Flooding Risk

Anybody who lives downstream from The Ridge will know that a lot of surface water runs into the valleys, paths and roads around St. Helen’s Woods. 

In the area, heavy rains in recent years have led to: 

  • deep crevices appearing in unpaved roads (such as St Helen’s Wood Road) that residents have had to repair

  • stream bank erosion

  • falling trees

  • landslips 

  • the undermining of the dam in St Helen’s Woods, resulting in the loss of the pond that supported a variety of wildlife

The unpredictability of rainfall is not expected to improve as climate change progresses.

In February 2025, a flood risk assessment report for the development, by HydroGround Civils, concluded that “A robust flood risk assessment will need to demonstrate how flood risk impact

downstream as discussed in this report can be mitigated.” 

It noted that there is a risk of flooding, and that “Improper management of surface water runoff generated by impermeable areas at the allocated land could potentially worsen this risk, with heavy impacts downstream.”

Currently, Sandrock Bends acts like a sponge, absorbing a good deal of this water. The development would remove this safety feature and worsen the chance of flooding, increasing the risk for the entire Blacklands Area, Alexander Park, and the town centre.

Anyone living downstream from The Ridge could be affected.

Please click here to see the report.

Relevant Comments from the Government National Planning Policy Framework

Inappropriate development in areas at risk of flooding should be avoided by directing development away from areas at highest risk (whether existing or future). Where 49 development is necessary in such areas, the development should be made safe for its lifetime without increasing flood risk elsewhere.

All plans should apply a sequential, risk-based approach to the location of development – taking into account all sources of flood risk and the current and future impacts of climate change – so as to avoid, where possible, flood risk to people and property. They should do this, and manage any residual risk, by: a) applying the sequential test and then, if necessary, the exception test as set out below; b) safeguarding land from development that is required, or likely to be required, for current or future flood management; c) using opportunities provided by new development and improvements in green and other infrastructure to reduce the causes and impacts of flooding, (making as much use as possible of natural flood management techniques as part of an integrated approach to flood risk management); and d) where climate change is expected to increase flood risk so that some existing development may not be sustainable in the long-term, seeking opportunities to relocate development, including housing, to more sustainable locations.

Within this context the aim of the sequential test is to steer new development to areas with the lowest risk of flooding from any source. Development should not be allocated or permitted if there are reasonably available sites appropriate for the proposed development in areas with a lower risk of flooding.

Applications which could affect drainage on or around the site should incorporate sustainable drainage systems to control flow rates and reduce volumes of runoff, and which are proportionate to the nature and scale of the proposal. These should provide multifunctional benefits wherever possible, through facilitating improvements in water quality and biodiversity, as well as benefits for amenity. Sustainable drainage systems provided as part of proposals for major development should: a) take account of advice from the Lead Local Flood Authority; b) have appropriate proposed minimum operational standards; and c) have maintenance arrangements in place to ensure an acceptable standard of operation for the lifetime of the development.