Flaxy canal widening

Completed in 2012 this project for TrustPower in the Bay of Plenty involved the widening of the Flaxy Canal, with removal of silt and weeds to allow improved flows into the Power station head waters and increased generation. The work entailed:

  • ” Evacuation and cartage of some 35,000m3 of rock and OTR to stockpile sites. MAP developed a construction method as the ECI contractor and completed a small trial section to demonstrate the effectiveness and safety of the planned process. The key to the project success was to provide the correct gear for the project and the use of line drilling to provide a defined edge to the widened canal. The rock bank in the middle of the project started at some 18m above canal water level and this was cut down in benches to just 4m above water level to allow for future access and cleaning. Material was excavated with 2 35t Excavators and a 29t Excavator using ripper tynes and breakers to achieve the 2m widening. Cartage to waste stockpile was completed using 2 MT 31 Moxy Off Road Dump Trucks
  • ” As part of the original scope MAP was required to remove weed from the downstream canal (18m width) for a length of some 2km. The weed was removed using a modified bucket on our 35t excavator. This work required a careful “feel” for the operator to ensure there was no damage to the canal liner or the rock rip rap. During the course of the works TrustPower elected to extend the silt removal some 50m upstream to clean the mouth of the canal. This was completed using the same gear however only working at low canal levels (and rising water) to minimise sediment loss downstream.