Souris River
The Souris River (; ) or Mouse River (as it is alternatively known in the U.S., a calque of its French name) is a river in central North America. It is about in length and drains about . It rises in the Yellow Grass Marshes north of Weyburn, Saskatchewan. It wanders south through North Dakota beyond Minot to its most southern point at the city of Velva, and then back north into Manitoba. The river passes through the communities of Melita, Hartney, Souris and Wawanesa and on to its confluence with the Assiniboine River near Treesbank, about southeast of Brandon. The  main tributaries which flow into the Souris in Manitoba are the Antler River, the Gainsborough, and Plum Creeks. At the end of the last ice age over 10,000 years ago the rapid draining of former Glacial Lake Regina eroded a large channel that is now occupied by the much smaller contemporary Souris River. Also, much of the drainage basin is fertile silt and clay deposited by another former glacial lake, Lake Souris. Flow rates and flood potential. During the period from 1930 to 1941 severe drought conditions prevailed and PFRA constructed four stock watering dams. In 1937 the Snyder and  Ross Dams were built near Melita. In 1938 the Napinka Dam was built and the Hartney Dam was built in 1941. These were all stop log dams with a total capacity of . The Souris Dam was originally built in 1911 and was rebuilt in 1935. The Wawanesa Dam was completed in 1951 storing about of water. Most of the annual flow of the Souris River comes from snow melt and spring rains. The annual flow volume varies dramatically from in 1937 to in 1976. It is expected that the total runoff for 2011 at Wawanesa will exceed about a one  in 500 year event. The average annual runoff is equivalent to 3 mm over the entire Souris River watershed. Two large dams in Saskatchewan, Rafferty Dam and Grant Devine Dam were built, in part, to reduce flood peaks on the Souris River. In summer 2011, a historic flood affected much of the Souris River basin, overtopping levees and causing the evacuation of about 11,000 residents in Minot as well as significant damage to farmland and other property along the length of the river. The channel capacity of the river in Manitoba varies from about near the border, to about through  Melita, to about near Lauder and near Hartney. North of Hartney the capacity increases to more than . The drop between the border and Hartney is only about . Fish species. Fish species include walleye, yellow perch, northern pike, white sucker, black bullhead, goldeye, brown bullhead, smallmouth bass, and burbot.