A parish councillor said that a ‘catastrophic’ network of drainage and sewage systems have led to persistent flooding in Pulborough.
Chairman of the Planning and Service Committee for Pulborough Parish Council, Andy Tilbrook, has been fighting for the council and Southern Water to properly monitor and maintain the village’s drainage and sewage pipes for many years, but the resident said an accumulation of development decisions have ‘amplified’ the problem.
Dr Tilbrook studied a Victorian map of Pulborough that shows an open stream at the bottom of the hill that was fed by the Great Pond and ran through the village centre.
This has since been covered over and the stream directed through an underground pipe, which runs below the A29, behind Pulborough Police Station, past Pulborough Medical Centre and westwards under the railway line.
“So if you put the stream, which took all the drainage from the hill into a pipe, the water can’t get into the stream very easily anymore,” said Dr Tilbrook. “When the Riverside Estate development by Sainsbury’s was built, another stream was diverted into there, so automatically this pipe is taking more water than it used to.”
A line of springs, when they flow, also add to the drainage water, causing a greater build up. “The real tragedy is you can see how successive planning decisions have accumulated a number of bad things, so that the drainage and sewage system is now frankly overwhelmed.”
The map also indicates the old course of the River Arun before it was straightened out for barges to navigate through more easily, but Dr Tilbrook said that by the 1930s the sewage pipe was directed along a section of the River Arun’s original course where the soil is still loose.
“When the springs run down they undercut the sewer system and that pipe is now sagging quite dangerously and it’s gotten blocked up fairly regularly.”
Dr Tilbrook claimed that Southern Water have submitted a plan to their regulator, Ofwat, to re-divert a lot of the sewage flow as part of their next ‘five year business plan’ in 2015, but the regulator must approve the proposal first.
“If the regulator does approve it then work isn’t necessarily done before 2020 and that could be a long time. It’s a convoluted process and we’ll need to find ways to get things done at a faster rate.”
Asking the question, can we take anymore significant developments in the village? Dr Tilbrook answered ‘no’.
The responsibility for drainage pipes was recently handed over to West Sussex County Council, but with further cutbacks, Dr Tilbrook is concerned that a solution to the problem is now less feasible.
The parish councillor said three factors need to be considered in order to solve the ongoing flooding plight.
One, Dr Tilbrook suggests that Southern Water should monitor the sewers and the impact of drainage water on the system. Secondly, the district councillors should insist that Southern Water make these calculations before the committee approves a new development. Finally, he recommends the county council and Southern Water assess how much springs will impact new developments during heavy rainfall.
A spokesperson for Southern Water said that any new development assessments made take into account wastewater capacity and potential growth.
“Strategically, we forecast long-term growth using predictions from a range of sources to inform our plans for the future, including where we may need to invest to improve or expand our assets, for example, our water mains network, our wastewater / sewer network, our water supply works and wastewater treatment works.
“To ensure that our wastewater assets have the capacity to meet local requirements, at a local level we use Local Development Frameworks to inform where growth is expected to occur to allow us to plan and prepare accordingly.
“We work closely with council planning departments and developers to help ensure that we have a clear picture of likely future demand for our services.” Southern Water added that it is not responsible for surface water, land drains or highways drainage.