Y Pwyllgor Deisebau | 27 February 2018
 Petitions Committee | 27 February 2018
 ,Roath Flood Scheme 




Research Briefing:

Petition number: P-05-801

Petition title: Save the trees and ground in Roath Mill and Roath Brook Gardens before it's too late

Text of petition: As local residents, we believe that the planned flood works in Roath Mill Gardens and Roath Brook Gardens in Pen-y-lan, Cardiff are unnecessarily destructive.

We have seen the devastation of Waterloo Gardens and oppose Phase 3 of Natural Resources Wales' Roath Flood Scheme, which will widen the brook in Roath Mill and Roath Brook Gardens and see the felling of over 30 trees in an area where there has never been any flooding in the past.

We want to save the trees and ground in Roath Mill Gardens and Roath Brook Gardens in order to preserve the character of the area, minimise ecological damage and protect the habitats of our local wildlife.

We believe that Natural Resources Wales have not properly considered all options available, have misled the public with inaccurate figures during their consultation period and that it is, in fact unnecessary to bulldoze park grounds in order to widen the channel of the brook and remove mature trees in the process.

We call on the Welsh Government to urge National Resources Wales to stop work at Roath Mill and Roath Brook Gardens and consider the other viable options available to mitigate the perceived flood risk to this area.


Detailed information on the Roath Flood Scheme can be found on the Natural Resources Wales (NRW) website. Details include information on the proposed tree removal and planting, and consultation (PDF 85.4KB) undertaken as part of the proposal.

At the time of writing this briefing a Change.org petition has gathered 8,578 signatures, calling for the Welsh Government to intervene in the proposed works and “urge NRW to consider other viable options”.

Figure 1. Roath Flood Scheme site [Source: NRW]


Properties have been flooded by Roath Brook on a number of occasions, including significant events in 1979, 1995, 1998 and 2009. The brook has burst its banks most recently during high river flows in 2007 and 2009, and during high tidal events in 2010 and 2012. It is anticipated that the likelihood of such events will increase over time due to rising sea levels and more intense rainfall events, as a result of climate change.



Figure 2. Roath flood risk area [source: NRW information poster (PDF11.3MB)]

The Flood Risk Management Scheme (FRMS), which has been in development for over 5 years, aims to reduce the flood risk to over 400 properties (360 residential, 45 business).

Current fluvial flood risk to the area is shown in Table 1 below:

Table 1. Fluvial flood risk in Roath. [Source: Roath Flood Scheme FAQs, April 2017 (PDF 172.1 KB)]

The FRMS aims to increase the level of protection for the community up to a 1 in 75 year flood event (1.3 percent chance of flooding in any given year) from high river flows, and 1 in 150 year flood event (0.6 percent chance of flooding in any given year) from extreme tidal flows.

The planning application for the Roath Flood Scheme and the decision to approve it, can be viewed on Cardiff City Council’s webpage.

Options Appraisal

A number of solutions were considered initially in an options appraisal exercise, including dredging and temporary defences. Details of these options have been displayed as posters in the area (PDF 26.1MB), and covered in the Roath Flood Scheme FAQs (PDF 172.1KB).

NRWs investigation identified the most appropriate flood risk management approach would be to contain floodwater within the river corridors.

Tree removal and planting

NRW has identified the need to remove some trees along the banks of the Roath Brook in order to construct the new flood scheme. An Arboricultural Impact Assessment (PDF 8.2MB) has been undertaken by independent arboricultural consultants (instructed by Nicholas Pearson Associates) on behalf of NRW. The assessment details the methods undertaken, findings and proposals. It also shows two revisions to the assessment (dated ‘28-02-2017’ and ‘27-11-2017’, highlighted throughout the assessment) showing a reduction in the number of trees selected for felling.

The assessment details measures taken to minimise the impact of the works, including designated ‘root protection areas’ and ‘no-dig construction areas’.

A total 141 trees are proposed for removal, 13 of which are classed as ‘category U[1] – unsuitable for retention’. The Cardiff Council Environmental Scrutiny Committee reviewed the development and implementation of the scheme on the 5 December 2017. The responseletter (PDF 469KB) to NRW noted:

approximately eight of the trees were removed on request from the Council, and that these trees would ordinarily have been felled as a part of a one to three year programme. Natural Resources Wales has accepted the financial cost for removing these trees.

However 37 are classed as high to moderate quality. The Aboricultural Impact Assessment states:

Although removal of the 37 “A” and “B” category trees is regrettable, this is considered the minimum number of trees that must be removed to implement the flood defence scheme.

NRW states that in order to mitigate the removal of trees, 105 new trees will be replanted within the gardens (between 2.5m and 5m high). Details of what types of trees will be planted, and where, can be found in the Tree Planting Plans (PDF 3.6MB). Tree types have been selected to support the existing  character of the gardens and are detailed in the plans.

A further <200 saplings will be planted within the Roath recreational ground.

Errors in data

Between 13October 2016 and 3 March 2017 NRW’s consultation material incorrectly stated that over 400 properties were at risk of flooding in a 1:5 chance event i.e. 20% chance of flooding in any given year. The correct figures were 405 properties at risk of flooding  in a 1:75 chance event i.e. 1.3% chance of flooding in any given year.

NRW acknowledge (PDF 64.9KB) this error and state:

We would like to stress that information included in the detailed planning application and in consultation material leading up to this was correct. Therefore, we do not believe that this error impacted the consultation process significantly, as much of project planning was complete by this time, and planning permission had already been granted in April 2016.

Public consultation

Alongside statutory consultation requirements NRW has undertaken public consultation including door knocking, displaying signage, drop-in sessions and  regular newsletters (available online). Please see the Key Public Consultations Events (PDF 87.4KB) document for full details.

Subsequently, as a result of further community campaigning, NRW held additional meetings with the campaign group (@RoathBrookTrees) on 12 and 17 January 2018, and further community engagement events were held in the week commencing 22 January 2018. Presentation materials used in these public events are available on the NRW website.


The proposed works have generated media attention with articles about the works on BBC News, and a number of articles on WalesOnline.

The artwork that has been commissioned as part of the regeneration has also gained BBC media attention.

Local Government Action

The Cardiff Council Environmental Scrutiny Committee met with NRW on 5 December 2017 to discuss the delivery and implementation of the Roath Flood Scheme. Following the meeting, the Committee wrote to NRW on 7 December (PDF 469KB).

Whilst the Committee noted that it did not have the ability to force changes to the scheme and “does not explicitly endorse either the scheme proposed by Natural Resources Wales or any alternatives presented”, it did ask for the following confirmation:

I would be grateful if you could provide confirmation of the overall dry land surface area that will be lost as a result of this scheme at this location once it is available.

The Committee would like assurance that these (scheme) alternatives have been considered and evaluated as a part of the development of the scheme

NRW responded in a statement (PDF 64.9KB) dated 8 December 2017. It concluded:

the Committee is content the scheme is appropriate and necessary, so we shall continue with our planned work from 11 December.

It also discusses the additional cost of delaying the works further:

For example, a 4-month delay to undertake an independent review would incur an estimated additional cost of £200,000 of public money and prolong our presence and the disruption in Roath. Additional cost incurred on this scheme means less funding for other flood risk projects required across Wales.

Letters in support of the scheme were received from two local councillors and submitted as part of the planning application.

Welsh Government action

In her letter to the Committee, The Minister for the Environment, Hannah Blythyn AM, states that, at her request, NRW paused the third phase of tree felling works (planning for 11 December) to allow for further consideration of the scheme. She says she met with officials and NRW on that day to discuss the concerns of residents as well as the wider options that NRW explored to address flood risk to the area.

The Minister for the Environment met with campaigners on 22 January 2018. The campaign group gave an update on Change.org saying:

“The meeting was constructive and positive and we await feedback”.

The Minister has since responded to the Assembly Petitions Committee in a letter dated 2 February 2018, in which she outlines correspondence with both NRW and elected representatives. She responds to the concerns around the ecological impact:

I am assured that NRW have carried out all of the necessary ecological surveys as required for the planning permission from Cardiff Council in order to construct this scheme.

She also stated that NRW “have identified a further 6 trees that could be saved from felling” . The letter concludes:

I will now await the outcome of NRWs public workshops and continue to seek a way forward that alleviates risk and addresses residents’ concerns.

National Assembly for Wales action

A total of 13 written questions on the Roath Flood Scheme have been tabled and answered by the Minister for the Environment. The necessity and suitability of the scheme has been questioned, including what alternative measures have been considered. The matter has been discussed in Plenary, where the Minister for the Environment gave an update on Welsh Government discussions with NRW.

NRW has written to the Petitions Committee in a letter dated 24 January 2018, where each point of the petition is addressed in turn. Whilst NRW recognise the short term impact as a result of the works, it concludes;

We should like to stress that we are confident that our proposals will provide the flood protection required, the least impact on the environment, whilst maintaining the Edwardian heritage of the parks and gardens for future generations.

Further information

Roath Flood Scheme Environmental Report (in 3 parts)




Every effort is made to ensure that the information contained in this briefing is correct at the time of publication. Readers should be aware that these briefings are not necessarily updated or otherwise amended to reflect subsequent changes.


[1] “Those in such a condition that they cannot realistically be retained as living trees in the context of the current land use for longer than 10 years” (source: Arboricultural Impact Assessment, appendix c (PDF 8.2MB)