Snowpack levels in the mountains north and west of Squamish area are the second highest they've been in past 30 years, according to provincial River Forecast Centre hydrologist David Campbell.
"It's 57 per cent above the normal snowpack level," he said, normal being the average snowpack in the area between 1970 and 2000.
The May 1 River Forecast Centre bulletin reported that the snowpack above Squamish River has 2,607 millimetres in water equivalency - meaning "there's 2.6 metres of water stored in the snow that is going to come down."
"In a place like Squamish we get something like 4,000 mm of rain a year," said Campbell.
"So we're looking at two-thirds of the annual rainfall sitting up there ready to melt down."
Levels have increased for most basins in the province since March, including the South Coast that includes Squamish River, Mamquam River, the Cheakamus River and smaller tributaries that feed them.
The high mountain snowpack could lead to "much higher flows than normal" during spring run-off, but Campbell said flooding is unlikely.
"In terms of flooding we haven't seen extensive flooding ever on the Squamish from the run-off we get in the spring," he said. "That said, there's certainly high flows that come through and we also get a huge volume of water that runs off during that period - but we don't anticipate any problematic flooding."
Nonetheless, Campbell said anyone taking part in summer activities on the river should be aware of the water level.
"It's one of those scenarios where the district should be prepared for higher than normal summer flows, so if there are activities that take place during the summer on or around the river, then that's something to keep an eye on," he said.
Mayor Greg Gardner said he was unaware of "any undue concern in the District of Squamish for the spring run-off."
"The risk of flooding always occurs when there's a large snowpack, which there is this year, and particularly if there happens to be a quick melt," Gardner said. "Fortunately in the District of Squamish, historically the most serious flood issues in the past are not in the spring freshet but in the fall rainy season."
Campbell said weather conditions over the next six weeks will dictate the flows, and the "worst-case scenario" would be continued cold weather followed by a week of hot weather, perhaps in combination with heavy rains.
"The snowpack is only one piece of the puzzle," he added.
This year, the District of Squamish has been looking carefully at mitigating flood risk, particularly after a report in January revealed that Squamish's dikes do not meet provincial standards and would overtop and breach during a one-in-200-year flood event.
"There are three projects on the go to improve the dike at the moment," Gardner said. "The riprap project, the seepage project and the gravel removal project."
