One of the most interesting features of the present-day Battle River is that the river appears to be much too small and 'under-powered' to have created the deep and wide valley that contains it. In fact, the Battle River is referred to as a 'misfit river' in that it presently occupies a valley that was eroded by volumes of water much greater than present.
This rapid, catastrophic erosion occurred more than 10,000 years ago when the last continental glacier began to melt in the central plains of Alberta, forming a series of large ice-dammed lakes.
One of the largest we know of was Glacial Lake Edmonton.
As Lake Edmonton filled with glacial meltwaters from the west and north, it eventually spilled over its southern margins. As it did so, the escaping waters eroded a deep, narrow spillway channel. After the lake drained, a large fast flowing river (known as a post-glacial river) ran through this channel. The Battle's large river valley and 'skinny' lakes southeast of Edmonton -Coal Lake and Dried Meat Lake -are evidence of this old glacial spillway.
Melting glaciers and glacial lakes created deep spillway channels that still criss-cross Alberta today. Over its length, the present-day Battle River follows a number of different spillway channels created by post-glacial rivers. In other areas the Battle River has carved its own channel -in these places the river 'fits' its valley.
This page is based on information provided by Kevin Parks with Alberta Geological Survey.
Climate Change & River Flow
Climate is always changing, and with it natural water flows change. 10,000 years ago, the Battle River was a large river fed by post-glacial Lake Edmonton (this is why the Battle River valley is so large).
Today, the Battle River is not glacier-fed, so when there is no snow or rain, there is little water flow. Because of this, the Battle River’s natural flow varies widely. In the past century, annual water volumes in the Battle have been as low as 50,000 decametres3 and as high as 1.2 million decametres3. See changes in the Battle River’s water flow between 1912 and 2001.
Climate change projections suggest that the prairies could become even drier than they are now. Scientists have found that natural flows in Alberta rivers have declined by about 20% over the last century. This means that a further 10% decline in natural river flows can be expected by 2050.
While average precipitation may not change much, evaporation & transpiration may increase. Greater fluctuations in river flows are also predicted, meaning more frequent droughts and floods. This means that the Battle’s flow will probably vary even more widely in the future.
Water management decisions must consider the future variability in the Battle River’s flows.
For more information