HomeMy WebLinkAbout2660030 - F.I. Received Doc. - Traynor Env. FI Response25/624 TE
1st September 2026
Monaghan County Council
Planning Department
Dublin Street
Monaghan
Re: Planning and Development Act 2000 (as amended).
Planning and Development Regulations 2001 (as amended).
26/60030 - permission for the construction of a storey and a half dwelling and single storey domestic
garage, new sewage treatment system, relocation of existing treatment system for existing
neighbouring dwelling, connection to group water scheme, new entrance, entrance walls piers,
and all ancillary site works at Coolmuckbane Monaghan Co Monaghan.
Dear Sir/Madam,
I refer to your letter dated 27th March 2026, we now comment as follows
Item 4 - Planning Authority data indicates that the site of the proposed development (including the area
where it is proposed to install the proposed wastewater treatment system) is located within an area which
is vulnerable to fluvial flooding. There are concerns that the development may be at risk of flooding
including the potential for adverse impacts upon the
proper functioning of the waste water treatment system. The Applicant shall submit a response to these
flood risk concerns which may include a Site-Specific Flood Risk Assessment for the proposed
development, completed by a competent professional with hydrological experience, confirming that the
development:
• Will not be at risk of flooding
• Will not result in flood water (fluvial) displacement off-site or exacerbate flooding in the
immediate vicinity or wider area;
• Will not obstruct or impede important flow paths;
• Will not result in residual risks to the area and/or development that cannot be managed to an
acceptable level
Response – A Site-Specific Flood Risk Assessment (SSFRA) has been prepared by Traynor Environmental
Ltd. in response to Item 4 of the Further Information Request and is submitted herewith. The assessment
has been undertaken in accordance with The Planning System and Flood Risk Management – Guidelines
for Planning Authorities (DoEHLG/OPW, 2009). RECEIVED: 08/09/2026
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The SSFRA considers the available OPW flood risk information, historical flood records, site topography,
the submitted site layout, the proposed wastewater treatment infrastructure and the proximity of the
Drumrutagh Stream. In response to the concerns raised by the Planning Authority, a site-specific
hydrological and hydraulic assessment of the Drumrutagh Stream was also undertaken using available
OPW Flood Studies Update (FSU) catchment information and surveyed watercourse cross-sections.
The hydraulic assessment considered the 1% AEP (100-year), 1% AEP plus 20% Mid-Range Future Scenario
(MRFS) climate change allowance, and 0.1% AEP (1,000-year) fluvial flood events. The assessment
indicates that the predicted flood waters are generally contained within the surveyed watercourse
corridor and below the adjoining bank levels in the vicinity of the proposed development.
An existing culvert located downstream of the proposed development between surveyed cross-sections
XS08 and XS09 was also assessed. A conservative 66% partial blockage sensitivity scenario was
undertaken. Under the 0.1% AEP event, the conservative screening level at XS06, approximately
representative of the proposed development location, is 51.659 mOD, which remains approximately
0.661 m below the lower surveyed bank level of 52.320 mOD. The assessment therefore indicates that
partial blockage of the downstream culvert would not be expected to result in overtopping of the
watercourse bank in the vicinity of the proposed development.
On the basis of the SSFRA, it is concluded that the proposed development:
• will not be at an unacceptable risk of fluvial flooding;
• will not result in the displacement of floodwaters off-site or exacerbate flooding within the
immediate vicinity or wider area;
• will not obstruct or impede important flood flow paths;
• will not give rise to residual flood risks that cannot be managed to an acceptable level;
• will not adversely affect the proper functioning of the proposed wastewater treatment system
as a consequence of fluvial flooding; and
• incorporates appropriate surface water drainage measures, including the discharge of clean
surface water to a suitably designed soakaway.
Accordingly, the submitted Site-Specific Flood Risk Assessment demonstrates that the proposed
development can be accommodated without giving rise to an unacceptable flood risk to the
development itself or to surrounding lands and satisfactorily addresses the flood risk matters raised under
Item 4 of the Further Information Request.Should you require any further information, please do not
hesitate to contact me.
Yours sincerely,
Nevin Traynor
BSc Env, HDIP IT, Cert SHWW, IAH RECEIVED: 08/09/2026