Dartford & Erith

CABINET 20 MARCH 2008

Appendix A - Thames Estuary Consultation information

Dartford & Erith

OS Maps © Crown Copyright 2007. All rights reserved. Licence number 100026380.

About the area

The area is located on the south bank of the Thames between Erith town centre and Greenhithe,

generally marshland surrounded by urban and industrial areas and large housing estates. The main

open spaces are on the Dartford and Crayford Marshes, and there is low-lying land alongside the River

Thames, around Slade Green and at Dartford and Crayford Town Centres. The marshes have some

agriculture and there is a shooting club on Dartford Marshes. There is heavy industry along the Thames,

and commercial outlets at Erith and Crayford, and Dartford town centres. The M25 and Dartford river

crossing at QE2 bridge and tunnel entrance are in this area with a major transport depot at Slade Green.

The mainline railway between Dartford and Erith crosses the edge of the area and there are three rail

stations, local trunk road (A206) between M25 and Erith, many feeder roads to town centres and

housing estates. Also of significance are Littlebrook Power Station, the Sewage works at Littlebrook,

large industrial estates on Manor Road, on Slade Green Road, in Crayford, at Temple Hill Dartford and

Stone Marshes next to the M25. Additional sites of importance are transport depot buildings and transfer

stations and the Thames Europort alongside Thames at Stone. Howbury Farm is a Scheduled Ancient

Monument.

View additional information about Dartford and Erith (pdf, 136Kb) see below

How flood risk is managed today

The risk of flooding is mainly due to extreme high tides with freshwater flood risk from the rivers Darent

and Cray. Flood walls and substantial earth embankments protect the area from flooding. The Darent is

protected from tidal flooding by the Dartford Barrier at Dartford Creek. Flood warning and emergency

planning are also part of the flood risk management arrangements in the area.

Our preferred policies: Policy 4 and Policy 6

Screened out policies: Policy 1 and Policy 2.


See visualisations of all policies (pdf, 244Kb) see below

Our preferred policy is a combination of Policy 4 and Policy 6 for the Dartford & Erith area. Policy 4

ensures the flood risk to people, property and essential infrastructure does not increase with climate

change. Policy 6 would to reduce flood risk or create habitat by working with natural processes.

We prefer a combination of Policy 4 and Policy 6 because they provide the greatest environmental

benefits, as well as ensuring that flood risk to people, property and essential infrastructure - including

the Dartford Tunnel and the transport depot at Slade Green - does not increase as sea levels rise.

Policy 5 would offer a further reduction in flood risk compared to Policy 4. However, we prefer Policy 4

because the additional costs of implementing Policy 5 are far higher than the additional benefits gained

from the reduced flood risk.

Policy 6 provides an opportunity to direct flood water away from developed areas or create habitat by

working with natural processes. The potential use of flood storage in this area may be an optimum

solution for achieving Policy 4 locally and contribute to achieving Policy 4 or Policy 5 upstream. This

approach is particularly beneficial in open and undeveloped low lying areas in between the Thames

Barrier and Tilbury.

In these diagrams, flood risk is shown as different water levels. Managing floodplain use can reduce the

consequences (buildings), but water on the floodplain shows there is residual flood risk with all policies.

Additional Information about Dartford and Erith Location • Right bank of Thames between Erith and Stone Marshes • In the London Borough of Bexley and Dartford Borough Council Physical description • Low ground in the marshes, alongside the River Thames, around Slade Green, at


Dartford and Crayford Town Centres • Higher ground away from these areas with housing estates • Surface water drains from the high ground into the riverside areas Area description • Marshland surrounded by urban and industrial areas • Some agriculture in the marshes • Large housing estates • Many playing fields in the area • Some heavy industry along the Thames • Commercial outlets at Erith, Crayford and Dartford town centres Flood management • Mostly hard defences of steel sheet piles at Dartford Tunnel and Stone • Earth embankments across Crayford and Dartford Marshes and along the Rivers Darent and Cray • Flood warning and emergency planning Transport • M25 and Dartford river crossing at QE2 bridge and tunnel entrance • Major transport depot at Slade Green • Mainline railway between Dartford and Erith crosses the edge of the area • Three rail stations • Local trunk road (A206) between M25 and Erith • Many feeder roads to town centres and housing estates • Main access roads to Darent Industrial Estate • Access to Temple Hill industrial complex in Dartford Principal buildings • Large industrial estates on Manor Road, on Slade Green Road, in Crayford, at Temple Hill Dartford and Stone Marshes next to M25 • Littlebrook Power Station • Sewage works next to Littlebrook • Several schools in Dartford and Crayford • Transport depot buildings and transfer stations • Thames Europort alongside Thames at Stone Recreation • Shooting club on Dartford Marshes • River views from the tidal embankments • Motocross course in Dartford Marsh • Bird watching along rivers and in marshes • Cycle paths Habitats • Slade Green and Howbury Farm • Reed beds and remnant salt grazing marshland • Ditches and drainage dykes for invertebrates and amphibians Historical • Howbury Farm is a Scheduled Ancient Monument Tidal Defence Embankment



Swanscombe & Northfleet

OS Maps © Crown Copyright 2007. All rights reserved. Licence number 100026380.

About the area

The area is the triangular peninsula that projects out into the river located on the south bank of the

Thames between Greenhithe and Gravesend. Originally low-lying marshland but now large areas are

covered with landfill sites. Two marsh areas remain at Swanscombe Marsh and Botany Marsh. The area

along the southern edge is mainly industrial with depots, storage units and light engineering works. The

eastern edge alongside the Thames has several large industrial complexes wharfs and jetties into the

river. Major cross-river overhead power lines are carried on pylons across the area. Ingress Park

housing development is on the western edge and new housing development, including schools,

community centres, health centres and industrial units are planned for the area. The Channel Tunnel

Rail Link runs through the area with the Thames tunnel head-works and ventilation buildings in the

centre of the marshland as does the A226 and local access roads to depots. Of historical interest there

is Ingress Abbey and a major Roman settlement at Ebbsfleet.

View additional information about Swanscombe and Northfleet (pdf, 148Kb) see below

How flood risk is managed today

The risk of flooding is mainly due to extreme high tides. The defences are mostly earth embankments

with retreated defences at Ingress Park, including a reinforced foreshore. There are some hard

defences along the industrial areas. Flood warning and emergency planning are also part of the flood

risk management arrangements in the area.

Our preferred policy: Policy 4

Screened out policies: Policy 1, Policy 2 and Policy 6.

See visualisations of all policies (pdf, 240Kb) see below

Policy 4 is our preferred policy for the Swanscombe & Northfleet area. Policy 4 ensures the flood risk to

people, property and essential infrastructure does not increase with climate change.

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20 MARCH 2008

We prefer Policy 4 to ensure the flood risk to people property and essential infrastructure, such as the

Channel Tunnel Rail Link, does not increase as sea levels rise. Policy 5 would offer a further reduction

in flood risk compared to Policy 4. However, the additional costs of implementing Policy 5 are far higher

than the benefits we would gain from the reduced flood risk.

In these diagrams, flood risk is shown as different water levels. Managing floodplain use can reduce the

consequences (buildings), but water on the floodplain shows there is residual flood risk with all policies.

Additional Information about Dartford and Erith Location • Right bank of Thames between Greenhithe and Northfleet • In Dartford Borough Council and Gravesham Borough Council Physical description • Alongside the Thames and on triangular peninsular that projects out into the river • Originally low-lying marshland but now large areas are covered with landfill sites • The unit backs up to high ground at Stone and the chalk cliffs of the old quarries at Swanscombe Area description • Two marsh areas remaining at Swanscombe Marsh and Botany Marsh • Dominated by landfill sites • Some drainage channels in the marshland • The area along the southern edge is mainly industrial with depots, storage units and light engineering works • The eastern edge alongside the Thames has several large industrial complexes wharfs and jetties into the river • Major cross-river overhead power lines and are carried on pylons across the area • Ingress Park housing development is on the western edge • New housing development, including schools, community centres, health centres and industrial units are planned for the area Flood management • Mostly earth embankments • Retreated defences at Ingress Park, including reinforced foreshore • Some hard defences along the industrial areas • Flood warning and emergency planning Transport

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20 MARCH 2008 • Channel Tunnel Rail Link runs through the area with the Thames tunnel head-works and ventilation buildings in the centre of the marshland • A226 and local access roads to depots Principal Buildings • Channel Tunnel Rail Link tunnel and associated buildings • Storage depots • Industrial complexes on east edge of area • Old sewage treatment works • Ingress Park housing development, contains flood resilient buildings Recreation • Restricted to riverside footpaths and adjacent marshland • Bird watching Habitat • Local nature reserves • Managed conservation areas planned as part of new developments Historical • Ingress Abbey • Major Roman settlement at Ebbsfleet QE2 Bridge

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Dartford & Erith