As part of the ‘Clean Water For All’ (CWFA) research initiative, Dr Sangaralingam Ahilan travelled to the U.S. on 3rd May for two weeks for co-location research work with U.S. academics at Portland State University (PSU) in Portland, Oregon. This post describes Sangaralingam Ahilan’s personal and research experiences of his first visit to Portland, Oregon.
Portland is a Blue Green city in which people and nature can co-exist in the highly developed urban environment. The city actively promotes storm water management through onsite infiltration and flow control measures to reduce storm water runoff into the street and sewer. In most parts of Portland, separate storm sewer systems are being implemented to overcome the risk of Combined Sewer Overflows during prolonged rain storms. This will help protect water courses from microbial pollution and greatly benefit human health, fish and wildlife habitat.
The UK team research work in Portland is mostly centred on the Johnson Creek (JC) which is one of the highly urbanised streams known for frequent flooding and does not meet water quality standards under the Federal Clean Water Act. The Bureau of Environmental Services (BES) carries out extensive restoration work along the JC reaches to return its floodplain to natural condition in order to provide more space for river flow and storage, which will enhance flood mitigation, water quality, and fish and wildlife habitat. Ahilan’s research is focused on the JC reach (East Lents) and JC sub watershed (Errol Heights).
The East Lents reach is one of the reconfigured banks of Johnson Creek and reconnects the reach to a restored floodplain on a 70-acre site with native forest. The Errol Heights sub watershed is mostly with unimproved streets, this causes substantial erosion and sediment yield from the unimproved street network into the urban drainage, resulting in blockages. The objective of this study is to integrate flood and sediment dynamics of these sites through detailed hydrodynamic and morphodynamic modelling. Utilising these models allows researchers to understand the existing sediment dynamics and explore potential blue green interventions to minimise the sediment movement into the urban drainage system and into the river.
In summary Ahilan was really convinced by the progress of the City of Portland through ‘grey to green’ initiative over the last decade. He strongly believes that this is the only way to cope with rapid urbanisation resulting from socio economic development and uncertain climate change in the developed and developing world during our lifetime and for future generations.
Let Knowledge Serve the City ……– Portland State University motto