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.

 

 

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.

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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.

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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.

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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.

Natural Flood Management on Countryfile

Countryfile on Sunday did a couple of films on how to manage the problems associated with the recent floods. The two pieces featured examples from the south west.

You can watch Sunday’s Countryfile by pressing here and viewing on the BBC’s  iPlayer. The first piece is about natural flood management schemes also known as ‘upstream measures’. This section is 7 minutes 32 seconds into the programme.

Nigel Hester - Countryfile
It features the work carried out by the National Trust on its Holnicote Estate in Somerset. This is a picture of Nigel Hester, the NT’s project manager with Tom Heap from Countryfile. It is a widely acclaimed scheme and I am visiting Holnicote next week to meet Nigel and be shown around – I will report back.

The National Trust have also recently published the report on the Holnicote project “From Source to Sea – Natural Flood Management” and you can download it here. The project was funded by DEFRA, the Environment Agency and the NT and involved the University of Exeter, JBA Consulting and Penny Anderson Associates Ltd. It is well worth a read as I am sure it will be a major  building block for much that we will see happen in the future to ‘slow the flow’.

The second part of the Countryfile piece on flooding tackled dredging and focused on the Somerset Levels. That part starts 26 minutes 58 seconds in. Again a very balanced piece and is well worth watching.

Part of the challenge with dealing with floods is to separate fact from fiction, hyperbole and prejudice. There are lots of competing interests when it comes to this topic and I thought Countryfile did a good job in setting this out.