In a tropical country like Malaysia, the availability of research works to monitor channel changes as a response to situating a dam over an observation period may help to establish new management strategies. These investigations will constitute a vital approach in assessing the changes to channel morphology downstream due to the presence of a dam and its operations. In the present study, the effects of Kahang Dam on Kahang River morphology, in particular, the downstream section was investigated and analyzed between January 2017 to January 2018. The rainfall pattern of the study period, the flow regime concerning the period, and geomorphological channel adjustments were carried out during the field surveys over a 400 meters reach. Different responses were leading to high flow and low flow regimes during periods with and without any interference due to dam operations. Similarly, the river channel was characterized by adjustments and realignments, causing modifications to the river morphology. Changes in cross-sectional area and local incision were also noticed as a direct response to sediment deficit and bank erosion process.

Urbanization in Malaysia has contributed to the increased of volume runoff to the drainage system. SUDS (Sustainable Urban Drainage System) / MSMA (Manual Saliran Mesra Alam) has been implement in Malaysia within several of components. Hence, swale is one of the designed and suggested by SUDS or MSMA in order to control the quantity and quality storm water runoff. The present study aimed to determine the quality of storm water runoff in swale and to analyse storm water runoff treatment using sand column as a part of filtration process.  Water quality parameters tested included COD, BOD5, DO and TSS. The samples was test with sand column on D30, D60, D90 and DMIX. The results revealed that sand column improved the water quality by 4% to 80%. In conclusion, the sand column can be used to improve the storm water quality and can enhance the natural habitat.