Los Angeles County Public Works Department has a video available called "No Way Out" which is meant to educate the public about the dangers of moving water.
It is available for $20 including shipping and handling by contacting:
Dr. Betty Hennessy Division of Curriculum, Instruction, and Assessment Los Angeles County Office of Education 9300 Imperial Highway, Room 299 Downey, CA 90242-2890
Below is a safety handout used by Los Angeles County for this purpose.
Some of this information is specific to their area, but any community seeking to provide some public education on this subject could modify to their particular needs.