North Kent Marshes Policy Unit: Thames Estuary 2100
What needs to be done to manage flood risk and adapt to rising sea levels in North Kent Marshes, one of 23 policy units in Thames Estuary 2100 (TE2100).
Applies to England
Map centred on the North Kent Marshes policy unit boundary. This extends from Gravesend to St Mary’s Marshes and includes Cliffe. The map extends 3 kilometres (km) north, 2.5km south and 1km east and west, to show areas surrounding the policy unit boundary. The flood risk layer shows there is a 0.1% or higher chance of flooding each year in most of this policy unit without the existing flood defences. In some areas, defences reduce the risk of flooding, particularly in the south west of the policy unit in the Gravesend area.
Description
The North Kent Marshes Policy Unit consists of 2 large areas north and west of the village of Cliffe. It extends from Gravesend to St Mary’s Marshes and includes Cliffe. There is little development apart from the east end of Gravesend.
The councils responsible for this area are:
- Gravesham Borough Council
- Medway Council
The area is a Site of Special Scientific Interest (SSSI).
There are extensive open drainage systems on:
- Shorne Marshes
- Higham Marshes
- Cliffe Marshes
- Halstow Marshes
Use the Thames Estuary 2100 (TE2100) map to view all the policy units.
Local areas at risk and types of flooding
The types of flooding that could affect this policy unit include:
- tidal flooding – when the tide overtops flood defences
- fluvial flooding from local watercourses – when heavy rainfall causes rivers to overflow their banks or defences
- groundwater flooding – when underground water stores (aquifers) overflow
- surface water flooding – when heavy rainfall is unable to drain away
- a combination of these
The areas at risk of flooding include freshwater grazing marshes and designated freshwater habitats. There are also designated intertidal habitats along much of the estuary frontage.
The marshes also contain valuable historic, military and industrial features, such as:
- Shornemeade Fort
- Cliffe Fort
- Cliffe Gunpowder Works
- a railway line across Shorne Marshes
The Lower Thames Crossing is a significant development proposal for the area. This transport link would involve construction in the flood risk area to reduce congestion on the Dartford Crossing.
Managing flood risk in this area
To manage these risks there are:
- tidal flood defences downriver (east) of the Thames Barrier
- drainage system outfalls including at Shorne, Cliffe and Halstow Marshes
The industrial area at Cliffe has its own secondary defence.
We also use flood alerts and flood warnings to inform people about potential flooding so they can take appropriate action.
Sign up to receive flood warnings in your area.
Flood risk management policies for this area
Thames Estuary 2100 sets flood risk management policies for each area of the estuary. The policies range from P3 to P5 and outline how we should manage that area’s tidal defences.
In this area, a P3 policy applies, except in the east end of Gravesend where a P4 policy is proposed.
A P3 policy means we will maintain flood defences at their current level, accepting that the flood risk will increase. We need to involve communities to prepare for this flood risk.
A P4 policy means we will take further action to keep up with climate and land use change so that flood risk does not increase. We will need to work with other risk management authorities to do more to manage flood risk.
We will need to work with our partners to find the most effective way to achieve a P4 policy for Gravesend East.
Find out more about flood risk management policies.
Local requirements: who needs to do what
Tidal flood defence owners and infrastructure providers
Flood defence owners and infrastructure providers will plan to realign flood defences and improve resilience.
By 2040, tidal flood defence owners in this policy unit should:
- work with the council, developers and local infrastructure providers to adapt defences and achieve multiple benefits through proposed development
- work with the Environment Agency to raise defences where required
For further information read outcome 2: improving fixed flood defences.
Local councils
There is currently no riverside strategy for this area. By 2030, councils should work with communities to plan how their riverside will look in future.
Find out more about the riverside strategy approach.
Environment Agency
The Environment Agency will work with the councils and community to implement resilience measures where a P3 policy applies.
Network Rail
Network Rail will work with councils and the Environment Agency to ensure transport infrastructure in Kent is resilient to increasing flood risk. This will support growth in the outer estuary.
Thames Estuary Partnership
The Thames Estuary Partnership will work with communities, councils, the Environment Agency and other partners to:
- update the Thames Strategy East upstream of Gravesend
- scope the need and potential extension of the Thames Strategy East or creation of an alternative Joint Thames Strategy downstream of Gravesend
Any agreed landscape visions for the river corridor will reflect how increasing tidal flood risk will affect the environment.