Horizons Regional Council staff were racing against the clock yesterday in an attempt to erect temporary flood protection along the lower reaches of the Whanganui River.
However, there was no flood - the flood protection was an exercise only, designed to test staff's ability to quickly construct a temporary wall outside Q-West Boatbuilders.
Horizons' emergency manager, Shane Bayley, said the Balgownie flood protection scheme had a gap of about 100m where the Q-West slipway entered the Whanganui River.
"Obviously, we can't build flood protection over a slipway. But this basically leaves a big hole in the stopbank, which could make the whole scheme useless during a big flood," Mr Bayley said.
The wall is made up of metal frames and large metal sheets, which are permanently stored in shipping containers in the Q-West carpark. Mr Bayley said the wall was designed to be erected by four people in four hours. "This is just an exercise, but we are timing it to see how long it takes."
Staff put up part of the wall during the exercise last year, but this is the first time they've constructed the entire wall. Mr Bayley said the exercise would become an annual one.
The team is put on stand-by when the Whanganui River reaches 11m at Pipiriki, and is deployed when the river reaches 13m.
"It takes around 10 hours for the flood peak to travel from Pipiriki, so we have plenty of time."