Snake River Aquifer facts for kids
The Snake River Aquifer is like a giant underground lake or storage area for water. It's found deep beneath the Snake River Plain in southern Idaho. This huge water source is very important for the state!
Most of the water in this aquifer comes from rain and melting snow. This water flows into the ground from the Snake River, Big Lost River, and other rivers in southern Idaho. Some rivers even seem to disappear into the ground!
The Snake River Aquifer stretches about 400 miles (640 km) from east to west. It provides a lot of water for farms in the Plain, helping crops grow. The aquifer is usually thought of as two main parts: the Eastern Snake River Plain Aquifer and the Western Snake River Plain Aquifer. These two parts are separated by a place called Salmon Falls Creek.
Eastern Snake River Plain Aquifer
The Eastern Snake River Plain Aquifer is north of the Snake River. It's an amazing water source that is very important for the economy of the area. It's not just one type of rock; instead, it's made up of many layers of volcanic rock called basalt. These rocks formed a long, long time ago.
In eastern Idaho, these basalt layers can be about 1 mile (1.6 km) thick! Each individual layer of rock is about 20 to 30 feet (6 to 9 meters) thick. The top few feet of each layer are often very rocky and porous, meaning water can easily flow through them. You can also find layers of sand and gravel, called alluvial sediments, mixed in between the rock layers.
The Snake River itself runs near the southern edge of the plain in eastern Idaho. Many rivers from the mountains north of the plain actually disappear into the ground when they reach the Snake River Plain. The Little Lost River is a good example of this.
Downstream from Milner Dam, near Twin Falls, a huge amount of water — about 200 billion cubic feet (5.7 cubic kilometers) — flows into the Snake River. This water comes from giant springs on the north side of the canyon. This area is famous and known as the Thousand Springs area.
The groundwater in the Snake River Plains aquifer generally flows towards the southwest. This matches the way the layers of basalt rock are tilted. The Snake River cuts through the aquifer, and the weight of the water in the basalt layers north of the river pushes the water out, creating those huge springs.
