Embedded Files
Lesson Overview
Lesson Overview
Guiding question: Where does water go once it is used?
Time Estimate: 3 hours
Purpose: After water is used, it either will be treated at a wastewater treatment plant (such as sewage) or it will runoff into the ocean, carrying with it potentially harmful pollutants.
Overview: Students will investigate the ways that increased agricultural and residential areas affect the water supply by analyzing public data related to runoff pollutants and completing a computer simulation modeling the relationship between rainfall and runoff in a variety of areas (developed - undeveloped).
Design Principles:
Global and Local dynamic
Public Data & Argumentation
Investigation
Modeling
Background Knowledge:
The role of runoff in the water cycle
How we use water for domestic and agricultural purposes
Common Misconceptions:
All rainwater immediately goes into rivers or lakes. Clarification: While some rainwater does directly flow into rivers or lakes, not all of it does. Rainwater can follow various pathways in the water cycle, including infiltration into the ground, where it becomes groundwater, and evaporation back into the atmosphere.
Runoff only occurs during heavy rainstorms. Clarification: Runoff can happen during any precipitation event, not just heavy rainstorms. Even light rainfall can result in runoff, particularly on surfaces like concrete or compacted soil that do not allow for easy absorption.
Runoff only happens in urban areas. Clarification: While urban areas with impervious surfaces like roads and buildings can contribute to increased runoff, runoff occurs in both urban and natural environments. In natural landscapes, such as forests or grasslands, runoff can occur when the soil is saturated or unable to absorb more water.
Runoff is always polluted or dirty. Clarification: Runoff can carry pollutants, such as chemicals, sediment, or nutrients, from various sources, including urban areas, agricultural fields, and industrial sites. However, not all runoff is inherently polluted. Runoff from pristine natural areas can be relatively clean and contribute to the overall water cycle.
Runoff only affects surface water bodies. Clarification: Runoff can impact not only surface water bodies like rivers and lakes but also groundwater resources. Excessive runoff can lead to increased recharge of groundwater, potentially affecting its quality and quantity.
Runoff is a purely negative aspect of the water cycle. Clarification: While excessive runoff can contribute to erosion, flooding, and pollution, runoff also plays a vital role in replenishing water bodies and maintaining the overall water cycle. It helps distribute water across landscapes, supports ecosystems, and contributes to the availability of water resources.
Safety:
Unit Connections:
📂 Materials
📂 Materials
Teacher Materials:
Teacher PowerPoint titled: 3.2 Where does the water go once it’s used?
Student Materials:
Student Worksheet: Agriculture and Home Pollutants (the images are in color, so it might be helpful if students have access to a digital copy for analysis)
Student Worksheet: Does More Rainfall Mean We Have More Water?
A device to access simulation (at least one device per 1-3 students)
Students' previous water cycle models
Paper to revise water cycle models
Supplemental:
Instructional Sequence
Instructional Sequence
Materials: 3.2 Where doe the water go once it is used?
Class Discussion (slides 1-4)
Show the graphic of how North Carolina uses its water, and ask students to summarize the data. For North Carolina, students should notice that the largest amount of water is used for thermoelectric energy, the average amount of water is used for public supply, domestic, industrial, and irrigation. Livestock and mining are the least used water sectors in North Carolina.
⏰ Recommendations for timing & modifications
The video on slide 3 introduces sewage systems. Although it is engaging, it can be skipped to save time.
✍️ Assessment Opportunity
Formative Assessment Opportunity:
What to look for?
During the class discussion around the data being presented on these slides, you should gauge whether students are understanding how to read and interpret the graphic. For example, students should see that an exceptionally large amount of NC water goes toward thermoelectric uses while a low amount goes toward livestock. Agriculture and public supply are the next highest uses of water in NC.
Materials: 3.2 Does More Rainfall Mean We Have More Water? & a device to access website
3.2 Does More Rainfall Mean We Have More Water?
Although our aquifers recharge through rainfall, it is not a guarantee (in fact, it is far from it) that all rainfall will infiltrate underground. Some conditions lend to better infiltration than others.
Review major findings from the simulation
⏰ Recommendations for timing & modifications
This is an excellent opportunity to arrange with your school’s extension agent to get an expert on land use in your specific area.
📒 Instructional Support
I recommend pulling up the model my watershed simulation and following along as you ask the following questions:
What happens when the area is mostly developed? More runoff
What happens in these highly developed areas when there is a major thunderstorm? The percentage of runoff increases significantly
Does more rain mean more water? In some ways, yes, because the total amount of infiltration increases, however, a lot more water is lost to runoff. It is better to have consistent rain than huge storms.
✍️ Assessment Opportunity
Does more rainfall mean more water?
What to look for?
In addition to correctly interpreting the data students record on their charts, the main takeaway of this activity is for students to understand the relationship between land use, water runoff, and water quality in a specific watershed. Developed land, impervious surfaces, and land cover all affect water runoff and quality within a watershed. Students should successfully apply this understanding to the Post Lab questions to see that an increase in rainfall does necessarily mean we get more infiltration. It is dependent on the type of land.
Severe weather, weather maps, fonts - teacher discussion and student notes
Materials: Severe weather and weather maps: Weather Supplemental and Student notes
This is a supplemental activity for you to use if it applies to your standards.
In addition to thinking about how severe weather storms are caused, pose questions throughout this section about how runoff is different based on the conditions explored in the previous activity.
⏰ Recommendations for timing & modifications
If weather is not a major part of your curriculum, these slides can be skipped. If a particular type of severe weather is common in your area, we recommend focusing on that. For instance, on the Southeast Coast we recommend focusing on hurricanes.
📒 Instructional Support
How will severe weather affect a city versus a rural village?
New York City has a highly developed urban infrastructure, including an extensive network of roads, sidewalks, buildings, and underground sewer systems. These impervious surfaces can hinder natural infiltration of water into the ground, leading to increased surface runoff. In contrast, a rural village might have fewer paved surfaces, allowing for greater infiltration and slower runoff. New York City is predominantly developed with buildings, roads, and other structures, leaving limited open space for water absorption. As a result, rainwater tends to flow quickly over the paved surfaces, accumulating in the sewer systems. In a rural village, there may be more open land which can absorb and retain rainwater, reducing runoff. On the other hand, if the land is not impervious in the rural area, runoff can still be extensive and cause flash flooding.
Irrigation & Agriculture (slides 6-9)
In the next activity, students will look at agricultural pollutants, so use this time to make sure they understand the ways that water will runoff in rural areas that are irrigated. As you discuss irrigation, remind students that irrigated water mostly comes from groundwater.
Flood and furrow are two techniques for irrigating land and crops. Drip/micro-irrigation and spray/sprinkler irrigation are other common methods of irrigating land. If this is an interesting topic to your students, have students divide into groups to research one of the irrigation methods. Tell them to be prepared to answer the following questions:
What is the cost per acre of this method?
How much runoff does create?
What are the pros?
What are the cons?
Materials: 3.2 Agriculture & Home Pollution Worksheet
3.2 Agriculture & Home Pollution Worksheet
This activity requires students to read a short (< 1 page) passage on the consequences of excess nitrogen and phosphorus in water systems. The students will answer questions using the provided graphs and their previous knowledge from the High Plains Aquifer lesson. The images are in color, so it might be helpful if students have access to a digital copy for analysis.
⏰ Recommendations for timing & modifications
Questions 7 & 8 are challenging. They might be better suited for honors classes and be considered bonus questions in general population classes.
✍️ Assessment Opportunity
3.2 Agriculture & Home Pollution
What to look for?
If students interpret the data correctly, they should see a correlation between agricultural areas and excess nutrients.
Revise water cycle models (slides 11-12):
Although an example is provided on slide 22, feel free to use a student's model instead. Lead the class through a discussion using the following questions:
What are ways we can represent cities in the model?
What are the consequences of adding more agriculture?
How can we show more agriculture in this model?
Students will revise their water cycle models for a third time. They will work with a group to add a highly developed area and an agricultural area to their models. As a group, they need to answer the two questions on the slide as a formative assessment.
How does urbanization affect the water cycle?
How does increase agriculture affect the water cycle?
Feel free to make this an exit ticket, a group discussion, or an individual journal entry.
🗣️ Discourse opportunities:
small group discussion
✍️ Assessment Opportunity
Formative Assessment: How does urbanization and increased agriculture affect the water cycle?
What to look for?
Students should recognize that urbanization affects the amount of impervious surfaces such as more roads, buildings, expansion of cities, as well as alternating the drainage patterns of runoff.
For agricultural areas, students should understand that irrigation practices can deplete local water sources and lead to increased water extraction from groundwater as well as the chemical outputs of fertilizers, pesticides, and herbicides that potentially contaminate water bodies through runoff.
Water Quality
Materials: Water Quality Lab Indicators slide deck and lab activity
In this lab, students review the indicators of water quality that are introduced in the previous assignment (Agriculture & Home Pollution Worksheet). Following that, they can complete a lab testing the water quality of an unknown or known source.
*Please note this lab requires teacher preparation before it can be assigned.
Information for Planning & Teaching
Information for Planning & Teaching
Background Knowledge
Background Knowledge
Eutrophication is a process that occurs when excess nutrients, such as nitrogen and phosphorus, enter a water body, leading to an overgrowth of aquatic plants and algae. This can have detrimental effects on the ecosystem and water quality.
In terms of agriculture, the excessive use of fertilizers is a significant factor. Farmers often apply fertilizers to enhance crop growth, but if these nutrients are not absorbed by plants entirely, they can be washed away by rainwater or irrigation runoff and find their way into nearby rivers, lakes, or streams. Similarly, when manure from livestock operations is not properly managed, it can be a significant source of nutrients in water bodies. Moreover, poor land management practices, such as inadequate erosion control measures, can result in sedimentation in waterways, further exacerbating eutrophication.
Home practices can also play a role in eutrophication. The excessive use of fertilizers on lawns and gardens can lead to nutrient runoff during rainfall, similar to agricultural runoff. Additionally, the use of certain cleaning products and the improper disposal of household chemicals can introduce phosphates and other pollutants into the water supply when washed down drains. Similarly, untreated sewage or poorly functioning septic systems can release nutrients into nearby water bodies, contributing to eutrophication.
Lesson Timing
Lesson Timing
Depending on your students, access to technology, and curricular priorities, there are several ways to implement this lesson.
For three 45-60 minutes class periods, we recommend:
If students are successful independent workers, these activities can be organized into do-at-your-own-pace checklists that students show mastery by completing a revised water cycle model.
Student Ideas & Experiences
Student Ideas & Experiences
If students have observed changes in water levels of local bodies of water or heavy rainfall that caused flooding in their neighborhoods, teachers can use these experiences to facilitate learning about runoff and pollution.
In rural areas, backroads students take to get to school can flood causing them to miss school. However, teachers can build on these experiences by pointing out how heavy rainfall can have significant impacts on our daily lives. It's not just about the inconvenience of getting to school, but it also relates to the way water interacts with the environment. Ask students to recall other changes to their surroundings during that time. If water levels were changing, tie that to infiltration and runoff as well. Heavy rainfall can cause water bodies like lakes to rise rapidly. When it rains heavily, the excess water doesn't always get absorbed into the ground as quickly as it falls. Instead, it can flow over the surface, leading to more runoff. Sometimes, when there's too much water, it can put pressure on the lake or river, potentially leading to flooding.
Students might also come with previous experiences of lakes being drained to prevent flooding which is an excellent way to tie back to the Hoover Dam and ways to manage water. Cities have to manage their water differently because runoff is experienced differently due to the different types of surfaces.
By tying in these observations and the significance of water management projects like the Hoover Dam, teachers can help students understand the importance of balancing water resources, addressing flooding risks, and providing a sustainable water supply for various human needs, including agriculture.
Using students' ideas helps them to connect their observations of local water bodies, such as changes in water levels and discussions about lake draining, to broader concepts of water management and the significance of large-scale infrastructure projects like the Hoover Dam in addressing these challenges.
Science Practices
Science Practices
Analyzing and Interpreting Data is an important skill across many disciplines, not only science. In the 3.2 Agriculture & Home Pollution Worksheet, students will have the opportunity to develop and apply their skills in analyzing and interpreting data. The worksheet focuses on visual data, such as maps and graphical representations, which are commonly used tools in various disciplines to extract meaningful information from data sets. By engaging with these forms of data, students can enhance their ability to identify patterns, trends, and significant features in the context of agriculture and home pollution.
The 3.2 Agriculture & Home Pollution Worksheet provides an opportunity for students to actively engage with real-world data, fostering a deeper understanding of the complexities and impacts of agriculture and home practices on pollution. By honing their data analysis and interpretation skills, students can become more informed and conscientious citizens who can make informed decisions and contribute to addressing environmental challenges.
Teaching Cases
Teaching Cases
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