Karst Topography & Spring-Fed Waterfalls
Grannis Creek falls is a moderate sized spring fed stream in the karst topography of the Driftless Region of northeast Iowa. It is a dramatic example (for Iowa) of fractured bedrock creating cool spring fed streams characteristic of the Driftless landscape.
Possible Guiding, Compelling and/or Anchoring Questions
- Where is the water coming from?
- How does the area of the spring differ from the surrounding landscape?
- Why is the spring area so different looking from the rest of the hillside?
- Really, where is that water coming from? (walk ‘upstream’)
- How could events at the top of the hill impact the water we see coming out here?
- What needs to happen within the ground to allow this phenomena to occur?
- Why are Iowa’s trout streams found in northeast Iowa? (The stream in this video is stocked with trout.)
- How does this spring help keep trout alive, when they won’t survive in other parts of the state?
- This phenomena could be used to highlight karst topography, sinkholes, springs, disappearing streams and why trout fishing is found in Northeast Iowa.
- Students could use it to begin investigation in bedrock formations, chemical weathering of rocks, cave formation, & a multitude of topics related to ground water - these could include water pollution, water oxygen, soil erosion, nutrient pollution, and ag practices.
- Karst and Water Pollution Lesson Plans: PDF file produced by the state of Minnesota with several lessons about Karst topography. Many are written for grades 6-8, but they could be adapted for other levels.
- Iowa DNR Trout Fishing Map: This interactive map shows the location of Iowa’s trout fishing streams located in northeast Iowa. A direct comparison of karst topographic areas.
Iowa Core Alignment
Submitted by Craig Hemsath