Water harvestingEnvironmental effectsPublic healthSocial aspectsEconomic aspects

Behailu, M.

Haile, M.

English

Research Papers in Economics

Water harvesting in northern Ethiopia:
Environmental, health and socio-economic
impacts
Mintesinot Behailu
1 and Mitiku Haile
2
1. Assistant Professor and Vice President, Mekelle University, Mekelle, Ethiopia
2. Associate Professor and President, Mekelle University, Mekelle, Ethiopia
Abstract
InnorthernEthiopia,waterscarcityisakeyfactorinfoodsecurity.Insomeareas,thewater
is so precious that the principle of ‘irrigating the crop and not the land’ is adopted in an
attempt to curb rural exodus. In other areas, considerable effort is put to introduce
innovative water harvesting and management systems. The introduction of small-scale
irrigation using micro-dams has become an excellent option considering the
hydro-climatological conditions of the region.
In Tigray, over the last 10 years, about 50 micro-dams were constructed; consequently,
considerable improvements were observed in the livelihood of the rural poor. Water
security brought food security. Some negative impacts are being observed especially on soil
salinity and erosion. Malaria has become a growing concern in micro-dam areas with
altitude lower than 2000 metres above sea level (masl).
In general, the positive and negative impacts of micro-dam water harvesting systems
need to be well understood before further up-scaling. Research should focus on system
design, farm hydrology, socio-economic constraints and systems transferability.
Introduction
Although several definitions of water harvesting (WH) have been suggested, Siegert (1994)
gave the most encompassing definition as: ‘…an umbrella term describing a range of
methods of collecting and conserving various forms of water originating from ephemeral
water flows produced during rainstorms’. The aim of water harvesting is to mitigate the
effectsoftemporalshortagesofrain,so-calleddryspells,tocoverbothhouseholdneedsand
productiveuse.Thisinvolvesstoragecomponentandvariousformsofstorageexistsuchas:
micro-dams, farm ponds, subsurface dams, tanks etc.
Waterscarcityisacriticalissueformanydevelopingcountriesingeneralandforthosein
the arid to semi-arid areas of the world in particular. It has long been understood that
intensive water resource development can have a decisive role in the economic and social
development of a country and in alleviating drought. Alleviating food security related to
MoWR/EARO/IWMI/ILRI Workshop 185drought and famine through sustainable agriculture and environmental rehabilitation
requires a short- and long-term planning of water resource development of an area.
InnorthernEthiopia,inanefforttoaddresstheproblemsofrecurrentdrought,famine
andfoodinsecurity,attemptsarebeingmadetoharvestrunoffwaterinmicro-damsforuse
bothinhouseholdsandsmall-scaleirrigationschemes.Itisrecognisedthattheconstruction
of micro-dams with proper irrigation and agronomic services will result in micro-climatic
and environmental changes with positive impact on sustained productivity.
Notwithstanding the positive impacts on increased agricultural productivity and
improved community welfare, the negative impacts of water resource development require
constant assessment and monitoring on environmental changes.
Thus, the objectives of this paper are to present:
• the positive and negative impacts of water harvesting and
• the knowledge gap and research priorities in water harvesting.
The study area
General description
Tigray is the northernmost region of Ethiopia extending from 12°15’ to 14°50’N latitude
andfrom36°27’to39°59’Elongitude.ItisboundinthenorthbyEritrea,tothewestbyThe
Sudan and to the east and south by the Afar and Amhara regions of Ethiopia. It covers a
little more than 80 thousand km
2, most of which are highlands between 1500 and 3900
metres above sea level (masl).
Tigray’s economy, like the other parts of the country, is based on plow cultivation for
predominantlycerealproduction.Thelevelofsubsistence,exceptforperiodsofgoodrains,
has declined radically during the past decade, with almost everything produced being
consumed at the farm household level.
Tigray’s agriculture depends entirely on availability of rainfall; because of this,
agricultural production is erratic, showing high temporal and spatial variability in yield.
Agricultural production operates with very low modern external input, resulting in
depletionofsoilnutrients.Increasinglossoftopsoilthrougherosionhasexposedtheregion
to serious environmental and ecological imbalances.
The agrarian system is pressed with a fast accelerating population growth and a high
arable land to population density, which far exceeds the carrying capacity of the land.
Recurrent drought, pest infestation and unfavourable climatic factors contribute to poor
production performances. The inevitable result of these prevailing conditions has been a
gradual and steady decline in soil and labour productivity.
Amajormeansofrehabilitatingandreconstructingthenaturalresourcebaseisthrough
water resource development. That water is the single most critical variable in Tigray’s
agricultural production has been long recognised.
186 MoWR/EARO/IWMI/ILRI Workshop
Mintesinot Behailu and Mitiku HaileSustainable agricultural and environmental
rehabilitation programme
Having realised the need to have a comprehensive rural development programme, the
regional government, in 1994, decided to establish a sustainable agricultural and
environmental rehabilitation programme. Through this programme, water harvesting was
seenasanoptionandhencewasplannedtoconstruct500earthenmicro-damsover10years
to supply 200 thousand tonnes of grain equivalent enough to feed 930 thousand people
who, without the project, would almost surely depend on food aid.
Of the estimated 1.2 million hectares of arable land, 95% is under rainfed cultivation.
Since1995,throughthemassiveirrigationdevelopment,about50micro-dams(eachwitha
capacity to hold about 50,000–2,000,000 m
3 of water), and 11 diversion plants have been
constructed in drought prone areas giving an increase of 2000 ha of irrigated land only.
Additional impacts anticipated from the environmental rehabilitation programme
were: degraded areas show signs of recovery, while millions of seedlings planted as a means
to biological soil conservation will result in forest products. Availability of forage for
livestockwillimprovesustainability.Withstorageandutilisationofseasonalsurfacerunoff
water, many prevailing social and economic problems should be alleviated; decreased
women’s burdensome and time-consuming responsibilities for fetching water and thus
improve women and children welfare. Furthermore, the introduction of fisheries could
improve the diet of the community and serve as a supplementary source of income to
families.
Water harvesting and irrigation management
In Tigray, a major means of rehabilitating and reconstructing the natural resource base is
throughcomprehensivewaterharvestingdevelopment.Thus,watersecuritythroughrunoff
harvesting has been chosen as a strategy to curb the acute water shortage in the region.
Farmers in Tigray have been producing different crops under traditional irrigation
managementforalongtime.Thediversionofperennialstreamsusingtemporarystructures
during the dry season is the major means of irrigation. In addition, flood spreading using
runoff water from higher altitudes and upper catchment areas is also practised.
Horticultural crops and maize are the main crops grown under these irrigation schemes.
Materials and methods
A study to document the effects of micro-dam water harvesting on the socio-economic,
environmentalandhealthaspectswasundertakenbyMekelleUniversityandTigrayRegion
Health Bureau.
MoWR/EARO/IWMI/ILRI Workshop 187
Water harvesting in northern Ethiopia: Environmental, health and socio-economic impactsFor the impact on health, 7000 children living in villages near to dams (less than 2 km
radius) and away from dams (more than 2 km radius) were monitored for the incidences of
malaria and schistosomiasis over three years (Tedros et al. 1999).
For the environmental impact assessment, salinity of soil and irrigation water was
monitored over four years (Mitiku and Sorsa 2002). A survey was also undertaken through
semi-structuredquestionnairestoanalysetheperceptionoffarmerstolanddegradation(as
a result of catchment erosion and subsequent sedimentation in reservoirs). In addition,
studies reveal that a reservoir water quality is deteriorated following biological
contaminants.
For the socio-economic impact assessment, a study was undertaken using
semi-structuredquestionnairetoseetheeconomicreturnsofwaterharvestinginsmalldams
used for irrigation (Mintesinot 2002).
Results and discussion
Environmental impact assessment
Most dams were constructed without prior rehabilitation of the catchments. Thus, one
serious environmental problem is erosion of catchments leading to increased
sedimentation, which reduces the storage capacity of the reservoirs. In some dams, the
situation is so severe that periodical excavation is becoming necessary. One opportunity is
that farmers are well aware of the problem and are willing to invest in sustainable land and
water management interventions (Mitiku and Sorsa 2002).
Another serious environmental impact is the introduction of salinity to the irrigated
schemes. With the current water management practice (furrow management without
appropriate scheduling), the absence of well-designed drainage ditches and very high clay
content, salinity hazard is imminent. The level of salinity in some schemes has reached a
situation where serious impacts are being observed both on crops and soils.
The pattern of salt distribution was studied by taking a transect and results have shown
that the salt content of irrigated fields nearer to the embankments were generally higher
thanfieldseitherinthecentreoratthetailend.This,accordingtoMitikuandSorsa(2002),
is attributed to the high seepage loss from the nearby embankments.
Although not as such wide spread incidence, there was also biological contamination
observed in the reservoirs of some dams. The watercolour in the reservoirs changes from a
normal blue green to deep red/brown. This change was so homogenous that a suspended
powder pigment was observed. Water quality studies revealed that the incidence was a
biologicalcontaminationcausedbybacteriaknownasMyxobacteria,aPolyangiaceaegenus.
The bacteria are mainly active cellulose decomposers that widely occur in soils and
water.Theyarecapableofformingfruitingbodies,whichcansurviveforalongtimeunder
unfavourable conditions. The study has continued to identify the original sources but
preliminaryfindingsshowthatsimilarbiologicalstructuresarefoundwithinlivestockdung
around the dams.
188 MoWR/EARO/IWMI/ILRI Workshop
Mintesinot Behailu and Mitiku HaileHealth impact assessment
The impact of prolonged available surface water in newly developed irrigation areas is on
water and vector-borne diseases. Areas that were periodically affected by malaria and
schistosomiasis are exposed to continued year round attack. Peak transmission that
coincides with seasonal onset of the big and small rains in the region will be prolonged to
other months, which were relatively free of malaria. Mosquitoes and snails have an ideal
environmental situation to breed.
Health studies (Tedros et al. 1999) revealed that villagers living near to dams that are
built in altitudes lower than 2000 masl are faced with increased risk of malaria incidence.
Incidence surveys conducted showed a seven-fold increased risk for children. Some of the
documented risk factors were open caves, keeping animals in living houses and earthen
roofs.
Identification of such local risk factors for malaria is important for the planning of
malariacontrol(Tedrosetal.1999).Tomitigatetheriskofmalaria,insecticideimpregnated
bed-nets were distributed to near micro-dams village under a cost-recovery scheme. Malaria
incidence was then measured and the risk was reduced to less than two-fold.
Studies on the incidence of schistosomiasis revealed that the overall prevalence of
infectionwas39%forchildrenand48%foradults(Tedrosetal.1999).Theeffectivenessof
endod (phytolacca dodecandra) in controlling snail is currently under investigation.
Socio-economic impacts
Irrigation development aims to bring about increased agricultural production and
consequently to improve the economic and social well-being of the rural population.
Studiesonhouseholdincomebyirrigation(Mintesinot2002)revealedthatirrigationusers,
on average, have three-fold increase in income compared with those that solely depend on
rainfed cultivation.
The same study indicated that irrigation compounded with rainfed cultivation ensures
year-round food security, although, off-farm employment during part of the year is a
common practice to obtain extra money.
Conclusion
With the growing demand for daily food and continued struggle to achieve long-term food
security,thereisadireneedtomaximisetheproductivityofbothlandandwater.Inputsto
land may improve land productivity but inputs to water may not change the productive
capacity of water. Improving the water security through increasing the water use efficiency
(more crop per drop!) can however result in higher productivity.
The issue of water security in Tigray (northern Ethiopia) is addressed through the
extensive water harvesting endeavours underway. The positive and negative impacts of this
effort are, however, little understood.
MoWR/EARO/IWMI/ILRI Workshop 189
Water harvesting in northern Ethiopia: Environmental, health and socio-economic impactsFarmers living in the vicinity of micro-dams are aware of the problem of land
degradation. They understand the effect of sedimentation on the reduced capacity of
micro-dams to store water to be used for irrigation. Apparently, they are willing to invest in
land management systems that are sustainable, productive and effective in reducing
sediment load.
Health studies indicated that villagers living near micro-dams that are built in the
lowlands (<2000 masl) are faced with the risk of increased incidences of malaria.
Community participation in draining excess water that can be a breeding ground for
mosquitoes coupled with the use of impregnated bednets has decreased the incidence of
malaria.Creditschemesareimportantavenuestoundertakethisventure.Themajorpoint
of departure is the benefit that is obtained from the use of the irrigation schemes. In the
schemes where economic benefits are obtained the farmers are willing to pay for the extra
cost of prevention of malaria (Lampietti et al. 1999)
Knowledge gaps and future avenues
Despite the vast knowledge and experiences accumulated in the field of water harvesting,
there are still large gaps in research that need to be filled. Some of the reasons for the poor
research in water resources could be attributed to:
• no institutional responsibility as such exists to take up research on sustainable water
resource development
• limited and/or very scattered capacity (trained manpower) available to undertake
interdisciplinary research
• very few institutions available to offer specialised training in water resource
development.
Ofthemanyresearchtopicsinmicro-damwaterharvesting,thefollowingthematicareas
are prioritised:
• hydrology at farm level
• upstream/downstream effects of water harvesting
• water productivity in agriculture
• water pricing
• co-operatives under smallholder irrigation managements
• soil–plant–water relationship.
To address the main causes for the limited attention in water resource research and
capacity building:
1. there needs to be mandate sharing among the various institutions (governmental
organisations and non-governmental organisations, NGO’s) for research in water
resources (basin-level, small-scale…)
2. higher learning institutions should play the needed role to meet the capacity building
needs of water sciences.
190 MoWR/EARO/IWMI/ILRI Workshop
Mintesinot Behailu and Mitiku HaileWhat does Mekelle University have to offer?
There is a faculty of dryland agriculture that gives a degree level training in land resources
management and environmental sciences. Through this programme, many courses are
being offered in areas of water sciences. In addition, periodical short-term trainings are
organisedforstakeholdersinareasofwaterharvesting,irrigationmanagementandsoiland
water conservation.
Apart from this, multi-disciplinary research is being undertaken in areas of small dams:
water productivity, socio-economics, and health aspects. In partnership with the
International Water Management Institute (IWMI) and the Ministry of Water Resources
(MoWR),astudyhasbeenlaunchedtoapplyPODIUM(policydialoguemodel)todevelop
variousscenariosforfuturewaterneeds(forfoodproduction,peopleandtheenvironment)
atbothbasinandnationallevel.Newstudiesarealsobeinglaunchedinareasofcommunity
water management (in collaboration with the International Livestock Research Institute
(ILRI), the Ethiopian Agricultural Research Organization (EARO) and MoWR and on
malariainsmalldams(withIWMI).Thereisalreadyanetworkavailable,butthisneedstobe
strengthened.
References
LampiettiJ.A.,ChristineP.,MaureenL.C.andMitikuHaile.1999.Genderandpreferencesformalaria
preventioninTigray,Ethiopia.GenderandDevelopment3.WorldBank,Washington,DC,USA.
Mintesinot Behailu. 2002. Assessment and optimisation of traditional irrigation of vertisols in
northern Ethiopia: A case study at Gumselasa micro-dam using maize as an indicator crop. Gent
12:203.
MitikuHaileandSorsaNatea.2002.TheexperienceofwaterharvestinginthedrylandsofEthiopia.
Workshop proceeding. Deutschen Cichliden Gesellschaft (DCG) report 19. DCG, Bonn,
Germany.
TedrosA.G.,MitikuHaile,KarenH.W.,AsfawGetachew,AmbachewM.,MekonnenY.,HailayD.,
Steven W.L. and Peter B. 1999. Incidence of malaria among children living near dams in
northern Ethiopia. British Medical Journal 319:663–666.
MoWR/EARO/IWMI/ILRI Workshop 191
Water harvesting in northern Ethiopia: Environmental, health and socio-economic impacts

Assessment and optimisation of traditional irrigation of vertisols in northern Ethiopia: A case study at Gumselasa micro-dam using maize as an indicator crop.

Incidence of malaria among children living near dams in northern Ethiopia.

Water harvesting in northern Ethiopia: environmental, health and socio-economic impacts

http://publications.iwmi.org/pdf/H032461.pdf

Water harvesting in northern Ethiopia: environmental, health and socio-economic impacts

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