May Leiba is a

reservoir A reservoir (; from French ''réservoir'' ) is an enlarged lake behind a dam. Such a dam may be either artificial, built to store fresh water or it may be a natural formation. Reservoirs can be created in a number of ways, including contro ...

located in the Dogu’a Tembien ''woreda'' of the

Tigray Region The Tigray Region, officially the Tigray National Regional State, is the northernmost regional state in Ethiopia. The Tigray Region is the homeland of the Tigrayan, Irob, and Kunama people. Its capital and largest city is Mekelle. Tigray is ...

Ethiopia Ethiopia, , om, Itiyoophiyaa, so, Itoobiya, ti, ኢትዮጵያ, Ítiyop'iya, aa, Itiyoppiya officially the Federal Democratic Republic of Ethiopia, is a landlocked country in the Horn of Africa. It shares borders with Eritrea to the ...

. It is named after the May Leiba River. The

earthen dam An embankment dam is a large artificial dam. It is typically created by the placement and compaction of a complex semi-plastic mound of various compositions of soil or rock. It has a semi-pervious waterproof natural covering for its surface and ...

that holds the reservoir was built in 1998 by the

Relief Society of Tigray The Relief Society of Tigray (abbreviated REST; ti, ማሕበራዊ ረዲኤት ትግራይ or ማረት, ''Maret'') is an NGO based in Tigray, northern Ethiopia. REST was founded in 1978 as an organisation providing relief efforts to civ ...

Dam characteristics

* Dam height: 18.9 metres * Dam crest length: 371 metres *

Spillway A spillway is a structure used to provide the controlled release of water downstream from a dam or levee, typically into the riverbed of the dammed river itself. In the United Kingdom, they may be known as overflow channels. Spillways ensure tha ...

width: 25 metres

Capacity

* Original capacity: 958 175 m³ *

Dead storage Death is the irreversible cessation of all biological functions that sustain an organism. For organisms with a brain, death can also be defined as the irreversible cessation of functioning of the whole brain, including brainstem, and brain ...

: 191 635 m³ * Reservoir area: 16 ha In 2002, the life expectancy of the reservoir (the duration before it is filled with sediment) was estimated at 15 years. Ruba Weyni irrigation

Irrigation

* Designed irrigated area: 50 ha * Actual irrigated area in 2002: 5 ha A first problem is administrative: the dam is located in one ‘’tabia’’ and the command area in another ‘’tabia’’, leading to disagreements with regard to the sharing of the water. The larger part of the water that could be used for formal irrigation is lost through

seepage Soil mechanics is a branch of soil physics and applied mechanics that describes the behavior of soils. It differs from fluid mechanics and solid mechanics in the sense that soils consist of a heterogeneous mixture of fluids (usually air and wat ...

across the limestone; the positive side-effect is that this contributes to

groundwater recharge Groundwater recharge or deep drainage or deep percolation is a hydrologic process, where water moves downward from surface water to groundwater. Recharge is the primary method through which water enters an aquifer. This process usually occurs in ...

, particularly around the downstream settlement of Addi Idaga, where a large irrigation perimeter has been developed.

Reservoir catchment

The

catchment A drainage basin is an area of land where all flowing surface water converges to a single point, such as a river mouth, or flows into another body of water, such as a lake or ocean. A basin is separated from adjacent basins by a perimeter, the ...

of May Leiba reservoir is 17.87 km² large, with a perimeter of 17.61 km and a length of 4540 metres.

Environment

The lithology of the catchment of the reservoir is

Antalo Limestone The Antalo Limestone, also known as the Antalo Sequence, is a geological formation in Ethiopia. It is between 300 and 800 metres thick and comprises fossiliferous limestones and marls that were deposited in a reef. Marine microfossils have shown a ...

, Agula Shale, sandstone of the

Amba Aradam Formation The Amba Aradam Formation is a Cretaceous sandstone formation in Ethiopia. It is up to 200 metres thick, for instance in the Degua Tembien district. As fossils are absent, the age of the Amba Aradam Formation was interpreted based on the age of a ...

and

Ashangi Basalts The Ashangi Basalts are the earliest Tertiary volcanic rocks in north Ethiopia, hence they are in the lowest position. These dark porphyritic basalts are separated from the Mesozoic formations below it by basal Conglomerate (geology), conglomerates ...

. The main driving factors that define the variability in soil types in this catchment are: 1) geology, through soil parent material and the occurrence of harder layers, often acting as

aquitard An aquifer is an underground layer of water-bearing, permeable rock, rock fractures, or unconsolidated materials (gravel, sand, or silt). Groundwater from aquifers can be extracted using a water well. Aquifers vary greatly in their characterist ...

s or aquicludes; 2) occurrence of

mass movement Mass movement may refer to: * Mass movement (geology), the movement of rock and soil down slopes due to gravity * Mass movement (politics) A mass movement denotes a political party or movement which is supported by large segments of a population. P ...

deposits that occupy large areas of the catchment; and 3)

anthropogenic Anthropogenic ("human" + "generating") is an adjective that may refer to: * Anthropogeny, the study of the origins of humanity Counterintuitively, anthropogenic may also refer to things that have been generated by humans, as follows: * Human im ...

soil erosion Soil erosion is the denudation or wearing away of the upper layer of soil. It is a form of soil degradation. This natural process is caused by the dynamic activity of erosive agents, that is, water, ice (glaciers), snow, air (wind), plants, and ...

and deposition. These factors lead to “red-black” Skeletic

Cambisol A Cambisol in the World Reference Base for Soil Resources (WRB) is a soil in the beginning of soil formation. The horizon differentiation is weak. This is evident from weak, mostly brownish discolouration and/or structure formation in the soil pr ...

– Pellic

Vertisol A vertisol, or vertosol, is a soil type in which there is a high content of expansive clay minerals, many of them known as montmorillonite, that form deep cracks in drier seasons or years. In a phenomenon known as argillipedoturbation, alternat ...

soil catenas on

basalt Basalt (; ) is an aphanite, aphanitic (fine-grained) extrusive igneous rock formed from the rapid cooling of low-viscosity lava rich in magnesium and iron (mafic lava) exposed at or very near the planetary surface, surface of a terrestrial ...

and Calcaric

Regosol A Regosol in the World Reference Base for Soil Resources (WRB) is very weakly developed mineral soil in unconsolidated materials. Regosols are extensive in eroding lands, in particular in arid and semi-arid areas and in mountain regions. Internat ...

– Colluvic Calcaric

– Calcaric

catenas on

. The reservoir suffers from rapid

siltation Siltation, is water pollution caused by particulate terrestrial clastic material, with a particle size dominated by silt or clay. It refers both to the increased concentration of suspended sediments and to the increased accumulation (temporary or ...

. Attempts have been done to reuse the reservoir sediment for crop production. While this doubled the

garlic Garlic (''Allium sativum'') is a species of bulbous flowering plant in the genus ''Allium''. Its close relatives include the onion, shallot, leek, chive, Allium fistulosum, Welsh onion and Allium chinense, Chinese onion. It is native to South A ...

yield, it proved also to be a costly venture to transport the sediment from the dry lake bottom to nearby barren land in order to establish the plots.Land reclamation using reservoir sediments in Tigray, northern Ethiopia
/ref>

References

{{reflist Reservoirs in Ethiopia 1998 establishments in Ethiopia Tigray Region Dogu'a Tembien