structure fitted with gates to prevent: the water flow from reversing when the Niger’s water levels are low, water flowing into the ponds and lakes before harvesting is complete; flood gauges to measure annual high water levels.
Various actors are involved in delivering this practice. Their roles are as follows: Beneficiaries are not required to participate in works delivered by contractors (works involving large pond and lakes), but they take charge of the development of VIS plots with support from the World Food Programme (WFP) in the form of supplies. External support from the project/programme finances the installation of facilities, the pump units and the first season’s inputs. Consultancies undertake feasibility studies, produce project specifications and plans, and carry out the monitoring and oversight of works. Local authorities, as a general rule, are involved in the planning of activities or, alternatively, make provision for activities in the PDESC. They also handle the upkeep and maintenance of installations.

2.3 Photos of the Technology

Media Gallery

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

Country:

Mali

Region/ State/ Province:

Mali

Further specification of location:

Timbuktu Region; Niafunké, Diré and Goundam circles; communes of Soboundou, Soumpi, Tonka, Tindirma

Specify the spread of the Technology:

evenly spread over an area

If the Technology is evenly spread over an area, specify area covered (in km2):

332.0

Comments:

Total area covered by the SLM Technology is 332 km2.
In terms of the ponds and lakes, the following objectives were achieved:
Six large ponds were rehabilitated: Fati (13,000 hectares), Takadji (9,000 hectares) and Ganga (3,000 hectares), making a total of 25,000 hectares, Koboro (4,000 hectares), Kassoum-Soumpi (1,000 hectares), Billi I and Billi II (2,000 hectares), the Nounou-Diengo causeway on Lake Takadji (an additional 1,200 hectares), making a total of 8,200 hectares
Area involved: 33,200 hectares
Number of beneficiaries: 190,000 producers

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.):

This good practice has been used for around 20 years (since 1990) in IFAD projects in the ‘zone lacustre’ (lake zone).

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

Land use mixed within the same land unit:

Yes

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

Agro-pastoralism (incl. integrated crop-livestock)

Cropland

Annual cropping

Number of growing seasons per year:

Specify:

Longest growing period in days: 120, Longest growing period from month to month: August-November

Grazing land

Comments:

Major land use problems (compiler’s opinion): the loss of harvests due to the flooding of fields before the crops have time to mature, and the rapid retreat of waters that inhibits the capillary effect across large areas
Livestock density: 1-10 LU /km2

3.4 Water supply

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

mixed rainfed-irrigated

3.5 SLM group to which the Technology belongs

irrigation management (incl. water supply, drainage)
water diversion and drainage
surface water management (spring, river, lakes, sea)

3.6 SLM measures comprising the Technology

structural measures

S3: Graded ditches, channels, waterways

3.7 Main types of land degradation addressed by the Technology

water degradation

Ha: aridification
Hs: change in quantity of surface water
Hg: change in groundwater/aquifer level

Comments:

Main causes of degradation: over abstraction / excessive withdrawal of water (for irrigation, industry, etc.), change of seasonal rainfall

3.8 Prevention, reduction, or restoration of land degradation

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

restore/ rehabilitate severely degraded land

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

4.1 Technical drawing of the Technology

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Technical specifications (related to technical drawing):

Map of the ZLDP/NKE intervention area, phases I and II

Technical knowledge required for field staff / advisors: high
Technical knowledge required for land users: low
Main technical functions: increase of groundwater level / recharge of groundwater, water harvesting / increase water supply, recharge lake and pond basins
Secondary technical functions: control of dispersed runoff: retain / trap, increase / maintain water stored in soil

4.2 General information regarding the calculation of inputs and costs

other/ national currency (specify):

CFA Franc

If relevant, indicate exchange rate from USD to local currency (e.g. 1 USD = 79.9 Brazilian Real): 1 USD =:

517.0

4.3 Establishment activities

	Activity	Timing (season)
1.	the water inlets for the lake and pond basins alongside the Niger River are reopened by deepening the feeder channels
2.	the high waters of the Niger River feed the ponds and lakes
3.	water supply is controlled using a cement structure fitted with gates to prevent: the water flow from reversing when the Niger’s water levels are low, water flowing into the ponds and lakes before harvesting is complete; flood gauges to measure annual high water levels.

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
Other	total construction	ha	1.0	580.0	580.0	100.0
Total costs for establishment of the Technology					580.0
Total costs for establishment of the Technology in USD					1.12

4.5 Maintenance/ recurrent activities

	Activity	Timing/ frequency
1.	upkeep and maintenance of installations

4.7 Most important factors affecting the costs

Describe the most determinate factors affecting the costs:

The average cost of large ponds is around 300,000 CFA francs per hectare (580 Dollar per hectare). The VIS installation works were conducted using a participatory approach. The project contributed 780,106 CFA francs towards the VIS installation, or 65%, whereas the farmers’ contribution was 429,079 CFA francs per hectare, or 35%.

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

Agro-climatic zone

semi-arid

Thermal climate class: tropics

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.

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)
fine/ heavy (clay)

Topsoil organic matter:

medium (1-3%)
low (<1%)

5.4 Water availability and quality

Ground water table:

5-50 m

Availability of surface water:

medium

Water quality (untreated):

for agricultural use only (irrigation)

5.5 Biodiversity

Species diversity:

medium

5.6 Characteristics of land users applying the Technology

Market orientation of production system:

mixed (subsistence/ commercial)

Off-farm income:

10-50% of all income

Relative level of wealth:

poor
average

Level of mechanization:

manual work

Gender:

Indicate other relevant characteristics of the land users:

Population density: < 10 persons/km2
Annual population growth: 2% - 3%
10% of the land users are rich.
50% of the land users are average wealthy.
30% of the land users are poor.
10% of the land users are very poor.

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

Comments:

The irrigated land is allocated by the chief

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

risk of production failure

increased

decreased

product diversity

decreased

increased

production area

decreased

increased

Income and costs

farm income

decreased

increased

Other socio-economic impacts

development of new farming technologies

reduced

improved

facilitation of transport through the installation of bridges

reduced

improved

Socio-cultural impacts

food security/ self-sufficiency

reduced

improved

conflict mitigation

worsened

improved

contribution to human well-being

Comments/ specify:

Increases in agro-sylvo-pastoral production, increases in local people’s incomes and standard of living. Rice production on a quarter-hectare VIS can increase family income by around 80% compared to traditional means of production involving 1.5 hectares of floating rice grown on the river. The percentage of households that are vulnerable to food insecurity has dropped from 20.4% in 1997 to 5.8% in 2006.

Ecological impacts

Water cycle/ runoff

water quantity

decreased

increased

harvesting/ collection of water

reduced

improved

groundwater table/ aquifer

lowered

recharge

Soil

soil moisture

decreased

increased

Biodiversity: vegetation, animals

habitat diversity

decreased

increased

Other ecological impacts

recharge of lakes and ponds

reduced

increased

6.2 Off-site impacts the Technology has shown

water availability

decreased

increased

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

	Season	increase or decrease	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

	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)?

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:

very positive

Long-term returns:

very positive

6.5 Adoption of the Technology

Comments:

The VIS installation works were conducted using a participatory approach. The project contributed 780'106 CFA francs towards the VIS installation, or 65%, whereas the farmers’ contribution was 429'079 CFA francs per hectare, or 35%.
In terms of the ponds and lakes, the following objectives were achieved: Six large ponds were rehabilitated: Fati (13,000 hectares), Takadji (9,000 hectares) and Ganga (3,000 hectares), making a total of 25,000 hectares, Koboro (4,000 hectares), Kassoum-Soumpi (1,000 hectares), Billi I and Billi II (2,000 hectares), the Nounou-Diengo causeway on Lake Takadji (an additional 1,200 hectares), making a total of 8,200 hectares, Area involved: 33,200 hectares, Number of beneficiaries: 190,000 producers

6.7 Strengths/ advantages/ opportunities of the Technology

Strengths/ advantages/ opportunities in the land user’s view
creates a favourable environment – restoration of the environment and biodiversity around lakes and ponds, the raising of the water table around ponds and lakes, increases in agro-sylvo-pastoral production, increases in local people’s incomes and standard of living
diversification of production and incomes through the farming of small family units and market gardening plots in the lake and pond areas
plantations growing around 100,000 plants have been developed over the lifetime of the project.
rice production on a quarter-hectare VIS can increase family income by around 80% compared to traditional means of production involving 1.5 hectares of floating rice grown on the river.
Management councils for each lake are established. User agreements are drawn up to regulate the management of the scheme (lake or pond) and local authorities are tasked with maintenance.

Strengths/ advantages/ opportunities in the compiler’s or other key resource person’s view
The installation of water control schemes has led to increases in the size of areas under cultivation. In Lake Takadji’s case, the installation of a second facility opened up a further 1,200 hectares of land for farming. The number of farmers working the lakeland areas has risen from 6.8% in 1998 to 18.5% in 2006, which is due to the growth in land area developed under the scheme and the high concentrations of people living in these areas. This underlying trend in production systems translates as increased agricultural productivity on the ground: per-hectare productivity has grown by 3.8 tonnes over the last eight years in areas using the irrigation and flood recession systems.
Research carried out with the support of the project team has enabled the development of new farming technologies that have subsequently been provided to households (cropping patterns, improved crop varieties), thereby increasing yields and production.
the installation of bridge crossings with causeways running across marshlands have helped to open up the area and facilitate the transport of farm produce, the provisioning of local communities and the circulation of road traffic
the percentage of households that are vulnerable to food insecurity has dropped from 20.4% in 1997 to 5.8% in 2006. The food security index has risen by 2.6 on a 25-point scale for all the households with access to the irrigation schemes.
migration dropped by 30% between 2001 and 2006.

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

Weaknesses/ disadvantages/ risks in the compiler’s or other key resource person’s view	How can they be overcome?
Difficulties arising from the natural water supply system are: a) loss of harvests due to the flooding of fields before crops have matured, and rapid retreat of waters that inhibits the capillary effect across large areas; b) upkeep and maintenance of facilities

7. References and links

Links and modules

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