Thames flood notes (1962 atomic strike)

Overview


Without due care the London would floods would get worse over time. Whilst some places like the low-lying Isle of Grain, Canvey Island, Hoo peninsular, Benfleet and Isle of Sheppey would flood more frequently, others further up stream like Plummeted, the Greenwich peninsular, West Ham CB and the Isle of Dogs would once more become permanent swamps and tidal marshlands.

Flood plain


Most of the Thames was surrounded by at leads a few feet of flood plain or marshland. Large tracts were swamps or mud flats were running all the way from the River Lea’s outflow to Canvey Island and the Isle of Grain.

Others existed along the River Roding in Redbridge LB and at the River Lea as far as Enfield Lock. These included Plumstead Mars, Rediff Marsh, Westham Abby marsh, the Plaistow level and Rainham marsh. Lambeth was a moorland, with a coastal swamp (Lambeth Marsh) and inland swamp (Lower Marsh) in the 1300’s.

The old Isle of Dogs, Stepney Marsh, Blackwall Level, Bugsby's Marsh and North Greenwich Marsh were drained in the 17th century and joined up as the then farming peninsulas that are now the Isle of Dogs and the Greenwich peninsula. The marshes were mostly reclaimed by the 1880's and totally drained by World War 2, but would revert if the dykes, drains and embankments failed. Thames Embankment (at Westminster) was overwhelmed and part of the Chelsea Embankment did collapse in the flood of 1923.

Teddington, Chiswick, Putney, Hammersmith, Westmister, Southwark, Barns, Battersea and Richmond (in Surrey) flood on occasion and some incidents have occurred as far north as Oxford, but any permanent mass flooding by the Thames would not get past about Battersea.

Other moorlands and bogs
Moorefield was a bog from which the Wallbrook takes most of its water from. The River Brent has a habit of flooding in Hendon, Perivale, Brentford and Hanwell. Parts of Hampstead heath were marshland and the River Wandle used to flood Wandle Park, Carshalton Pond and Waddon Marsh when they were farmland.

The Thames Flood Barrier and the Canvey Island Sea Wall.
The Thames Flood Barrier was not built in 1962 and the Victorian Canvey Island Sea Wall was in decay. The Victorian (1880's) wall was falling apart and the 1947 and 1954 wall were only localised. The 1970's and 1980's wall did not exist.

Urban tribal water supply
The River Quaggy could provide water to tribal folk in parts of Bromley LB, the River Lea in south east Hertfordshire, the River Roding to those near Epping and in parts of Uttlesford DC, the River Colne for those in Hillingdon LB and Spelthorne DC and the River Mardyke could be used for those in Upminster UDC.

The phenomena at play
Some possible factors that could come in to play-

War damage
The 10kt, 25kt, 100 kt, 150kt and 200 kt bombs would cause a wide, but shallow crater if detonated on ground or just above it. All buildings and structures would be burnt, demolished or vaporised depending on the location’s relation to the bomb’s point of detonation.

Floods


A possible long turn flood scenario would run like this-

Before to 1969

 * 1) Heavy to total war damage as of 1962.
 * 2) London Underground quickly floods as the pumps fail or are destroyed. It fills with rain water, aquifer water and water excess from the Thames as well as sewerage from broken sewers. Sections are flooded as the rivers Fleet, Wall Brook, Bayswater, Lambourne, Kilburn, New River, Beverly, Tyburn, Ranelagh and Westborne all burst out of damaged pipes to in the next few days.
 * 3) Much of the coastal land between the Isle of Canvey, the Isle of Grain, the Grenwich Peninsular and the Isle of Dogs, like Plumstead Marsh, steadily becomes wetter as dykes and pumps fail, leading to it becoming a swamp in a few years.
 * 4) London Underground's tunnels fully flood out with in a few years.
 * 5) The River Lee Navigation canals, the New River flood elevation canal and the related storm drainage channels finally block up with debris and corpses from up stream causing it to flood in to its former marshland by 1966.
 * 6) Typhoid, dysentery, cholera and typhus have never had it so good.
 * 7) Great Flood of 1968 causes trouble and floods in Catford, Lewisham and parts of Woolworth. Coastal Kent and Essex (particularly Isle of Canvey, the Isle of Grain, Benfleet and Thurrock) are flooded out and revert to marshland. The local sewers fail the streets are awash with long forgotten sewage.
 * 8) Remaining sewers, water mains, culverted rivers and piped rivers break out due to a lack of maintenance.
 * 9) The Serpentine becomes polluted and reverts to nature. Highgate and Hampstead Ponds are less polluted, but still radioactive and revert to nature. Tokyngton Park in Tokyngton is flooded and also returns to nature
 * 10) The Thames overwhelms any rubble or remaining dykes and lock gates. Sewage and drainage outflow pipes become blocked or tidally inverted at high tides.

After 1968

 * 1) The sewers in the tidal zones fail due to poor maintenance, so the streets and rivers are awash with the remaining long forgotten sewage. The already damaged Brent Reservoir's dam-wall collapses and it returns to nature in the early 1970's.
 * 2) Most of the River Brent floods in 1976, 2007 and 2009. The Newham LB an Redbridge LB parts of River Roading floods in 2007
 * 3) The River Thames short cuts through the lakes that were formed by the former London Docklands and undermines remaining dock foundations causing their collapse.
 * 4) Greenwich Peninsular and the Isle of Dogs become permanently flooded as remaining dock foundations collapse.
 * 5) River Medway floods over at its mouth in 1993, 1997, 2007 and 2009, reclaiming some of its flood plains.
 * 6) The Thames floods in 1993, 1998, 2007 and 2009.
 * 7) The flooded London Underground tunnels are near to collapse.
 * 8) The Isle of Dogs, the Greenwich peninsular, Rotherhithe, Beckton, Canada Warf and the relevant stretch the River Thames become a muddy, radioactive swamp land with various rivers, lakes and piles of rubble in it by the millennium. Other places like Moorefields, Lambeth, Battersea, Barns, Brentford, Putney and Wandle park become marshland once more.

Also see

 * 1) Atomic nuts
 * 2) Atomic\nuclear war
 * 3) Thames flood notes (OTL)
 * 4) UK OTL atomic reactors in 1962
 * 5) London's flooded and in ruins!
 * 6) Attempted nuclear war simulation (TL)
 * 7) UK war time regional seats of government