asked the Minister for Finance if he will give details of drainage works to be undertaken by the Office of Public Works on the Mask/Robe drainage scheme this year; the amount of blasting that is envisaged on the Corrib/Lough Mask Canal; if he is satisfied (a) that any blasting that might be found necessary to deepen the canal will not result in environmental loss to this high amenity area and (b) that the objectives of the drainage cannot be met by means other than blasting; and if he will provide details of the professional advice sought and received concerning the effects of any such blasting on the rock structure in this particular area.
Written Answers. - Corrib-Mask-Robe Drainage Scheme.
406.
The works to be undertaken this year on the Corrib-Mask-Robe catchment drainage scheme include the continuation of those scheduled for the Cong Canal and the Robe, Aille, and Lough Carra sub-catchments.
The proposed works in the Cong Canal, which involve the deepening of the channel bed through some 1,200 yards of solid limestone rock, are required to achieve a reduction of high water levels in Lough Mask by increasing the flood discharge capacity of the canal. The most effective way of carrying out these works is by drilling and blasting. The works will not adversely affect the environment except to the extent that it may be necessary to deposit rock spoil on the banks of the canal.
Since the high amenity value of the Lough Mask area has always been fully recognised the Commissioners of Public Works commissioned a leading hydrogeologist to carry out a detailed study of the implications of the works proposed under the scheme on groundwater. His report re-affirmed the commissioners' view that the proposed works in the canal would not affect either lake or groundwater to any significant degree other than in the manner intended under the scheme.