The development at Chelmsford Riverside is a predominantly residential development of approximately 190 dwellings with some commercial space that is located along the west bank of the River Chelmer, in Chelmsford. The current site is a brownfield site that previously held the now demolished and relocated Chelmsford Leisure Centre. Given the proximity of the site to the River Chelmer there are active flow routes through the site for the design flood event and assessment was required to fully understand these flow routes and assess the impacts of the proposed development.
We were appointed to assess the flow characteristics of the site in its brownfield state, including storage and conveyance, and ensure that mitigation measures were included in the design to remove any adverse off-site impacts.
We worked closely with the regulatory body to develop a model that was updated with the latest information to accurately represent the characteristics of the brownfield site and to identify the metrics against which the performance of the developed site would be judged. The success of the design was judged upon off-site impacts in extreme flood events, level for level storage potential of the site, maintenance of flow corridors and flood resiliency of the built environment (including routes for access and egress).
WHAT WE DID:
STRATEGIC PLANNING / POLICY STAGE
- Water Flow Characteristics Assessment
- Flood Mitigation Advice
KEY ACHIEVEMENTS / BENEFITS
- We worked closely with the client and the architects, iterating the design by judging it against the key flow characteristics identified in the baseline model. These iterations significantly altered the proposed design ensuring that the resulting design iteration had sufficient low level amenity space along the lines of the existing flow paths and storage areas to maintain the flow characteristics of the baseline model by making space for flood water. This resulted in a good performance for the post development model when judged against the EA agreed parameters, and a resilient design that can be taken forward to planning.