Comment

Representation ID: 22205

Received: 16/03/2020

Respondent: Environment Agency (Eastern Region)

There are many sites within Norwich which are adjacent to the River Wensum (GNLP2137, GNLP0409R, GNLP0360, GNLP0377, GNLP0401, GNLP0068, GNLP3053), firstly we need to ensure that SuDS within the development are sufficient to protect the water quality of the River Wensum and secondly any opportunities to improve riparian habitat to mitigate against the impacts of the development would help us to secure improvements necessary to meet good WFD status and help ensure that the development does not cause any deterioration.

GNLP0409R
The site lies almost entirely in Flood Zone 2 present day, however once climate change is applied to the flood levels, the site lies mainly in future Flood Zone 3a.
The development should be sequentially sited in future Flood Zone 1 where possible.
If development is required to be sited within these future Flood Zone 3 (1% annual probability with 35% climate change) and Flood Zone 2 (0.1% annual probability with 35% climate change) flood outlines then the more vulnerable development, and ideally the less vulnerable development too, will need to be designed with floor levels raised 0.3m above the flood levels for the future 1% (1 in 100) annual probability flood event with 35% and ideally 65% allowances for climate change. Refuge will also need to be provided above the 0.1% (1 in 1000) annual probability 25% climate change flood levels. Compensatory flood storage will also need to be provided for any built development or land raising within the 1% (1 in 100) annual probability flood outline with 35% climate change.
We note that there is an extant planning permission for the site, to which we had no objection, so these requirements should have already been taken into account.