Washington River Erosion – Dam Removal Impact

This task is for 4th grade students. After class discussions about how dams affect rivers, students analyze aerial photographs of the Elwha River taken just before and at intervals after the removal of the Elwha Dam. Students incorporate what they have learned about erosion to explain the phenomenon of change in the turbidity of the water and structure of the beach at the mouth of the river.

Assessment 3D Learning Target

Make observations to provide evidence of the effects of erosion on water turbidity and beach structure.

Standard Addressed

PE: 4-ESS2-1 Make observations and/or measurements to provide evidence of the effects of weathering or the rate of erosion by water, ice, wind, or vegetation.

By Dimension: Specific dimension pieces that this assessment will center on.


Analyzing and Interpreting Data

  • Analyze and interpret data to make sense of phenomena, using logical reasoning, mathematics, and/or computation.


ESS2.A: Earth’s Materials and Systems

  • Rainfall helps to shape the land and affects the types of living things found in a region. Water, ice, wind, living organisms, and gravity break rocks, soils, and sediments into smaller particles and move them around.


Cause and Effect

  • Cause and effect relationships are routinely identified, tested, and used to explain change.



  • Brianne Caviness, Clover Park School District
  • Larissa Threats, Clover Park School District