Water management in wetlands: a hopeful conclusion

I have come to my last post, and although I am far from having explored all topics I was interested in, I hope this blog was able to show that colonial patterns are still reproduced by our global neoliberal economic system, and that they persist in relation to infrastructure, knowledge and decision-making around water.

I promised in my first post that this blog wouldn’t only be negative. Until now I have highlighted more problems than solutions. Now is the time for some optimism.

The African continent has extremely variable rainfalls, both inter and intra annual. This is reflected by high river flow variability, which in Southern Africa is the highest in the world. The coefficient of variation in annual river discharge there reaches 82%; it is as low as 24% in Europe. This is in turn a challenge to various aspects of life, from growing food, to accessing safe drinking water, to providing safe sanitation. Despite these unpredictable weather conditions, people have developed elaborated adaptation strategies. 

 

Let’s look at the Hadejia-Nguru Wetlands in Northern Nigeria. There is a high seasonal variability, with a dry and a wet (flood) season; but there is also drastic inter annual variability: in the late 1960s, over 2000 km² of land were flooded, when it was only 300 km² 1984. Many adaptation strategies have therefore been developed; I explore a few in this post. 

Firstly, land use is highly varied and specifically adapted to hydrological conditions (see map below). 

Land use in the Hadejia-Nguru Wetlands. Source: Thompson & Polet 2000: 653.

Crops are adapted to hydrological conditions. Specific crops and strains are planted at specific places and specific times. For instance, the moment when farmer plant rice is defined by weather conditions: it has to be planted when rains start, but before floods begin, in order to ensure ideal growing conditions.

Small scale irrigation techniques have been developed to adapt to inter annum variability in rainfalls and to floods. Below are two examples.

Lambu gardens allow controlling irrigation over small parcels. Source: Thompson 1995: 55.

 

Jingas are small bunds that prevent floods from damaging crops. Source: Thompson 1995: 55.

Fishing is also highly seasonal and it represents the first wealth-generating activity in the Hadejia-Nguru Wetlands. Irrigation schemes are often correlated to fishing activities: for example, one can easily trap fish when opening a Jinga.

In the dry season, cattle farmers take advantage of the moist soil for cattle grazing.  

To summarise, below is an overview of human activities’ adaptation to flood seasonality. 

Overview of relationships between water level and activities on a floodplain. Source: Thompson 1995: 53. 

I have only mentioned here a few of the adaptation mechanisms used in one specific region; but highly efficient water adaptation strategies can also be observed elsewhere in Africa. For instance, in informal settlements such as Methare, Nairobi, households have an in-depth understanding of water management.

This gives good reasons to be hopeful regarding the ability of mankind to adapt to climate change and induced variable and unpredictable weather patterns, as also suggested by a 2005 Africa Climate Report. However, the perpetuation of these local adaptation techniques and their potential transposition elsewhere will depend on the overcoming of colonial knowledge and decision-making patterns.

We cannot impose top-down development plans anymore.  

We cannot refuse to involve people in decision-making anymore. 

We cannot ignore and oppress local knowledge anymore.