Habitat Restoration

The term “habitat restoration” refers to the process of restoring the functional aspects of a given ecosystem to a semblance of its pre-disturbed state. As a result of more than 100 years of human land use, the majority of the Puente Hills contains disturbed habitats, including those dominated by non-native vegetation. Past land uses that have created or contributed to disturbed, altered habitats include livestock grazing, development, the intentional planting of non-native vegetation, and the use of non-native invasive vegetation on properties adjacent to open space where invasive plants spread into natural areas. Our goal is to put our natural areas back in order for the benefit of future generations. As such, the Habitat Authority actively restores areas by removing non-native vegetation, which are considered weeds (such as non-native grasses, mustard, castor bean, tree tobacco, etc.), and planting native vegetation that would have been present prior to the disturbance.

Approximately 207 acres of Habitat Authority lands have been or are currently being restored/enhanced. This includes 88.5 acres of mitigation restoration, and 118.5 acres for general enhancement and restoration not associated with any mitigation. The mitigation projects are regulated by state and federal natural resource agencies. Restoration projects include coastal sage scrub and sycamore riparian habitats at the Hacienda Hills Trailhead; coastal sage scrub restoration on the former Unocal property (east of Colima Road in Arroyo San Miguel); the restoration of coastal sage scrub at the Arroyo Pescadero Trailhead; and the restoration of oak and walnut woodland, coastal sage scrub, native grassland, and riparian habitats in Powder Canyon. The Habitat Authority just successfully completed restoring approximately 15 acres of native habitat which used to be occupied by non-native eucalyptus woodland on either side of Colima Road.

The following are examples of habitat restoration projects on Habitat Authority lands that are either initiated and conducted by the Habitat Authority or implemented through the mitigation process with oversight by the Habitat Authority.


Powder Canyon In-lieu Fee Mitigation (La Habra Heights) (No photos shown here. Click for information.)


East Colima In-lieu Fee Mitigation (Whittier)

Once a forest of eucalyptus, the Habitat Authority conducted coastal sage scrub mitigation on this 15 acre site. By year two of restoration, federally threatened coastal California gnatcatchers (CAGN) were already using the site for breeding and the site has met all year five success criteria. A conservation easement has been recorded on this mitigation site and we are in the process of seeking written sign-off from regulatory agencies. This has not only been successful in terms of vegetation management but especially since CAGN’s have successfully nested onsite for four years!

Former Canlas Property In-lieu Fee Mitigation (Whittier)
The Habitat Authority in cooperation with the United States Fish and Wildlife Service initiated the restoration of this 8-acre property in 2005, which previously supported non-native grasses and other invasive vegetation. The site was planted and seeded in 2005 with coastal sage scrub species.

Former Diaz Property-Not Mitigation (La Habra Heights)

The former Diaz property contains approximately 25 acres of habitat restoration, including coastal sage scrub and oak/walnut woodland. The property previously contained an uninhabitable house, which was demolished in order to restore with native vegetation. The property also contained an avocado orchard and other non-native vegetation.

Former Unocal Property Permittee Implemented Mitigation (Whittier)

The Habitat Authority has approximately 52 acres of habitat restoration implemented at the former Unocal property (Arroyo San Miguel) as mitigation for local development projects, including coastal sage scrub and riparian restoration. As proof of its success, use by the federally listed coastal California gnatcatcher has been documented within restored coastal sage scrub, including breeding gnatcatchers in 2008. All of the photos shown below were taken in May 2008.

Sycamore Canyon Permittee Implemented Mitigation (Los Angeles County unincorporated)

Approximately 3.5 acres in the lower portion of Sycamore Canyon was restored in 2007 with sycamore riparian woodland vegetation. The restoration was conducted as mitigation for a development project in Claremont.