Drinking water / Tsunamis / Rehabilitation / Wells / Water quality / Salinity / Sri Lanka

International Water Management Institute (IWMI).

English

Research Papers in Economics

Helping restore the quality of 
drinking water after the tsunami  
Issue 7 - 2010
The tsunami
The tsunami that struck the Indian Ocean on December 26, 2004, devastated parts of Sri Lanka’s southern and eastern coastline. As well 
as killing 31,000 people, it also destroyed wells that fell within the range of the saline floodwater. As a result, many families living along the 
island’s east coast found their supplies of freshwater abruptly cut off.   IWMI’s research formed the basis of guidelines on cleaning wells that 
restore water quality and avoid outbreaks of infectious diseases.  
Rapid action required
Within the first week following the tsunami, a Senior Scientist from IWMI, Karen Villholth, was on the ground 
assessing the situation along the east coast. She soon realized that representatives from several different 
NGOs were attempting to clean wells but were not following any standard protocols or recording the locations 
or details of any actions taken. 
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WaterM anagement
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InstituteFamilies living along the island’s east coast found their 
supplies of freshwater abruptly cut off.
Many people were attempting to clean wells by simply pumping 
out the saltwater and discharging it on the surface close to the 
well. This simply caused more saline water to flow into the well 
and the water recently pumped out soon percolated back into 
the well. This chaotic approach prolonged contamination of the 
water and prompted Karen to draw up guidelines and contact 
NGOs and relevant authorities to help explain that well owners 
should remove debris and dirty water from their wells but not 
keep pumping out water. The well water could be used for 
bathing and over time, rainfall would dilute the saltwater and the 
wells could once again be used for drinking water. 
 
Monitoring the impacts 
As various coordinating committees were set up for food and 
shelter, drinking water and sanitation, Karen attended meetings 
to disseminate the new guidelines and conduct training sessions 
to prevent further damage being caused from pumping. Two and 
a half months after the tsunami, IWMI initiated a monitoring 
program to assess the extent of the damage and monitor the 
recovery of water quality. Scientists selected 150 wells in 
Kallady, Kaluthavalai and Oluvil, within the Batticaloa and 
Ampara districts, each lying within 2 kilometers (km) of the 
coast. Although many of these wells had been affected by the 
tsunami, others had not, and these provided a useful baseline 
for pre-tsunami conditions. 
Directly after the tsunami, salinity levels of flooded wells were 
similar to those of seawater. The levels dropped after a few 
weeks but then remained more or less constant during the ongoing 
dry season. Following the first rains after the tsunami, salinity levels 
in the affected wells continued to decrease and came close to the 
range of drinking water, although they were on average still above 
the levels observed in the unflooded control wells. This indicated 
that the groundwater had still not fully recovered from the saltwater 
intrusion. Continued monitoring revealed that the water quality in 
affected wells was restored to pre-tsunami levels one and a half 
years after the event.
Recommendations for emergencies
Following the monitoring program, IWMI scientists drew up a series 
of recommendations. They suggested cleaning wells immediately 
after a tsunami to remove debris and avoid outbreaks of infectious 
diseases from pathogenic microorganisms. They also 
recommended no further pumping as this has little positive impact. 
Instead, they advised letting the natural cycle of rainy seasons dilute 
the salinity until acceptable drinking water levels are reached. In 
2008, the World Health Organization (WHO) officially endorsed the 
well-cleaning protocol from IWMI and partners as part of its series of 
Emergency Guidelines. 
Donors and collaborators
During its post-tsunami well-cleaning and groundwater-monitoring 
operations, IWMI worked with CARE, Canadian International 
Development Agency (CIDA), United Nations Children’s Fund 
(UNICEF), Eastern University of Sri Lanka, Italian Red Cross, 
International Committee of the Red Cross (ICRC), International 
Union for the Conservation of Nature (IUCN), Action Against Hunger 
(ACF), Veolia, Oxfam, US Army Corps of Engineers, ZOA Refugee 
Care, Medair, Solidarités, local NGOs and the local and national 
authorities, University of Copenhagen, US Science Foundation and 
other Sri Lankan and US universities. Funding for the work was 
provided by CARE and CIDA.
For more information
WHO guidelines: 
www.who.int/water_sanitation_health/hygiene/envsan/technotes/en/
index.html
IWMI report: 
www.iwmi.org/tsunami/pdf/Tsunami_Impacts_on_Shallow_Groundwat
er.pdf 
Field, laboratory and numerical studies:
www.fiva.dk/doc/thesis/Thesis_MVithanage.pdf
Improving the management of land and water resources for food, livelihoods and the environment 
All IWMI Publications are available online free of charge at www.iwmi.org/Publications
Comments and questions are welcome. Please contact us at: IWMI-Publications@cgiar.org
Publications Unit, International Water Management Institute, PO Box 2075, Colombo, Sri Lanka
Tel: +94 11 2880000 Fax: +94 11 2786854
www.iwmi.org
Issue 7 - 2010
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Helping restore the quality of drinking water after the tsunami

http://www.iwmi.cgiar.org/Publications/Success_Stories/PDF/2010/Issue%207%20-%20Helping_restore_the_quality_of_drinking_water_after_the_tsunami.pdf

Helping restore the quality of drinking water after the tsunami

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Research Papers in Economics