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Ganl. Bull. Singapore 70 (Suppl. 1) 2018 
4 
Legend 
■-- Stream 
9 Po«*t Source ( 9 A 96 ) 
A Po.fftSou.reo ( 9 C. 9 DI 
Elevation 
I j 0 9 - is 
16 - 26 
■§ 29-44 
IB 44 - f>2 
■ 92-Si 
A 
0 500 1,400 
'-CTftrf?-' 
Fig. 7. Locations of the proposed point sources for drought mitigation management strategies 
of Scenario 9. 
Fig. 7, and discharge rates (volume) are inserted and simulated in the numerical model. 
Fig. 8 and Fig. 9 respectively present the simulated groundwater table maps and 
surface water maps in their current condition, after 5 years of Scenario 9, and after 5 
years of Drought Mitigation Management Strategies 9A, 9B, 9C and 9D. The point 
sources of Strategies 9C and 9D are located in the catchment downstream (nearer to 
the stream) as compared to Strategies 9A and 9B. Therefore, the piped-in water in 
Strategies 9C and 9D has more direct effect in nourishing the swampy area near the 
stream than in Strategies 9A and 9B. 
Fig. 10 illustrates a suggested drought mitigation system for management of the 
point source strategies. A pump and pipe system would be required for Strategies 9 A 
and 9B, whereas Strategies 9C and 9D would only need a pipe system due to the lower 
elevation of the point sources than the maximum operating reservoir water levels 
(thus, a gravity flow system). Despite providing lower coverage, a pipe system would 
not only incur lower cost in construction and management, but would also require less 
water consumption compared to a pump and pipe system. 
Severe flood case 
Flooding often results in poor soil aeration, polarisation of soil pH, accumulation of 
organic matters, unfavourable sedimentation and/or erosion, etc. It, therefore, hampers 
