Grand Coulee facts for kids
The Grand Coulee is a huge, dry valley in Washington, USA. It used to be a powerful river! This long, dry riverbed stretches about 60 miles (97 km). It goes from the Grand Coulee Dam all the way to Soap Lake. A special place called Dry Falls splits the Coulee into two parts. Scientists believe Dry Falls was once the biggest waterfall ever. It was much taller than Niagara Falls!
Contents
How the Grand Coulee Was Formed
Ancient Rocks and Volcanoes
The Grand Coulee sits on very old rock called granite. This rock is between 40 and 60 million years old. Later, volcanoes erupted and covered the area with a type of rock called basalt. This basalt layer is incredibly thick, about 2,000 meters (6,560 feet) deep!
Ice Age River Changes
Scientists think the Grand Coulee was created during the last Ice Age. A huge glacier blocked the path of the Columbia River. This forced the river to find a new way to flow. The river carved out the wide valley we now call the Grand Coulee. It is about a mile (1.6 km) wide!
When the Ice Age ended, the glacier melted. The Columbia River then went back to its original path. This left the Grand Coulee as a dry, empty riverbed.
Modern Uses of the Grand Coulee
Dry Land and Lakes
The area around the Grand Coulee is mostly shrubland. It does not get much rain, only about 12 inches (30 cm) each year. The lower part of the Grand Coulee has several natural lakes. These include Park, Blue, Alkali, Lenore, and Soap lakes. For a long time, the upper part of the Coulee was completely dry.
Water for Farming
In 1952, the Columbia Basin Project began. This huge project built dams on the Columbia River. It also used the Grand Coulee to help with irrigation. Irrigation means bringing water to dry farmlands.
The upper part of the Grand Coulee was dammed to create Banks Lake. This lake is filled with water by giant pumps from the Grand Coulee Dam. Banks Lake then feeds a huge irrigation system. This system stretches for about 100 miles (160 km). It helps farmers grow crops in the dry region.
Images for kids
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Looking northward in Grand Coulee.
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Part of the Grand Coulee has been dammed and filled with water as part of the Columbia Basin Project.
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Formation of Grand Coulee
See also
In Spanish: Grand Coulee para niños
