Pond Habitat Restoration
by Avery Cruz
*Updated on January 16, 2026*
Tucked away among the rolling golden hills of Rancho Cañada del Oro Space Preserve lie three cattle ponds that now also serve as critical habitats for native, aquatic species.
The two small ponds and one large pond, which are situated along the eastern foothills of the Santa Cruz Mountains, were originally built by a local rancher to provide water for grazing cattle. Today, the land is owned and managed by the Santa Clara Valley Open Space Authority and is part of the agency’s vision for the future expansion of Rancho Cañada del Oro Open Space Preserve. The two smaller ponds dry up in early summer and the larger pond maintains water year-round. While the original intended use of the ponds was for cattle, native and sensitive species like the California red-legged frog, the California tiger salamander, newts and the western pond turtle have taken refuge there.
In the larger pond, invasive catfish became the predominant species, creating an unwelcoming environment for native species. This issue, combined with erosion of all pond structures, prompted the Open Space Authority to study conditions more closely and seek funding to restore the ponds to support sensitive species and their offspring. Thanks to grants received through Valley Water's Safe, Clean Water and Natural Flood Protection Standard Grants Program and Point Blue Conservation Science, the restoration work began during the summer of 2025 and was led by Rachel Clemons, the Open Space Authority’s Watershed Restoration Specialist.
Restoration of these ponds is important because stock ponds like these have become some of the last remaining habitat for sensitive aquatic species like [California red-legged] frogs and [Northwestern pond] turtles. Historically, [these species] would have been very populous in the valley, but because we’ve developed a lot of our valley floor habitat for agriculture and businesses and homes, spaces like these in the foothills are some of the last remaining habitats, even though they’re artificial.
Because they’re man-made, the ponds require restoration as well as ongoing maintenance to make certain that native species are able to thrive.
At the start of the restoration project, it was essential for the team to address the ponds’ structural issues. The two smaller ponds were excavated to deepen them, reshaping their geometry. As a result, the water will remain in the ponds for a longer period of time, extending the wet season and providing a more stable environment for native species during the dry months.
At one of the smaller ponds, a berm that borders the pond — a raised mound of earth that helps hold water in, much like a miniature dam — was eroding, threatening the habitat of the California red-legged frog which is protected by the Endangered Species Act. In the larger pond, Rachel focused her efforts on reducing populations of invasive species and leakage of pond water through the existing berm. Prior to construction, a team, including Rachel, relocated native species into Upper Llagas Creek to protect them during the pond restoration process.
The relocation process also gave the team a rare chance to get a close look at what's been living in the ponds. The results were pretty incredible: three adult and 41 tadpole California red-legged frogs, seven western pond turtles, five adult and 417 tadpole California newts, and 318 Pacific tree frog tadpoles. Once the restoration is finished, Rachel hopes these species—or their future offspring—will find their way back home.
We’re not totally sure how long it will take the turtles or frogs to return. It’s possible that the exact individuals who relocated may not return to these ponds. It may be their offspring, grandchildren or great-grandchildren, but they found their way to these ponds in the first place, so hopefully relocating them in a safe place will support the population overall.
In the second half of 2025, Rachel, along with many partners, staff and volunteers, completed the primary restoration work at the three ponds. At the two smaller ponds, new pipes were installed to redirect water flow in and out of the ponds, reducing the likelihood of erosion of the surrounding land. At the large pond, the water was drained to control the invasive fish population, and a clay liner was placed along the berm to stop a prior leakage issue.
Across all three ponds, water gauges were installed to help monitor the water levels, while several new turtle basking ramps will provide native Northwestern pond turtles with safe and stable areas to soak up sunlight. Authority field staff collaborated with the Student Conservation Association to install fencing around the ponds to protect the native species and prevent future erosion of these sensitive areas.
The Open Space Authority also partnered with the San Jose Conservation Corps and hosted two volunteer events, to plant water-loving vegetation that will enhance wildlife habitat and support the stability of the ponds. In total, 2,500 plants were planted at the three ponds and will be monitored, along with other aspects of the restoration work, to track the success of the project.
Over a period of five years, Rachel also plans to monitor the ponds for erosion and the number of sensitive species that return to the ponds after being relocated. Pond monitoring will take place three times each year, giving the Authority’s restoration project team the ability to fine-tune their methods along the way to meet the project's restoration goals.
While it’s still early in the monitoring process, Rachel visited the ponds in January 2026 and observed Northwestern pond turtles in the large pond and adult California newts at all three ponds.
Through this restoration effort, the Open Space Authority is protecting vulnerable populations and helping native species thrive in their habitats for many generations to come. Get involved in the Open Space Authority's ongoing restoration efforts by becoming a volunteer!
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