Friday, February 23, 2007

The Floods

The rains have arrived, and not a moment too soon either. The famine was one experience that most Kenyans are not likely to forget in a hurry. However, during the course of the famine, when the clamor for the rains had reached a fever-pitch, the ‘pessimistic’ (read ‘pragmatic’) Kenyans were quick to note that
“…during times of drought Kenyans starve, yet even when the rains come Kenyans will still be starving.”

Despite our prayers for rain to ease the current hardship, it is a very well known fact that too much rain (as has assaulted us recently) can be just as bad as lack of it. Whereas lack of rain might stunt plant growth, a deluge of it is likely to kill or simply wash away growing crops. This is the nature of the double-edged sword that is “rain”. However, since we are not exactly privy to being able to control the manner in which rain falls, we do at least have a duty to modify our environment in such a way that the rain causes as few problems as possible.
This is particularly the case in urbanized areas. By their very nature, the developments characterizing urban areas – roads, buildings, walkways and such – give rise to impermeable surfaces that hinder the extent to which the rainwater can infiltrate into the ground. Any responsible urban planning must thus entail an efficient drainage system. 

With all the recent development going on in Nairobi, I wonder if the developers have tallied the exact effect that they will wreak on our city’s drainage capabilities. Needless to say, the drainage needs to be improved, and sometimes the best way to determine what needs to be done is to troubleshoot to find out where the drainage system is failing. For our current situation, such faults can immediately be assessed in terms of things like flooded residential areas and roadways, clogged ditches and waterlogged fields. With the knowledge incurred from this troubleshooting, the relevant official bodies would at least know where to start fixing the problems once the drier season prevails.

The drainage issues in the rural areas pose another problem; this is because they arise from a different set of circumstances. The environment in these areas are less likely to be fitted for flood alleviation, people are more likely to live in the vicinity of rivers, and things as simple as clearing forests and leaving the land bare serve to exacerbate the situation of flooding. In one sense, flooding can be partially be reduced by directly combating these aforementioned causes. However, another potential solution can be found in floodwater harvesting; firstly, rural runoff tends to be relatively less polluted than urban runoff, and if it could be adequately harvested and stored, it could be a vital resource for easing the water shortage issues (particularly considering the fact that this same water can be used - without any treatment - for growing plants). Perhaps, this is the very venue by which a greater majority of Kenyan farmers can be allowed access to water for irrigation.

The whole notion of floodwater harvesting can actually be applied to both urban and rural settings. However, urban usage presents a more complicated problem because a larger amount of toxins are present within the runoff, and this water would require specialized treatment before it could be used for the more delicate forms of human consumption. However, with some minimal treatment, it can still be used for toilet flushing, hot water systems; watering lawns, gardens and playing fields; car washing, fire extinguishing systems and even creating artificial lakes, ponds and other wetlands.

Floodwater harvesting might appear to be an expensive venture initially, but in light of the expenses that end up being incurred due to our failure to preempt the destructive effects of excessive rainfall, it might actually be cheaper in the long run to actually initiate floodwater harvesting practices. It is no easy task to perform, particularly because it is a multidisciplinary approach that will require the input of various professionals. However, we are fortunate enough that some of the initial inexpensive groundwork can be laid at such an opportune time as this. Using Nairobi’s city centre as a pilot test for starters, scientists (or even fledgling scientists in the form of university students) can map out portions of the city and choose specific locations in which to sample and carry out tests on the quality of the water runoff and the variance of its quality within the stages of a storm event; further, they could also investigate the quality of the water left in stagnant pools around the city. If this data is published, it will provide an ideal source of information concerning the level of toxins in the water, which in turn would allow urban planners to specify an appropriate form of remediation to enable the water to be recycled.

It would be wise of us to follow the example of a country like Australia, which is already investing its resources into researching and implementing floodwater harvesting as a means to recycle an important resource as well as to reduce the environmental hazard posed by the discharge of floodwater directly into rivers and other receiving water bodies. I am not insinuating that Kenya’s development is exactly at par with Australia’s; I am, however, suggesting that our development does not have to be at par with a developed country for us to adopt an obviously wise idea that is within our reach. Learning to store water (particularly in cisterns), remediating it and putting it to use are measures that we should look into for our own sakes, and for those who are to come after us.

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