Opportunity
During heavy rainfall events around 100 homes on the Brunton Park estate in Newcastle were identified as being at risk of flooding. In the search for a sustainable, cost-effective flood protection solution, a key aspect of the multilateral investigation was the critical interaction between water levels in the Ouseburn, a small river that flows into the Tyne, and the drainage systems on the estate.
Solution
We built a hydraulic model using InfoWorks CS to analyse the causes of foul and surface water flooding in the area. Our model was verified using flow monitors and rain gauges, and through extensive manhole, topographical, CCTV and sonar survey work. We merged our model with the Environment Agency’s river model to identify options to reduce the risk of flooding. This enabled us to eliminate the unviable or unfavourable options. The combined model was placed in the ICM (integrated catchment modelling) solution and the preferred option enhanced using 1D and 2D aspects of the software.
Key to the preferred option was the creation of a 380m channel set back from the estate to divert the Ouseburn from its existing route. This solution provided the following changes:
- surface water drainage outfalls from the estate could discharge freely into the old river channel
- creation of a 9,400m3 sustainable urban drainage system (SuDS) area by widening the old river channel to provide storage for discharged surface water
- creation of 0.5ha water dependent habitat
- restoration of areas of lowland heath and variations in the watercourse bank and bed profiles to maximise ecological diversity
- addition of Kingfisher tunnel, perches and otter holts
- construction of a flood defence embankment adjacent to the new channel, reducing the risk of inundation of Brunton Park from the Ouseburn
- collaboration with the community to reinstate a play park and reduce disruption to an adjacent golf course
Outcome
Our innovative solution created a natural sustainable asset that reduced both project and whole life costs, meeting the requirements of parties and significantly reducing the risk of flooding. It also provides valuable additional water dependent habitat and benefits to the local community. An ecological report commissioned early in the project highlighted environmental constraints and opportunities for enhancement. An objective was established to bring the Ouseburn up to ‘good ecological potential’ standard under the EU Water Framework Directive.
Stakeholder engagement and collaboration were key to the success of the project. Disruption during construction was a significant issue for the local community, and Newcastle Golf Club had concerns regarding the impact of the scheme on the course due to the re-aligning of the Ouseburn. Adjustments were made to the original proposals and the new diverted channel incorporated into the golf course, while taking onboard feedback from consultations with residents and councillors ensured the final design for the scheme got local backing. An engagement plan ensured Brunton Park residents, golfers and other third-party stakeholders received regular updates.
The Brunton Park scheme is regarded as an excellent example of a sustainable approach to flooding. It has been included in Blue Green Cities consortium research with the findings bringing together Newcastle City Council, the Environment Agency and Northumbrian Water in being the first organisations in the UK to explicitly commit to installing sustainable installations where possible.