Water for Irrigation (Long or short term strategy)

Last week there was a debate on weather current efforts to promote agriculture in Tanzania by expanding land under irrigation is a short term solution. what triggered the debate was based on the fact that the rivers tha where we intend to tap this water are rainfall dependent and that water levels have declined tremendously over the past few years. on the ohter hand rain water harvesting is challenged by issufficient rain.

It is understandable that current food insecurities has forced many people to think that rainfed agriculture is responsible for what has been happening over the past few years.Partly yes. 

In Tanzania and elsewhere in East Africa expanding land under irrigation is seen as the only solution to current fall in food production. It is not suprising therefore that the Budget for putting up infrastructure for irrigation will triple in the next few years. But looking at the issue critically, the follwing questions come into my mind
(a) how long is irrigated agriculture going to work margic?
(b) what other options have we skiped?

Looking at the many documents on improving irrigated agriculture what strikes your eyes is numbers, what numbers? - hectares of land to be put under irrigation over a given time frame. These days we are also accumstomed to seeing reports on enviornmental impact assessment confining discussion on issues of ecosystem disturbances, loss of employment, desplacement of people and participation of local community is project implementation.

While this is acceptable, I have not seen reports on strategies for maitaining water sources and catchments, negleting this important aspect will in future determine the sustainability of many irrigation projects. many water authorities as interested in managing water use but neglecting the component of sustainable use (i.e. conservation)  take an example of DAWASA the former DAWASCO, most of the water controlled by the Company comes from Ruvu River, - which is several kilometres way from Dar es Salaam. I am afraid that none ofthe DAWASA officials has ever developed interest in ensuring constant water flow is manitained leave alone knowing what happens at the source.  Lack of interest translates in less effort to support conservation at the source, this applies also to TANESCO and other bodies which I beleive have budget for supporting conservation as aprt of corporate responsibility. While it is clear that rainfall is erratic, it is equally important to know that water flow will soon be erratic if we do not conserve our forests and other wetlands and incorporate water source conservation in every irrigation shcheme. 

And since most irrigation shcemes will be set up at lower plains of many rivers no one will take interests on what happens at the source (usually several km away).  In a slow but sure process the water level will drop as we have seen in many cases. even big rivers can dry up when no care is taken, this will bring us back to square one. This has happenned in the case of IHEFU  and is happening to Masai Mara river due neglect at the sourcce particularly in MAU forest in Kenya but now the impact is being felt in our homeland as well.