• Over half of priority landslide zones unmapped at 1:10,000 scale
• NAO flags gaps, cites funding and manpower delays for slow mapping
• Residents confused as warnings fail to specify exact high-risk locations

Despite identifying over 84,000 houses, shops, schools, and religious buildings in high-risk landslide zones, the National Building Research Organisation (NBRO) has left a significant portion of high-risk areas unmapped, according to the latest National Audit Office (NAO) report.

The audit revealed that of the 25,649 sq km selected for detailed mapping at a scale of 1:10,000, only 10,560 sq km had been surveyed as of the audit date. This leaves 15,089 sq km – potentially home to thousands of vulnerable structures – unassessed.

The findings come against the backdrop of Cyclone Ditwah, which caused widespread destruction in the country’s Central Province. 

Following the disaster, the NBRO faced severe criticism over the effectiveness of its landslide warnings, with residents claiming they were left confused about whether to evacuate or remain in their homes, as the alerts had failed to specify the exact high-risk locations.

However, in response to the audit report, the NBRO stated that the preparation of landslide hazard zone maps at a 1:10,000 scale required extensive field data, significant financial resources, and time. Unlike the broader 1:50,000 scale maps, detailed mapping is labour-intensive.

The organisation emphasised that 1:10,000 scale maps covering 10,560 sq km of the first-priority areas had already been completed, while the remaining areas were planned for mapping in the coming years.

The audit also highlighted financial management concerns. Treasury allocations totalling Rs. 236,767,553 had not been utilised for the intended activities and had instead been deposited in fixed accounts as of 31 December 2024.

These allocations had been intended for the landslide risk mitigation project, Sri Lanka chemical risk assessment project, resettlement programme for people living in high-risk areas with technical assistance, and the construction of office and laboratory facilities in Badulla and Kalutara.

The NBRO reported that delays and late funding affected the use of allocated resources: Rs. 134 million for the landslide risk reduction project is being utilised after receiving Rs. 100 million post-August 2024, with several contracts completed or nearing completion, while Rs. 19 million for the resettlement project has seen slow spending due to implementation delays. 

Construction of district offices and laboratories, with Rs. 81 million allocated, has been postponed following a Government suspension of new projects. The remaining Rs. 2.4 million for the chemical risk assessment project is set to be used to finalise the project, including stakeholder consultations and policy reviews.

The NAO has urged the NBRO to expedite these projects and ensure that allocated funds are fully utilised for their intended purposes.

The audit further revealed gaps in the early landslide warning system.

As of 31 December 2024, 330 automatic rain gauges had been installed across 14 vulnerable districts, but 67 were inactive. Of the 251 active gauges, only 192 were contributing to issuing early warnings, while 126 inactive gauges had not been reactivated. 

The NBRO explained that many of these gauges were over seven years old, with expired internal electronic components, making repairs costly and impractical.

The organisation stated that under the Climate Resilience Multi-Phase Programmatic Approach (CresMPA), all rain gauges were scheduled for replacement, with about 200 already installed at the time of the audit.

The NAO has recommended that the NBRO take urgent steps to expedite the mapping of landslide zones, ensure the full operational capacity of early warning systems, and utilise allocated funds as planned to minimise disaster risks.

When contacted by The Sunday Morning, NBRO Landslide Research and Risk Management Division (LRRMD) Senior Scientist Dr. Wasantha Senadeera explained that the organisation issued regional warnings because it currently lacked the specific data needed to provide localised risk alerts.

“We are issuing localised warnings only for areas where we have already identified relevant equipment, through which we collect data and provide alerts to those specific locations. At present, we do not have sufficient specific data to issue widespread localised warnings.

“However, we have already conducted awareness programmes and educated residents in risk-prone areas on how to remain vigilant during heavy rains. Collecting the data needed for localised warnings is a costly process and we are gradually working to build it,” he said.

Dr. Senadeera also highlighted that most landslides were manmade, noting that many people bypassed the NBRO certification process when constructing buildings.

He explained that obtaining a certificate cost around Rs. 15,000, but those unable to pay could apply through the respective grama niladhari to the NBRO. Following a thorough study, the organisation issues a certificate indicating whether the area is low, medium, or high risk.

Referring to satellite imagery from Cyclone Ditwah, Dr. Senadeera said that around 1,200 landslides had been identified, but approximately 900 of them did not cause any damage.

“Most of these disasters are due to unregulated development projects carried out across the country,” he said.

Responding to the NAO findings on mapping delays, Dr. Senadeera stated that the NBRO had been conducting mapping since 1985, but the slow progress was largely due to funding delays and insufficient human resources.

When asked whether mapping could have prevented the recent landslide disasters in Sri Lanka, he stressed that while mapping provided an indication of low-, medium-, and high-risk areas, even low-risk zones could experience landslides during severe events, which were inherently unpredictable.