State of the Planet

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Low-cost water management in Ethiopia

Water capture and storage for irrigation has been an ongoing theme of research in Columbia’s earth and environmental engineering department, but Professor Upmanu Lall has recently taken things a step further. With funding from the Pulitzer family, Lall challenged a group of students in his senior engineering course to design a low-cost system of water capture and storage for irrigation in Koraro, Ethiopia, one of the Earth Institute’s Millennium Villages.

The challenge is not an idle one. Ethiopia is at a critical crossroads, with a burgeoning population, a severely depressed national economy, insufficient agricultural production and a minimal number of developed energy sources. Hydroclimatic year-to-year variability has long hindered the country’s growth and prosperity. Eighty-five percent of the people lives in rural areas, and most of them practice subsistence farming. A heavy reliance on agriculture, combined with a susceptibility to frequent climate extremes, has left it in a precarious position, striving not only to stay on par, but to prevent vast numbers of people from falling deeper into poverty. One devastating year can nullify the gains of several successful growing seasons.

Northern Ethiopia, especially the region of eastern Tigray, where Koraro is located, is notoriously dry. Yet local farmers continue to work the land. Irrigation is practically nonexistent, as the capital costs for infrastructure far surpass farmers’ means. Water storage through small-scale ponds designed to capture rainwater runoff is becoming more commonplace. However, this source alleviates only short-term dry spells (weeks to months) and isn’t sufficient for dry seasons or drought conditions. The ponds also create ideal breeding grounds for mosquitoes, increasing the risk of malaria transmission.

For the students in Lall’s class, one of the major challenges in providing a better irrigation system is to develop alternative means for capturing rainwater runoff, as soils are highly permeable. The team has designed a system to retard the runoff in higher elevation gullies through rock dams, allowing the water to infiltrate and recharge the upper aquifer. The goal is to provide water to agricultural areas at lower elevations through simple pipe networks, minimizing evaporation. So far, the work looks promising, though additional analysis and field visits are necessary before implementation.

A short audio slideshow describing this project in Koraro is available below or by visiting the International Research Institute for Climate and Society (IRI).

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ariel shai BScAgr, MScAgr
ariel shai BScAgr, MScAgr
15 years ago

Hi professor Lall

My name is Ariel Shai, Israeli farmer and grower, who knows Ethiopia and its drier areas and long dry seasons

I suggest to capture/harvest water from rivers/runoffs etc and store in plastic bags of 1 cubic meters each – placed in 1 cubic meter round holes dug in the ground that fit the size of the bag.

I speak about up to 40’000 holes to be dug every few miles and these will enable second and third season farming in one year. The water will be pumped from these 40’000 holes by a Syphone into a simple drip system.

Infact I grow fruit trees and vegetables in 10 litter pots inserted/planted into the ground with a dripper. The dripper may be connected to a 2 liiter bottle filled manually or connected toa dripper system. The planting in planted pots save soil issues, saves water, prevents weeds and competition ets and may enable adding of specific mycorhiza

This bag idea will prevent mosquitos and other hazardous contaminations
This type of water harvesting is easier along rapid rivers using Venturi type force to lift the water up and direct these into the water holes(farm). Treating the water for 6 month of storage is easy

Will glad to hear from you