ASSESSMENT OF THE HISTORIC HYDROLOGY OFTHE ASSINIBOINE RIVER AND WATERSHED 1793-1870
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Date
2001
Authors
Rannie, W.F.
Journal Title
Journal ISSN
Volume Title
Publisher
Geological Survey of Canada
Abstract
In the aftermath of the 1997 Red River flood, archival materials were used to
reconstruct the hydrologic history of the Red River prior to 1870 as part of the Geological
Survey of Canada/Manitoba Geological Survey contribution to the study of the Red River
(Rannie, 1999). All historic Red River 1l00ds were documented and general runoff
conditions were characterized for most water-years from 1793-94 to 1869-70. Although
the report noted several large 1l00ds on the Assiniboine and described general climatic
conditions as they related to the state of the Red, the Assiniboine River and watershed
were given less-detailed attention.
Inthis respect, the report was typical of the treatment of the Assiniboine River in
other hydrologic studies. "Always the bridesmaid, never the bride", the Assiniboine has
been considered mainly insofar as it contributes to the 1100d problems on the Red rather
than as an important river in its own right. The two largest public expenditures in the
watershed (the Shellmouth Dam and Assiniboine Diversion) were initiated as measures to
assist in managing Red River floods by reducing the Assiniboine's contributions;
conservation and flood control along the Assiniboine were secondary (although not
unimportant) objectives. Paleoclimatic investigations in the Palliser Triangle (part of which
includes the headwaters of the Qu'Appelle and Souris tributaries to the Assiniboine) have
emphasized the region to the west of the Assiniboine basin and there has been little
systematic study of pre-instrumental climate and How within the Assiniboine basin itself.
The relative anonymity of the Assiniboine is the more surplising since it may be
described as the "quintessential large Prairie river". Located between the flood-prone,
subhumid, Red River valley on the east and the drought-prone, semiarid, Palliser Triangle
region to the west, the Assiniboine displays characteristics of both regions. The axis of the
watershed runs through the parkland ecoregion, approximately along the boundary
between forests to the north and east and grasslands to the south and west. In contrast
to the large rivers of the western Prairies (such as the Saskatchewan, Red Deer and
Oldman) which derive much of their flow from mountain sources, the Assiniboine is
dependent on the Prairies for its entire flow and, with a drainage area of 153,000 km2 at
Headingley, it is the largest purely prairie-fed river in western Canada. Furthermore, the
Assiniboine watershed is one of most topographically and climatologically varied of large
prairie streams.
This report will focus on the historical hydrology of the Assiniboine River and
watershed. Its specific objectives are
• to provide an overview of the hydrometeorological characteristics of the
basin which are relevant to hydrologic and dendroclimatic reconstructions;
• to review the literature on the pre-instrumental hydroclimate and
environmental conditions in and near the watershed; and
• to reconstruct the hydrologic history of the Assiniboine River prior to the
beginning of gauging records, ':Jsing archival and other historical materials.
Description
This series is produced to expedite the release of information by making unedited manuscript material available to the public in advance of formal publication, and to act as a repository for relevant supporting data that are referred to in published reports. Open Files can be maps; reports; voluminous data sets resulting from multiparameter geophysical and geochemical surveys; consultants' reports; preliminary, unvetted field and laboratory results. They are all critically reviewed by one specialist. The series is geared towards specialists (mining industry, land-use planning, geoscience students) rather than the general public.
Keywords
hydrology, Assiniboine River, water, watershed