City's leaders in Swansea lagoon debate
CITY leaders are today debating the biggest engineering scheme in Swansea for generations.
And the vast tidal lagoon planned for the bay has raised plenty of questions.
Swansea councillors have a 115-page report to absorb ahead of this afternoon's meeting, with feedback from key departments.
The council does not have the final say-so on the lagoon, given its scale. That falls to the UK Government.
Elected members will be asked to commend the report to developer Tidal Lagoon Swansea Bay and ask it to address the findings of a council- commissioned study.
That study, by White Consultants, assessed the developer's preliminary environmental information report, and concluded that it covered a lot of ground "but does not focus sufficiently on what is important for Swansea Bay".
White Consultants also said that viewpoints provided in the developer's literature "should be amended to ensure the worst case situations are addressed".
And it added: "There is concern that the development may have significant adverse effects on the essential qualities of Swansea Bay, adversely affecting one of the city's best assets."
The £650million-plus scheme is recognised in the council report to have many benefits, not least generating the equivalent of nine per cent of Wales' domestic electricity needs.
The 11.5sq km lagoon, which would extend 3.5km into the bay and work on both the ebb and flow tides, also ticks tourism boxes and would generate an estimated 2,880 jobs during construction and 50 operational ones.
But it is the structure's potential effect on sediment patterns - and the developer's modelling, thus far, of this potential effect - that is repeatedly brought up in the report.
White Consultants said: "Sedimentation patterns may be changed. It would be of concern if mud deposited by the River Tawe or (River) Neath increases in proportion to sand on beaches, especially the beach along the promenade at Swansea/Mumbles. The modelling . . . appears to be based on a smaller proposal so this issue needs to be carefully considered."
Effects on bathing water quality, given stricter European targets around the corner, are another big factor.
According to the council's head of environment, management and protection, the lagoon would have a major impact because Swansea's sewage treatment works outfall is within the impounded area, tidal flows around the lagoon would change, and any slight change in the way sand is deposited in the bay's intertidal area could result in swimming areas becoming "more turbid", allowing bacteria and viruses to live longer.
Mr Morgan has requested that extensive survey work of the bay carried out in 2011 by the council is repeated.
The manager of Swansea Marina, meanwhile, suggested that large waves could develop along the western lagoon wall, which leads to the marina entrance, and wondered if the suction effect of the lagoon's turbines could cause problems for drifting boats whose engines may have failed.