Preventing Erosion STEM Challenge – Unit 5 Week 4 NGSS-Aligned | 2-ESS1-1 & 2-ESS2-1 | 2nd Grade Weathering & Erosion In this hands-on STEM challenge, students move from understanding erosion to thinking like engineers — designing and testing solutions to stop soil from washing away. Students investigate a real-world erosion problem (soil washing away under playground swings) and apply the engineering design process to slow, block, or redirect moving water. This week strengthens: Cause-and-eff