A North Central Catchment Management Authority board member has warned the building of super-drains in urbanised areas is setting up the country north of Bendigo for a major flood.
“The drainage is done without any consideration for downstream users,” James Williams said.
“In the past, water used to take five days to travel from Bendigo to Drummartin, now it’s 48 hours.
“Traditionally, heavy rain would create a small flood and be gone, now we get it all at once.”
Mr Williams, a former Drummartin farmer who is running in the Whipstick Ward in next month’s City of Greater Bendigo council election, said downstream outcomes should be a big part of the drainage strategy.
The NCCMA is currently finalising a $450,000 Bendigo Urban Flood Study, due to be released in November, with information processed from 20,000 drainage pipes across 21 sub-catchments of Bendigo Creek.
Mr Williams said more efficient drainage in urban areas, combined with the increase in development in outer areas, has eroded the floodplain area.
“The floodplain area which used to be grazing is now getting more and more frequent flooding,” he said.
“It now only takes an inch of rain in Bendigo and we get flooded.
“It’s a floodplain and we need to spread it out.”
Mr Williams said there are also “huge issues” associated with changing the creek flow pattern.
While he applauded the detailed floodplain mapping, he said the study needed to be wider.
“People don’t realise in extreme circumstances there are half a dozen streams flowing into a very flat part of the world,” he said.
“Because the Bendigo Creek and the Loddon are joined, there’s a whole raft of compacting issues people aren’t aware of.”