Land instability started in the area around the 98 km post on the Colombo-Kandy road in the Pahala Kadugannawa area of ​​the 25 / A Ganetenna Grama Niladhari Division in the Mawanella Divisional Secretariat in the Kegalle District and the tension cracks developed on 2021-11-10. Officials from the National Building Research Organisation (NBRO) conducted a preliminary field study of the site. NBRO and the Road Development Authority (RDA)  are taking urgent actions to temporarily close the main road on the instructions of the Kegalle District Secretary in view of the dangerous emergency situation prevailing at the site.

Following steps taken as short-term measures

1. Covering the cracks associated with the upper slope of the unstable zone
2. Introduce a surface drainage system to regulate the surface drainage pattern in the upper zone of the potential unstable slope and divert rainwater from the unstable zone.
3. Construction of 6-8 horizontal drains depending on the location of the land for quick removal of ground water collected internally from the unstable zone.

4. A geophysical survey was carried out along the main axis of the unstable zone and along two selected axes along the unstable slope zone parallel to the Colombo-Kandy main road to study the thickness and slip surface depth of the surface of the unstable zone.

According to the geophysical investigation carried out on the above unstable ground and the available data, there is a layer of soil about 5-6 m thick around this place and depending on the location of the rock in the interior (undulating surfaces of the bed rock / Corrugated nature) it is also observed that there is a natural resistance to move down this volatile zone.

The gradual increase in stress cracks created in this unstable zone was observed in 11 locations over the past 3 days. According to the data, a slight displacement is observed in these areas, but no significant horizontal or vertical displacement has been observed so far.

NBRO and the RDA have been able to temporarily control the situation. In view of the above, the NBRO has proposed to open the Colombo-Kandy main road to traffic in the above zone since 17^th November 2021 in accordance with the recommendations made by the NBRO under normal weather conditions.

It is imperative to introduce long-term sustainable methods designed based on the data obtained from the preliminary research currently being conducted and the results of future detailed studies. A report containing detailed plans will be issued in the near future.