Abstract:
The pipe-borne drinking water supply systems have been in operation since the
colonial period in Sri Lanka. After the Independence, and with the involvement
of the Galoya Development Board, the water supply system was developed
covering the township of Ampara district also, and it was later taken over by
National Water Supply & Drainage Board. The distribution system was extended
from time to time in surrounding areas in an ad-hoc manner. There was no proper
hydraulic model available to identify the sizes of pipes and capacity of storage
required to satisfy the demand without any “no water” complaint. Hence, this
research was undertaken to identify whether the existing system is adequate to
supply water to satisfy the required demand in the Ampara region. Furthermore,
this study also covered the capacity of storage tanks and sizes of pipelines
required to satisfy the demand after ten years and twenty years of period. In this
research, Existing pipe networks of the Ampara region were drawn in Arc-GIS
and WaterGem model was developed to identify the pipe sizes and storage
capacity of tanks. The results show that, since the existing elevated storage tanks
are not enough for direct supply throughout the day, the network bypassed
the pumping pipeline. Moreover, storage tanks were used as balancing tanks
while introducing necessary controls. Furthermore, to maintain limited residual
pressure and required flow in the system, a variable frequency drive pumping
system is introduced at the pumping station and inconsistency in the network
model has been improved while introducing necessary changes for physical
components. The proposed physical changes are documented for construction
relevant to this field in the future.
