Castanet – January 13, 2023
The Okanagan Basin Water Board is looking to replace its aging milfoil harvesters.
Board directors this week approved a request for proposals, seeking an amphibious replacement.
The water board’s milfoil control program includes winter rototilling.
In spring and summer, the crew uses a harvester and takes the weeds to shore for pick up and disposal.
“Currently, the two harvesters are almost 45 years old, and at least one is in need of costly repairs,” the water board says.
“An amphibious harvester, although more costly, potentially addresses several issues including improved access for milfoil control and weed storage issues.”
Last spring, the board said both harvesters would need replacing in the next year, at an estimated cost of $250,000 each.
“The current harvesters were both manufactured in 1978 and have surpassed their expected lifespan of 35 years,” a board report stated in May.
The aquatic weed harvesters are floating, paddlewheel-driven barges with a conveyor that can be lowered approximately two metres into the water, where blades at the front edge and sides cut milfoil below the water.
Once cut, the conveyor lifts the weeds into the belly of the machine.
The milfoil control program treats more than 50 kilometres of shoreline in the Okanagan, from Osoyoos to Vernon.
The program uses aquatic rototillers to de-root the plant during the winter, and the harvesters to cut and remove plant material during the summer.
The original milfoil control program was established in 1973 as a partnership between the B.C. Ministry of Environment and the water board. In 1999, the province cancelled its participation in the program and since then, all costs have been borne solely by the OBWB.