AKUT Umweltschutz Ingenieure Burkard und Partner

„Water Harvesting“

Strengthening Oasis Farming in the Region

of Ouarzazate

Dipl.-Ing.

Thilo Burkard

Dipl.-Ing.

Siegfried Matthes

AKUT Umweltschutz Ingenieure Burkard und Partner • Wattstraße 10 • 13355 Berlin Tel.: 030/5200095-0 • Fax: -9 • mail@akut-umwelt.de

Project participants

AKUT Umweltschutz Ingenieure Burkard und Partner • Wattstraße 10 • 13355 Berlin Tel.: 030/5200095-0 • Fax: -9 • mail@akut-umwelt.de

Project area Tidrheste

AKUT Umweltschutz Ingenieure Burkard und Partner • Wattstraße 10 • 13355 Berlin Tel.: 030/5200095-0 • Fax: -9 • mail@akut-umwelt.de

Tidhreste Aerial View Main Channel

AKUT Umweltschutz Ingenieure Burkard und Partner • Wattstraße 10 • 13355 Berlin Tel.: 030/5200095-0 • Fax: -9 • mail@akut-umwelt.de

Main Problems Solution Approach

Channel intake insufficient Intake improvement: e. g. lower intake upstream

Damages of channel structures in

the Oued Irzaki riverbed by

flashfloods

Bank and channel stabilization

Repairing works of concrete and earth constructions

Lack of available irrigation water Rainwater harvesting (rainfed runoff - runon farming.

Runoff water infiltration water storage in 2 m deep loess soil

layer.

Low groundwater level Ground water recharge using runoff: for recharging temporary

groundwater layers near the surface (which can be reached by

plant roots).

Groundwater use is not feasible (deep wells with motor pumps)

Heavy soil erosion: destruction of

oasis fields (gullies)

Draining and terracing of main erosion gullies.

Use of gully runoff for irrigation.

Soil degradation Soil rehabilitation: intercropping of fruit trees and annual

cultures with soil and nitrogen fixing plants (trees),

improvement of microclimate: shadowing by fast growing trees.

AKUT Umweltschutz Ingenieure Burkard und Partner • Wattstraße 10 • 13355 Berlin Tel.: 030/5200095-0 • Fax: -9 • mail@akut-umwelt.de

Tidhreste Aerial View Problem Areas

AKUT Umweltschutz Ingenieure Burkard und Partner • Wattstraße 10 • 13355 Berlin Tel.: 030/5200095-0 • Fax: -9 • mail@akut-umwelt.de

Main Goals

Retaining the maximum of runoff water within the oasis

Decentralized water harvesting solutions:

• avoiding the concentration of big runoff volumes;

• avoiding erosion, destruction of hydraulic structures and

finally the loss of valuable runoff water.

AKUT Umweltschutz Ingenieure Burkard und Partner • Wattstraße 10 • 13355 Berlin Tel.: 030/5200095-0 • Fax: -9 • mail@akut-umwelt.de

Two main components

Water from the Oued Irzaki by the Main

Channel:

Improvement of the channel structure and intake

Rain Water Harvesting:

The collection and concentration of rainfall for

irrigation

More independence from uncertain discharges of

the Oued Irzaki

AKUT Umweltschutz Ingenieure Burkard und Partner • Wattstraße 10 • 13355 Berlin Tel.: 030/5200095-0 • Fax: -9 • mail@akut-umwelt.de

Runoff-Runon Farming Methods

AKUT Umweltschutz Ingenieure Burkard und Partner • Wattstraße 10 • 13355 Berlin Tel.: 030/5200095-0 • Fax: -9 • mail@akut-umwelt.de

Runoff-Runon Farming Methods: Some Basics

Runoff - Runon Proportion

The ratio of the cultivated area to the catchment area

is 1 : 20 to 1 : 30

Negarim micro catchment basin with almond trees

AKUT Umweltschutz Ingenieure Burkard und Partner • Wattstraße 10 • 13355 Berlin Tel.: 030/5200095-0 • Fax: -9 • mail@akut-umwelt.de

Minimum Rain Quantity

For small catchment areas (approx. 800m²) and microcatchments

(e.g.'Negarim’) the runoff initiating threshold will be

approx. 2,5 mm.

Runoff-Runon Farming Methods: Some Basics

AKUT Umweltschutz Ingenieure Burkard und Partner • Wattstraße 10 • 13355 Berlin Tel.: 030/5200095-0 • Fax: -9 • mail@akut-umwelt.de

• Annual rainfall: 100 mm (mean annual rainfall in the Ouarzazate region);

• Evaporation will be between 30 to 50% of the rainfall

• Losses by soil infiltration will be 10 to 30%

• The runoff yield (for utilization in the plantation) is approx. 25 % of the

rainfall = 25 mm of 100 mm/ year; this estimation is for small catchment

areas or microcatchments.

Estimation of available runoff-water for the Tidrheste area :

Runoff-Runon Farming Methods: Some Basics

AKUT Umweltschutz Ingenieure Burkard und Partner • Wattstraße 10 • 13355 Berlin Tel.: 030/5200095-0 • Fax: -9 • mail@akut-umwelt.de

• Annual rainfall: 100 mm (mean annual rainfall in the Ouarzazate region);

• The ratio of cultivated to catchment area is 1 : 20;

• The runoff yield is 25 % of the rainfall (= 25 mm).

So the planted area receives

20 x 25 mm = 500 mm of runoff water

additionally to the 100 mm of rain

= 600 mm/ year of available water for the planted area.

Exemplary (simplified) calculation of available runoff-water with supposed

data for the Tidrheste area :

Runoff-Runon Farming Methods: Some Basics

AKUT Umweltschutz Ingenieure Burkard und Partner • Wattstraße 10 • 13355 Berlin Tel.: 030/5200095-0 • Fax: -9 • mail@akut-umwelt.de

Microcatchments (‘Negarim’):

Runoff = Runon Area

(Micro-) Catchment area for trees

(olive, almond):

approx. 250 m² for each tree

≈ 16 x 16 m, measured inside

the bunds

Tree bassin at the deepest point

of

the catchment area:

3,50 x 3,50 m to 5,0 x 5,0 m and

30 to 50 cm depth

Runoff-Runon Farming Methods: Some Basics

AKUT Umweltschutz Ingenieure Burkard und Partner • Wattstraße 10 • 13355 Berlin Tel.: 030/5200095-0 • Fax: -9 • mail@akut-umwelt.de

Runoff-Runon Farming Methods: Some Basics

A runon area with an approx. 2 m deep loess layer has a sufficient

water storage capacity for one growing period of an olive tree or a

grape vine.

Storage of Harvested Water

The collected water can be effectively "stored" below the soil surface

where it is available for plants but protected from evaporation

1 mm of water is sufficient to moisten 8 to 10 mm of soil up to its full

water holding capacity.

The amount of 30 cm retained water on a runon – field is sufficient to wet

completely a 2 to 3 m thick (loess) soil layer.

For an olive tree this water can be sufficient for one year.

The harvested water will be stored in the soil of the cultivated area

AKUT Umweltschutz Ingenieure Burkard und Partner • Wattstraße 10 • 13355 Berlin Tel.: 030/5200095-0 • Fax: -9 • mail@akut-umwelt.de

Runoff-Runon Farming Methods: Some Basics

AKUT Umweltschutz Ingenieure Burkard und Partner • Wattstraße 10 • 13355 Berlin Tel.: 030/5200095-0 • Fax: -9 • mail@akut-umwelt.de

Test plots

AKUT Umweltschutz Ingenieure Burkard und Partner • Wattstraße 10 • 13355 Berlin Tel.: 030/5200095-0 • Fax: -9 • mail@akut-umwelt.de

Microcatchments Negarims

AKUT Umweltschutz Ingenieure Burkard und Partner • Wattstraße 10 • 13355 Berlin Tel.: 030/5200095-0 • Fax: -9 • mail@akut-umwelt.de

Test area for rain catchment

AKUT Umweltschutz Ingenieure Burkard und Partner • Wattstraße 10 • 13355 Berlin Tel.: 030/5200095-0 • Fax: -9 • mail@akut-umwelt.de

Reservoir

AKUT Umweltschutz Ingenieure Burkard und Partner • Wattstraße 10 • 13355 Berlin Tel.: 030/5200095-0 • Fax: -9 • mail@akut-umwelt.de

Terraced run-on fields, infiltration plots

AKUT Umweltschutz Ingenieure Burkard und Partner • Wattstraße 10 • 13355 Berlin Tel.: 030/5200095-0 • Fax: -9 • mail@akut-umwelt.de

Results

• The integration of AED members was very successful. 24

people from Tidrheste were capacity build by linking to planning

and construction.

• The knowledge transfer and training comprised:

– field survey as part of the preliminary planning process;

– selection criteria to locate sites for RWH harvesting constructions;

– main construction criteria for microcatchment areas

– main construction criteria for 3 types of dams;

– integration of ancient and new RWH structures.

• People form 4 villages besides Tidrheste have participated in

workshops and seminars. They have shown interest in copying

these techniques. They will be able to start new constructions

with the help from Tidrheste.

AKUT Umweltschutz Ingenieure Burkard und Partner • Wattstraße 10 • 13355 Berlin Tel.: 030/5200095-0 • Fax: -9 • mail@akut-umwelt.de

Thank you for your attention

AKUT Umweltschutz Ingenieure Burkard und Partner,

Wattstrasse 10, 13355 Berlin, +49 (0)30 520 00 95-0,

mail@akut-umwelt.de, www. akut-umwelt.de

Schulze und Matthes G.b.R.

Großbeerenstraße 80,10963 Berlin, +49 (0)30 617 027 82

info@schulze-matthes.de, http://www.schulze-matthes.de