The Tuvaluan Government is asking for more water tanks in its National Adaptation Programme of Action (NAPA) in order to secure fresh water access for its citizens. « More water tanks, we need more water tanks », says many Tuvaluans when you ask them about their access to fresh water. But is this really what Tuvaluans need?
Rainwater harvesting from private rooftops is the main source of fresh water on Tuvalu. A house without one or several large rainwater tanks connected to a chain of gutters is a rare sight in the capital Funafuti. It is all about having the most rainwater tanks in order to secure the needs of your family. If you are out of water, you will have to buy a (highly subsidised) refill from the public catchment and desalinisation plant. If you are unlucky and run out of water at the same time as everyone else (something that is not so uncommon, naturally), you might have to wait for your refill for weeks. Then you will have to get all the water that you need in buckets from the public cisterns. Tuvaluans say that the rainwater tanks often starts drying up after just two weeks of low rainfall.
Vulnerable island states
According to the fourth assessment report of the IPCC, many small island states will be exposed to serious water stress under all SRES-scenarios. Further on, the report states that there is a high possibility that island states as Tuvalu, which is highly or completely dependent on rainwater harvesting, will not be able to meet the needs of its citizens in periods of low rainfall. (Read the chapter on Small Islands here).
The Tuvaluan capital Funafuti is a good example for what Working Group 2 under the IPCC describes. There is no surface water or springs. The freshwater in the shallow underwater lens below the main islet is so poisoned, polluted and salinized that it is completely irresponsible to even think of drinking it. Therefore, Funafuti is completely dependent on rainwater harvesting and desalinization to cover the need for freshwater and reach the national target of securing 50 litres of water per person a day. At the same time water access is becomming more and more unpredictable as Tuvalu, as so many places in the world, experiences changing weather patterns and more frequent and prolonged droughts.
Enough capacity is not enough
Despite a range of projects to increase the rainwater catchment and storage capacity on Funafuti since the 1980s, there are still families without enough rainwater tanks, or good enough roof or gutters to catch the rainwater. These families have to go to the public catchment two times a day, every day, in order to get water for their families.
The longest drought recorded on Funafuti between 1933 and 2008 lasted for three months. Rainafall on Funafuti is high with 3500 mm/y. In order to secure 50 litres of water a day, each person needs 5000 litres of storage and 6m2 of catchment surface (roof). The total water storage capacity and the total surface catchment capacity are sufficient to cover the needs of all Tuvaluans living on Funafuti.
So, why are Tuvaluans still running out of water after just a few weeks, when their capacity is above three months?
Read more about this tomorrow.