Future Estuary

Tim ReederClimate Change Advisor

Tidal Flood Risk

1m0m 4m3m2m

New barrier, retain Thames Barrier, raise defences

Raise Defences

New barrier, raise defences

Existing system

Improve Thames Barrier and raise d/s defences

Over-rotate Thames Barrier and restore

interim defencesFlood storage, improve Thames

Barrier, raise u/s & d/s defences

Flood storage, over rotate Thames Barrier, raise u/s & d/s defences

Flood storage, restore interim defences

Note:

Each box represents one or more portfolios of responses

Maximum water level rise:

Def

ra 2

100

Hig

h ++

210

0

Improve defences

Maximise storage

New Barrier

New barrage

TE2100 developed options

Water Shortage in London?

Summer Precipitation

2020s 50% probability level:central estimate

2050s 50% probability level:central estimate

2080s 50% probability level:central estimate

Climate Change Adaptation Sub Committee

Low EmissionMedium Emission High Emission

Change in Summer Mean Temperatures 2080s London

Potential environmental changes affecting the Thames estuary London

Higher ambient air temperature

Salinity gradient shifts further upriver

Less rainfall during the summer

Higher ambient air temperature

Salinity gradient shifts further upriver Raised sea

water temperature

Reduced freshwater flow, warmer river temperature

Bigger population - increased polluting load from sewage treatment works?; increased heat load from heating networks?; increased abstraction in the freshwater Thames?

Result: An estuary with less dissolved oxygen

Warmer drier environment - a changed ecosystem?

“New ecology” resulting from southern species expanding their range, and new invasive species thrivingNew species have different requirements – current water quality objectives may no longer be relevant

Very young Seabass are sensitive to cold winters; a warmer estuary might be a better nursery for this speciesIn the Medway estuary, a marginal rise in temperatures (from power stations) produced Golden Grey and Thin Lipped Grey Mullet populations