Low rainfall over the past month has resulted in a notable drop in the level of Lake Wānaka but it is not out of the ordinary variation range, Guardians of Lake Wānaka chair and WAI Wānaka trustee Don Robertson says.

Data supplied by NIWA at the time of writing (the afternoon of Wednesday February 19) showed a lake level of 276.456 metres above sea level.

The level fell around 35cm in the past month but, after light rainfall, increased a little in the previous couple of days from the month’s low of 276.407 metres above sea level.

It was still well above the lowest recorded level, which was measured on September 25, 1935, at 276.26 metres above sea level.

Beacon Point Road Beach looking more like a tidal inlet than an alpine lake on Wednesday.

Don said the drop in lake level is unlikely to have an impact on aquatic health.

“In the ranges we are seeing, in normal circumstances I wouldn’t expect to see very much in the way of impact on biodiversity or anything else,” Don said.

“If it carries on down like this it could get to the point where it is causing damage to plants.”

The foreshore below Bullock Creek on Wednesday.

The median level of Lake Wānaka (between 1962 and 2023) was 277.22 metres above sea level, with most years falling within 0.19 metres of this range, according to a report completed by aquatic ecologist Ian Hawes for Otago Regional Council (ORC).

The lake level has “considerable year-to-year variability”, the report said.

Don noted that the low lake level had made visible a substantial alluvial plain where Bullock Creek enters Lake Wānaka.

It is the result of the “huge increase in sediment” entering Bullock Creek from the Alpha Series subdivision, he said.

A forecast for heavy rain overnight on Wednesday suggests the lake level will trend upwards.

PHOTOS: Wānaka App