Have we learned our lessons on flooding?
After the disastrous 2007 floods that swamped 55,000 homes, the government commissioned the Pitt Review to ensure it didn't happen again.
The review was chaired by Sir Michael Pitt, a career civil servant with a first-class degree in civil engineering. On the back of its recommendations, the government did take action, and the Environment Agency says its flood defences are now protecting 1.3 million homes.
Yet tracts of the UK lie under water, and scientists warn this is likely to happen more often with man-made climate change.
So it seems more must be done - by government and people alike.
The coalition government cut flood spending as an austerity measure; it scrapped a cabinet flooding committee; and Environment Secretary Owen Paterson removed flood protection from his department's key priorities. However, spending this year has risen and is set to rise further in 2014-15.
Meanwhile, many people living in flood-risk areas have declined to adapt their homes to rising waters, believing that the authorities should take responsibility.
So, here's what Sir Michael said should happen… and what did happen.
Scrap the sandbag
The simplest unlearned lesson from Pitt: don't put a sandbag in your doorway. Pitt recommended people to block doorways with a close-fitting flood board instead.
But most flood victims haven't. Did the government fail to get the message across or were homeowners complacent?
The Pitt report recommended above-inflation spending on flood defences. The Labour government then increased capital spending by three-quarters. The coalition cut it heavily, then reinstated part of the sum.
But a note in the House of Commons library (SN/SC/5755) makes it plain that total capital spending, even when unconfirmed contributions from local authorities are included, will still be lower in real terms in 2011-15 than in the previous four years.
Historically, there seems to be a cycle of increased spending after a flooding event but it tends to taper off as the flood waters recede.
In 1999-2000 total expenditure on all flood defences in England and Wales was estimated by the Environment Agency to be about £400m.
After the autumn floods of 2000, spending by the Labour government did go up but the increase was less than some advisers recommended.
According to a report by the Parliamentary Office of Science and Technology in 2001, consultants then for the Department for Environment, Food and Rural Affairs (Defra) estimated that the funding would need to increase by £30m to £60m per year to maintain current levels of protection in the face of a changing climate.
Before the floods in 2007, funding had increased to £500m, but was still below the recommended level.
In the wake of 2007, there was another surge of spending that brought cash allocated up to a high point of £670m in 2010-11.
It has since dipped back below £600m.
As well as the amounts, questions have been raised about how the money is now spent.
MPs warn that the flood defence maintenance budget is shrinking as the number of defences increases.
A hard rain's gonna fall
Pitt strongly recommended that people should be stopped from smothering gardens with hard surfaces that create run-off water. Rules have been implemented but enforcement is lax, and gardens are still being paved.
Stop making it worse
Pitt said it was impractical to stop all building on floodplains but advised a strong presumption against it. He insisted that buildings should avoid creating flood problems for themselves or their neighbours.
But large-scale building on floodplains has continued - even in Somerset (so are local councils partly to blame for the flooded Levels?).
Catch it where it lands
New developments should generally allow water from roofs and streets to seep into the ground rather than running into the sewers, the review recommended.
New rules are in place but haven't been implemented because of turmoil within Defra over how the drainage is maintained. The flood minister has now promised this will be resolved by April.
Pitt said car parks should be engineered to catch water up to kerb height. The Environment, Food and Rural Affairs Parliamentary Committee (Efra) says water from roads should also be filtered into the ground, rather then hitting the sewers. MPs complain that the government is bowing to pressure from developers.
Sustainable drainage solutions
Who's in charge?
A dedicated cabinet committee should be set up on flooding, Pitt said.
Labour did that. But the coalition disbanded it, and produced its final progress report on the review in January 2012, with more than half the 92 recommendations uncompleted.
Defra says it replaced the cabinet committee with the National Security Sub Committee, looking at all hazards. The prime minister has now resurrected the cabinet floods committee.
Speaking this week, Mr Cameron said that all but one of the Pitt recommendations had now been implemented.
One of Pitt's successes. The Environment Agency and the Met Office have worked together to produce five-day flood warnings, giving planners an extra 24 hours' notice of floods.
It's a leap in science - but clearly the messages aren't always getting through, as many people still don't protect their homes in time.
Keeping the lights on
Businesses need to invest in resilience, Pitt said. Power companies have struggled to cope with this year's floods, with 80,000 homes without a supply.
Could they have done more to protect the network?
Pitt said estate agents should reveal flood risk, and new rules stipulate that - although many buyers have decided that the joys of a river view outweigh the risk of getting wet.
The report said that the right to connect rainwater drainage to the sewers should be removed for new developments because existing residents shouldn't be expected to pay to improve the system. This has yet to be implemented.
Looking after yourself
Pitt highlighted a model flood victim who lifted electric sockets up the wall, laid a concrete floor, painted skirtings with yacht varnish and installed a lightweight door to be unhinged and carried upstairs when the floods came.
This seems very much the exception rather than the rule. Some 46% of people told the review they wouldn't change their homes; it was up to the authorities to protect them from flooding.
Pitt said: "Dredging is considered as an option for flood risk management, but it is limited to areas where it is most appropriate, with money that is saved being used for more effective methods of flood protection."
His recommendation 25 stated: "The Environment Agency should maintain its existing risk-based approach to the levels of maintenance."
This policy has been followed by the Environment Agency and defended by water management professionals. But it has been criticised by farmers, and politicians are under pressure to revoke it.
So will we heed Pitt the second time around? Don't bet on it.
Public funds are limited and massive investment is needed to make infrastructure resilient.
Government value-for-money rules mean that spending on flood defences has to create £8 of benefit for every £1 spent - in contrast to some road schemes, which need to clear a much lower hurdle on value for money. It has been reported that the Treasury is reconsidering the rules.
Then there's people: evidence given to Pitt suggests that a large proportion of householders won't take basic steps to protect their homes from flooding. And many of those who are willing to take responsibility just don't quite get round to it.
And here's further bad news: the official adviser, the Climate Change Committee, warns that we are clearly not adapted to current climate variability, let alone changes in risk associated with climate change.
Follow Roger on Twitter @rharrabin