The Dunedin City Council has waited until today to assess the situation, hoping the sand will begin to return, as it has done in the past.
But the Dunedin Rugby Football Club, which uses the ground, is "obviously very concerned", and chairman Andrew Rooney expects to discuss the issue with council staff soon.
The most recent encroachment into the sand dunes at Middle Beach was noticed by former club committee member John Piper, who said he had seen rapid changes during his daily walk at the beach with dog, Millie.
He said he raised the alarm when it became clear the lights "were almost in the sea".
"It got so bad, and nothing seemed to have been done about it," Mr Piper said.
There was no need for the council to spend millions of dollars, but something needed to be done every year to protect the grounds.
The council is coming to the end of an extended consultation and research period, as it tries to find a way to deal with the constant erosion at the beaches from St Clair to Lawyers Head, made worse following severe storms in 2007.
It has been shoring up the dunes since then, dumping extra sand and placing "reno blankets" - rock-filled wire netting - along the beach.
This week, those were exposed, and waves were surging up to the dunes where the line of reno blankets ended, cutting into the sand below the poles.
Yesterday, new temporary fencing had been put in place near the lights, to keep the public away from the steep edges of the eroded dunes.
Just metres away towards St Clair Beach, sand dumped at the end of Moana Rua Rd, on an area that had been badly eroded, was still in place.
Council community and recreation services manager Mick Reece said the area around Middle Beach was volatile, with rips forming and reforming, and erosion occurring at different spots. Staff had visited the site, and there would be an assessment of the situation today.
Earlier this year, the council community development committee agreed to consult the public on a draft Ocean Beach management plan prepared by consultant Tonkin and Taylor.
The report recommended continuing the council's holding pattern of monitoring and sand replenishment work, in the meantime.
However, it also canvassed 13 longer-term options and recommended a managed retreat from Middle Beach and Kettle Park, or construction of an inland buried backstop wall to protect the area, over the next 10 to 50 years.
Mr Rooney said he was keen to understand what the council's short-term, and longer-term plans were, and was concerned about public safety, with electricity cables running underground to the lights.
