The CSIRO has dropped levee options for Ballina and West Ballina from its Richmond River flood-mitigation shortlist, shifting the focus upstream.

The latest shortlist being open to community consultation this week includes  a network of temporary flood-detention basins in the upper catchment  designed to hold back peak flows.

Lead scientist Dr Jai Vaze briefed about 40 locals in Ballina on Monday evening, saying community feedback to the revised list was “largely positive”. 

One Greens councillor voiced disappointment that more “nature-based solutions” weren’t included, but Dr Vaze said the program is aimed squarely at large-flood mitigation.

“We are talking about large-scale mitigation for large floods, we are not talking about beautification of the catchment,” he said.

What’s still on the table for Ballina Shire

• The re-opening of Boundary Creek as a flood channel (on the Ballina–Richmond Valley boundary) remains the only Ballina Shire work in the final shortlist.
  

What’s changed

• Urban levees once canvassed for Ballina/West Ballina have been removed.
  
• Priority has shifted to nine upper-catchment detention basins on key tributaries (Fawcetts, Upper Nimbin, Rocky Valley, Corndale, Barlings, Booyong, Dunnon, Collins and Rocky valleys), plus targeted highway/embankment upgrades where roads are known to back up floodwater.
  

Dr Vaze said the shortlisted basins are sited to avoid homes.

“We’ve selected locations where residential impact is minimal.

“Final modelling will show exactly which farmland would temporarily inundate and for how long.”

The basins would use remotely operated gates—lowered only when a major flood peak is imminent—then released as waters recede.

Two “bundles” to model

CSIRO will now test two implementation bundles:

• Bundle 1: a smaller set of nine works.
  
• Bundle 2: an expanded package of 13– projects, adding further basins and road drainage upgrades (main image above).
  

How much each bundle reduces flood levels will be determined by the next round of computer modelling.

“We’ll implement the shortlist in the model and publish the outcomes,” Dr Vaze said.

Have your say

The final community session is at Woodburn, 4–6pm tomorrow (Wednesday). After that, the team returns to Canberra to run the full-catchment simulations.

A final report with recommendations for the Richmond catchment is due June 2026. Funding decisions will rest with the NSW and Australian governments.

“We’re targeting measures that meaningfully shave the peak of big floods,” Dr Vaze said. “That’s where the risk—and the potential benefit—is greatest.”