Richmond’s location – at the point where the Fraser River meets the Pacific Ocean – puts our island City adjacent to some of the most productive ecosystems in the world. The mixing of saline ocean water with the Fraser River’s freshwater creates an estuary environment that supports a rich and diverse community of aquatic and terrestrial life.
From Ice to Estuary
The natural history of Lulu Island began around 11,000 years ago. As a 2 million-year-long ice age was coming to an end, the last great Cordilleran ice sheets retreated towards the mountains, shedding their meltwater and mineral-rich sediments into what we now call the Fraser Valley. The ice retreated quickly in geologic terms, with key events including:
- 15,000 years ago the ice may have been 2 km thick where Richmond City Hall currently sits
- 6,000 years ago, a network of sand bars and mud flats began to emerge as Lulu Island: first only at low tides and shifted about by oncoming floods. Then Lulu Island emerged in a more permanent way as grasses and shrubs began to take hold.
- 4,000 years ago, the valley-filling ice had retreated as far as present-day Chilliwack. The land was slow to rebound from the crushing weight of the ice, and the Fraser River had yet to fill the valley with sediment, so the Salish Sea covered the area we now know as Richmond.
- As of 3,000 years ago, much of what we currently know as Lulu Island was forested bog or grass-covered wetlands, although much of the present Sea Island was still below even the lowest tide.
Over the millennia, the Fraser River Delta grew westward. Fine clay and mud sediments were deposited first, and as the river mouth moved closer, the sediments became more sandy.
As the sediments accumulated and the land rose, these shifting sand bars joined together, allowing plant life to flourish. Every flood would change the channels running across the delta plain. Some areas would be cut off from the river completely, and as plant debris accumulated, the first bogs began to form. By this time, the first people of North America began using these young lands – to hunt small game in the grassland, to fish the channels, and to pick berries in the bogs.