Sempervirens, also known as Sempervirens Reservoir, is a state-owned earth dam located in Santa Cruz, California, within the stunning Big Basin Stake Park. Built in 1951, this dam stands at a height of 42 feet and serves the primary purpose of flood risk reduction. With a storage capacity of 78 acre-feet and a drainage area of 0.36 square miles, Sempervirens plays a crucial role in managing water resources in the region.

Managed by the California Department of Water Resources (DWR) and the Safety of Dams regulatory agency, Sempervirens is inspected regularly to ensure its structural integrity and safety. The dam is classified as having a significant hazard potential, although its condition has been assessed as satisfactory. Despite the dam's relatively small size in terms of storage and surface area, it plays a vital role in protecting the surrounding area from flooding and providing water supply.

As a site of both environmental and engineering significance, Sempervirens Creek and its associated reservoir continue to be a focal point for water resource and climate enthusiasts. With its strategic location within the Santa Cruz county, the dam remains a critical piece of infrastructure for flood risk reduction and water supply management in the region.