Through eight lessons, students are introduced to many facets of dams, including their basic components, the common types (all designed to resist strong forces), their primary benefits (electricity generation, water supply, flood control, irrigation, recreation), and their importance (historically, currently and globally). Through an introduction to kinetic and potential energy, students come to understand how dams generate electricity. They learn about the structure, function and purpose of locks, which involves an introduction to Pascal's law, water pressure and gravity. Other lessons introduce students to common environmental impacts of dams and the engineering approaches to address them. They learn about the life cycle of salmon and the many engineered dam structures that aid in their river passage, as they think of their own methods and devices that could help fish migrate past dams. Students learn how dams and reservoirs become part of the Earth's hydrologic cycle, focusing on the role of evaporation. To conclude, students learn that dams do not last forever; they require ongoing maintenance, occasionally fail or succumb to "old age," or are no longer needed, and are sometimes removed. Through associated hands-on activities, students track their personal water usage; use clay and plastic containers to model and test four types of dam structures; use paper cups and water to learn about water pressure and Pascal's Law; explore kinetic energy by creating their own experimental waterwheel from two-liter plastic bottles; collect and count a stream's insects to gauge its health; play an animated PowerPoint game to quiz their understanding of the salmon life cycle and fish ladders; run a weeklong experiment to measure water evaporation and graph their data; and research eight dams to find out and compare their original purposes, current status, reservoir capacity and lifespan. Woven throughout the unit is a continuing hypothetical scenario in which students act as consulting engineers with a Splash Engineering firm, assisting Thirsty County in designing a dam for Birdseye River.

In this first part of a two-part lab activity, students use triple balance beams and graduated cylinders to take measurements and calculate the densities of several common, irregularly shaped objects with the purpose to resolve confusion about mass and density. After this activity, conduct the associated Density Column Lab - Part 2 activity before presenting the associated Density & Miscibility lesson for discussion about concepts that explain what students have observed.

Concluding a two-part lab activity, students use triple balance beams and graduated cylinders to take measurements and calculate densities of several household liquids and compare them to the densities of irregularly shaped objects (as determined in Part 1). Then they create density columns with the three liquids and four solid items to test their calculations and predictions of the different densities. Once their density columns are complete, students determine the effect of adding detergent to the columns. After this activity, present the associated Density & Miscibility lesson for a discussion about why the column layers do not mix.

After students conduct the two associated activities, Density Column Lab - Parts 1 and 2, present this lesson to provide them with an understanding of why the density column's oil, water and syrup layers do not mix and how the concepts of density and miscibility relate to water chemistry and remediation. Topics covered include miscibility, immiscibility, hydrogen bonds, hydrophobic and hydrophilic. Through the density column lab activities, students see liquids and solids of different densities interact without an understanding of why the resulting layers do not mix. This lesson gives students insight on some of the most fundamental chemical properties of water and how it interacts with different molecules.

Watch warm water float on top of cold water in this video segment adapted from ZOOM.

This video segment adapted from ZOOM offers a clever demonstration of buoyancy by showing how to pour a cup of air into a cup filled with water.

Students learn the concept behind the engineering design of a polymer brush—a coating consisting of polymers that is “tethered” to a particular surface. Polymer brushes can be used on water filtration membranes as an antifouling coating. After designing a model that represents an antifouling polymer brush coating for a water filtration surface, students take on the challenge to engineer their brush design on the surface of a Styrofoam block (which serves as a model for a surface filter) using various materials.

In this Dinosaur Train clip, Dr. Scott the paleontologist explains the water cycle, and why living creatures need water to live. This clip helps students understand the negative effects a drought has on plants and animals, and how plants and animals adapt to stay alive during periods of drought. [1:26]

In this activity, students investigate different methods (aeration and filtering) for removing pollutants from water. They will design and build their own water filters.

Students gain a basic understanding of the properties of media soil, sand, compost, gravel and how these materials affect the movement of water (infiltration/percolation) into and below the surface of the ground. They learn about permeability, porosity, particle size, surface area, capillary action, storage capacity and field capacity, and how the characteristics of the materials that compose the media layer ultimately affect the recharging of groundwater tables. They test each type of material, determining storage capacity, field capacity and infiltration rates, seeing the effect of media size on infiltration rate and storage. Then teams apply the testing results to the design their own material mixes that best meet the design requirements. To conclude, they talk about how engineers apply what students learned in the activity about the infiltration rates of different soil materials to the design of stormwater management systems.

Students see how surface tension can enable light objects (paper clips, peppercorns) to float on an island of oil in water, and subsequently sink when the surface tension of the oil/water interface is reduced by the addition of a surfactant; such as ordinary dish soap.

This EPA website has links to many science topics about which the Environmental Protection Agency has concerns.

Find an array of environmental and science-based lesson plans, activities and ideas from the EPA, other federal agencies, and external organizations.

This resource provides information on watersheds, maps, activities, and links to local watershed information.

Let your students discover how much water they use in one day. Then allow them to brainstorms ideas on how to conserve that water and why it is important. PDF format.

Explore how water found in oceans, rivers, and other water bodies changes form and flows downward in these four videos produced by WGBH. Liquid water is found in water bodies across the planet. In locations where freezing temperatures occur, liquid water turns to solid ice. Students can use the video gallery to explore and identify characteristics of water and describe how water is found in different forms in different locations on Earth. An Activity, Background Essay, and Teaching Tips are provided.

Observe different forms of water and how it covers about 75 percent of Earth's surface in this media gallery captured by NASA and the U.S. Geological Survey (USGS). Use the satellite and ground images in this resource to enhance student observations as they identify and describe bodies of water on Earth's surface.

The slideshow offers students opportunities to observe, identify, and describe various characteristics of water bodies and compare near-ground-level and aerial views of each water body. The PLUM LANDING video offers student opportunities to observe and describe distinct characteristics of a lake while the PLUM LANDING video offers student opportunities to observe and describe distinct characteristics of a river. Teacher materials are provided.

Learn from NASA scientists about two forms of water (liquid and solid), and about the special properties of ice that are important to Earth's life and climate, in this video (2:35) from NASA eClips. Ice can be found in bodies of water across the planet. In the polar regions, ice that is present all year long affects temperatures and climates throughout the world. Students can use the video to understand different forms of water and to observe and identify ice in a variety of water bodies. An Activity, Background Essay, and Teaching Tips are provided.

Introduction to how water, carbon, nitrogen, and phosphorus are cycled through ecosystems. [7:54]

Khan Academy learning modules include a Community space where users can ask questions and seek help from community members. Educators should consult with their Technology administrators to determine the use of Khan Academy learning modules in their classroom. Please review materials from external sites before sharing with students.