Wadi Az-Zeimar has a catchment area of about 140 Km2 which starts from the eastern side at Nablus and flowing to the western side passing Tulkarm city to the Mediterranean Sea.
The main Wadi is going in the vicinity of Nablus-Tulkarm Street. As such the Street is crossed by the Wadi at several locations where Culverts had been constructed to handle the flood of the Wadi.
In January 2012, an extreme rainstorm event occurred in Palestine. As a result, a disaster flood occurred. The consequences were catastrophic, three persons killed and vast damages happened for buildings, Streets and other infrastructures.
General assessment indicates that the main reason behind such flood consequences is that the existing culverts failed to handle the peak flood flow. This can be attributed either to improper size of culverts or to the dumping of garbage in the Wadi which partially closing some culverts.
The main objective of this study is to conduct hydrological modeling to estimate peak flows at each culvert along the main Nablus-Tulkarm Street and accordingly to do the hydraulic design of the culverts.
To achieve this objective, the study started by data collection of all relevant information (contours, land use, soil types, rainfall data, etc.). The data was processed using ArcGIS so as to setup the rainfall runoff model, and HEC-HMS will be used to estimate peak flows given prepared input data from GIS. Culverts will be designed using culvert master given peak flows under different return periods from HEC-HMS Finally, ground truthing is planned to compare the obtained results with the existing ones and to do some conclusions and recommendations accordingly.