BY SILABAT MANAYE
In case of Ethiopia ,about 90%of the available water is received mainly in three months.Hence,dams could effectively store water during heavy rain seasons between June to September and to some extent during the short rain.Large storages are,therefore essential.
In addition the following advantages could be expected from building big dams in the Blue Nile basin:The flood waters are wasted unless large major dams are constructed, Large dams are eminently suited for carry over storages and thus impart greater reliability and stability to the system,Large dams generate cheap and clean hydro power, Dams provide the most effective way of flood regulation and control.Large dams are most reliable during drought when small storages run out,and suffer excessive evaporation loss.In drought years the reliability of small dam is very poor.
Long life as large silt pockets can be provided.per unit areas stored with big dams is much less as compared to small dams.
Diversion and transfer of surplus water to water scarce basins can be possible only through big dams.Employment potential is higher in large dams throughout the year .In case of small dams there is little employment potential as seasonal rains affect only small local areas .
The imperatives of large water storages was supported by the former President of the World Water Forum Council who stated that’’some 8 000 000 dams (of these 45 000 are major ,higher than 15 meters in height)exist around the world ,delivering energy,flood protection and water for household,industrial and agricultural use”. He further stated that “despite the drawbacks,the world’s growing population and their need for greater economic development call for more water ,in which demand will exceed availability.
More and bigger storages will be needed to meet the challenges of development and cultural inheritance and make sure that those people affected by the development of dams will be better off than before the dams were built.
While giving special attention to the environmental and displacement issues carefully, Ethiopia should construct large scale dams that :Increase economic and social productivity and hence increase consumption of goods and services, Irrigate 2.2 million ha identified in the basin ,Distributed benefits to millions of inhabitants through employment in mechanized agriculture in the basin,provide better settlement,equipped with socially, economically and technically sound services in the basin for millions and change their life; producing complex hydroelectric power for trade with the trans-boundary countries.
Therefore, Ethiopia needs urgent action on matters concerning the building of major dam structures in the Abbay ,Baro-Akobo and Tekezze catchments and other River basin areas in accordance with some detailed studies and engineering designs.
Evidently, Ethiopia has made many valuable studies and design works without much chance of putting them in to action mainly because of lack of funds. Generally To-date Ethiopia is the least user of the Blue Nile run-off in the Eastern Nile Basin,compared to Sudan and Egypt.
At the national level ,economic and institutional capacities are also limited.In spite of many hindrances,Ethiopia should concentrate on the modern agricultural development options,focused on the rivers so that these resources could be utilized to realize a meaningful irrigation programs
THE ETHIOPIAN HERALD JULY 14/2021
