Water-Sensitive Urban Design (WSUD) Performance in Mitigating Urban Flooding in a Wet Tropical North Queensland Sub-Catchment
Existing wet tropical urban drainage systems often fail to accommodate runoff generated during extreme rainfall. Water-sensitive urban design (WSUD) systems have the potential to retrofit the existing urban drainage system by enhancing infiltration and retention functions. However, studies supportin...
Saved in:
| Main Authors: | , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2025-06-01
|
| Series: | Hydrology |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2306-5338/12/6/151 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1849432797892050944 |
|---|---|
| author | Sher Bahadur Gurung Robert J. Wasson Michael Bird Ben Jarihani |
| author_facet | Sher Bahadur Gurung Robert J. Wasson Michael Bird Ben Jarihani |
| author_sort | Sher Bahadur Gurung |
| collection | DOAJ |
| description | Existing wet tropical urban drainage systems often fail to accommodate runoff generated during extreme rainfall. Water-sensitive urban design (WSUD) systems have the potential to retrofit the existing urban drainage system by enhancing infiltration and retention functions. However, studies supporting this assumption were based on temperate or arid climatic conditions, raising questions about its relevance in wet tropical catchments. To answer these questions, in this study a comprehensive modelling study of WSUD effectiveness in a tropical environment was implemented. Engineers Park, a small sub-catchment of 0.27 km<sup>2</sup> at Saltwater Creek, Cairns, Queensland, Australia was the study site in which the flood mitigation capabilities of grey and WSUD systems under major (1% Annual Exceedance Probability—AEP), moderate (20% AEP), and minor (63.2% AEP) magnitudes of rainfall were evaluated. A detailed one-dimensional (1D) and coupled 1D2D hydrodynamic model in MIKE+ were developed and deployed for this study. The results highlighted that the existing grey infrastructure within the catchment underperformed during major events resulting in high peak flows and overland flow, while minor rainfall events increased channel flow and shifted the location of flooding. However, the integration of WSUD with grey infrastructure reduced peak flow by 0% to 42%, total runoff volume by 0.9% to 46%, and the flood extent ratio to catchment area from 0.3% to 1.1%. Overall, the WSUD integration positively contributed to reduced flooding in this catchment, highlighting its potential applicability in tropical catchments subject to intense rainfall events. However, careful consideration is required before over-generalization of these results, since the study area is small. The results of this study can be used in similar study sites by decision-makers for planning and catchment management purposes, but with careful interpretation. |
| format | Article |
| id | doaj-art-85e9e326112e495eb93b902f618ed9c1 |
| institution | Kabale University |
| issn | 2306-5338 |
| language | English |
| publishDate | 2025-06-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Hydrology |
| spelling | doaj-art-85e9e326112e495eb93b902f618ed9c12025-08-20T03:27:15ZengMDPI AGHydrology2306-53382025-06-0112615110.3390/hydrology12060151Water-Sensitive Urban Design (WSUD) Performance in Mitigating Urban Flooding in a Wet Tropical North Queensland Sub-CatchmentSher Bahadur Gurung0Robert J. Wasson1Michael Bird2Ben Jarihani3College of Science and Engineering, James Cook University, Cairns Campus, Cairns, QLD 4878, AustraliaCollege of Science and Engineering, James Cook University, Cairns Campus, Cairns, QLD 4878, AustraliaCollege of Science and Engineering, James Cook University, Cairns Campus, Cairns, QLD 4878, AustraliaCollege of Science and Engineering, James Cook University, Townsville Campus, Townsville, QLD 4811, AustraliaExisting wet tropical urban drainage systems often fail to accommodate runoff generated during extreme rainfall. Water-sensitive urban design (WSUD) systems have the potential to retrofit the existing urban drainage system by enhancing infiltration and retention functions. However, studies supporting this assumption were based on temperate or arid climatic conditions, raising questions about its relevance in wet tropical catchments. To answer these questions, in this study a comprehensive modelling study of WSUD effectiveness in a tropical environment was implemented. Engineers Park, a small sub-catchment of 0.27 km<sup>2</sup> at Saltwater Creek, Cairns, Queensland, Australia was the study site in which the flood mitigation capabilities of grey and WSUD systems under major (1% Annual Exceedance Probability—AEP), moderate (20% AEP), and minor (63.2% AEP) magnitudes of rainfall were evaluated. A detailed one-dimensional (1D) and coupled 1D2D hydrodynamic model in MIKE+ were developed and deployed for this study. The results highlighted that the existing grey infrastructure within the catchment underperformed during major events resulting in high peak flows and overland flow, while minor rainfall events increased channel flow and shifted the location of flooding. However, the integration of WSUD with grey infrastructure reduced peak flow by 0% to 42%, total runoff volume by 0.9% to 46%, and the flood extent ratio to catchment area from 0.3% to 1.1%. Overall, the WSUD integration positively contributed to reduced flooding in this catchment, highlighting its potential applicability in tropical catchments subject to intense rainfall events. However, careful consideration is required before over-generalization of these results, since the study area is small. The results of this study can be used in similar study sites by decision-makers for planning and catchment management purposes, but with careful interpretation.https://www.mdpi.com/2306-5338/12/6/151urban floodingwater-sensitive urban designgrey infrastructureflood mitigationtropical catchment |
| spellingShingle | Sher Bahadur Gurung Robert J. Wasson Michael Bird Ben Jarihani Water-Sensitive Urban Design (WSUD) Performance in Mitigating Urban Flooding in a Wet Tropical North Queensland Sub-Catchment Hydrology urban flooding water-sensitive urban design grey infrastructure flood mitigation tropical catchment |
| title | Water-Sensitive Urban Design (WSUD) Performance in Mitigating Urban Flooding in a Wet Tropical North Queensland Sub-Catchment |
| title_full | Water-Sensitive Urban Design (WSUD) Performance in Mitigating Urban Flooding in a Wet Tropical North Queensland Sub-Catchment |
| title_fullStr | Water-Sensitive Urban Design (WSUD) Performance in Mitigating Urban Flooding in a Wet Tropical North Queensland Sub-Catchment |
| title_full_unstemmed | Water-Sensitive Urban Design (WSUD) Performance in Mitigating Urban Flooding in a Wet Tropical North Queensland Sub-Catchment |
| title_short | Water-Sensitive Urban Design (WSUD) Performance in Mitigating Urban Flooding in a Wet Tropical North Queensland Sub-Catchment |
| title_sort | water sensitive urban design wsud performance in mitigating urban flooding in a wet tropical north queensland sub catchment |
| topic | urban flooding water-sensitive urban design grey infrastructure flood mitigation tropical catchment |
| url | https://www.mdpi.com/2306-5338/12/6/151 |
| work_keys_str_mv | AT sherbahadurgurung watersensitiveurbandesignwsudperformanceinmitigatingurbanfloodinginawettropicalnorthqueenslandsubcatchment AT robertjwasson watersensitiveurbandesignwsudperformanceinmitigatingurbanfloodinginawettropicalnorthqueenslandsubcatchment AT michaelbird watersensitiveurbandesignwsudperformanceinmitigatingurbanfloodinginawettropicalnorthqueenslandsubcatchment AT benjarihani watersensitiveurbandesignwsudperformanceinmitigatingurbanfloodinginawettropicalnorthqueenslandsubcatchment |