Licensing

Every original material on this site, including every lesson plan, worksheet, problem set, prompt, rubric, and answer key, is dedicated to the public domain under Creative Commons Zero (CC0 1.0). In practical terms, these materials belong to everyone. You may:

• Print class sets, year after year, for any number of students.
• Edit anything, including rewording problems, changing names, adjusting difficulty, or translating.
• Post copies to Google Classroom, your learning management system, or a shared school drive.
• Share materials with your department, school, or district without any per-teacher licensing.
• Include them in your own units, curricula, or publications, including commercial ones.

No attribution is required. You do not need to credit this site, ask permission, or keep any notice on the copies you make. Printed pages and downloaded files carry a small line noting where the material came from so that colleagues can find the library, but you are welcome to remove it.

Why public domain

The purpose of this site is for water-grounded teaching to spread as widely as possible. Professional development workshops, utility outreach programs, textbook authors, and individual teachers can all use these materials without legal questions, because there are no conditions to satisfy.

Third-party resources

The external directory points to organizations whose materials carry their own terms. A directory listing describes what you will find, while the linked site's own license governs what you may do with it. Where access requires payment or a workshop, the listing says so.

Standards text

Standards quoted on this site (NGSS, Common Core, and the C3 Framework) are the property of their respective owners and are quoted for identification and alignment purposes, with links to the official sources.