Purisima Creek Redwoods Preserve is located on the western slopes of the Santa Cruz Mountains overlooking Half Moon Bay. The centerpiece of this 4,711-acre Preserve is Purisima Creek Canyon, with its towering redwoods and rushing creek. Magnificent views of the coast and Half Moon Bay are visible from the northern part of the preserve.
Clues to a not-so-pure or peaceful past surround this area. The redwoods here are lush, tall, and strong, but they’re young, from the 1800s after logging denuded the landscape. This now-serene valley was once the center of a massive redwood harvesting operation. The logging industry’s impact on this preserve’s landscape can still be glimpsed alongside some trails, in remnant ditches, clearings, and surviving trees still charred from slash fires set by loggers to burn bark and other debris. You can also see the remains of skid roads: heavy wooden crossbars laid across this path to keep the butt ends of logs from digging into the dirt as they were dragged out of the forest, according to University of California Santa Cruz historian Tonya Huff.
By the early 1900s, all of the trees that were not too small, too twisted, or too inaccessible were gone from Purisima Canyon. There are seven recorded mill sites along the creek banks in this Preserve. Evidence of these sites can be seen today. The redwood was used for shingles in the building of San Francisco after the Gold Rush, and for lumber for the development of Half Moon Bay, include the construction of a flume on Montara Mountain.
The Los Altos Hills stream system contains some of the most intact and valuable riparian habitat in the San Francisco Bay region. Many miles of streams and their tributaries flow through the Los Altos Hills Planning Area, including Purisima Creek. During the summer dry season (June through September) water used for landscaping on average is five times that of the rainy season. To encourage the conservation of water resources, Purissima Hills has established a progressive, multi-tiered rate structure.
Species
A list of the species that have been spotted at the Purisima Creek Redwoods Preserve can be found on iNaturalist. Among
them include the arboreal salamander, northern rubber boa, and pygmy nuthatch. Conservation of this site is vital for the wellbeing of these species.
Value as Water Supply
The Los Altos Hills drinking water is provided by two water suppliers: Purisima Hills Water District and the California Water Service Company (Cal Water). Purisima Hills Water District is a public agency that provides water to residents in the northern twothirds of Los Altos Hills; Cal Water is an investor-owned utility that serves the remaining area. A few residents supplement their water supply with well water. Purisima Hills presently obtains all of its water from San Francisco’s Hetch Hetchy system and is exceeding its supply assurance by 25-35 percent. Capacity limitations in the Hetch Hetchy system may be reached in six to eight years, or sooner in times of drought. Purisima Hills may be limited to its contractual allotment, and Cal Water may have to implement some restrictions based on the supply available during drought or other occasions of constrained supply. Landscaping that is heavily dependent on irrigation may not survive. Over two-thirds of all water used each year in the Purisima Hills Water District is for irrigation of landscaping. For the dry season, Purisima Hills and Cal Water have implemented programs such as the provision of homeowner assistance in water management and the distribution of water-efficient appliances. These water conservation programs have the added benefit of reducing energy consumption. Statewide, pumping water is the leading use of electrical power. For Purisima Hills Water District, the cost of power is a significant expenditure, trailing only the costs for water and manpower.
Value as Farmland
Near to Purisima Creek Open Space Preserve are the 534 acres that make up Purisima Farms. This area contains not only fertile agricultural land that produces significant quantities of artichokes, brussel sprouts, and other row crops, but also important wildlife habitat which supports a diverse community of local animal and plant life, including the endangered red-legged frog and possibly the San Francisco garter snake.
Local Organizational Involvement
Midpen has completed planning for additional trails and trail extensions at Purisima-tothe-Sea Regional Trail and along the San Francisco Bay Trail north of East Palo Alto, and in March 2015, purchased the 40-acre Riggs property as an addition to Purisima Creek Redwoods OSP. The property helps to protect the Lobitos Creek watershed, which provides spawning habitat for Coho salmon and steelhead trout, and protects scenic views from Highway 1 on the San Mateo Coast.
Current Situation
Today, the eight-mile-long Purisima Creek is mostly pure again, flowing down the ridge year-round through steep-sided gulches. But in the 1880s, its water was appropriated to drive the steam-powered saws and the “donkey engines” that hauled logs to the halfdozen mills then operating here.
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