FAQs – Technical/Environmental


7. Are you convinced that Rowen Spit will not continue to provide protection from sea level rise as

per SMP1? What is your scientific basis for this change? How much investment was done in

drawing up these plans on the accretion increasing the height and therefore the natural defence

properties of the whole length of the Spit?

Rowen Spit (PU11.4) is the length of spit which is to the north of the newly refurbished estuary

defences and as such does not provide a direct defence to Fairbourne village. We know that the

shingle bank is suffering from starvation because of the depletion experienced at Friog and that

there is no net accretion in the system. We know that on 3 January 2014 the sea overtopped the

shingle bank and the overtopping wall – this will occur more frequently as sea levels rise as a

result of climate change.

The strategic monitoring which has been recording measurement along Fairbourne frontage

since 1992 does show that some accretion is occurring along the Rowan Spit frontage. The

accretion however is localised and as no new shingle material is being fed into the overall system

the level of protection is diminishing over time.


22. Has the impact of silting up of the estuary and the benefits of dredging been explored?

Dredging can have limited benefits when dealing with rivers by providing extra capacity

regarding flow and storage because of the finite volume of water being considered. The sea has,

in effect, an infinite volume and therefore, dredging would have no benefit with regard to flood

risk to Fairbourne.


23. What is saved by allowing Fairbourne to flood in terms of ongoing maintenance costs? Does it

protect Barmouth and Dolgellau?

Further details of current maintenance will be provided in due course. The sustainability of

defences at Fairbourne are not however determined by the on-going maintenance requirement

but rather by the need, in the future, for major capital improvements to maintain standards of

defence in face of sea level rise and climate change. Certainly there is no suggestion that a

decision not to defend Fairbourne would be to allow better defence at Barmouth or Dolgellau.

There is no consideration of direct flood risk benefit to either Barmouth or Dolgellau in

considering Fairbourne’s future. Any decisions made as to flood risk either from the sea or

fluvially in Fairbourne will be based on the conditions and the sustainability of the existing

defences. There is no long term significant maintenance savings by not carrying out annual

maintenance. As far as Natural Resources Wales are concerned there is currently no intention to

curtail the maintenance programme. In fact we are currently working with landowners to

improve localised drainage at a known problem area behind Penrhyn Drive South.


42. Anecdotal evidence indicates significant silting up of the Mawddach Estuary. Is this being

monitored? Has the impact of the new Barmouth seawall been assessed?

The Mawddach Estuary is referred to as a sink because material is accumulating in the estuary

and has been doing so since the last ice age 14,000 years ago. This accumulation of material

also created the land Fairbourne is founded on today. This process will continue until an

equilibrium state is achieved and the process is reversed and material is lost from the estuary. It

is impossible to say when or indeed if an equilibrium state will ever be achieved because of the

effects of climate change.

Gwynedd Council do not monitor the siltation in the Mawddach Estuary. However there is a data

set of aerial photographs which can indicate the changes which have occurred over the years.

Aerial surveying using LiDAR is being used more frequently these days and the latest was

undertaken by The Wales Coastal Monitoring Centre in April 2014.

I assume that the new sea wall referred to is the causeway constructed between the mainland

and Ynys y Brawd in the early 1970’s to close the north channel into the estuary. One of the main

reasons for closing the channel was public safety because of numerous drowning incidents but

there is also evidence to suggest that the channel was closing naturally and the causeway just

accelerated the process.

The silting of the estuary is a natural process with each tide carrying a load of suspended

sediment into the estuary of which a small percentage settles out and is deposited on the

sea/river bed. which has accumulated to a depth over 50m by today, a rate of less than 5mm per

annum. There is no evidence to indicate that the causeway has had a detrimental effect on the

siltation of the estuary. The causeway is only the latest episode in a catalogue of anthropogenic

interventions which have changed the characteristics of the estuary. The catalogue includes:

• Fixing the estuary mouth by Trwyn y Gwaith

• Constructing the railway viaduct in the 1860’s

• Land reclamation along the length of the estuary including where Fairbourne is now

• Constructing the causeway in early 1970’s

• The placing of reno mattresses under the railway viaduct in the 1980’s

There is no evidence to link the current flood risk facing Fairbourne with estuary siltation and the

construction of the causeway.


44. What program of Storm Drain Maintenance is intended for the village? Will NRW publish a map

of adopted and non-adopted drainage ditches and water courses and how will any lack of

maintenance on non-adopted drainage ditches impact on the risk of flooding?

Fairbourne is within the Internal Drainage District (IDD), so we have permissive power on all

watercourses, not just those which have been nominally “adopted” so a map of adopted

watercourses is not totally relevant.

We will carry out channel maintenance on the Main River system leading down to the tidal doors

in December/January together with the non-main river ditches that we normally clear.

We will monitor the system for blockages and ensure that the grids are kept clear on a regular


There is no scaling down of maintenance planned, in fact with the new scheme there will

probably be an increase in maintenance. This is the first year, so we don’t have experience of

what is required yet.

There is certainly no cut back which might increase flood risk to the village.

A project to review IDDs may change the way adopted ditch maintenance is handled, but Main

River works are unlikely to change.


45. Will pebbles and stones displaced in the storms be returned to the appropriate areas on the

beach and shingle bank?

The shingle bank referred to does not belong to Natural Resources Wales (NRW) it is Crown

Estate Land mostly bordering land owned by Gwynedd Council on which sits the Concrete Sea

Wall that NRW maintains. The rock armour at Friog Corner is to sustain the Concrete Sea Wall.

The question of shingle at Friog corner which we answered earlier under Q52 of the FAQs still

stands as Gwynedd Council’s beach monitoring and NRW’s Friog Corner study will identify

options which may include shingle nourishment which would be considered for further

assessment. NRW would be involved in any shingle management essential to maintain the

concrete sea wall and Flood risk in the community, but not clearing up of shingle washed over

onto the path/road walking unless a direct flood risk management issue has been identified.

NRW thinks that debris was cleared during a previous storm by Gwynedd Council; perhaps their

maritime team?


46. There is significant concern from the Community regarding 2 areas in the Rowan Embankment

where the shingle has been washed out opposite Penhryn Drive South. This is leaving the

Embankment in both areas vulnerable to over-topping during high tides and storms. Are the

relevant agencies aware of this and what plans do they have to rectify the situation?

Natural Resources Wales are aware of the concerns however the integrity of the sea wall is not

compromised and the shingle bank has been profiled naturally by sea wave action. We will

continue to monitor the situation together with Gwynedd Council, who have already undertaken

beach profile studies and this is also covered within the contents of the brief for NRW’s

proposed Study of Friog Corner. There is no evidence as yet that this will exasperate the


The local action undertaken on the access has inevitably cut off the splashover flood route to

the properties affected during the January storm. An improved flood warning service will also

provide a more specific warning to residents along the frontage.


47. Have the relevant agencies given consideration to using movable interlocking concrete barriers,

similar to temporary motorway interlocking central reservations, that can be placed at risk areas

during winter and removed when not needed?

Is this referring to the provision of a secondary defence behind the existing sea defence? If so,

then we would not currently consider this option as it may accumulate more water behind the

defence rather than let it seep away. This is something that Natural Resources Wales could

discuss further with the Fairbourne Facing Change Action Group.


51. It is understood that spoil from weir clearing and from the bridge over Afon Wnion in Dollgellau

has been used for a number of years to build up defences along Afon Mawddach on both sides

at Bontddu and Penmaenpool. Has this work been authorised and is the impact of flows during

high rainfall events monitored?

Gravel from Pont Fawr Dolgellau was taken to the Ynys floodbank at Penmaenpool some fifteen

years ago and is not to be confused with material which went to many locations on the

floodplain as part of the recent Gelligemlyn road improvement scheme. The gravels were

utilised behind the embankment to strengthen identified weak sections maintainable by our

then predecessors Environment Agency Wales which was fully assessed. No further gravels have

been used for this purpose and have since been disposed of at various other locations to include

Friog corner.The material recently imported from the road scheme has been assessed to have

no detriment to Fairbourne.


52. Will the relevant agencies consider/commit to the replacement of pebbles and shingle at Friog

corner and surround?

This decision will come as a result of both Gwynedd’s monitoring process and the outputs from

NRW’s Friog study.


58. SMP2 provides the following definition:

“Sustainability is a concept, which deals with mankind’s impact, through development, on the environment.

Sustainable development is ‘development which meets the needs of the present without

compromising the ability of future generations to meet their own needs’ (Brundtland, 1987). It

should also take account, for example, of the long-term demands for non-renewable materials.”

Can you explain how preserving Fairbourne for the next 100 years will compromise the ability of

future generations to meet their own needs?

In answer to question 55 we have hopefully addressed the issue raised by this question in setting

out the thinking behind the conclusions of the SMP in relation to sustainability.

It is acknowledged that, as stated in the Defra Guidance that ‘sustainability’ can mean different

things depending upon the individual viewpoint; it is not necessarily the same for conservation

bodies, the national treasury, or local residents within a coastal settlement. What is required is

consideration of the conflicting pressures on the coast and constraints upon its management, to

seek to provide an optimised plan, one which provides ‘balanced sustainability’ i.e. it needs to

consider people, nature, historic and socio-economic realities.”

If, however, we do not address the issue raised by the SMP now and understand and examine

how we address the issues, then we consider that we are merely handing on the problem to

future generations, with far less time and opportunity to deal with the important issues that have

been raised.


61. In low‐lying towns and villages such as Jaywick in Essex that are defended by a high sea wall,

pumps have been successful in clearing the water and preventing it from coming back. Could we

not have water‐powered pumps from a waterfall and tidal movement to push water back out to

sea when there is heavy rainfall? Uplands can also be better managed.

There are obviously many areas around the coast where there is land and villages at risk from

flooding. In each of the SMPs this risk has been considered and in some cases recommendations

have been made for a need for change. As identified in the question Essex is an area where there

is substantial risk and this has been considered in the respective SMP. In some areas in Essex

managed realignment has already been carried out and further cases are still under

consideration in the longer term.

Much of Jaywick, itself, tends to be built over slightly higher ground, although vulnerable both to

erosion and flooding on extreme water levels. In 1953 the main village was not inundated. It

was, however, cut off for several days due to flooding around the back of the village severing the

main road to the village. There was also a major failure of the sea wall, although this did not

result in direct flooding but the sea wall was overtopped by wave action.

During the 1970s and 80s, the main concern was that beach scour was undermining the main

sea defences. The shore had been reduced to its underlying clay. Major works were undertaken

to restore the beach and significant investment followed in maintain these beach levels.

Notwithstanding this, serious consideration is being given to the long term sustainability of

management in the area. It is understood that over the longer term there may be need for

further adaptation.

We are unsure of where precisely pumps have been installed as suggested by the question.

However, possibly this is in relation to areas to the back of the village rather than to the village

itself as, as previously mentioned the village is generally on slightly higher ground. It is possible

that pumps have been used to remove water after a severe flood event.

In the case of Fairbourne the concern is that ground water levels will cause a problem rather

than just flows from the rivers or flooding due to overtopping. To address this overall problem

would require a different level of management which would need to be increased progressively

as sea level rises further. Pumping would need to be in effect continuous to reduce ground

water to an acceptable level. This issue of ground water is one of the areas being monitored and

from the information collected how this might be managed will form part of the overall


Pumping would obviously need a reliable source of power and certainly with developing

technology, it seems unlikely that this could be won from tidal generation. Similarly, obtaining

such a power source from water falls is unlikely to be sufficient. This whole issue could be

reviewed but seems unlikely to provide a solution. This is being realistic, rather than negative, as

the project has to maintain an open approach to all ideas.

On the final point, upland management tends to be most beneficial where there is an

opportunity to provide storage, either as some form of reservoir or through land management.

The project will review what investigations have been undertaken already as part of the study

looking at management of flows through the area.


68. What the Council believes is what matters – can we engage a legal environmental champion to

take our concerns forward?

We can certainly investigate the cost of doing this, however, we need to be mindful of our

limited budget and ensure that what we spend our money on returns a fair investment for the

project and community alike.


84. Rainfall recently hasn’t been a lot heavier than other years based on 20 years of historic local

data, so what does the future hold? What is different?

The work reported by UK Climate change programme (UK CP09) makes projections of change in

rainfall intensity. UK Climate projections indicate that winter high intensity rainfall could

typically increase by:

0 to 10% over the period 2010 to 2039

10% to 20% over the period 2040 to 2069

30% to 40% over the period 2070 to 2089


85. The sluice gates aren’t big enough to handle the amount of water off the mountains in

December. Is there a negligence issue? Recent observations of higher retained water levels by

railway, backing‐up of water behind gates and older, earlier gates working better.

If it’s regarding the penstock control structure upstream of the railway at the point where flows

are diverted into the new channel then this performed well during the December flooding by all

accounts but there are a few issues here that will need to be directly observed during any repeat

of higher rainfall events. This is a new flood scheme and we will be monitoring its performance

and this will involve operatives visiting this site on the higher scale events.

We’ve had positive comments from some residents that despite the significant rainfall of

December there hasn’t been a major fluvial flooding issue in the village.


88. Why can’t we simply raise the height of our existing sea defences? How would Holland deal with

this problem? If they can manage the problem, why can’t we?

The SMP poses this exact challenge. It is always of course possible to build higher defences,

restore beach levels, deal with the flooding due to the rivers and pump to reduce ground water.

There remains the problem that whatever is done, there remains the risk that defence measures

fail or are exceeded. This is a problem that will become worse with the effects of climate change.

At present Fairbourne is protected to a good standard of defence and emergency planning has

been put in place to address the risk that defences are overwhelmed. By moving down the

course of action suggested in the question there is ever increasing dependence of defences. In

the Netherlands this is the situation that they are in. They are, however, looking in some places

at alternative solutions.


89. Has Fairbourne had a T100 level in recent records? What about in 1998? If we had had a T100

level and not had a breach, then why the current concerns?

No there has not been a recorded T100 event because our records do not go back that far. The

1998 event was estimated to be around a 1:2 year event based solely on water levels. The event

in 2014 was, based solely on water levels, around a T20 extreme. The waves associated with this

event possibly raise this to a higher return period.

With sea level rise the typical event that might be considered now as a T100 event is likely to

occur on a far more frequent basis. Typically with 0.5m sea level rise, the extreme water level

that might on average occur every 100 year now, might occur every couple of years.


90. Why wasn’t the defence raised during January 2014 repairs? Would it currently do a proper job

in defending the community?

We presume this question relates to repairs at Friog Corner in January 2014. The concrete wall

at Friog Corner is given as meeting the 1 in 200 year return period event standard and meets the

standard of protection design criteria for present day coastal schemes as agreed by Welsh

Government. The repairs at the Corner in January 2014 reinstated the crest to its design level.

The repair works were undertaken in accordance with the SMP2. It is very unlikely that higher

defences would have got planning approval.