What are some locations of Canyon clean up events?

I would like to know some places where canyon clean up events are held within san diego. It would help me and my friends with our GIS/Bio enviornmental project. This question is important becuase the answers would go on a map that we would use to show people where invasive species are being pulled from an enviornment they arent suppose to live in. This map will show people where they can go to help. A LIST OF LOCATIONS WOULD BE EXTREMELY HELPFUL!!!!!!!!!!!!!!!!!!!!! Thank you for your time in helping us with our project. :D