The drainage system is a very important in flood
management in srilanka. In Colombo city some locations are heavily affected by
flooding. The main reason for this flooding is urbanization, population and
changes in climate. If the urban flooding occurs there can be a disaster for
environmental as well as infrastructure damages such as roads, buildings, houses,
and the lives of people as well as
their properties. the existing drainage system is very ancient and design on the early design data’s.
So, in order to do some modification in an efficient way to overcome the
flooding. The main aim of drainage system is to dispose of rain water and
sewages to overcome un wanted diseases and pollution to the environment. The increase
of urbanization may lead to flood discharge where there are changes in surface
profile also causes runoff patterns. When we compare the forest land and the urban
land we can clearly see that in forest land surface runoff is very low
percentage and in the urban land the percentage of the surface run off is very
high. From this how the urbanization influence in the flood management in
For the drainage system for the Colombo city is
planning to design in SWMM (Storm Water Management Model) which is very easy to
design by inputting hydrological data’s.
Colombo city is busy city in srilanka. So, in order to
do a flood management in a proper way.so we have to design a good drainage
system to overcome the flooding. If the flooding occurs because of poor
drainage system and causes damages to human beings as well as property. So Give
a good solution is a must in Current scenario.
Significance of the research
as all now
that flooding is a natural disaster. We can’t stop that as we want.so we must
make a solution to over come that issue in Colombo city. urbanization in
Colombo city is a main problem for flooding. but we can’t stop the urbanization
because of Colombo city is very much people are dense because of the higher
studies and career development.
So, any way we have to do some analysis on flood
management in Colombo city. First we have to do the analysis in the critical
area which is heavily affected by flooding.so if we do this research in very
effective manner in the end of this we can clearly give a valuable results to
the people who are affected .so in that view the drainage system development is
very useful for the nation. We have identified the issues in that existing
system and do modification or design a new drainage system according to the now
a day’s climate changes and futures expectation. That is also very useful for
future generation as well.
Scope of the study
For the case study we are using SWMM (Storm Water
for analyzing the results of the existing drainage system
and find out the blunders in that system using this software. This is very commonly
used software and effective tool in utilized flooding.
From the SWMM software we can design the drainage
system as we want and also we can adjust the current drainage system. For the
particular area. first we have to identify the catchment area and also receive
of precipitation. Then we must get the rainfall data’s and other relevant
things from the department. Not only that we must identify the sub catchment
area and find out the quality and quantity of run off generated in each area.
From SWMM software
Time to time varying climate changes as the reason for
Evaporation from the surface
Infiltration in to the ground
this consideration should be done in SWMM software
then only we can design a perfect drainage system.
Aims and Objectives
Identify the most critical frequently affected area in
Colombo city and develop a drainage system with very cost-effective manner to
the nation people.
Analyzing and finding critical area in Colombo city where
flooding occurs frequently
Gathering data’s in particular zone from the relevant
department such as rainfall ,run off data’s and other hydrological data’s
Interview the residence people about their problem when
Get an rough idea about the run off land profile of the area.
Get familiar with the SWMM software for the designing.
Design the drainage system using gathered information in
Finalize the model and implementing the design