from roughly northwest to roughly southeast. The gradient of the river channel within the delta reach to the west is relatively high, so the river water velocities are fairly high and the waters of the river carry significant amounts of sediment. The gradient in the flat Red River plain is much less and the velocity of the river water flowing over this plain is much lower. Therefore, the sediments carried by the river waters as they flow through the delta reach are deposited onto the plain. The Assiniboine winds its way east eventually joining the Red River at "The Forks" in Winnipeg, Manitoba. Today, Assiniboine Herald at the Canadian Heraldic Authority is named after the river. Asessippi Provincial Park, an RV park was built on the east shore of the Shellmouth Reservoir. Tributaries include the Whitesand River which joins it near Kamsack, Saskatchewan, the Souris River, which joins it near Wawanesa, Manitoba, the Birdtail River which joins at the Birdtail Sioux First Nation, the Little Saskatchewan, which joins west of Brandon, and the Qu'Appelle River, which joins near the site of the Hudson's Bay Company historic Fort Ellice site. The Assiniboine River has followed its modern course for approximately 700 years. The Assiniboine River formerly met the Red River near the present-day mouth of the La Salle River. Flow rates and flood potential There are three hydrometric stations on the river that have been taking measurements since 1913. The Assiniboine River near Headingley has an average discharge of . One millimeter of runoff from half the watershed would take 70 hours to drain at flow rates of . The following discharge rates were recorded during the 1995 flood: It is prone to spring flooding. Some flood flows can be diverted into Lake Manitoba at Portage la Prairie. In 1967, the Shellmouth Dam was built in Shellmouth to help reduce flood peaks and to supplement flows during dry periods. The Portage Diversion was completed in 1970. Despite these efforts, in May 2011 it was necessary to breach one of the dikes beside the river to relieve flood stresses east of Portage la Prairie. A Manitoba-wide state of emergency was declared in the wake of one in three hundred-year floods on the Assiniboine River at Brandon. Below are the actual observed flow rates for major floods at different locations along the river: Note: Flows in 1882 occurred before any flood protection measures