Restoration of ancient sewerage system in Galle Fort

In 1976 IJmuiden (Municipality of Velsen) and the Northsea Channel existed 100 years. Because of that event the Municipal Council of Velsen had the wish to start a relationship with a city in the Third World. They came to know that the city of Galle, Sri Lanka, eagerly wished a twinning with a Dutch city, preferably lying at the coast and with a fishery industry. So, the twinning started. In 1985 SOS Velsen (Foundation Development Co-operation Velsen) was erected, in order to execute the twinning on behalf of the Municipal Council.

A unique feature of the Galle Fort is the underground drainage system constructed beneath the roads. The Dutch who decided that Galle should be their administrative capital of Ceylon built this system. The underground drains served as a sewerage system as well as an outlet for rainwater. The cleaning out of the sewers was by a system of flushing using seawater. A windmill had been set up in 1888 in the British period to raise the seawater to flush out the sewer. The total length of the drain system is approximately 3500 metres and there are 8 outlets to the sea.

In 1985 Dr. Hella Wellmer, residing in Portugal, did a survey of the old drainage system and found out that coral and sand, which had come into the system by high tide, blocked the system, it blocked the system. At several places, this caused still standing pools in which malaria mosquitoes could prosper well. Dr. Wellner also discovered that it was not the seawater that cleaned the sewers, but the rain. To renovate the drainage system an amount of 100.000 Dutch guilders was necessary. The Municipality of Velsen contacted the Ministry of Foreign Affairs in order to see whether the project could be executed jointly. The Ministry of Foreign Affairs and SOS Velsen both spent 50.000 Dutch guilders.
Around 1992-1994 a special project was set up to clean the drains. This was carried out by the Municipal Engineer’s Department, Mr. Dayasena. However since then no major cleaning has been done and after the tsunami an inspection revealed that the drain system had been severely damaged. The drains were completely blocked and some arches were collapsed.

OBJECTIVES
An inspection revealed that the drain system had been severely damaged. The drains were completely blocked and some arches were collapsed. Therefore, this project aimed at clearing the system, reconstructing the walls, the arches and of the side drains of the roads.

RESULTS
The project was carried out between 1992 and 1994 with the assistance of the NAAL (Netherlands Alumni Association of Sri Lanka). In 1994 dr. Wellmer noticed that the sea-bottom in front of the outlets to the sea had to be dragged out, otherwise the rough sea in monsoon times would block them in short time again. However since then no major cleaning had been done and after the Tsunami on December 26th 2004, inspection revealed that the drain system had been severely damaged. The drains were completely blocked and some arches were collapsed. Therefore, a next project was implemented in a Master Plan since the 1st of July 2006, which aims at clearing the system, reconstructing the walls, the arches and of the side drains of the roads. The project should be completed at the end of 2008.