A scheme which would alleviate flooding of homes, farm sheds and farm land in south Galway is up for public consultation.
A feasibility study was carried out into flooding in Gort and the surrounding areas which has suffered from severe flooding during the winters of 1994/1995, 2009, 2014, 2015/2016 and 2020.
The scheme comprises 16km of channel works, 303,000m3 of excavation and 30 large culverts to carry water out to Kinvara Bay. It may also result in land take and potentially land severance.
Dairy farms cut-off
Surveys and assessments of the area concluded that during a one in 100 year (1% annual exceedance probability) flood event dairy farms are at risk of being “cut-off due to prolonged flooding” and at least 20 slatted sheds flood.
It also found that up to 463ha of agricultural lands flood above the assessed target maximum flood level for each flood plain and over 200 homes were at risk of flooding.
If it comes to be, the scheme would alleviate the flood risk to farm buildings and the 463ha of farmland.
“Of this 463ha, approximately 347ha is located in the main system floodplains and will benefit by alleviation of flooding that would otherwise flood this land for durations [up to] one month.
“Flooding for such a prolonged duration would cause extensive damage to agricultural grass lands, would lead to loss of productivity for a full year, and would likely force re-seeding to allow the grassland to re-establish.”
Land take and change in use
As a result of new flood relief channels proposed in the flood relief scheme, flow velocity through some areas will be increased, and as such the “safety and health of land users must be considered” in the design of the scheme, according to the study.
“Accommodation works may be necessary to ensure safe movement of people and livestock in and around the flood relief channels.
“Also, depending on channel design, it may not be feasible to hand back affected lands to the landowner or to return them to their original land use (eg for grazing) outside of the flood period.
“As such, there may be an associated land take or severance associated with the scheme. Scheme design should aim to minimise the need for land take,” the report said.
People whose land is proposed to be interfered with as part of the scheme will be notified in accordance with the 1945 and 1995 Arterial Drainage Acts and will be invited to view the proposed scheme and make their observations on it during the public consultation.
The minister with responsibility for the OPW will consider their observations before confirming the scheme.
When the scheme is completed, the landowners will be entitled to apply for compensation from the OPW for the interference to their land.
The report found that it may be necessary to permanently remove land boundaries, such as hedgerows and stone walls, along the alignment of the flood relief channels such that hydraulic throughput is accommodated.
In order for a scheme to be considered cost beneficial, the economic benefits must outweigh the whole life costs of the scheme.
In the case of the South Galway (Gort Lowlands) flood relief scheme the preliminary analysis indicates that a cost beneficial scheme potentially exists, with direct construction costs estimated at €14m, excluding VAT and the net present value of the benefit cost coming in at €22m.