Site - Tigray: Water harvesting ponds and shallow wells

The main objectives for the construction of water harvesting ponds in Ethiopia are:

• To harvest water needed to meet household domestic needs (including livestock);
• To provide supplementary irrigation to long rain season cereal crops mainly during the drier months of September and October;
• To provide full irrigation to crops during the dry months of the year.

In Tigray only, the goal is to construct 500,000 ponds in the next years. The target for the year 2003 was to construct 40,000 ponds, 80% made with plastic liners and the rest with clay lining. About 30,600 were actually built. The target for the fiscal year 2004 was 160,000; 23,300 of which were built up to July 2004. The individual household pond is characterized by its catchment the pond itself and the command area; all managed at house hold level. The great advantage of this storage system is the relatively simple social operation and maintenance structure in relation to communal ponds.

Water is directly harvested by runoff or taken from a gully or stream with a diversion structure and stored in a pond to be used when required. The ponds have a square shape, usually 12x12m with internal slope of 1.5-2:1 and a capacity between 30 and 182 m3. Other sizes and shapes are being tested, e.g. 25x25 m with stepped sides. The ponds usually have complementary structures such as feeder canals, access stairs but often do not have a spillway and water lifting is done by bucket. Some of the ponds are fenced but most are not. The location of the pond near the house has been justified by the expectation that this will enable close management by family members and reduce the burden on the already busy daily schedule.

According to an EU Evaluation Report, there is a lot of potential in the region for shallow wells. The Tigray Regional Government is therefore strongly committed to promote the construction of shallow wells, the three-year action plan provide the construction of 8,200 shallow wells (3,000 in 2004). Until June 2004, 931 shallow wells have been dug. Decisions on the dimensions of the well are taken by the farmers. In the majority of cases the farmer digs the well himself with the support of his family. Depth of the well depends on the water table, on average 8 meters deep in the plateau and 15 meters in the highland. The well wall is lined with stones to waterproof it, but usually they are not covered and have no fence; this can be very dangerous and some incidents have already happened. The water is collected with a bucket on a rope; this method is cheap but at the same time dangerous and hard, especially if water has to be transported to the field. In order to improve irrigation techniques in one Woreda (administrative unit), 18 motor pumps are now available and farmers can rent them for 10 birr/day plus fuel price. This solution cannot be considered very practical as farmers consider the renting price too high and because there are not enough motor pumps available.

Several studies have been done on water harvesting ponds and shallow wells in Tigray, mainly by MSc and BSc students from Mekelle University, such as:

- Gebreegziabher Lemma Hagos (Dec05) The role of household ponds on the expansion of homegardens in Tigray, Ethiopia. MSc thesis Mekelle University