serangoon reservoir catchment forest

footpath flats housing urban landscape asia serangoon blocks nature woods water shrubs clear woodland island lush national garden ecosystem freshwater area hdb town marsh buildings bushes plants cool trail security sky apartment tropical forest corridor trees leaves track environment recreation brackish buangkok catchment green mangroves singapore park sengkang rain channel effect punggol natural wetlands district greenery river ecological vegetation manmade cloudy secondary suburbs dense space suburban heat foliage rural reservoir city road purify back rainforest neighbourhood aquatic public estate residential