Across the country, we have seen our neighbours' homes and farms devastated by the floods. We understand their anger and frustration.

We also understand their demands for swift action, but what they have been given is political gamesmanship: blame-shifting from party to party and from minister to minister, late responses, dramatic reversals of opinion. This reached its well-publicised nadir at the weekend with Eric Pickles's appearance on the Andrew Marr show: "I apologise unreservedly and I'm really sorry that we took the advice; we thought we were dealing with experts." Throwing your own government experts to the wolves is not an apology.

This political vitriol, at least with respect to the Somerset Levels, appears to come down to a relatively simple question – should we have been dredging? It is an incredibly complex question, in the Somerset Levels and elsewhere, and this simplistic discussion does the people of those communities a great disservice.

More fundamentally, this is not the time to be deciding long-term flood mitigation strategy. In times of disaster, you do disaster management. Later, you learn the lessons from that disaster. And finally, informed by evidence and motivated by what has happened, you set policy. That is the most frustrating aspect of the current political debate, because in an effort to outmanoeuvre one another, our leaders are making promises to enact a policy for which the benefits are dubious.

First, the reason the rivers are flooding is primarily the exceptional rainfall. January was the wettest winter month in almost 250 years, and this rain fell when the soil moisture content was already high. However, these issues are exacerbated by how we have changed our floodplains, with both agricultural and urban development reducing water storage capacity.

Second, while much of our nation is flood-prone, flooding comes in a variety of forms and has a range of underlying causes. Some floods have been due to coastal storm surges, some due to flash flooding caused by rapid flow from poorly managed lands, and some due to sustained rain and soil saturation. We have a wet and volatile climate, 11,073 miles of coastline and little geographical room to manoeuvre on our small island. Our solutions have to take all of these issues into account, and they must recognise that any change in a river catchment will affect our neighbours downstream.

Third, returning to the specific challenge of the Somerset Levels, it is unclear what benefit dredging will have. The Somerset Levels sit near sea level, such that the river-to-sea gradient is very shallow. This means that even if they are dredged, rivers will only drain during low tide. And widening the channels will actually allow more of the high tide to enter. Some have argued that in the past dredging was more common and flooding apparently less so. But this winter has seen far more rain and our land is being used in very different ways, so the memories of three decades ago are not entirely relevant.

Fourth, where dredging is done, it is being made more costly and challenging by farming practices elsewhere in the catchment area. The rivers are filling with sediment that has eroded from intensively farmed land in the headwaters of the catchments and from the Levels themselves. Practices that have greatly accelerated erosion include: heavy machinery operations in wet fields; placement of gates at the bottom of slopes so that sediment eroded from the field is very efficiently transported to impermeable road surfaces, and thence to streams downslope; cultivation of arable crops on overly steep slopes (increasing the efficiency of sediment transport from land to stream); overwintering of livestock on steep slopes; and excessive stocking densities on land vulnerable to erosion.

Nutrient enrichment from livestock waste and artificial fertilisers (when used in excess of crop requirements) also contributes to the dredging problem. The nutrient loading often exceeds the system's recycling capacity, such that nutrients flow into ditches and waterways, stimulating the growth of aquatic plants that can clog up minor ditches and waterways. With less space to dissipate water within the network, it is forced into the main channel.

In other words, some of these floods are the consequence of subsidised agriculture – and by extension the low prices we demand for our UK-produced food.

Finally, if we are going to consider long-term planning we must consider climate change impacts. Flooding will become worse due to the rise in sea level, which has already risen by about 12cm in the past 100 years, with a further 11-16cm rise projected by 2030. It is less clear how climate change will affect the intensity and frequency of the most extreme rainfall events. Although almost all projections indicate that dry areas will become drier and wet areas will become wetter, predictions for specific geographical regions are highly uncertain. And our historical records do not go back far enough to unravel long-term trends in the frequency of uncommon but high-impact weather events.

This should not be reassuring – it is another major element of uncertainty in an already complex problem.

As challenging as these issues are, they are not intractable. The solutions will involve stronger planning control and scientifically informed planning decisions, a reconsideration of some intensive farming practices, some dredging in key areas, some controlled flooding in others, and a better disaster management strategy for when the inevitable flooding does occur. But now is not the time to resolve such a complicated knot of issues. It is certainly not the time to offer false promises or miracle cures.

Now is the time to help our neighbours in distress, listen to their stories, and remember them when the floodwaters recede. Then we should let the experts get on with their jobs.

• Paul Bates is professor of hydrology at the The Cabot Institute, University of Bristol