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)

CARITAS (Switzerland) - Switzerland

1.3 Conditions regarding the use of data documented through WOCAT

When were the data compiled (in the field)?

21/09/2016

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 has instead addressed the perennial water shortage among the beneficiary households

1.5 Reference to Questionnaire(s) on SLM Approaches

2.1 Short description of the Technology

Definition of the Technology:

A rock catchment system is a water harvesting structure comprising a bare slopping rock surface (catchment area), a built concrete wall at a strategic point (weir), pipeline from the weir to the storage tank(s), storage tanks and water kiosk(s) connected to the water tanks by pipelines.

2.2 Detailed description of the Technology

Description:

A rock catchment system is a water harvesting structure comprising a bare slopping rock surface (catchment area), a built concrete wall at a strategic point (weir); a pipeline system running from the weir to the storage tanks; storage tanks and water kiosk(s). The Technology is built on an a gently sloping outcrop of a continuous rock on the hillside. The bare rock is the catchment surface from which rainwater is harvested. The weir is constructed at a strategic point for maximum collection at the lower end towards the foot of the hill. The weir dams the harvested water and channels the water through a piping system to the reservoirs, mostly masonry tanks, located at the foot of the hill. A weir is usually a concrete wall constructed and reinforced with iron bars to give it adequate strength that can withstand the weight of the dammed water. The length, height and thickness of a weir vary with the size and the slope of the rock catchment area. On average a weir will be 10 meters long, 2 meters high and 0.5 meters thick. At the base of the weir, an infiltration box of approximately 1 square meter is constructed and filled from the bottom with fine sand, coarse sand and gravel in that order for the purpose of sieving off impurities before the water is directed into the tanks. Metallic piping is recommended for connecting the weir to the storage tanks downhill due to high pressure exerted by flowing water. The piping distance would range from 15 to 300 meters from the weir to the storage tanks. Provision is usually provided for additional pipelines in case there is need for expansion of the system. At the bottom of the hill, masonry tanks are constructed ranging from 100 cubic meters and above depending on the catchment area, population, and available resources. The pipes join the tanks through a control chamber box meant for regulating water flow into the tanks. Adjacent to the tanks are a water kiosks room, where the community draws water. To gauge how much water is issued, a water meter is fitted inside the kiosk. Metering the water is a structural measure for accountability and control.

Construction of a rock catchment system needs heavy investment of materials - cement, quarry stones, ballast, iron bars, sand, hard-core stones, water, metallic (GI) pipes and fittings for plumbing. Construction of the system is labour intensive for both skilled and non-skilled. The main purpose of the rock catchment system is to harness, harvest, and store rainwater for domestic and a limited number of livestock use. For the case of the documented project, the benefiting communities are pastoralists who live in northern Kenya, a region characterised by chronic droughts, seasonal floods and acute water shortages.The communities have chronic and seasonal acute water shortages. The water situation is aggravated by increasing drought frequency and severity. On the other hand, the little rain received has often been destructive downstream, usually cutting off roads and causing massive soil erosion due to high water velocity flowing downhill. During the dry periods when the open water sources such as earth pans dry up, women travel long distances to search for water from hand dug shallow wells along the dry seasonal riverbeds. These wells are hazards to both livestock and the locals.

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:

2015

2.7 Introduction of the Technology

Specify how the Technology was introduced:

• through projects/ external interventions

Comments (type of project, etc.):

The technology was introduced after technical assessments which looked at areas that had rock catchment potential with willing communities to participate in their construction

3.1 Main purpose(s) of the Technology

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

• The common hazard in the region where the Technology has been implemented is drought. The Technology aims at reducing the drought impacts among the pastoralists

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

Comments:

The pastoralists practice sedentary to semi-nomadism way of living. However, even for those who are sedentary, they do not cultivate land. They entirely rely on livestock and relief assistance.

3.3 Further information about land use

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

• rainfed

Specify:

Do not apply as the communities to not grow crops. However, there is a bi-modal rainfall season with more rains received between October to December.

Livestock density (if relevant):

The livestock owners constantly move with their livestock from one location to another.

3.4 SLM group to which the Technology belongs

• pastoralism and grazing land management
• cross-slope measure
• water harvesting

3.5 Spread of the Technology

Specify the spread of the Technology:

• applied at specific points/ concentrated on a small area

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

4.1 Technical drawing of the Technology

4.2 Technical specifications/ explanations of technical drawing

A Rock catchment consists of the following main components:
Catchment area - vary between more or less than 100 square meters
Infiltration box - concrete box with approximately one square meter and 0.5 meters deep
Weir - a wall approximately 20 meters length, approx. 0.3-0.5 meters width, and 1.5 meters height; depending on the site the catchment can store between 150 and 700 cubic meter above the weir
Pipes - Galvanised steel pipes of varying diameters and length depending on catchment size and storage location and capacity
Tanks - tanks with varying capacities, of the same order of magnitude as the catchment storage capacity above the weir. Together, tanks and catchment can store some 10-20% of the annual precipitation falling over the rock catchment, which is enough to sustain water use during a normal year, but not during a year of exceptional water scarcity.

Here is a link where you can see a sketch of typical rock catchment: http://www.climatetechwiki.org/sites/climatetechwiki.org/files/images/extra/media_image_3_22.png

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.	Surveys - topographical, environmental impact assessment	Other measures	no specific time
2.	Drawings and bill of quantities	Other measures	no specific time
3.	Procurement of materials	Management	advisable should be done during the dry season when roads are passable without difficuities
4.	Recruitment of artisans	Management	no specific time
5.	Start of construction works	Structural	no specific time
6.	Continuous technical supervision and completion	Structural	Continuous throughout the year

Comments:

The key activities are not generally affected by the seasonality or any other type of timing with exception of procurement, for which it is advisable to do it when roads are passable.

4.5 Costs and inputs needed for establishment

If possible, break down the costs of establishment according to the following table, specifying inputs and costs per input. If you are unable to break down the costs, give an estimation of the total costs of establishing the Technology:

1.0

	Specify input	Unit	Quantity	Costs per Unit	Total costs per input	% of costs borne by land users
Labour	Skilled labour	Days	607.7	15.0	9115.5
Labour	Unskilled labour	Days	1973.0	3.0	5919.0	40.0
Construction material	Construction materials for all the four components together	1 catchment system	1.0	75407.0	75407.0
Total costs for establishment of the Technology					90441.5

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

Caritas Switzerland

Comments:

The project was implemented with funding support from Caritas Switzerland to assist the community recover from the 2011 devastating drought experienced in Kenya and the entire Horn of Africa

4.6 Maintenance/ recurrent activities

	Activity	Type of measure	Timing/ frequency
1.	Periodic washing of tanks and scooping out of sand and silt at the weir	Structural	Twice a year
2.	Repairs of broken parts - valves, pipes, taps etc..	Structural	Through the year

Comments:

Rock catchment systems generally have minimal maintenance and repairs

4.7 Costs and inputs needed for maintenance/ recurrent activities (per year)

If possible, break down the costs of maintenance according to the following table, specifying inputs and costs per input. If you are unable to break down the costs, give an estimation of the total costs of maintaining the Technology:

1.0

	Specify input	Unit	Quantity	Costs per Unit	Total costs per input	% of costs borne by land users
Other	Seasonal scooping of sand and silt from the weir	seasons/year	2.0	100.0	200.0	100.0
Other	Broken parts and repairs	lumpsum	1.0	300.0	300.0
Total costs for maintenance of the Technology					500.0

4.8 Most important factors affecting the costs

Describe the most determinate factors affecting the costs:

1. Availability of parts, whether they can be bought locally or from far
2. Quality of parts
3. Extent of the system exposed to vandalism and/or destructive weather events
4. Early detection of broken/spoilt parts

5.1 Climate

5.2 Topography

Indicate if the Technology is specifically applied in:

• not relevant

Comments and further specifications on topography:

The Technology applies where there is adequate gradient of a rock surface.

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.

The technology is implemented on a rock surface.

5.4 Water availability and quality

Is water salinity a problem?

Yes

Specify:

The community currently benefiting from the rock catchment have reported health problems (kidney stones) due to use of salty borehole water. The water is saline.

Is flooding of the area occurring?

Yes

Comments and further specifications on water quality and quantity:

The borehole which has been the main source of water is strongly saline and the community only use it when they can no longer find water from nearest (approximately 5 kilometres away) shallow wells. In addition, the borehole is run by diesel generator attracting high operations and maintenance costs. Earlier, breakdowns would necessitate water relief from NGOs and the government.

5.5 Biodiversity

Comments and further specifications on biodiversity:

The area is covered with arid and semi arid type of vegetation mostly characterised by acacia trees and other thorny shrubs. There is limited variety of wild animals, insects and birds. This could be due to harsh climatic conditions.

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:

• communal/ village

Land use rights:

• open access (unorganized)
• communal (organized)

Water use rights:

• open access (unorganized)
• communal (organized)

5.9 Access to services and infrastructure

6.1 On-site impacts the Technology has shown

Socio-economic impacts

Water availability and quality

Income and costs

Other socio-economic impacts

Socio-cultural impacts

Ecological impacts

Water cycle/ runoff

Soil

Climate and disaster risk reduction

6.2 Off-site impacts the Technology has shown

Comments regarding impact assessment:

Some aspects of information are difficult to establish and could be best evaluated by a household survey.

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?
seasonal temperature	dry season	increase	very well
annual rainfall		decrease	moderately
seasonal rainfall	dry season	increase	very well

Climate-related extremes (disasters)

Meteorological disasters

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

Climatological disasters

	How does the Technology cope with it?
drought	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 benefits are instantaneous as soon as the structure is completed and especially if it is during a rainy season. The technology has minimum to near zero maintenance costs which remains relatively the same in the long term. The main tasks for maintenance is seasonal removal of silt at the weir and the washing of the tanks.

6.5 Adoption of the Technology

• more than 50%

If available, quantify (no. of households and/ or area covered):

This is a one Technology which is benefiting the entire community. At the time of project implementation the estimated total population was 1000 people.

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:

N/A

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
1. Relatively low cost of operation and maintenance. 2. The technology does not require specialised technical skills for the day to day operations

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?
1. Relatively high initial investment cost that is unlikely to be raised by communities themselves. Without external financial support it is therefore unlikely that the system can be expanded when water needs increase.	1. A long term plan that includes savings from fees from water sales. 2. Funds could also potentially be acquired from the county government or NGOs

7.1 Methods/ sources of information

7.2 References to available publications

Title, author, year, ISBN:

A Handbook of gravity-flow water systems for small communities; Thomas D. Jordan Junior; 1980; 978 0 94668 850 0

Available from where? Costs?

CACH office library, Nairobi

7.3 Links to relevant information which is available online

Title/ description:

Rock Catchments for Community Water Supply in Eastern Equatoria State, South Sudan

URL:

http://waterconsortium.ch/wp-content/uploads/2016/09/Poster_Rock_Catchments_Caritas_South_Sudan_2016.pdf

Title/ description:

Adopting locally appropriate WASH solutions: a case study of rock catchment systems in South Sudan

URL:

http://wedc.lboro.ac.uk/resources/conference/37/Leclert-1935.pdf