COMHAIRLE CONTAE ÁTHA CLIATH THEAS
SOUTH DUBLIN COUNTY COUNCIL

MEETING OF LUCAN AREA COMMITTEE

Tuesday, March 26, 2013

MOTION NO. 16

MOTION: Councillor G. O'Connell

"While acknowledging the support provided by staff in responding to my individual queries, the situation regarding flooding in the Lucan Area needs to be clarified as some residents complain that Insurance Companies are raising issues leading to refusal to insure on some notion that the “area” where the house is located is subject to flooding." 

REPORT:

Following is a synopses of the flood relief works that has been carried out in the Lucan area since the bad flooding in 2000:-

FLOODING of LUCAN AREA NOVEMBER 2000 

The severe flooding that occurred in the lower reaches of the Griffeen River on the 5^th and 6^th November 2000 resulted in flooding of properties at Old Forge, Grange Manor and Lucan Village.  Flooding also occurred at Tubber Lane on the lower reaches of the Tobbermaclugg Stream. The improvements to each river are outlined below.

Griffeen River Improvements

Following the above flood event the Council carried out emergency works such as the construction of a berm at Vesey Park to prevent the river bursting its banks onto the Adamstown Road.                                                                                                                                                                                                                                                                                               The Council also commissioned consulting engineers to investigate the causes of the flooding and prepare a report on the flood event.  This report was produced in March 2001 and its principal conclusions were that the November 2000 flood was estimated at approximately 24 cubic meters per second  which is equivalent to an estimated return period in excess of 100 years and that the existing river channel and culverts/bridges were unable to convey a flow of this magnitude.                                                                                                This report and a further report in May 2001 on Flood Alleviation Proposals recommended that the river channel and bridges be upgraded to provide conveyance capacity for the 100 year flood event. This involved the following works:

 (i)                  Widening and deepening of the river channel between the Grand Canal and the River Liffey.

(ii)                New culverts under Hayden’s Lane, the Dublin Cork railway line, Griffeen Avenue and Adamstown Road.

(iii)               New pedestrian bridges in Griffeen Valley Park between railway line and Griffeen Avenue.

(iv)              Lowering of weir at Vesey Bridge and raising of river walls in Lucan Village.

(v)                New bridge at St Johns Bridge.

(vi)              Diversion of services which impede flow in river.

 The recommended works between the Grand Canal and Griffeen Avenue were substantially completed in 2003.  Construction of the flood alleviation works between the River Liffey and Griffeen Valley Park commenced in January 2003 and were completed in 2004. The works which cost approximately €5 million will provide flood protection up to the 100 year flood event.

 Tubbermaclugg Stream Improvements

 Following the severe flooding of November 2000 a scheme was devised by the Council in association with Chartridge Ltd to alleviate the flooding in the environs of Tubber Lane and to provide a surface water outfall for the Adamstown SDZ lands. The scheme was designed to provide flood protection up to the 100 year flood event. The scheme consists of the following works:                                                                                                                                                                                                                                                                                 (i)         Lay 880m of 2.4m diameter pipeline and 25m of 2.1m diameter pipeline from Tubbermaclugg Pumping Station to Millstream Road mostly through lands owned by Lucan Golf Club .                                                                                                                                                                                                                                                                                                                     (ii)        Provision of 2 culverted road crossings at Millstream Road and Tubber Lane Road.                                                                                                                                                              (iii)       The construction of a 5000 cubic meter attenuation pond and a  195m of storm overflow pipeline through an existing culvert discharging to the River Liffey.

 Construction work commenced on the scheme in October 2008 and the works were substantially completed in August 2009.

The total final cost of the scheme was in the region of €7.7million which was shared between the Council and Chartridge Ltd.

Not withstanding all the above mentioned flood relief work carried out in the Lucan area since the floods in 2000 and the fact that no house in the Lucan area has been flooded by river water since that date, some Insurance Companies are still refusing  to insure houses in some parts of Lucan for flooding or else are loading the premiums for flooding. The reason for this is that some Insurance Companies have commissioned Consulting Engineering Firms to produce flood maps for them and some of the information they used to produce these maps is out of date. Hopefully when the OPW (Office of Public Works) produce their flood maps under the CFRAMS programme this may change. The OPW CFRAMS flood maps are due to be published by the end of 2013.