Banks Lake is a man-made reservoir that was created for use of its three surrounding towns: Grand Coulee, Coulee City, and Electric city. Not only as a source of entertainment and as a tourist attraction but the nearby Grand Coulee Dam just of the lake, provides the towns with electricity.
Banks Lake is actually filled by the graded river called The Columbian River. The Columbian river flows straight down from North and cuts right into the heart of eastern Washington where it then meanders down zigzagging back and forth until it reaches its base level on the western cost of Washington at the ocean.
Because the Columbia is a large graded stream not much erosion or deposition occurs along its channels and thus from the picture above, it is easy to infer that little to no depositions occurs at the base of the river because there isn’t much of a sign of a delta. This river has a very linear flow such that it allows for the transport of tress that have been logged in the north down to the south, and into the Snake River that splits of from the Columbia and moves them east to the lumber mills.
Although there deposition that take place at the base level of the Columbia there is still a large amount of sediment dropped just before the end of the river, enough so to create small islands. Based on volume, the Columbia is the 4th largest river in North America and it effects more people’s lives than just those in the small towns surrounding Banks Lake.
