Water board considers upgrade in war on weeds

Eurasian water milfoil has a year’s grace in its ongoing battle with two aging milfoil harvesters in the Okanagan. That war could see a new weapon in 2024 as the Okanagan Basin Water Board considers the purchase of an expensive new amphibious milfoil harvester.

“We already had permission to buy two new conventional harvesters over the next five years — $500,000 in the next year, not including GST and shipping,” explained James Littley, deputy administrator for the board.

However, the board recently learned of a new amphibious harvester manufactured in Germany, a traditional floating harvester mounted on an excavator hull.

It can launch itself, crawl out of the water and dump a full load higher up on land making it easier for a truck to haul weeds away without blocking boat launches or beaches, Littley explained.

“The cabin can physically lower as it’s operating. Right now, we have to do fairly significant changes to the machine to get under the bridge in Osoyoos to float between the south and north basin,” he said. “This would address a lot of our access and operational issues that are increasing as shoreline development increases.”

Another challenge lies in the price difference: traditional harvesters are $250,000 to $300,000 while the new amphibious harvester could cost more than double at $700,000 to $750,000.

“For now, the amphibious harvester would be a replacement for the two so we would buy one in the next five-year period and defer future purchases until we’ve had an opportunity to really get to know the machine and figure out if it is a better solution,” he said.

The deadline for proposals for an amphibious harvester or two conventional harvesters, as previously approved, has not yet been set but delivery would not be in time for this summer’s harvesting.

“If it is a new unit, we’ll probably want to find out who has one and make sure that our most senior operator and supervisor check it out. That would be part of our due diligence. We would be looking at the following summer to get it delivered here,” said Littley.

The two existing harvesters are almost 45 years old and one of the units needed $20,000 worth of repairs just to keep it operational for the next couple of years.

The milfoil control program includes winter rototilling but in spring and summer, the crew uses a harvester, and deposits weeds on the lakeshore for pick-up and disposal.

Because it is driven by propellers on the stern and not paddlewheels, the amphibious harvester is capable of fitting into narrow areas between docks and at marinas, he said.

“The machine only uses one conveyor belt to collect and offload the weeds, leaving it with more capacity to hold weeds while making it shorter in length than our current harvesters, and reducing mechanical components prone to breakdown,” he added.

In November, the water board put out public expressions of interest for an amphibious harvester to ensure it was aware of any manufacturers that currently make them or who would be willing to design and build one.

This procedure is similar to how the water board procured its conventional rototillers.

“We received only one expression of interest from a German manufacturer. Despite a potential difference in cost, I recommended that OBWB continue to pursue the option to procure an amphibious harvester as the lifespan of the equipment is expected to be a minimum of 30 years, and the accessibility issues we currently face will likely continue to get worse,” Littley said.

“An amphibious harvester may also negate the need to explore other on-water storage options for the cut weeds, such as a shedding and storage barge,” he added.

If the board ultimately decides to purchase the amphibious harvester, it may have to defer the purchase of a second harvester, a replacement staff vehicle and a replacement milfoil boat beyond its current five-year asset replacement plan.