Portnoo Harbour Feasibility Study, Co. Donegal

A feasibility study was undertaken for Donegal County Council, for Portnoo Harbour in West Donegal to propose improvements to the wave climate within the harbour. The first requirement for the study was to organise the collection of field data including bathymetry, current measurements, tide data, wind data and sediment samples. Using our inhouse Seaworks software package, mathematical models were created to reproduce the existing currents, tides and sediment movement, as well as extreme wave conditions at the harbour.

Nine design options were considered to provide shelter from adverse wave conditions that could propagate across the Atlantic from as far as Canada before reaching Portnoo Harbour. These options considered various extensions of the existing breakwater as well as separate land and offshore rubble mound breakwaters. Any possible future problems with sediment entrapment were also modelled.

The recommended design option proposed the construction of a vertical breakwater with rock armour and a second rubble mound breakwater, the provision of new access roads and car parking on currently privately owned land, the removal of rock within the harbour area, the supply of pontoons within the new harbour and the construction of a new slipway were also considered.