Conservation Assessment of Orange County, California

December 2009

Executive Summary

Over the past few decades, population growth has mushroomed in Orange County, as in the rest of Southern California, with the development of new communities and the infrastructure to support them.  This growth has come at the expense of natural habitats and species in an area recognized as part of a global hotspot of biodiversity.  The loss of habitat to development created a growing list of threatened and endangered species in Southern California, presenting challenges to federal, state, and local agencies responsible for natural resource protection, as well as to developers and land use planners trying to maintain a healthy economy.  To respond to this dilemma, in 1991 the California legislature passed the Natural Community Conservation Planning (NCCP) Act to encourage a collaborative process for regional planning.  As a result of the NCCP, natural open space reserves have been set aside in the coastal and central portions of Orange County which, when combined with National Forest lands, total approximately 163,000 acres of conserved habitat-majestic peaks, chaparral and oak-studded canyons, rolling scrub- and grassland covered hills, and the remnants of formerly extensive coastal lagoons and estuaries-lands that not only contribute to the preservation of biodiversity, but to the quality of life enjoyed by all Southern Californians.  The legacy of this regional planning process continues, with the goal of protecting a green network of natural lands for wildlife habitat and open space recreation across jurisdictional boundaries in Southern California.

In 2006, Orange County voters approved the renewal of Measure M, a transportation sales tax designed to raise money to improve Orange County's transportation system.  As part of this program, at least $243 million will be allocated to mitigate the environmental impacts of freeway improvements, under the Orange County Transportation Authority's (OCTA) Mitigation and Resource Protection Program (MRPP).  The goals of the MRPP are to engage in comprehensive, rather than piecemeal, mitigation to provide higher-value environmental benefits such as habitat protection, maintenance of wildlife corridors, and species preservation in exchange for streamlined project approvals for the freeway program as a whole.

The opportunity to acquire additional conservation lands via the Renewed Measure M funding requires identifying those lands that would contribute most to conserving the remaining natural resource values of Orange County, while ensuring that existing conservation investments remain intact and functional.  In support of this process, the Conservation Biology Institute worked with OCTA and members of the MRPP Environmental Oversight Committee Working Group to conduct a science-based conservation assessment to describe and map selected conservation values across Orange County.  This assessment is intended to provide a tool to assist decision-makers in prioritizing lands for acquisition for Measure M mitigation purposes.  The objectives of this study were to:

• Develop an objective, science-based process for focusing decision-making on regional conservation priorities.
• Using existing data and applying NCCP tenets of conservation planning, map the distribution of conservation values of undeveloped lands in Orange County, including both protected and unprotected lands.
• Identify components of a regional reserve network, focusing on adding to existing reserve areas to build large core habitat areas with habitat linkages between them to enhance their persistence.
• Develop specific conservation objectives to maximize conservation values for each core and linkage area.
• Based on these objectives, identify areas where conservation of biological resources should be prioritized to improve landscape integrity and connectivity, protect rare species and their habitats, and ensure long-term persistence of natural processes.

As a result of this process, 11 core habitat areas and 4 existing or potentially viable linkages that include both protected and unprotected natural lands were identified.  Focusing on the unprotected natural lands, designated as 'Opportunity Areas,' individual parcels were assessed relative to their (a) position on the interior or edge of the core area and (b) proximity to protected open space.  The positional factor considers 'edge effects,' or habitat degradation that occurs at or near the urban-wildland interface (i.e., the habitat 'edge'), while the proximity factor recognizes the value of adding to existing conservation investments.  Using this evaluation process, unprotected lands expected to contribute most to the integrity of the regional reserve were then identified for each core and linkage area.

Establishing specific conservation objectives for each core and linkage area allowed identification of those parcels or groups of parcels for which acquisition would be a 'no regrets' decision, based on their contribution to the regional reserve system.  These 'no regrets' lands, or Priority Conservation Areas (PCAs), represent the final step in the conservation assessment filtering process, and should be the focus of initial conservation efforts.

Thirty-nine PCAs were identified, offering a range of options for acquisition.  Moreover, the conservation value of each area was characterized.  Thus, decision-makers can use these results to prioritize lands for acquisition that consider specific mitigation needs for impacts of transportation projects.  As the analyses were conducted at a landscape level, field assessments of individual parcels will be required prior to decisions on acquisition.  The hierarchical nature of this study, which includes identification of reserve elements, opportunity areas, and priority conservation areas, also provides a framework for establishing restoration priorities and/or second-tier lands for acquisition, as well as a landscape characterization for beginning OCTA's NCCP process.

Despite being the smallest county in Southern California, Orange County is also the state's most populous county, and land values are among the highest in the country.  Therefore, land use and conservation planning decisions require a strategic and integrated approach that is systematic, scientifically defensible, and fully transparent for stakeholder and scientific review.  Moreover, acquisition decisions must be prioritized to yield the 'biggest bang for the buck.'  This document establishes the framework for such decisions, and this framework will serve as the foundation for the Renewed Measure M MRPP.

For more information, contact Patricia Gordon-Reedy in the CBI San Diego office (phone: 858-547-9801).