Why climate (not beavers) is the real threat

Their burrowing has repeatedly been blamed for the failure of Tayside flood embankments and untold numbers have been killed on the highly questionable notion that they present a risk to food security.

However, investigations into the floodbank issue by both Dundee University and NatureScot have now surfaced online and they significantly widen the debate.

Native to Scotland, beavers were hunted for their meat, fur and castoreum, and driven to extinction around 400 years ago.

Their return allegedly began in 2001 when animals escaped a wildlife park and moved from the River Earn into the Tay.

Beavers are superb ecosystem engineers.

Their deadwood-filled wetlands boost insect, bird, bat and fish numbers. Their dams store water in times of deluge and of drought. In the face of climate change and biodiversity loss these animals are a force for good.

At our farm, Argaty, we have seen a marked reduction in flood incidents since relocating beavers here in 2021. Their wetland engineering slows the flow of water, increasing the time it takes to run off the land.

Of course in certain situations, such as on flat arable farmland, they can and do cause localised difficulties, and as their numbers have grown so have levels of concern about flooding on Prime Agricultural Land.

Recently, a prominent farming representative argued that beaver damage to embankments cost farmers seven figure sums last winter.

There is truth to the argument. Burrows of any animal, not just beavers, can fill with water and collapse during peak rainfall periods. Proving that a floodbank failed due to burrowing isn’t always possible – when they blow out the evidence is often swept away – but there is no doubt that it does sometimes happen and the results for farmers can be devastating.

However, as the NatureScot report Mitigation Options for Reducing Beaver Burrowing Impacts on Agricultural Land in the River Isla Catchment confirms, burrowing is a lesser challenge compared to the greatest threat of our time. The bigger concern is that climates are rapidly changing and our farmed landscapes lack the resilience to cope.

This truth was evident before beavers even returned to Scotland. A Dundee University study, Flood-Induced Embankment Failures on the River Tay, discovered 228 bank failures in the Tay system between 1990 and 1998 alone. 97% of those were caused by the river overtopping the bank and scouring floodbanks from the field side. Since then our climate has grown increasingly erratic. The average year in the last decade (2010-2019) was 9% wetter than the 1961-1990 average.

Last winter was the UK’s wettest on record. Flash flood events are now a regular occurrence and river levels can rise rapidly.

If banks made of silty, dredged materials were not up to the job of protecting farmland back in the 90s, one can only imagine how much more vulnerable floodplain fields are now.

None of this is rocket science, most land managers fully understand the concepts and this makes recent farming union demands concerning river management all the more worrying.

Over and again they call for the right to dredge rivers, an act that would only serve to speed flows (and increase the risk of flood damage further downstream) in the long term, whilst also trashing habitat for important and vulnerable species such as Atlantic Salmon, not to mention the aquatic fly-life which pollinates crops.

Again and again beavers are blamed for all flooding issues.

Calls are made for exclusion zones, areas that beavers are kept out of via a system of watergates and hundreds of metres of fencing. Aside from being both expensive and difficult to implement, would such zones represent a sensible use of taxpayer money?

Granted, it might solve issues of damming in drainage ditches, but if those floodplain fields continue to flood could we really call these projects money well spent? Exclusion zones, it should also be noted, deny beavers eventual access to the headwaters where their benefits can be fully realised.

Yet land management representatives continue to call for such measures, backing their arguments with claims that beavers are costing the nation millions, perhaps even billions.

Ask how those totals were reached and whether beavers’ impact reducing peak flows has been included in their calculations and you will be greeted only with silence.

Could it be that beavers have been made a scapegoat? Are they an easy hit for representatives seeking to demonstrate how hard they are fighting for their members?

Is it easier to attack an animal, especially a reintroduced one, than to face the difficult truth that the world is changing and farming might have to adapt?

So what might a solution look like? How can we make our farming systems more resilient to this rapidly changing climate?

Surely we must begin by taking a whole catchment approach to river management, asking how we slow flows in the headwaters in order to reduce the risk of downstream flooding. Stocking densities, upland broadleaf tree planting and the restoration of ponds and bogs are all topics for discussion here. Reintroduction of beavers to ecologically suitable headwater habitats is a must.

On fertile floodplain land, NatureScot’s River Isla report make two suggestions: realigning floodbanks to set them back from the river and creating buffer strips of riparian woodland. Would a cash-strapped Scottish Government commit to incentivising such measures? Maybe, maybe not. However, the chances of success would be so much higher if farming representatives recognised that climate, not beavers, is the greatest threat that the industry faces and lobbied for measures that would actually improve the situation.

The Dundee University study: Flood-Induced Embankment Failures on the River Tay: Implications of Climatically Induced Hydrological Change in Scotland by Gilvear & Black is available to read at www.TandFonline.com

A summary of it and of NatureScot’s River Isla report can be read in the latest Scottish Wild Beaver Group blog, Blame Climate not Castor, available at www.ScottishWildBeavers.org.uk