Register with GEF for FREE to enjoy these great benefits! 

    • member only contests and raffles

    • sustainability program news and updates

    • significant discounts at GEF Institute

Note: If you have problems registering, contact This email address is being protected from spambots. You need JavaScript enabled to view it.


Taking a GEF Institute Course? Login by clicking here.






Join Us

Sign Up for National Green Week!
Please note: Your privacy is very important to GEF. We do not share or sell any of your data.  It is with the sole purpose of providing you with relevant information that GEF will contact you.

Welcome to the Sustainability Lesson Clearinghouse

Here, you can find free sustainability lessons to use in your class and upload your own lessons to share. Be sure to rate the lessons you use and leave comments for your colleagues!

All of GEF's lessons and programs are offered at no cost.  Become a member to support GEF and enjoy member only benefits! 
Join button_03

Professional Development

GEFinstitute LOGO_WEB GEF Institute offers affordable, online sustainability courses eligible for professional development or academic credit.
Give your resume a boost!

Sponsor a Teacher

Support educators in your community by helping them earn a Certificate in Sustainability or take an online course. Find out more about sponsorship!
Sustainability Lesson Clearinghouse

Can We Keep the Lake Clean?

Lesson Description:

This lesson introduces students to the water cycle by having them help draw a picture of a lake ecosystem, adding human impacts that affect water quality. Students will help fill in the components of a drawing of a water system. They will conclude by creating their own illustrations of human-induced changes to the freshwater habitat of a lake ecosystem.

Students will:
  • Help draw a picture of a lake ecosystem.
  • Discuss the water cycle and the reasons why lakes are important.
  • Describe how humans can impact the water cycle.
  • Draw pictures illustrating a scenario involving human-induced changes to a lake ecosystem.

Lesson Type:
  • Project

Sustainability Topic:
  • Ecosystems
  • Water

GEF Program Category:
  • Sustainable Water Challenge
  • Waste Reduction Challenge

Time Needed:
One to two hours
Standards Addressed:
Connections to the national geography standards:
Standard 14: "How human actions modify the physical environment"
Materials Needed:
  • Computer with internet access
  • Blackboard or whiteboard
  • Colored chalk (or erasable markers if you are using a whiteboard)

School or Group:
National Geographic
Contact Email:
Located in: Social Studies

The Sustainability Lesson Clearinghouse is brought to you in partnership with

Center for Green Schools