Water Conundrums

As I mentioned in the last post, I was at a water conference all last week and that’s why I didn’t have time to post.  But I wasn’t without post-worthy thoughts.  Actually I have been stewing quite a bit on some of the contradictions of water highlighted by the conference and the technical visits that I attended on Monday and Friday.

Here’s one to chew on:  Floods and heavy rains make lots of water available.  Hurray!  Places with limited water availability can rejoice that more water has fallen from the sky.  Not-so-fast…. In Nairobi’s water system, surface water (including rainwater) is impounded behind Thika Dam (not actually located in the town of Thika, but rather damming the Thika River).  During the rainy season, the dam fills up.  Cool beans. Sediment in water sitting behind a dam generally has the opportunity to settle out, making the water very clear.  However, water must then be conveyed to the water treatment plant to make it potable.  Between Thika Dam and Ngethu Treatment Plant are first a series of pipes, but then dam water is dumped in to a river that is used as the final conduit to the treatment plant.  Because of this river-stretch, when there are heavy rains, this clear settled water becomes super turbid, meaning when the water reaches the plant in the rainy season, it needs double the treatment to reduce turbidity and render it drinkable.  This all means that water is actually more easily treated and therefore more easily available during the dry season than the rainy season.  How about that?

Here’s another one:  Water leaving the Ngethu Treatment Plant and making its way via a closed pipe to the city of Nairobi is totally clean, potable, and drinkable.  If this is the water that arrives at my tap, why am I still not able to safely drink my tap water?  Two reasons:  1. Despite the ample rainfall in this part of the world, Nairobi Water is still not able to satisfy water demand.  I heard numbers of around 60% of demand is satisfied.  This means that the utility must shut off pipes to various parts of the city on a rotating basis in order to “equitably” share the resource that exists (I did get into it with some folks about what “equitably” means, but that’s another story.)  Because the pipes are not full of water 24/7, air gets in and so does rainwater and any sewage or urban runoff around, thereby polluting this potable resource.  Also 2.  We do not have significant storage tanks at our apartment, but we manage to always have water flowing out of out tap.  How?  Because our apartment complex (and everyone else of our socio-economic class and higher) has access to a borehole or well on our property.  To supplement our water supply, we pump water directly out of the ground.  This well is on our property.  This groundwater is not treated to the same standards of the piped water from the treatment plant, meaning that we basically supplement our water with a sub-standard quality in order to assure adequate quantity.  How about that?

Water sure is a tricky one.