Ennis South Flood Relief Scheme | Projects

OVERVIEW

Ryan Hanley was employed by Clare County Council as engineering and environmental consultants to develop a Flood Relief Scheme for the southern environs of Ennis. The scheme achieved substantial completion in July 2021, with a construction value of €14.5 million. The project team was presented with the Judges Silver Award at the Irish Construction Excellence Awards in 2022.

The urban district of Ennis South area includes flood prone areas at St. Flannan’s/ Toberteascáin, Ballybeg, and properties adjoining the Clareabbey floodplain, which include Quin Road Business Park and Abbeyville Housing Estate. The most severe flooding in living memory occurred in 2009, affecting St. Flannan’s College, Árd Aoibhinn and Tober Beg housing estates within the Toberteascáin area, and Ballybeg. Properties adjoining the Clareabbey floodplain, including Quin Road Business Park and Abbeyville Housing Estate were also at high risk of flooding.

A Steering Group was established for the project in 2011. The group was chaired by Clare County Council and included Office of Public Works (OPW), the funding authority. The project progressed through hydrological and hydraulic analysis, outline design, geotechnical investigations, and cost benefit analysis, leading to a successful planning application to An Bórd Pleanála (under Section 177AE of the Planning and Develop Act).

The scope of works required to relieve flooding in Ennis South was identified as follows:

Construction of two 1,200 – 1,350mm diameter flood alleviation culverts (1,120m and 520m in length in congested urban environment), along with service diversions, and
Upgrade of 1.5km of existing flood defence embankment, with associated works to back drain and sluice gates, and construction of a new 1.0 cumec (m3/sec.) pumping station, with works required within the Lower River Shannon SAC Natura 2000 Site.

In Q2 2013, L&M Keating constructed part of the St. Flannan’s culvert at the Toberteascáin Railway crossing under an Advance Works Contract. This work was timed to avail of a programmed line closure by Irish Rail.

Ryan Hanley executed the detailed design, tender and procurements stages of the overall scheme, following which Ward and Burke Ltd were appointed as Civil Works Contractor and construction works on the remainder of the scheme commenced in Q1 2019.

Construction works on the Ballybeg culvert were substantially complete by Q3 2019. The longer and more complicated flood relief culvert for St. Flannan’s was substantially complete in Q2 2020. Both culverts now provide critical flood protection to properties at flood risk in these two areas. The construction works on the Clareabbey flood defences were completed in July 2021 within the 27-month programme, successfully overcoming the unforeseen challenge posed by Covid-19 restrictions on construction projects.

In the words of the Principal Teacher at St. Flannan’s College, “My life as Principal Teacher, and the life of the school has been completely transformed. The flooding threat when the weather was really bad literally kept me awake at night, but those sleepless nights have abated like the water since the relief scheme was installed. The name of the scheme (flood relief) is very apt because the end product has been true to its name. Relief comes nowhere near expressing our gratitude to the benefits of this scheme to us here in St Flannan’s College.“

Ryan Hanley is proud to have contributed to this award-winning flood relief scheme as Designers, Environmental Consultants, Employer’s Representative and Project Supervisor Design Process (PSDP).