Students learn about contamination and pollution, specifically in reference to soil in and around rivers. To start, groups use light sensors to take light reflection measurements of different colors of sand (dyed with various amounts of a liquid food dye), generating a set of "soil" calibration data. Then, they use a stream table with a simulated a river that has a scattering of "contaminated wells" represented by locations of unknown amounts of dye. They make visual observations and use light sensors again to take reflection measurements and refer to their earlier calibration data to determine the level of "contamination" (color dye) in each well. Acting as engineers, they determine if their measured data is comparable to visual observations. The small-scale simulated flowing river shows how contamination can spread.

Students are introduced to the basic biology behind Pacific salmon migration and the many engineered Columbia River dam structures that aid in their passage through the river's hydroelectric dams. Students apply what they learn about the salmon life cycle as they think of devices and modifications that might be implemented at dams to aid in the natural cycle of fish migration, and as they make (hypothetical) Splash Engineering presentations about their proposed fish mitigation solutions for Birdseye River's dam in Thirsty County.

Students learn about floods, discovering that different types of floods occur from different water sources, but primarily from heavy rainfall. While floods occur naturally and have benefits such as creating fertile farmland, students learn that with the increase in human population in flood-prone areas, floods are become increasingly problematic. Both natural and manmade factors contribute to floods. Students learn what makes floods dangerous and what engineers design to predict, control and survive floods.

Students learn about the water cycle and its key components. First, they learn about the concept of a watershed and why it is important in the context of engineering hydrology. Then they learn how we can use the theory of conservation of mass to estimate the amount of water that enters a watershed (precipitation, groundwater flowing in) and exits a watershed (evaporation, runoff, groundwater out). Finally, students learn about runoff and how we visualize runoff in the form of hydrographs.

Students perform a macroinvertebrate survey to gauge the health of a local river. They collect water samples and count macroinvertebrates to learn how the health of a river's ecosystem can be determined by its river insect population.