New and highly-detailed 3-D maps will aid in flood preparations across the Okanagan, managers of our water – state
Aerial imaging of the Valley, now underway, will give officials a better sense of what areas are at most at risk during times of high water levels.
“This will show where water is likely to flow. It will include modelling of how much water can be expected and help determine vulnerable locations,” Anna Warwick Sears of the Okanagan Basin Water Board said Tuesday.
The board has received $1.45 million in federal and provincial funding to prepare the updated flood mapping using a technology called **LiDAR
Planes with LiDAR devices are now taking images along the shorelines of Okanagan lakes, with upland areas to be mapped in the coming months.
“All of the flights will be done probably by August, and then there will be a couple of months of data processing,” Warwick Sears said. “We wish that we had done this five years ago, but it does take a while for these things to come together.”
Existing floodplain maps cover only a few areas of the Okanagan and are up to 25 years old, Warwick Sears said.
“Updated maps are important for the public because we’ll have a lot better understanding about how we can reduce the flood risk to our homes and properties,” she said.
If LiDAR-generated flood maps had been available last year, the damage caused by record high lake levels might not have been as severe as it proved to be, said Shaun Reimer, who manages the level of Okanagan Lake.
“It would have helped local governments identify the most vulnerable places, and it would have helped to prioritize resources, and I think that would have been very useful,” Reimer said.
Okanagan Lake is currently at its lowest level since 1999 as water levels are drawn down to create extra capacity for the spring runoff. The mountain snowpack is at 150 per cent of normal.
Drawing the lake down so much can impact impact shore spawning kokanee, Reimer acknowledged.
“As the lake gets too low, it’s difficult for them if they haven’t hatched completely,” Reimer said. “But my understanding is most of them are well advanced and they can move out of the way and get out of the gravel.”
“But certainly some of the very high flows in the Okanagan River south of Penticton, that we have to have right now in order to drop the lake, are potentially scouring out some of the sockeye salmon eggs,” he said.
Management of lake levels and river flows is a matter of “collaboration” between provincial officials and the federal Department of Fisheries and Oceans, Reimer said.
“They certainly are very understanding of what we’re having to go through in years when we have a very high snowpack,” Reimer said.
**Lidar  is a surveying method that measures distance to a target by illuminating the target with pulsed laser light and measuring the reflected pulses with a sensor. Differences in laser return times and wavelengths can then be used to make digital 3-D representations of the target. The name lidar, now used as an acronym of light detection and ranging
Files from Black Press Digital