The second temple in Mount Edgecombe was the Gengaiammen Temple, on the banks of the Duma Dam. The dam was named after the managing director and chief chemist of the mill, Alfred Dumat. The dam was built in 1878 to supply water to the mill and the community of Mount Edgecombe. The Temple Committee approached the company management to build a temple dedicated to Gengaiammen – Goddess of rivers, oceans, lakes and dams. Permission was granted and the Gengaiammen Temple was built with wood and iron close to the dam. The Hindu community offered annual Amman prayers to Mother Gengaiammen to keep the dam full at all times.

In 1935, heavy rains and flooding burst the dam walls and washed away the Gengaiammen Temple. William Campbell stopped the operation of the mill and ordered all workers to help rebuild the dam walls with hessian sugar bags filled with sand. He also provided cases of brandy to keep workers warm while they worked in the wet and damp conditions.

In 1935, the new Gengaiammen Temple was built on higher ground. In 1995, the Gengiammen Temple was relocated to the Kaliammen Temple grounds. This was to accommodate the development of a golf estate around the dam. The Committee objected strongly to the temple being demolished, but gave in/submitted to re-siting the deities to the present Kaliammen Temple location.