Hydrological and environmental processes in railway drainage systems: towards sustainable drainage system (SuDS) approaches

As a result of climate change and urbanization, more frequent flooding, diffuse pollution, and unsatisfactory combined sewer overflows (CSOs) are impacting on the quality of life and wellbeing of urban dwellers, and on the ecological status of water systems. Sustainable drainage systems (SuDS) have been developed to manage stormwater at source, control flooding, CSOs and diffuse pollution and, if vegetated, promote ecosystem services and reduce urban heat islands.

The main focus of this project is to investigate hydrological processes in railway systems to optimize the design of new railway track drainage systems and retrofit SuDS in existing systems. The project aims at addressing an increasing disconnection between current storm water management and runoff discharges from railways and the recent legislation on flood prevention and water quality. Current design methods do not allow drainage engineers to bridge this gap.

This project addresses virtually all railway drainage systems installed within the United Kingdom, and within other countries. The value of work carried out on railway track drainage throughout the UK is substantial. For the year 2013-14, Network Rail reported that about 44.5km of drainage was renewed at a value of over £20m. In 2013, Network Rail estimated the total expenditure on railway track drainage up to 2019 would be approximately £40m. Records from the Western Route Region show that in the year 2012/13 there were 32 flooding incidents resulting in 8724 cumulative minutes train delays. This region also reported that between 2009 and 2012 there were over 1500 incidents of waterlogged railway foundations annually, potentially resulting in settlement, train delays and potential derailments.

The project aims at developing a methodology to simulate the hydrological behavior of railways systems which will allow assessing their impact and evaluating different sustainable drainage system design options.

Within the project, the latest storm water management guidance issued through the regulatory authorities, the latest design criteria for SuDS, and the requirement of the Network Rail design standards will be reviewed. As part of the project, previous research regarding drainage systems in railways and different modeling methods relevant to the purpose will be assessed. There is a lack of existing data from railway drainage systems to calibrate and validate proposed modelling approaches, thus the project aims at collecting hydrological data through a monitoring programme in selected railway sites. The methodology will be tested using c. 30-years UK climate change, based on best climatic model projections (UKCP 09).

This project is in collaboration with ARUP that will also provide liaison with the railway companies.

The main stakeholders for railway drainage are the railway infrastructure owners, including Network Rail, London Underground, MerseyRail, Nexus, the train operating companies and the Government (a significant proportion of the funds to run the railways is public money) and Environment Agency and DEFRA.

Applications are invited from candidates who hold a First or Upper Second Class Honours Degree (or equivalent) in an engineering or scientific discipline with a strong environmental or water related focus. Due to the nature of the project initiative and motivation to work in an interdisciplinary research environment are essential. Knowledge of storm water management and subsurface flow processes would be an asset, along with strong communication and team working skills.