Storm Angus, the Amber rain and Holnicote

Following Storm Angus last weekend a piece appeared in the Guardian which reported that the Natural Flood Management measures introduced by the National Trust on its Holnicote Estate on Exmoor had been effective at protecting over 100 houses downstream from flooding.

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You can read that article here.

Nigel Hester, the Holnicote NFM Project Manager for the National Trust posted some pictures of Allerford during the storm

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screen-shot-2016-11-24-at-09-38-42As Storm Angus was quickly followed by the Amber rain event I was keen to find out what happened after Angus

screen-shot-2016-11-24-at-09-30-01The first peak is Angus and the second is the Amber rain event – I wanted to check with Nigel that the villages and homes had survived flood free both of the events. I asked him “looking at your picture of the Packhouse Inn – does that mean that eventually the river broke its bank and flooded the village?”

screen-shot-2016-11-24-at-09-31-39This is his reply – no flooding.

This is very good news and a very impressive outcome considering there were two large flood events in succession. When the Amber rain arrived there was still a lot of water in the system from Angus.

This is a major story and one that should be of interest to local communities and politicians everywhere.

It appears to me that a well designed and correctly located natural flood management scheme can make a real difference on the ground. Now all that is needed is some modest funding and some political will.

 

 

No trains to and from Exeter for 48 hours

Storm Angus and yesterday’s ‘Amber’ rain have taken their toll, flooding is widespread and disruption is extensive.

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This graphic from the website FloodAlerts from yesterday afternoon sums up the problems in Devon and Somerset

screen-shot-2016-11-22-at-07-54-24This is the gauging station data from the Exe in Exwick where I live – the first peak (20/11) shows the water levels caused by Storm Angus, the second peak (yesterday) is as a result of the ‘amber’ rain – note this is a new record high.

screen-shot-2016-11-22-at-08-21-43As a result this has just been issued by the BBC – no trains in and out of Exeter for 48 hours – we’ve been here before ……. (see here)

We have undoubtedly had a lot of rain but many of us think the problems have been exacerbated by certain land management practices – I have written extensively about this in the past with particular reference to maize cultivation (see here for all my writing on that topic) and today my Twitter feed is full of other people saying pretty much the same thing.

screen-shot-2016-11-22-at-08-39-55Here is a tweet from an Environment Agency Manager in Herefordshire – look familiar?

screen-shot-2016-11-22-at-08-39-32And here is the Chief Executive of the West Country River’s Trust making the same point by commenting on flood management expert Phil Brewin’s tweet and photos from Somerset

Understanding management practices on land are essential in the fight against flooding and maize in inappropriate places really makes things worse. Many of us have also been arguing  for ‘natural flood management’ solutions such as those implemented at Holnicote (see here)

screen-shot-2016-11-22-at-09-05-12Here is a tweet (yesterday evening at 5pm) from Nigel Hester of the National Trust who project managed the Holnicote Natural Flood Management Project

Ironically yesterday the Guardian published a piece which featured Holnicote and stated that the Government is not funding any Natural Flood Management Schemes at present – see here.

Lets hope some of these things change soon.

Future Flood Prevention

Following the winter flooding in 2015/16 characterised by Storms Desmond, Eva and Frank, the Parliamentary Environment, Food and Rural Affairs (EFRA) Select Committee launched an Inquiry into flooding. Their report ‘Future Flood Prevention’ was published last week – you can download it here.

The report contains a number of recommendations to Government. Whilst Select Committees are advisory and Government are under no obligation to implement the recommendations reports such as this are considered influential in the debate. The EFRA report follows on the back of the Government’s own National Flood Resilience Review (see here) which specifically covered protecting strategic assets such as power stations etc during flood episodes.

Of particular interest to me are the sections in the report that relate to catchment wide measures to prevent flooding and natural flood management measures. I have written extensively about this topic – follow this link and you will see the blogs I have produced.

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The report contains this graphic produced by Dr Paul Quinn which indicates a range of measures that can and should be taken at a catchment level.

There is more research to be conducted on this topic but a number of trial projects are mentioned in the report favourably e.g. Holnicote in Somerset, Pickering’s ‘Slow the Flow’ and the Moors for the Future work in the Peak District and the Pennines.

The two specific recommendations from the Report are:-

  •  Defra should commission by July 2017 a large-catchment trial of the effectiveness of natural flood risk management approaches such as installation of leaky dams, tree planting and improved soil management, alongside other measures;
  • Farmland should be used in some places to store flood water: the National Farmers’ Union and Defra must develop storage approaches with low impact on farm productivity and appropriate incentives to recompense farmers

It wasn’t that long ago that natural flood management measures and the need to work on a catchment scale were simply the mantra of a few environmental organisations and academics – it is now seen as a mainstream solution.

The second point regarding the use of farmland to store flood water is also significant. The NFU have long opposed such a move and indeed ‘flood defence’ measures from  the 1970s to very recently have been designed to protect farmland from flooding rather than allowing flood plains to flood. As the recommendation suggests there is still some way to go but there is a clear marker that in some places this needs to happen – better to allow flood water onto farmed flood plains than allow it to rush into people’s homes downstream of the protected farmland.

The Report has also tasked the Environment Agency and the Met Office with improving flood risk communication i.e. ‘the 1 in a 100 year flood’ message is confusing to the public and is becoming meaningless in a world where the climate is changing and extreme storm events are increasing.

EFRA also call for various measures to be taken around the planning system to improve resilience to flood. For example developers who flout planning requirements should be made liable if flooding subsequently occurs.

The final set of recommendations in the Report centre around ‘a new model for managing flood risk’. It says

“Our model gives a strong focus to joined up, efficient action to improve flood protection by:

Establishing a new National Floods Commissioner for England, to be accountable for delivery of strategic, long-term flood risk reduction outcomes agreed with Government. Delivery would be via:

New Regional Flood and Coastal Boards to coordinate regional delivery of national plans, in partnership with local stakeholders. These Boards would take on current Lead Local Flood Authority and Regional Flood and Coastal Committee roles;

A new English Rivers and Coastal Authority, taking on current Environment Agency roles to focus on efficient delivery of national flood risk management plans.”

These ideas are not very different from those proposed by Dieter Helm, the Chair of the Natural Capital Committee – see here.

I’m not really sure what I make of these recommendations, on one hand it takes us back to something akin to the old National Rivers Authority which was considered effective and successful, on the other hand though in a world of Brexit and all the upheaval that will ensue I’m not sure that DEFRA will have the capacity and the brainpower available to re-organise the Environment Agency. (DEFRA will be extremely busy working out what follows the Common Agricultural Policy and gaining access to the Single Market for farmers).

The CLA aren’t very impressed with these recommendations either calling them a ‘backward step’ – see here.

Apart from EA re-organisation proposals the report has been well received by a wide variety of organisations interested in reducing flood risk.

Perhaps the most odd press release on the EFRA report comes from the Countryside Alliance which suggests that the report ‘recognised that there is no proven link between grouse shooting and flooding’ – see here. It is an odd statement as nowhere in the report is there a mention of grouse shooting.

 

From source to sea – Holnicote natural flood management

Yesterday I went to the National Trust’s Holnicote Estate near Porlock on Exmoor in north Somerset and was shown the widely acclaimed natural flood management project there by the Project Manager Nigel Hester.

In light of the recent floods natural flood management is widely discussed as an option for solving flooding problems in the future . Yet the Holnicote project was started in 2009. The project have been funded by DEFRA, the Environment Agency and the National Trust. It has been run as a demonstration project so it involves a great deal of modelling and monitoring to show what has worked and the effects have been.

Holnicote 7
A report has been published by the National Trust which gives a detailed account of what has been done and what the results have been – you can download the report here.

The project is a catchment wide approach to ‘slowing the flow’ of the local rivers using low key and natural interventions in an attempt to reduce / stop flooding in the local villages downstream.

Holnicote 5
Allerford – one of the local villages at risk from flooding

Perhaps the most obvious feature of the project has been the subtle re-engineering of the flood plain on the Estate which enables the river to flood onto the land – slowing the flow and greatly increasing the flood water storage capacity. The Trust has worked with its tenant farmers who have all bought into and supported the project.

Holnicote 1
A number of non intrusive bunds have been produced to create water storage areas

Holnicote 2A simple woody dam has been installed which in periods of high flow diverts the flood water from the river into the storage areas on the flood plain

Holnicote 3In the streams higher up in the catchment a number of simple woody dams have been created to provide ‘hydraulic roughness’ and slow the flow

Holnicote 4Up on the high moor ancient features such as this track have tended to funnel water and increase its flow down to the villages below – here small dams and pools have been created to slow the flow

Holnicote 6In this lovely coombe scrub is beginning to form which again increases the hydraulic roughness

As well as playing a major part in reducing flooding these small measures also provide new and interesting habitats for wildlife  – given a bit of time the coombe above might become attractive to breeding ring ouzels (which are now extinct on Exmoor) and maybe, could even be suitable habitat if a black grouse re-introduction project was ever considered. The little scrubby trees will certainly be useful to cuckoos who need such features so they scan perch and survey the landscape for food and meadow pipit nests.

It is early days for the project but to date despite some heavy rain episodes the villages down stream have not flooded since the natural flood management features were created.

This is a very brief summary of a multi-objective project – read the full report to gain a fuller picture. Really pleased to have seen it for myself – thanks Nigel for showing me around.

The National Trust should be very proud of this pioneering work – very important now to ensure that the House of Commons Select Committees working on solutions to the recent floods see and hear about this project.

This is not complicated or expensive  and the approach can be adapted and used across the country to play an important role in reducing flooding.

More on natural flood management

I found this video yesterday about natural flood management in the catchment around Stroud in Gloucestershire. It is a detailed video which shows specific measures that have been taken to slow the flow by a range of individuals and organisations. It is well worth a watch.

Another blog ‘Tree planting and reducing flooding – will it work?‘ was also brought to my attention by a reader of my blog. It is by Miles Marshall of the Centre for Ecology and Hydrology. He was the lead researcher who carried out the work at Pontbren in mid Wales. In the study trees were planted on previously grazed pasture and they measured the subsequent effects on soil hydraulic properties and runoff processes. They found that soil infiltration rates were 67x times faster and surface runoff volumes were reduced by 78% under trees compared with grassland.

Marshall rightly cautions the reader saying that more research is required to determine which species of tree work best, what age of tree is best, can the ideas be scaled up to make a real difference etc.

He also says that tree planting to reduce flooding is only one of the options that needs to be considered. He argues that catchment wide initiatives such as the one described above for the Stroud Valleys are needed as well. As I have argued many times before land use is also a key issue e.g. maize on steep slopes near to streams and roads.