St. Louis

St. Louis, Missouri is sited just below the confluence of the two largest river systems on the North American continent. In total the Missouri and Mississippi River system is the fourth largest river system in the world. The Mississippi river is 600m wide and typically around 8m deep at St. Louis, although it is extremely unpredictable. Annual spring floods range from 2m-3.5m, and preclude typical commercial and residential uses along the riverfront. The record flood level at St. Louis was set in the great flood of 1993 at a height of 7.42m above normal.

As a result of its geographical location, immense size, and strategic importance, the majority of the Mississippi riverfront in St. Louis has been historically devoted to industries ranging from power generation, coke production, cold storage, brewing, shipbuilding and grain transshipping. Commodity transportation is still a big business along the St. Louis waterfront as the Cargill grain elevator across the river from Eero Saarinen's Gateway Arch holds the equivalent of 14,500 hectares of grain.

As a result of the economic history of the riverfront and the infrastructural complications caused by flooding, 58% of the riverfront is totally inaccessible to the public. Of the segments that are publicly accessible, 80% are part of the 10km North Riverfront bike trail and are only connected to neighborhoods at six points. Even the approximately 12% of the riverfront that has been improved into civic space face severe challenges: the Jefferson National Expansion Memorial, site of Saarinen's iconic Gateway Arch, is severed from downtown by a combination eleven lanes of traffic including depressed and elevated lanes of the Interstate 70 highway.