Cadfor construction works

Mulloon Consulting’s (MC) Jack Smart and Max Brunswick recently completed construction of works at Cadfor near Binda in the NSW Southern Tablelands in early March 2024. The works involved two rock chutes (the primary rock chute being 16m wide by 27 m long) with accompanying diversion channels and spillways to safely manage the return of flows to the Binda Vale Creek.

Historically, flows had been diverted out of the creek upstream of Cadfor in the 1970s to manage creek erosion issues with flows directed via a network of dams and contour banks back to the Binda Vale Creek. Unfortunately, the original works failed several times resulting in localised erosion issues and recent efforts to address the problem were unsuccessful.

The works completed by MC were designed to manage baseflows through the existing dam’s trickle pipe while providing multiple flow points to safely re-enter flows during large flood events to assist in spreading and dissipating the energy of the flows across a larger area.

The top diversion channel directs flows towards the dam. Base flows re-enter Binda Vale Creek through a trickle pipe in the dam while larger flows will engage the primary rock chute top right-hand corner). During extreme flood events, some water will exceed the diversion channel spill level and safely re-enter via a secondary ‘repaired’ rock chute (top left-hand corner).

Bottom diversion channel downstream of the dam with the sill of the primary rock chute in the distance. Photo taken immediately after construction after topsoil had been re-spread.

Primary rock chute during construction with rock rip rap and topsoil being applied progressively up the rock chute.

Primary rock chute (looking from upstream) immediately after construction and re-spreading of topsoil.