Aloha
A great idea, many people collect rain water off of their roofs, in different parts of the world, If your school could also start stenciling Storm Drains, in English and Spanish, ( GOES TO OCEAN) (NO GARBAGE, NO BUTTS) or (GOES TO OUR DRINKING WATER, NO GARBAGE) Along with a picture of fish, If you check out what we are doing at The Pollution Solution Group
http://solution2pollution.blogspot.com
There might be some helpful information, what your doing is great, we need more people like you, people like you, need to educate the unknowing or uncaring by setting examples.
May the force be with you.
With Aloha KOTO One of the keepers of the Ocean