At high tide, parts of the Fraser delta are below sea level, protected only by our extensive dike system. Historically, the delta was a mix of cattail and bulrush marshes, bogs and wet prairie. A huge lake lay near Sumas Mountain, relic of the last glaciers.
The Fraser River kept changing course, its strong freshet flow seeking new routes through the sand banks at its mouth. We can only imagine now how vast the flocks of waterfowl and shorebirds using this enormous wetland must have been.
Looking at the highlydeveloped landscape around us, it is difficult to realize that much of this land is still at the mercy of the sea, relying on 250 kilometres of dikes to protect it. The dikes were first built in the late 1800s by farmers draining
land for livestock and crops. Early homes had no basements and were linked by boardwalks; roads were laid on corduroy beds of logs. Localized flooding was common.
Yet within a few decades, the landscape was transformed into agricultural land with many small communities. The dikes along the Fraser constrained the river to a permanent route, changing the way its sediment is deposited. Side channels silt up and endless dredging is required to maintain transportation routes. Extensive land filling has allowed the growth of cities.
Dikes define the local landscape: the neat line between land and sea. They provide trails for walking and cycling, farm machinery routes, and a few bonus metres of elevation from which to view the wide delta skies and the mountains, islands and ocean that surround us.
Boundary Bay dike, at 20 kilometres long, must be the longest stretch of publicly-walkable ocean dike in the delta. It allows beautiful views of the Coast Mountains, the snowcapped peak of Mount Baker, and the San Juan and southern Gulf Islands.
At this time of year, high water occurs during daylight hours as the rhythm of the tides changes with the season. To the north, fields are busy with farm operations, while the bay waters to the south are alive with tens of thousands of migrating waterfowl flying in for the winter, flocks of gulls and shorebirds, and raptors hunting for prey.
If you visit, park only in designated locations: at the south ends of 64th Street, 72nd Street, 104th Street (Delta Heritage Airpark), Delta, or Mud Bay Park, 48th Avenue, Surrey.
Anne Murray's books on Delta's natural and ecological history, A Nature Guide to Boundary Bay and Tracing Our Past, a Heritage Guide to Boundary Bay, are available in local stores or from www.natureguidesbc.com. She blogs at www.natureguidesbc.wordpress.com.
