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)

Preventing and Remediating degradation of soils in Europe through Land Care (EU-RECARE )

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

Technical University of Crete (Technical University of Crete) - Greece

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?

Nee

2.1 Short description of the Technology

Definition of the Technology:

Rain water harvesting from greenhouses roofs.

2.2 Detailed description of the Technology

Description:

The roof of a greenhouse is used as catchment area for rainwater harvesting. A system of gutters is installed to channel water into a storage facility that can be either above ground or at ground level, open or covered. The water harvested from the roofs is used for irrigation purposes, either on its own or mixed with other sources.

In central and eastern Crete, a negative water balance emerges due to agricultural exploitation and lack of sustainable water resources management. Regarding water availability, it is notable that the spatial and temporal variability of precipitation are the limiting factors, rather than overall precipitation quantity. Especially in coastal areas where the main source of irrigation is groundwater, seawater intrusion often takes place, and eventually leading to irrigation with saline water. In the intensive agriculture and water stress conditions existing in greenhouses this situation can progressively lead to soil salinisation with subsequent adverse effects on production. The technology promotes sustainable land management through prevention and mitigation of land degradation by increasing water resources self-sufficiency thus allowing the user to rely less on the scarce groundwater resources and reduce the risk of production failure. Furthermore, the technology improves the overall irrigation water quality. The main disadvantage of the technology is the increase of agricultural inputs (fertilizers) because of the lack of minerals necessary for the crops (especially tomatoes) in the rainwater. This disadvantage can be mitigated by mixing rainwater with other sources.

The majority of the greenhouses in the region normally have built-in gutters between the basic construction units in order to discharge rainwater from the roof for structural safety. Thus, initially little structural measures are required including the implementation of some further gutters that channel rainwater in the storage system and preparation of the area for the tank installation. Overland tanks may consist of galvanized steel or similar material. Ground level storage usually requires earth removal. In both case, the installation of the relevant waterproofing material is required to avoid leaks. A cover may also be installed to reduce evaporation. Here we assess the use of a harvesting system comprising of (a) an above ground circular tank made out of galvanized steel with total volume of 320 m3 and (b) a gutter network spreading on the roof of a 0.7 ha greenhouse. Furthermore, a water filter and water treatment may be required for removal of particles and waterborne disease mitigation. Finally, a suitable pump and mixing facilities are installed to control water quality and quantity.

The average annual precipitation in the area is 500 mm and the climate ranges between sub-humid Mediterranean and semi-arid. Average annual temperature is 18.5 °C with 6 months below 18 °C but above 5 °C, thus classifying the area as subtropical. In the location where the technology is applied, land is mostly privately owned and water rights can be public, cooperative or private. Although the financial means of the land user who applies this technology are more or less on par with those of the rest of the community, he has a wider empirical education and relatively higher social status acquired thought his involvement with the commons and the water resources management of the region.

This Technology was documented within the scope of FP7 RECARE Project, funded grant agreement no 603498.

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

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.):

The land user has implemented the water harvesting technology in order to be subsidized from an agri-environmental scheme under the CAP.

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

Comments:

Major land use problems (compiler’s opinion): The main problem in the region is the change in the groundwater quality, caused by groundwater over-exploitation and the subsequent seawater intrusion, resulting in soil salinisation through irrigation.
Major land use problems (land users’ perception): The limited availability of good quality (non-saline) water for irrigation resulting in increased production risk and agricultural inputs.

3.4 Water supply

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

• full irrigation

3.5 SLM group to which the Technology belongs

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

3.6 SLM measures comprising the Technology

Comments:

Main measures: structural measures
Specification of other structural measures: Greenhouse roof gutter network

3.7 Main types of land degradation addressed by the Technology

Comments:

Main type of degradation addressed: Cs: salinisation / alkalinisation, Hg: change in groundwater / aquifer level
Secondary types of degradation addressed: Bq: quantity / biomass decline
Main causes of degradation: over abstraction / excessive withdrawal of water (for irrigation, industry, etc.) (Overpumping.), other human induced causes (specify) (Irrigation with brackish water.), droughts (Lack of sustainable water resources.), inputs and infrastructure: (roads, markets, distribution of water points, other, …) (Poor coverage of freshwater irrigation network.)
Secondary causes of degradation: soil management (Intensive cultivation), disturbance of water cycle (infiltration / runoff) (Covering of land with green houses decreases leaching.)

3.8 Prevention, reduction, or restoration of land degradation

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

• prevent land degradation
• reduce land degradation

4.1 Technical drawing of the Technology

4.2 General information regarding the calculation of inputs and costs

other/ national currency (specify):

Euro

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

0.93

4.3 Establishment activities

	Activity	Timing (season)
1.	Construction of the tank base (including material transportation)
2.	Tank construction (including material transportation)
3.	Installation of the plastic gutters
4.	Pump and cleaning filter

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	Labour		1.0	858.0	858.0	60.0
Equipment	pump		1.0	536.0	536.0	60.0
Equipment	cleaning filter		1.0	536.0	536.0	60.0
Construction material	galvanized steel		1.0	3379.0	3379.0	60.0
Construction material	waterproof membrane		1.0	2360.0	2360.0	60.0
Construction material	sand		1.0	675.0	675.0	60.0
Construction material	concrete		1.0	290.0	290.0	60.0
Other	gutters		1.0	2252.0	2252.0	60.0
Total costs for establishment of the Technology					10886.0
Total costs for establishment of the Technology in USD					11705.38

Comments:

Duration of establishment phase: 0.5 month(s)

4.5 Maintenance/ recurrent activities

	Activity	Timing/ frequency
1.	Maintenance costs are negligible, e.g. filters are cleaned with water when needed. Fuel can't be accurately estimated as it depends on the machine hours that the pump works to irrigate. Two considerations: 1.Practically, the pump would have to work regardless of the water harvesting system. 2.The water harvesting system is irrelevant of the pumping scheme.

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

Comments:

The cost described are calculated in current prices for the whole construction.

4.7 Most important factors affecting the costs

Describe the most determinate factors affecting the costs:

The greater deterrent against implementing the technology is the high cost of the tank construction.

5.1 Climate

5.2 Topography

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.

Soil texture characterized mainly as sandy clay loam or clay loam

5.4 Water availability and quality

Comments and further specifications on water quality and quantity:

Water quality (treated): good drinking water

5.5 Biodiversity

5.6 Characteristics of land users applying the Technology

Indicate other relevant characteristics of the land users:

Land users applying the Technology are mainly common / average land users
Population density: 10-50 persons/km2
Annual population growth: 1% - 2%

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:

• leased
• individual

• Cooperative

Water use rights:

• communal (organized)
• individual

• Cooperative

5.9 Access to services and infrastructure

6.1 On-site impacts the Technology has shown

Socio-economic impacts

Production

Income and costs

Other socio-economic impacts

Socio-cultural impacts

Ecological impacts

Water cycle/ runoff

Soil

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?
annual temperature		increase	well

Climate-related extremes (disasters)

Climatological disasters

	How does the Technology cope with it?
drought	not well

Other climate-related consequences

Other climate-related consequences

	How does the Technology cope with it?
Decrease of water temperature	not well

Comments:

The optimum water temperature for the crops cultivated in the greenhouse (tomatoes) is about 20 °C. If water temperature is less than 14 °C then the land user has to rely on an alternative source.

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:

In the long term soil health is greatly maintained.

6.5 Adoption of the Technology

• > 50%

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

70% or 7 land user families

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

• 11-50%

Comments:

30% of land user families have adopted the Technology without any external material support
3 land user families have adopted the Technology without any external material support

Comments on spontaneous adoption: Land users are probably not able to afford or justify the cost without external material support.
There is a little trend towards spontaneous adoption of the Technology
Comments on adoption trend: Word of mouth conveys the successful results and several users are eager to adopt the technology but not without external material support.

6.7 Strengths/ advantages/ opportunities of the Technology

Strengths/ advantages/ opportunities in the land user’s view
Increased irrigation water availability, and security; reduced crop failure risk; ability to diversify or intensify production

Strengths/ advantages/ opportunities in the compiler’s or other key resource person’s view
Self-sufficiency of water; sustainable agriculture management (soil protection and conservation) and reduced failure risk; decreased soil salinity

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?
High construction cost.	The construction of a water harvesting system for greenhouses can be subsidized.
Tomato cultivation requires water with higher electric conductivity than that of rainwater, therefore increased agricultural inputs may be required to treat the harvested rainwater.	Rainwater may be mixed with brackish water at a prescribed ratio.

Weaknesses/ disadvantages/ risks in the compiler’s or other key resource person’s view	How can they be overcome?
Is dependent on climatic conditions (precipitation/evaporation)	During dry years the storage tank can be used as a buffer from other sources. Installing a cover reduces evaporation.
High construction cost.	The construction of a water harvesting system for greenhouses can be made obligatory.
The storage area decreases the area available for cultivation (or can't be established in very small properties)

7.1 Methods/ sources of information