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)

Southern African Science Service Centre for climate change and Adaptive Land management (SASSCAL)

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

Namibia University of Science and Technology ( NUST) - Namibia

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

German Federal Ministry of Education and Research (BMBF) - Germany

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

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

2.1 Short description of the Technology

Definition of the Technology:

Construction of contour ditches and ponding banks/ bunds to trap rainwater for infiltration. Improved growth of plants and replenishment of groundwater is promoted, while safely discharging excess water to avoid erosion. Integrated with other technologies that treat the root causes of rangeland degradation - rather than a stand-alone technology.

2.2 Detailed description of the Technology

Description:

The technology can be applied in rangeland: (a) where rainfall runoff occurs, (b) where the soil is deep enough to dig contour ditches and construct ponding banks, (c) where there is a low slope over a wide enough area for safe discharge of overflow during intense rain, (d) where valuable plants can benefit from the extra infiltrated rainwater, (e) where the costs of earthmoving can be rapidly recovered through sale of extra production and, very importantly, (f) where the root causes of rangeland degradation have been addressed, usually through management of grazing and fires.
In the appropriate area, contour lines are marked out by laser or dumpy level - or mapped by drone. Where bush is dense, it may be necessary to clear narrow contour strips, leaving larger trees in place. Ditches are dug up to 50cm deep by mechanised grader or backhoe (a digger attached to a tractor), or manually by pick and spade. The soil should first ideally be ripped where the bund is formed, to ensure a firm foundation. To stabilise the bund, it should be compacted, and creeping (stoloniferous) herbaceous plants encouraged to colonise it. When ditches are full, water is discharged through spillways within the bund. These spillways are formed by lowering the bund to about half its height (i.e. 25 cm) for a distance of 10 metres. Water overtops the spillways and flows across the soil surface to the next bund in the sequence. Spillways are set near alternating ends of shorter ditches for water to zigzag its way down through the landscape, but along longer ditches the spillways are set approximately 200 metres apart. There are other configurations, including one where excess runoff flows around the end of the bund and along another channel constructed immediately below the bund. It can then spill out of this channel, evenly over the soil surface below. Where bunds meet roads or tracks, a hump is made in the road to prevent water crossing and causing damage but instead channelling the road runoff into contour ditches.
Since the channel is never exactly on the contour, water starts to flow over the lowest section. This results in self-reinforcement over time because herbaceous plants establish more densely at that point, resulting in more sediment being trapped there. To avoid spillage around each end of the ditch, the bund is shaped to form a short upslope wingwall. Organic material can be placed in the ditch, or in larger sediment traps within the ditch, to improve nutrient cycling.
Infiltration ditches were constructed at vertical intervals of 0.5 m on a 30 ha, densely bushed portion of the Middleplaats farm. Trees were planted below the ditches to grow into a “fruitful landscape”. Species included broad canopy trees such as Faidherbia albida and Acacia erioloba, shorter thornless trees for “chop and drop” mulching, such as Peltophorum africanum and Bolusanthus speciosus, and fruit bearing trees, such as Sclerocarya birrea and Berchemia discolor, or trees with edible leaves, such as Moringa oleifera. Tree seedlings were raised in a nursery. Fencing around the 30ha had to be strengthened to protect the seedlings from oryx. It was also necessary to water the seedlings for one to two years until well established. Ponded water encourages natural growth of herbaceous plants, and to encourage this some grasses were transplanted there.

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:

2014

2.7 Introduction of the Technology

Specify how the Technology was introduced:

• through projects/ external interventions

Comments (type of project, etc.):

Projects involving students

3.1 Main purpose(s) of the Technology

• improve production
• reduce, prevent, restore land degradation
• preserve/ improve biodiversity
• create beneficial economic impact

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

Comments:

Main animal species and products: Beef cattle and game animals

Number of growing seasons per year: 1
Livestock density: 10ha/LSU averaged out over time and not continuous

3.4 Water supply

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

• rainfed

Comments:

Except for Initial watering of planted tree seedlings, which was necessitated by drought

3.5 SLM group to which the Technology belongs

• agroforestry
• pastoralism and grazing land management
• water harvesting

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
• restore/ rehabilitate severely degraded land

4.1 Technical drawing of the Technology

4.2 General information regarding the calculation of inputs and costs

Specify how costs and inputs were calculated:

• per Technology area

other/ national currency (specify):

NAD

4.3 Establishment activities

	Activity	Timing (season)
1.	Marking of contour lines	Dry season
2.	Clearing of bush strips along contour	Dry season
3.	Ripping along contour	Dry season
4.	Digging ditch and heaping bund over ripline	Start of rains
5.	Raising tree seedlings in nursery	Mostly dry season
6.	Planting tree seedlings below ditches	Rainy season
7.	Watering tree seedlings	Dry season
8.	Strengthening fence around landscape to exclude oryx	When needed

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	Marking of contour lines	Person days	6.0	72.0	432.0	100.0
Labour	Raising tree seedlings in nursery	Person days	20.0	72.0	1440.0	100.0
Labour	Planting tree seedlings below ditches	Person days	10.0	72.0	720.0	100.0
Labour	Watering every 10 days in first year, except after rain	Person days	150.0	72.0	10800.0	100.0
Equipment	Strengthening fence to exclude oryx (Labour)	Person days	100.0	72.0	7200.0	100.0
Equipment	Bulldozer to clear strips and rip	Bulldozer hours	89.0	850.0	75650.0	100.0
Equipment	Grader to dig ditches and heap bunds	Grader hours	35.0	650.0	22750.0	100.0
Equipment	Diesel for bulldozer and grader	Litres	1000.0	12.0	12000.0	100.0
Equipment	Tractor & 7000 lt water trailer every 10 days in first year, except after rain	Tractor days	30.0	1250.0	37500.0	100.0
Plant material	500 Plastic bags / seeds with soil to raise seedllngs	Filled growing bags	500.0	4.0	2000.0	100.0
Construction material	Fencing wire and posts to strengthen fence around fruitful landscape	km of fencing	3.0	2200.0	6600.0	100.0
Total costs for establishment of the Technology					177092.0
Total costs for establishment of the Technology in USD					177092.0

4.5 Maintenance/ recurrent activities

	Activity	Timing/ frequency
1.	Maintenance of ditches and bunds by grader	Rainy 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
Equipment	Grader cost to maintain the swales every 3 – 4 years	Grader hours	8.0	700.0	5600.0	100.0
Total costs for maintenance of the Technology					5600.0
Total costs for maintenance of the Technology in USD					5600.0

4.7 Most important factors affecting the costs

Describe the most determinate factors affecting the costs:

High cost of hiring or operating earthmoving machinery.

5.1 Climate

5.2 Topography

Indicate if the Technology is specifically applied in:

• not relevant

Comments and further specifications on topography:

Scattered rocky outcrops

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.

A calcrete layer is occasionally exposed at the soil surfacce

5.4 Water availability and quality

Is water salinity a problem?

Yes

Specify:

The water is only slightly brackish

Is flooding of the area occurring?

No

5.5 Biodiversity

5.6 Characteristics of land users applying the Technology

5.7 Average area of land used 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

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	increase or decrease	How does the Technology cope with it?
other gradual climate change	Increased variability in temperature and rainfall	increase	well

Climate-related extremes (disasters)

Meteorological disasters

	How does the Technology cope with it?
local rainstorm	well
local thunderstorm	well

Climatological disasters

	How does the Technology cope with it?
heatwave	well
cold wave	well
drought	well
land fire	moderately

Hydrological disasters

	How does the Technology cope with it?
flash flood	well

Biological disasters

	How does the Technology cope with it?
insect/ worm infestation	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)?

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?

• 0-10%

6.6 Adaptation

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

Yes

If yes, indicate to which changing conditions it was adapted:

• climatic change/ extremes

Specify adaptation of the Technology (design, material/ species, etc.):

After initial death of tree seedlings from extreme drought, the decision was taken to irrigate them until sufficiently well established.

6.7 Strengths/ advantages/ opportunities of the Technology

Strengths/ advantages/ opportunities in the land user’s view
Avoids wastage of rainwater lost as runoff from the farm and puts it to good use on the farm.

Strengths/ advantages/ opportunities in the compiler’s or other key resource person’s view
Improved water and nutrient cycling, resulting in better plant growth and higher animal production.
Reduced erosion of soil.

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?
Death of many tree seedlings	By irrigating tree seedlings until they are sufficiently well established which may take one or two years.

Weaknesses/ disadvantages/ risks in the compiler’s or other key resource person’s view	How can they be overcome?
High cost of earthmoving	Growing of high value plants to recoup costs as quickly as possible, such as Moringa and dates.

7.1 Methods/ sources of information

7.2 References to available publications

Title, author, year, ISBN:

Rainwater harvesting for drylands and beyond: Vol 2 – Water-harvesting earthworks, Lancaster, 0-977-246418

Available from where? Costs?

https://www.amazon.com/Rainwater-Harvesting-Drylands-Beyond-Vol/dp/0977246418 $28

7.3 Links to relevant online information

Title/ description:

Planning and managing farm roads Manual

URL:

www.sasscal.org/downloads/Planning_and_managing_farm_roads_in_Namibia.pdf

Title/ description:

Rangeland Rehydration Field Guide

URL:

https://emulandrecovery.org.au/~emulandr/files/Rangeland-Rehydration-Field-Guide.pdf