COMHAIRLE CONTAE ÁTHA CLIATH THEAS
SOUTH DUBLIN COUNTY COUNCIL
MEETING OF TALLAGHT AREA COMMITTEE (1)
Monday, November 15, 2010
MOTION NO. 2
MOTION: Councillor S. Crowe
That this Committee, concerned at the state of many of the rivers and waterways in this County and in this Committee area, and with the increased wet weather and flooding causing problems in some areas last year, calls on the Manager to give a report outlining how often they meet with the relevant people in the ESB, Inland Fisheries Board and other agencies and who is actually responsible for removal of growing and fallen trees and other possible barriers that contribute to widespread damage and flooding.
REPORT:
South Dublin consists of two significant flood risk catchments, both of which have been approved in recent years for studies into flood risk management. The Dodder Catchment Flood Risk Assessment Management Study CFRAMS and the Liffey (Eastern) CFRAMS are at different stages of completion, but essentially these reports deal with all of South Dublin’s significant watercourses. A brief description of each study is given below. The Dodder CFRAM deals with the Dodder, Tallaght Stream, Owendoher and Whitechurch, whilst the Liffey CFRAM deals with the Liffey, Tobermaclugg, Griffeen, Camac, and Poddle. In addition, is should be noted that major flood alleviation works have been carried out in South Dublin over recent years.
The Liffey Catchment.
Three meetings and one workshop on the Liffey Catchment Flood Risk Assessment Management (CFRAM) Study Steering Group have been held to date. The scope of this study has been widened from Liffey CFRAM to Eastern CFRAM, thus including all South Dublin’s Rivers (not already completed in the Dodder Study)
The main stakeholders attending the steering group meetings include officials from South Dublin County Council, Fingal County Council, Kildare County Council, Wicklow County Council, Dublin City Council, OPW and ESB. The OPW are about to carry out cross sectional surveys of the Liffey and it’s tributaries.
Lucan has been identified as an Area of Potential Significant Risk (ASPR) for additional focus. Nearest other ASPRs are Leixlip in Kildare and Chapelizod in Dublin City. Dublin City Council are proposing a new weir at Lucan for flow measurement. The Camac, Poddle and Griffeen are part of this overall study.
All Local Authorities along the Liffey, Kildare, SDCC, Fingal and Dublin City Council plus the Office of PublicWorks (OPW) work closely with the ESB with regard to regulating the flows in the Liffey and if there was a problem which required the deliberate discharge of additional water from either Poulaphouca or Leixlip Dams the Local Authorities would be informed in advance. The ESB send daily / weekly / monthly communications to the engineers in South Dublin identifying the status of the Liffey at the time – these communications increase in high risk periods of heavy rainfall. The highest flood risk from the Liffey in recent years was experienced in November 2009 – no significant river flooding occurred in South Dublin.
The Dodder Catchment.
In late 2005/early 2006 the three local authorities in whose functional areas the river Dodder flows i.e. South Dublin County Council(SDCC), Dun Laoghaire Rathdown County Council(DLRCC) and Dublin City Council(DCC) agreed that a study of the river would be commissioned in order to provide a comprehensive report on the Flood Risk Assessment Management of the river. The Office of Public Works (OPW) is funding the study as it forms part of the national Catchment Flood Risk Assessment Management Studies (CFRAMS). Dublin City Council is the Contracting Authority on behalf of the three local authorities. The core purpose of this study is to assess the spatial extent and degree of flood hazard and risk within the Dodder catchment, to examine future pressures that could impact on that risk, and to develop a long-term strategy for managing the risk that is economically, socially and environmentally sustainable.
The Report will include measures for the development of a robust model representing the hydrological and hydraulic characteristics of the River Dodder catchment, such a model will provide for the mapping of the flood risk. Using model output the technical and economic merit of various options for flood management, taking account of current and future land developments, will be presented within the report.
Draft Planning System and Flood Risk Management Guidelines:
The new Draft Planning System and Flood Risk Management Guidelines for Public Consultation was published in September. These are aimed at ensuring a more consistent, rigorous and systematic approach to fully incorporate flood risk assessment and management into the planning system. The implementation and coordination of WFD policies and Flood Risk policies is ongoing and has been included in the County Development Plan 2010-2016
Local Authority Role in Maintenance / Management of Flooding.
The Drainage Maintenance & Operations Section of South Dublin County Council operates a stream / river cleaning programme on a yearly basis. Debris, overgrowth and blockages are removed from sensitive public sections of the various rivers and streams. In addition, flytipping, illegal dumping and fallen trees are removed from public watercourses on an ongoing basis. Similarly public rivers / stream screens are continually maintained. (Drainage crews will only attend to rivers where the engineers deems that there is a risk of flooding from material or debris already in the Watercourse)
Notwithstanding the ongoing maintenance work outlined above, South Dublin does experience significant flood events. The County has significant watercourses and in the context of abnormal weather events, flooding could be experienced in the vicinity of any one of those watercourses.
The Drainage Maintenance and Operations Section is not responsible for maintenance of riparian lands along sections of watercourses in private ownership. South Dublin County Council however is in a position to advise such landowners of their responsibilities. Owners and occupiers of riparian lands (lands adjacent to a river or stream) are advised that they should be prepared for any flood eventuality. The Office of Public Works (OPW) have prepared a document called “flooding, plan, prepare protect” which can be viewed on www.flooding.ie. This document outlines how to assess a flood risk and prepare for a flood. It also deals with insurance, livestock and pets, restoration of gardens and how to create a flood plan.
South Dublin County Council also advises that ongoing maintenance of a private watercourse is essential in limiting the risk of flooding of property. Ongoing removal of excess growth, bulky items and rubbish are very important. In addition is it important that garden furniture is not placed in close proximity to a watercourse. The greatest risk of flooding is cause by debris being picked up from the banks of rivers and streams causing blockages further downstream.
Legal Position
South Dublin County Council can, when and where it is deemed necessary, use its powers under legislation where it identifies that a private stretch of river presents an unacceptable risk of flooding. Under the Local Authority (Works) Act 1949 where a Local Authority is of the opinion that ---
(a) any land in their functional area…….
(b) any permanent construction in their functional area …..
has sustained or is likely to sustain damage from flooding, landslide subsidence or other similar occurrence and that it is in the public interest to afford relief or protection from the damage, the local authority may execute such works as they consider reasonable for the purposes of affording such relief or protection. It should be noted though that the Local Authority is liable to pay compensation for entry onto such land.
In addition, under the Local Government (Sanitary Services) Act 1964, Local Authorities have specific powers in relation to the carrying out of works to prevent a place from becoming or potentially presenting as a dangerous place / structure. There are however specific requirements in relation to allocation of costs, recouping of costs, offences and notice to landowners regarding carrying out of works. In such cases the Council will endeavour to recover all costs associated with entering onto private lands – but this is not clearly defined in the legislation.
Ongoing maintenance is essential. However, pollution must not be caused in the carrying out of river maintenance. The requirements of the OPW and the Eastern Regional Fisheries Board (ERFB) must also be adhered to. Certain typesof river cleaning activities are not permitted between September and February by order of the Inland Fisheries Board.
Works that may be required, on an ongoing basis, or in an emergency scenario where the risk of flooding is deemed to be high, includes, but is not limited to, dredging of river bed, widening of watercourse, removal of overgrowth, erection of banks and laying of pipes and maintaining culverts and overpasses.
The Drainage Maintenance and Operations Section is also not responsible for any risk of flooding from a canal – this is the responsibility of Waterways Ireland.