Geology

Before urban development, Victoria Harbour consisted mostly of rocky shorelines with numerous pocket beaches, a few sand and gravel shorelines, intertidal mud flats, and salt marsh. Many areas were subsequently filled in, such as the marsh to the west of Point Hope, much of Rock Bay, most of the shoreline and coves between Odgen Point and Shoal Point, and the intertidal mud flats at the east end of James Bay, where the Empress Hotel now stands. Only a small percentage of the shoreline of Victoria Harbour remains in a relatively natural condition. The physical features of the harbour are now mostly characterized by altered shorelines such as wharves, seawalls, angular rock and a breakwater (at Ogden Point).

A few of the more ecologically valuable remaining shorelines include intertidal mud flats in West Bay, the rocky shoreline between Macaulay and McLoughlin points, and several bedrock islands.

Most of the subtidal substrate consists of sediment (mud/sand), with smaller areas of bedrock and gravel. Man-made debris also covers much of the harbour seafloor, particularly near historic industrial sites and public wharves.

There are relatively strong tidal currents in the harbour, particularly in the outer harbour near the entrance.

Water in all its forms has shaped Victoria’s harbour. Between 15,000 and 29,000 years ago, the massive weight of The Fraser Glaciation depressed the land below present sea level. Striations in rock exposed around the harbour indicate the direction of the glacier’s movement. Glaciation deposited stony, sandy loam till and as the ice retreated, its melt water left thick deposits of sand, gravel and marine clay on what would later become dry land.

For about 1,000 years after the glaciers retreated the land slowly rebounded and sea levels rose due to the melting glaciers. They exposed and shaped the harbour’s present-day terrain. Glacial soil depositions around the harbour are highly variable in texture, and abrupt textural changes are common.

Glaciation in the Pleistocene epoch, the recent period of repeated glaciations, put Victoria under thick ice cover, the weight of which depressed the land below present sea level. As the glaciers retreated, their melt-water left thick deposits of sand, gravel, stony sandy loam till, and marine clay on what would later become dry land.

Post-glacial rebound exposed the present-day terrain to air, raising beach and mud deposits well above sea level. The resulting soils are highly variable in texture with abrupt textural changes.

Carse-textured subsoils and loamy topsoils are found around the harbour. These soils are unleached and less acidic than soils elsewhere on the British Columbia Coast. Thick dark topsoils denote a high level of fertility that made them valuable for farming until urbanization took over.