On Saturday, December 7th, EarthTeam interns from Arroyo, Castro Valley, San Leandro, and San Lorenzo high schools joined forces to clean up the San Lorenzo Creek at De Anza Park in Hayward. Together, the 50 interns and other local volunteers cleared out over 16 bags of trash and 1000 gallons of invasive plants.
Interns started the morning bright and early at 9 AM by visiting tables for the Friends of San Lorenzo Creek and the Alameda Clean Water Program. They were able to chat with local experts about creek and watershed health. After the tabling session, students then circled up to hear about the rainbow trout to steelhead salmon lifecycle from local salmonid expert, Bruce King. Rainbow trout have a fascinating life cycle adapted to the local ecosystem. These fish hatch from eggs laid in gravel nests during winter or early spring and spend their juvenile stage in cool, oxygen-rich freshwater. Some fish remain in the creek their entire lives as resident rainbow trout, while others migrate to the ocean, returning as steelhead to spawn and complete the cycle, showcasing not only their adaptability but also their ecological importance.
After the trout lesson, interns received a safety briefing from Jennifer Trevis of the Alameda County Resource Conservation District and broke into 3 groups. The groups would focus on litter mapping, invasive removal, and creek cleanup.
The first group focused on litter mapping by completing On-Land Visual Trash Assessments (OVTA surveys). Since we had such a large group, those completing the OVTA’s were given paper versions of the itemized count section of the assessment. Taking itemized litter counts involves systematically recording and categorizing specific types of litter found in a given area, such as plastics, metals, or paper, to assess pollution levels and identify trends. This method helps interns track the effectiveness of cleanup efforts and informs future waste management strategies.Interns ended up individually counting and categorizing 536 pieces of litter while removing over 16 bags worth of debris and waste.
The second group focused on the litter in the water. Four interns and program coordinator Jamie suited up in waders and ventured down to the water. After the cold shock of entering the creek, interns were quick to spot many large pieces of trash like shopping carts, scooters, bikes, tires, and wood that needed to be removed. Brandon took the lead on this part of the project, able to hoist the heavy objects out of the water and up onto the shoreline. The other interns; Koney, Angel, and Keyan; crossed the water and took out waste from the other side of the creek. They found lots of scrap wood, plastic, and clothing. Six of the bags of waste came just from the far side of the creek.
Finally, our third group focused on removing the invasive plant species from the hillside. Jeff from the Friends of San Lorenzo Creek was an incredible resource to the interns. He was very knowledgeable about local native plants and helped students remove invasive ivy from the creek. All together, interns and community volunteers removed about 1000 gallons of invasive plants from the area.
After the bulk of the restoration and litter removal work was done, the group circled up again to test the water quality of the creek. With the help of Jennifer, students were able to test the nitrates, phosphates, dissolved oxygen, and other parameters of the creek water. Water quality testing aligns with core science standards and engages students in hands-on investigations, critical thinking, and the application of scientific practices to real-world issues. In addition to the real world STEM practice, water quality testing also highlights the interconnection of systems, emphasizing cause-and-effect relationships and the cycling of matter and energy in the environment.
The day concluded with a reflection on the collective impact of the interns’ efforts. By removing litter, clearing invasive plants, and assessing water quality, the students contributed not only to the health of San Lorenzo Creek but also to their understanding of the vital role humans play in preserving natural ecosystems. Their work highlights the power of community action in environmental stewardship and demonstrates how hands-on experiences can inspire the next generation of environmental leaders. If the internal gratification of a creek cleanup wasn’t enough, the students were also able to watch as the City of Hayward sanitation team stopped by with a large truck to take away the waste!As we packed up and looked back on the transformed creek, the interns left with a deeper appreciation for the interconnectedness of nature and the importance of their role in protecting it.
Earth Team would like to thank Jennifer Trevis and the Alameda County Resource Conservation District for their support during the event. Earth Team would also like to thank the Alameda County 2024 Fish and Wildlife Propagation Fund and the Altamont Education Advisory Board for providing funding for this project.
