CCCC SDC requested CDR to perform morphological calculations for the planned reclamation and breakwater progress of the Colombo Port City Development Project for the 2018 monsoon to analyse expected morphological changes of the ongoing reclamation during this period. An earlier set-up and calibrated morphological numerical model of this area was used for this task. Morphological computations were performed for 3 periods of 2 months, each using the relevant planned reclamation progress. Computations were done with varying Breakwater length as the progress before start of the monsoon was uncertain at that time. Based on analysis and recommendations by CDR of the initial reclamation planning, the planning was updated, and additional computations were performed. The morphological modelling and advice by CDR based on the results analysis were performed to optimize the reclamation planning and minimize sand losses.

CDR has carried out the requested morphological calculations with the following risk assessment:

  1. Analyse the sediment transport and local erosion / accretion;
  2. Analyse the amount of sand loss i) outside of the project area and ii) outside of design levels;
  3. Determine the safe distance between the Reclamation and Breakwater footprint such that earlier placed rock material will not be covered by sand material;
  4. What is the safe level for sand dumping in the NW area to avoid erosion.