Fresh water supplies are under threat in tsunami-hit countries, says a UN Environment Programme (UNEP) interim report. Thousands of wells are contaminated by salt water, sewage and hazardous materials. In Indonesia, an estimated 60,000 wells and 15,000 hand pumps have been contaminated, damaged or destroyed. In Sri Lanka, 62,000 water wells are contaminated with salt water or sewage. Groundwater in 30 Maldives islands has been contaminated by sewage, and 90% of rainwater tanks have been damaged.

UNEP's mission The highest priority is to clean, repair and replace damaged wells, sewage lines and water distribution systems. Hazardous debris piled up by the backwash of the tsunami is a major concern. In Somalia, hazardous wastes contaminated groundwater.

UNEP recommends restoring mangrove forests and traditional fish and shrimp farming and replanting coastal forests. There is evidence that the tsunami caused less damage where coasts were protected by coral reefs, mangrove swamps and vegetative sand dunes. Buildings should be designed to protect people. Many mosques survived because open ground floors allowed waves to pass through.

http://www.unep.org/tsunami/reports/TSUNAMI_report_complete.pdf