What you need to do to deal with flood risk and drainage.
When we make a decision on a planning application we'll consider flood risk and draining issues. It's more likely that we'll approve your planning application if the development will be built on land with a lower flood risk.
Flood risk areas in Bristol
To see areas of Bristol that are at risk of river and tidal flooding, you can look at a flood map at the Environment Agency website.
You can also look at maps of areas with a high risk of surface water flooding in the Strategic Flood Risk Assessment (SFRA) available in Planning evidence.
We've done some studies to find out more about flood risk in some parts of Bristol. This may be relevant to your planning application. Find out more at Planning evidence.
Development in flood risk areas
If you're carrying out development in a known flood risk area, there may be restrictions to make sure the development will be safe while it is in use.
We've prepared a pdf planning position statement for development in areas at risk of flooding from the river Avon (939 KB) .
This document does not introduce new policy requirements. It draws together existing strategy and policy to help applicants and communities assess how flood risk can be managed through development in Bristol.
If you make a planning application to carry out development in a flood risk area, we can carry out a Sequential Test to decide if there are other sites you could use that have a lower flood risk. Look at our pdf Flood Risk Sequential Test Practice Note (1.63 MB) for more information and to see if this applies to you.
You'll need to do a flood risk assessment as part of your planning application if your proposed development site is in a flood risk area or is larger than one hectare in size. Find out about flood risk assessments at GOV.UK.
If you're applying for a major development, we recommend you carry out a Sustainable Drainage Assessment. This will show you've followed national and local policies. It should also explain how you'll maintain your sustainable drainage system. If you get pre-application advice from us, you'll need to show us a proof of concept for how your site will be drained.
Avonmouth Severnside Enterprise Area project
We're working with the Environment Agency and South Gloucestershire Council to improve flood defences. This is part of the Avonmouth Severnside Enterprise Area Ecology Mitigation and Flood Defence Project.
Bristol Avon Flood Strategy
The Bristol Avon Flood Strategy sets out a strategic long-term plan for managing flood risk from the River Avon to Bristol and its neighbouring communities.
The approach has been approved by cabinet but this does not mean that development can rely on the flood defences being delivered at this time.
Significant additional investment over and above the funding identified in the business case is needed before there can be certainty that the defences will be delivered.
Find out more on our flood risk strategy and responsibilities page.
What to do about surface water drainage
You should consider surface water drainage at the start of your design process, as it is likely this will influence the rest of your design.
You need to use water management measures when carrying out development. This is to reduce surface water runoff and make sure it doesn't increase the flood risk in other areas.
Sustainable drainage systems (SuDS) are a way of managing surface water to reduce the risk of flooding and deal with any pollution in the water. Find out about sustainable drainage systems at GOV.UK.
All new developments should use sustainable drainage systems where possible. If you're applying for a major development, you'll need a detailed sustainable drainage system strategy.
There are technical standards for sustainable drainage systems at GOV.UK.
You should look at the West of England Sustainable Drainage Developer Guide before preparing your planning application:
- pdf West of England Sustainable Drainage Developer Guide Section 1 (2.76 MB)
- pdf West of England Sustainable Drainage Developer Guide Section 2: Bristol Local Sustainable Drainage Design Guidance (2.95 MB)
- pdf West of England Sustainable Drainage Developer Guide Section 2 Annex: Bristol Local Sustainable Drainage Design Guidance Note (827 KB)
SuDS case studies
Green roofs:
- pdf WoE SuDS Case Study 1: Ashley Vale green roof (980 KB)
- pdf WoE SuDS Case Study 2: At-Bristol green roof (839 KB)
- pdf WoE SuDS Case Study 4: Barton Hill green roof (1.30 MB)
- pdf WoE SuDS Case Study 7: Bristol University Auditorium blue green roof (579 KB)
- pdf WoE SuDS Case Study 8: Bristol Zoo green roof (1.15 MB)
- pdf WoE SuDS Case Study 11: Hartcliffe Children's Centre green roof (1009 KB)
- pdf WoE SuDS Case Study 13: Redland Green School SuDS (758 KB)
- pdf WoE SuDS Case Study 14: Riverstation Restaurant green roof (1.50 MB)
- pdf WoE SuDS Case Study 17: The Green House green roof (1.49 MB)
- pdf WoE SuDS Case Study 18: Maples Restaurant (854 KB)
- pdf WoE SuDS Case Study 19: Wessex Water Operations Centre SuDS (1.54 MB)
Ponds, paving and other systems:
- pdf WoE SuDS Case Study 3: Aztec West SuDS (1.36 MB)
- pdf WoE SuDS Case Study 5: Bristol Airport carpark SuDS (1.73 MB)
- pdf WoE SuDS Case Study 6: Bristol Business Park SuDS (1.13 MB)
- pdf WoE SuDS Case Study 9: CREATE Centre SuDS (2.35 MB)
- pdf WoE SuDS Case Study 10: The Dings SuDS retrofit (1.32 MB)
- pdf WoE SuDS Case Study 12: Knowle West Media Centre SuDS (169 KB)
- pdf WoE SuDS Case Study 15: Sanders Garden World SuDS (1.07 MB)
- pdf WoE SuDS Case Study 16: Stroud Co-housing SuDS (677 KB)
- pdf WoE SuDS Case Study 19: Wessex Water Operations Centre SuDS (1.54 MB)