Official says underwater maps of Valley lakes would be helpful
Accurate maps could aid in weed control and flood prevention, says head of water board
New and highly accurate underwater maps could help with flood control and weed mitigation in Okanagan lakes, officials says.
The underwater imagery, captured with sophisticated radar and sonar systems, would show the subsurface contours of the lakes, identify concentrations of Eurasian milfoil and aid in calculating precisely how much water is in the Okanagan drainage system.
Such detailed mapping has already been done by U.S. authorities at the southern end of Osoyoos Lake, and their Canadian counterparts hope to secure funding for a similar analysis of lakes on this side of the border.
“We’re interested in better understanding the volume of water in the lakes and how quickly it passes through the system under different flow conditions,” Anna Warwick Sears, executive director of the Okanagan Basin Water Board, said last week.
The information provided by the maps could be used by the Ministry of Environment to finetune its operation of the Penticton dam, which regulates the amount of water that drains out of Okanagan Lake, Warwick Sears says.
Funding for such a project, called a bathymetry study, could come from either the provincial or federal governments, possibly with local government support, Sears says.
The town of Lake Country has already financed a bathymetry study for part of Kalamalka Lake, hoping to see if sediment kicked up by boat propellers was contaminating drinking-water intake pipes.
Maps that indicate lake depth do exist, but they have in many cases been devised with fairly rudimentary methods, Sears says. For example, crews might have fixed weights to marked ropes and simply lowered them into the water at a relative handful of spots to get a cross-section of depths.
“The instrumentation that’s available today, of course, is very different, capable of giving precise information for many locations on the lakes,” Sears said.