N Old Kesbewa Road Old High Level Road
Boralesgamuwa Wewa
Rattanapitiya Ela
Maharagama-Dehiwala Road
Weras Ganga
Colombo-Piliyandala Road Maha Ela
Legend Scale 0 200 400 600 800 m Boundary of Sub-basin Principal Drainage Channel Urban Drainage Channel The Study on Storm Water Drainage Plan Figure 1.1.5 for the Colombo Metropolitan Region Boralesgamuwa South Sub-basin in the Democratic Socialist Republic of Sri Lanka JAPAN INTERNATIONAL COOPERATION AGENCY
A7 - F5 N Scale Boundary of Sub-basin Principal Drainage Channel Small Stream or Irrigation Creek Legend 0 400 800 1200 1600 2000 m High Level Road Maha Ela Moratuwa-Piliyandala Road Colombo-Piliyandala Road Weras Ganga Kospalana Bridge
The Study on Storm Water Drainage Plan Figure 1.1.6 for the Colombo Metropolitan Region Maha Ela Sub-basin in the Democratic Socialist Republic of Sri Lanka JAPAN INTERNATIONAL COOPERATION AGENCY
A7 - F6 N
Ratmalana Airport
Borupana Bridge Kandawala
Telawala Weras Ganga
Legend
Boundary of Sub-basin Kospalana Katubedda Bridge
Minor Tributaries
Scale 0 200 400 600 800 m
The Study on Storm Water Drainage Plan Figure 1.1.7 for the Colombo Metropolitan Region Ratmalana-Moratuwa Sub-basin in the Democratic Socialist Republic of Sri Lanka JAPAN INTERNATIONAL COOPERATION AGENCY
A7 - F7 N
Colombo-Piliyandala Road
Borupana Bridge Maha Ela
Weras Ganga
Moratuwa-Piliyandala Road Kospalana Bridge
Legend Scale Boundary of Sub-basin 0 200 400 600 800 m Minor Tributary or Creek
The Study on Storm Water Drainage Plan Figure 1.1.8 for the Colombo Metropolitan Region Thumbowila Sub-basin in the Democratic Socialist Republic of Sri Lanka JAPAN INTERNATIONAL COOPERATION AGENCY
A7 - F8 N
Dehiwala Canal
Dehiwala Zoo Galle
Kawdana Scheme Hill Street (1.6 km2) K4
K2 Bolgoda Canal Rattanapitiya Ela
K1 K2 Bellanwila-Attidiya Marsh Attidiya Road
A6 A2 A4
A3 A5
A7 Weras Ganga
A1
Colombo Airport Attidiya Scheme (2.7 km2)
Legend Boundary of Sub-basin Principal Drainage Channel
GCFC&EIP Phase III Scale Drainage Area 0 200 400 600 800 m Urban Drainage Canal / Conduit to be Improved
The Study on Storm Water Drainage Plan Figure 1.9.1 for the Colombo Metropolitan Region General Plan of GCFC&EIP Phase III in the Democratic Socialist Republic of Sri Lanka JAPAN INTERNATIONAL COOPERATION AGENCY
A7 - F9 N Bellanwila-Attidiya Marsh
Bolgoda Canal Weras Ganga Swamp Channel Width: 100 to 500 m Channel Depth: 1.5 m Riverbed Level: -1.0 m
Ratmalana Airport
Natural Stream Channel Width : 60 to 160 m Borupana Bridge Channel Depth: 1 to 1.5 m Opening Width 30m x 2-span Riverbed Level: -1.2 to -0.9 m
Maha Ela
Natural Stream Channel Width: 160 to 600 m Ratmalana-Borupana Road Channel Depth: 1.5 to 2 m Riverbed Level: -1.5 to -0.6 m
Natural Stream Channel Width: 40 to 160 m Channel Depth: 2 m Riverbed Level: -1.5 to -1.3 m
Moratuwa-Piliyandala Road
Moratuwa University
Scale Kospalana Bridge 0 200 400 600 800 m Opening Width 12m x 3-span
The Study on Storm Water Drainage Plan Figure 2.2.1 for the Colombo Metropolitan Region Present Condition of Weras Ganga in the Democratic Socialist Republic of Sri Lanka JAPAN INTERNATIONAL COOPERATION AGENCY
A7 - F10 Borupana Bridge Maha Ela Confluence Distance (m) Weras Ganga Katubedda Tributary Confluence Kospalana Bridge Left Bank Right Bank Bed North Bolgoda Lake Weras Ganga 0 500 1000 1500 2000 2500 3000 3500 4000 4500
5 4 3 2 1 0 -1 -2 -3 Elevation (above MSL) (above Elevation
The Study on Storm Water Drainage Plan Figure 2.2.2 for the Colombo Metropolitan Region Longitudinal Profile of Weras Ganga in the Democratic Socialist Republic of Sri Lanka JAPAN INTERNATIONAL COOPERATION AGENCY
A7 - F11