Vancouver Sun ePaper

Water levels in Fraser River will fluctuate much more

The behaviour of the Fraser River in the future will differ from our historical experience with the river. Building more and higher dikes, as a strategy, will become increasingly futile over time.

We can expect greater seasonality in precipitation. We can expect longer summer droughts and more extreme winter storms, dumping unprecedented levels of precipitation. The disappearance of mountain glaciers and earlier snow melts will cause greater seasonal fluctuations in the levels of the Fraser River.

The sea level could rise faster than expected. During the last interglacial era, the sea level was perhaps 10 metres higher. Salt water is likely to intrude farther inland, increasingly determining river levels for the lower stretches of the Fraser (and other B.C. rivers). Perhaps tides will extend up the river.

Building taller dikes based on our past (limited) weather and climatic records of B.C. is counterproductive. More research into the province's paleoclimates is a must. New thinking should be driven by scenario planning and detailed modelling of probable future weather behaviour, along with anticipated changes in sea levels and regional climate. A significant buffer should be built in for surprises.

Planning and implementation must be driven by the provincial government. The plan must be for the lower stretch of the river. The cost of implantation will exceed the tax bases of individual municipalities. Some politically challenging decisions may be required. We need provincial leadership for this challenge.

John Shepherd, Richmond

OPINION

en-ca

2022-05-28T07:00:00.0000000Z

2022-05-28T07:00:00.0000000Z

https://vancouversun.pressreader.com/article/281797107620515

Postmedia