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)

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)

HELVETAS (Swiss Intercooperation)

1.3 Conditions regarding the use of data documented through WOCAT

When were the data compiled (in the field)?

31/12/2015

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 technology promoted sunstainable water conservation. It is cost effective and requires no external energy supply as it is based on gravity flow.

1.5 Reference to Questionnaire(s) on SLM Approaches

2.1 Short description of the Technology

Definition of the Technology:

The purpose of this water harvesting technology is to capture, collect and distribute sub-surface water. First, an infiltration gallery is developed, which allows the percolation and collection of sub-surface water through perforated pipes at a depth of approximately 3-4.5 metres. Sub-surface water is filtered by gravel/sand underground and infiltrates into the gallery. The harvested water is used for household needs as well as for livestock and irrigation through gravity flow.

2.2 Detailed description of the Technology

Description:

This method is applied in areas with low rainfall, where soils have a sandy-gravelly texture and where the sub-surface water can not percolate deeply, but instead flows laterally in shallow sub-surface channels. The technology consists of the following main elements: filtration materials (sand / gravel), collection chambers, perforated pipes, conveyance lines made from solid blocks, and storage tanks. Construction includes the following main activities and inputs:
• Excavation of rectangular trenches with machinery or by hand
• Construction of a solid base line with PCC (plain cement concrete) blocks on the top of
boulders
• Installation of perforated and blind pipes - and storage tanks where necessary
• Coverage of the trench first with boulders and then sand on top.
Once the gallery is constructed there is no further need for intervention; this means that maintenance costs for the user (farmer, households of the local community) are minimal. Traditionally, the technology has been implemented by local farmers for many years. Where improvements are required, support by local technicians is provided. The technology is based on local knowledge, and locally available construction materials. The method is technically simple, cost-effective and environmentally friendly. Farmers and other users consider this technology as very efficient as there is no need for external energy supply, and it can be easily replicated. Furthermore, it requires a minimum of external construction material and the operation costs are minimal. The captured water is filtered through the subsurface layers and - as long as there is no specific external contamination - it is safe and can be used for various purposes as already noted. This extra water supply is particularly effective for irrigation, contributing to increased production and allowing diversification of crop production (potentially also of high value crops), thereby improving the livelihoods of remote rural communities. The primary impact of this technology is to reduce risks related to droughts or water scarcity as natural phenomena or consequences of climate change effects. Additionally infiltration of water into the galleries reduces surface erosion of fertile soil, hence it lessens soil degradation.

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

Indicate year of implementation:

2013

2.7 Introduction of the Technology

Specify how the Technology was introduced:

• as part of a traditional system (> 50 years)

Comments (type of project, etc.):

Water for Livelihoods Project (rural development project)

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
• reduce risk of disasters
• adapt to climate change/ extremes and its impacts
• create beneficial economic impact
• create beneficial social impact

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

Comments:

As a result of the introdued technology, farmers can now produce multiple crops and have increased the cropping efficiency.

If land use has changed due to the implementation of the Technology, indicate land use before implementation of the Technology:

Prior to the establishment of the infiltration gallery, cropland was mainly rain-fed and only a single crop was produced with 50 % cropping efficiency.
The cropping efficiency increased up to 150 % (growing 3 crops instead of 1 crop in a year.

3.3 Further information about land use

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

• rainfed

Comments:

- The technology is simple and not costly to establish.
- It further contributes to adapt to climate change, especially in areas where water becomes increasingly scarce.

Number of growing seasons per year:

• 2

Specify:

Rabi (October to March) & Kharif (April to September) season

3.4 SLM group to which the Technology belongs

• water harvesting
• irrigation management (incl. water supply, drainage)
• ground water management

3.5 Spread of the Technology

Specify the spread of the Technology:

• applied at specific points/ concentrated on a small area

Comments:

This technology is suitable for area with little slope to retain a maximum amount of water. when the stream bed has a higher gravel content, it provides more water. The technology is suitable for strata with no/ low vertical percolation, such as underlying hard rocks.

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:

• reduce land degradation
• adapt to land degradation

Comments:

Further the technology contributes to reduce risks and losses linked to droughts as natural hazard and/or the effect of climate change.

4.1 Technical drawing of the Technology

4.2 Technical specifications/ explanations of technical drawing

Dimensions of the cross section:
- Depth: 10 to 15 feet, width: 6 to 8 feet, length: 300 to 1000 feet
- Slope: 3% on 200 feet
- Volume of storage tank: 30 x 30 x 4 feet

4.3 General information regarding the calculation of inputs and costs

Specify how costs and inputs were calculated:

• per Technology unit

Specify currency used for cost calculations:

• US Dollars

4.4 Establishment activities

	Activity	Type of measure	Timing
1.	Excavation	Structural	2 weeks
2.	Dry stone packing	Structural	1 week
3.	Laying of PCC block (plain cement concrete)	Structural	2-3 days
4.	Installation & fixing of perforated pipes (6" diameter)	Structural	2-3 days
5.	Establishement of filtration media (boulder, gravel, sand packing)at gallery's end point/ water user's access point (if required) material: concrete	Structural	2 weeks
6.	Construction of water collecting chamber	Structural	1 week
7.	Convayance line (3" diameter)	Structural	3 weeks
8.	construction of storage tank (if required)	Structural	4 weeks as parallel activity

Comments:

Totally, it takes 3 months to complete the construction of the infiltration gallery unit (600 feet) including the conveyance line and storage tank. Some of the activities can be carried out in parallel.

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	Skilled Labour	Days	109.0	12.0	1308.0
Labour	Un-Skilled Labour	Days	465.0	6.0	2790.0	100.0
Equipment	Machinary (Excavator)	Hour	118.0	25.0	2950.0
Construction material	Bricks (Number)	1000	12.5	95.0	1187.5
Construction material	PCC blocks, rough stone (cubic foot)	100	44.5	50.0	2225.0
Construction material	Cement (50 kg bags)	50	275.0	5.0	1375.0
Construction material	sand, crush, boulder, gravel (cubic foot)	100	63.0	35.0	2205.0
Other	PVC pipe perforated (6" diameter filter section class D) (ft)	1	590.0	5.0	2950.0
Other	PVC blind pipe (3" diameter class B) (ft)	1	3600.0	1.0	3600.0
Total costs for establishment of the Technology					20590.5

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

Project / Government partner - i.e. on Farm Water Management department & public Health engineering Department, shared the cost at the ratio of 80 % : 20 %.

Comments:

Total cost of the technology is basically proportional to the length of gallery and futher dependson the size of the storage tank.

4.6 Maintenance/ recurrent activities

Comments:

This technology is based on a single cost investment. Except minor repairs of storage tank, there are no relevant maintanance costs.
The filter function of the boulder layer and the perforated pipes reduce sedimentation problems. Minor amounts of silt and fine sediments in the storage tank can be removed with minor effort by the user (unskilled labo no tools required),

4.8 Most important factors affecting the costs

Describe the most determinate factors affecting the costs:

- Length of the infiltration gallery
- Length of the conveyance line
- Size of storage tank (not alway included)

5.1 Climate

5.2 Topography

Indicate if the Technology is specifically applied in:

• not relevant

5.3 Soils

5.4 Water availability and quality

Is water salinity a problem?

No

Is flooding of the area occurring?

Yes

Comments and further specifications on water quality and quantity:

Due to floods in monsoon season, the discharge capacity increases.

5.5 Biodiversity

5.6 Characteristics of land users applying the Technology

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:

• communal (organized)
• individual

Water use rights:

• communal (organized)
• 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

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 rainfall		increase	well
seasonal rainfall	summer	increase	well

Climate-related extremes (disasters)

Climatological disasters

	How does the Technology cope with it?
drought	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

• 1-10%

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

• 10-50%

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.):

Design of infiltration galleries (diameter of pipes, size of perforation, slope etc.) was adjusted to local conditions including the consideration of local rainfall / amount of water.

6.7 Strengths/ advantages/ opportunities of the Technology

Strengths/ advantages/ opportunities in the land user’s view
Low cost measure, which requires only a one-time investment, low/no repair or maintenance costs are required.
Well assimilated and replicated by local farmers of the area since it is a simple and traditional technology.
No requirement of external energy (no pumping).
Allows harvest of sub-surface water for different purposes (domestic use, irrigation, livestock).
Environmentally friendly, making use as much as possible of local construction material (gravel, sand).

Strengths/ advantages/ opportunities in the compiler’s or other key resource person’s view
The technology can be replicated in areas of similar conditions, as well as up-scaled with little efforts in other areas with a similar environment.

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?
If the land, where the sub-surface water is harvested is communal property, the distribution of water rights may be an issue.	Involvement of farmer organizations, distribution of water rights based on land holdings have to according check water rights.

Weaknesses/ disadvantages/ risks in the compiler’s or other key resource person’s view	How can they be overcome?
Filtration media might clogge in the long run in case silt content is high.	Filtration media should be prepared with graded materials (sand, gravel, boulder).
Considering the initial investment cost, the measure cannot be done by an individual alone.	It requires an organized (group of) community. Though this pre-condition can also be interpreted as a strength for a coordinated and efficient use of water.

7.1 Methods/ sources of information