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Case Study: "Reconnecting the San Gabriel Mountains"

Reconnecting the San Gabriel Mountains is a project reported on The Sustainable Sites Initiative web site and as such has received National Recognition.

Reconnecting the San Gabriel Mountains

Portion of the fire management project area (Angeles Forest)

Size & Type of Project:
640 square miles/ Regional watershed plan; Greyfield and greenfield

San Gabriel Valley, California (east of Los Angeles, Los Angeles County)

Budget varies significantly per project and associated needs (impact and restoration priorities, availability of volunteers, etc.) but on average, it is within a range of approximately $2,500 to $15,000/acre

Project Phase:

  • Study and conceptual planning completed in 2000.
  • Follow-up watershed management plan first draft completed in 2002 with revisions in process; anticipated completion late Summer 2009.
  • Follow-up purchase of properties to protect watershed three-quarters completed; anticipated completion when funds become available.
  • Follow-up habitat assessment research completed 2006.
  • Follow-up management projects in process.

Project Overview

Reconnecting the San Gabriel Valley regional watershed plan (Plan) was accomplished by a university/land conservancy coalition in 2000. The intent of the Plan was to assist conservancies and volunteers in knitting together and restoring fragmented parcels and habitats, cleansing and increasing water resources, providing poor and underutilized areas with amenities, uniting various multicultural recreational opportunities and developing education and partnership strategies for the more than one million mostly economically disadvantaged residents of this highly urbanized watershed.
The specific study, Reconnecting the San Gabriel Valley: A Planning Approach for the Creation of Interconnected urban Wildlife Corridor Networks (Reconnecting), has proven to be well-used and invaluable as a regional to local resource as well as a model for Southern California watersheds encountering similar planning issues and concerns. Reconnecting laid the first foundation in 70 years for regional planning as well as providing a local and inter-regional tool for the San Gabriel Valley/ River/ Foothills/Watershed and Los Angeles County. Reconnecting is recognized as the first and baseline introduction to regional watershed planning for the new millennium with numerous plans following and referencing the planning model and recommendations of the primer and case study.
The Plan, based on Reconnecting, is viewed as a living document to catalyze increased partnerships, funding and solutions for local and regional watershed management projects in the Upper Watershed of the San Gabriel River. Several large projects are underway at various stages of preservation and/or restoration such as habitat preservation for endangered species (state and federal), restoration of regional and urban creeks, community-based stewardship project for control of invasive species, development of a regional wildlife corridor, and monitoring of natural resources and preservation for sustainable habitat health.
Thus, the clients, the San Gabriel Mountains Regional Conservancy (SGMRC), and Cal Poly-Pomona University, have galvanized scores of volunteers and spinoff groups to address the numerous issues and proposed resolutions offered by the Plan for the 640- square mile watershed. As data are collected and analyzed, priorities identified in the Plan adapt and shift to address the most pressing issues and opportunities. A number of new connections, including the new Fire Management Partnership Projects, have been made with unanticipated solutions occurring. The Fire Management Partnership Projects have arisen in recognition of the central role of fire in the region and resulted in fuel-load reduction, habitat health improvements, invasives species control, and water-resources enhancements. For all projects, selection and focus of techniques is geared toward sustainability principles, natural cycles, relationship connectivity, and regenerative practices.

Site Context

As an introduction to the complex region, the San Gabriel Valley is situated in the California Chaparral and Woodlands Ecoregion, which is categorized by Mediterranean forests, woodlands and shrubs. As one of the principal valleys and river/watershed systems of southern California, the San Gabriel Valley lies to the east of the city of Los Angeles, to the north of the Puente Hills, to the south of the San Gabriel Mountains, and west of the Inland Empire.  A number of plant communities exist such as the Coastal Sage Scrub, Oak Woodland, Grassland, Riparian, and Alluvial Fan Sage Scrub. More than 600 native plant species exist in the foothills sub-regions. Development pressures contribute to loss of biodiversity and loss of water supply in aquifers. 

Like much of the Los Angeles region, the San Gabriel Valley enjoys warm, sunny and Mediterranean-like climate year round with low annual rainfalls of 10 to 15 inches. Annual temperatures range from 25°F to 105 °F.

Ecology and topography of watershed (Yucca in forefront)

Sustainable Practices

Sustainable Practices implemented to date (and ongoing)

Engage the Community: A number of partners and stakeholders, including agencies, nonprofits, regional groups, and representatives, have played key roles in the process and development of the Plan. Overall, planning and collaboration by the conservancies started in the mid-1980s and continues today. Timelines are continuous and vary, depending on the specific project and stakeholder/partnering group. Several partnering entities (30 or more) and stakeholder participants (several hundred) for a variety of projects have shown interest, investment and/or participation in conservancy projects of various kinds. Ultimately, the revision and refinement of the Plan will capture? the growth, expansion, detail, successes, recommendations, and hope for the future of these theories into practice, thus providing examples for restorations, carrying capacity, connectivity, sustainability and regenerative practices.

Sustainable Practices in the planning and implementation phase:

Mitigate for Potential Hazards/Control and Removal of Invasives: The Fire Management Planning/Projects are among the largest projects in the Plan with two major goals: 1) To reduce the threat of wildland fires through integrative, proactive management, and 2) To prevent wildland-to-urban corridor fires by creative and resourceful planning/projects. This fire management alternative is anticipated to replace the older fire control management strategies (e.g. utilizing more equipment, fire fighters, and fire roads) commonly used in the region.
Integrative, proactive management includes the following techniques:

  • Fuel Load Reduction and invasive species management is being conducted using a variety of techniques and methodologies. Repeated cuttings and removal of overabundant plant biomass is the most common approach for fuel reduction. The appropriate level of plant biomass for ecological integrity varies with the vegetative community and considers growth patterns, flowering season, site specific location, and a number of other factors. The fuel load reduction plan focuses on nonnative species with the intent of reducing seed production, fuel load, fire temperature and intensity. Preliminary fuel reduction by cleanup and mulching will also necessitate massive removal of residual plant matter, debris, and biomass. Prescriptive burns are planned in conjunction with season, temperature, humidity, air quality, sensitive species life cycles, and permits. Other methods include use of masticators along roadsides, specialized mowers, labor intensive hand removal of plants/debris with chipping away from roads, and difficult, site-specific necessities for goats in areas with steep slopes or intense concentrations of poison oak. The complexity results in a mosaic of diagnostic/prescriptive action plans to effect best management results.
  • Water Resources Considerations focus on encouraging more water infiltration into the ground/ groundwater through better soil and plant management. Chaparral plants are notorious for oils and resins coating the soils, creating hydrophobic conditions that increase runoff and reduce infiltration. Periodic burns in such areas greatly improve infiltration of water into the soils, benefiting aquifers, springs, and groundwater supplies.
  • Habitat Enhancement is being conducted through a variety of restoration projects in coastal sage scrub, chaparral, grassland, riparian, plus oak and black walnut woodland habitats.  The projects focus on protection, preservation, recovery and revitalization of sensitive species within native habitat areas.  Notes can be taken from established and regenerative populations of sensitive species and habitats in the immediate area to assist with restoration project and management planning.  Restorations include removal of non-natives, as well as competing natives, encroachment into endangered species habitat areas, and recovery from rogue trails and re-establishment of trail systems to circumvent sensitive habitat areas.  Signage typically does not work and may become counterproductive, so natural alternatives and barriers, such as rocks and cacti strategically placed for avoidance, have to be creatively thought through to succeed in effectiveness.  Protection and restoration of endangered plant species is a high priority, e.g., grassland and chaparral species such as the federally and state-listed brodiaea and companion assemblages of sensitive plant species of the Glendora Volcanics soil types, including chocolate lilies, shooting stars, golden stars, and mariposa lilies.  Invasives management of both non-native and native plant species have been defined for non-native mustards and grasses, and native species of cacti and buckwheat. Chaparral plants and habitat, as part of natural life cycles, depend on somewhat frequent fire cycles. Several habitat health factors are impacted by the fuel load relationship to fire temperatures and scarcity of soil minerals and nutrition. Most notably, management methods utilizing cool fires resulting from more frequent burns tend to do less damage to native chaparral plants as well as re-introduce minerals and matter into the typically very poor soils of chaparral habitats.  Such results have been shown to stimulate health and vitality of endangered species such as the brodiaea mentioned above.
    Additional watershed-wide restoration efforts using best management practices target a number of non-native, invasive species which greatly impact water and habitat in riparian areas.  Examples include giant reed/arundo, castor bean, salt cedar, cape ivy, ailanthus, domestic figs, and a number of palm species. Control and removal of invasive species gives native species habitat multiple advantages of space, water, and a competitive advantages for nutrients, contributing to recovery and re-establishment.
    Field trials are also anticipated to be added to the integrative methods with the new potentials of re-establishment of mycorrhizal relationships along with fire, water, invasives, and habitat recovery management.

Creative and resourceful planning/projects include the following:

  • Incorporation of linear buffer parks (LBPs) bordering urban areas and open space corridors as well as municipal parks. Benefits and purposes of LBPs include problem-solving alternatives for small to extensive linear boundaries, serving as transition zones for safety and creative enhancements, or recreational/ educational opportunities. LBPs are a new construct in design, emerging from the work and creative efforts of several conservancies in the region to focus on solving a number of resource and transition issues, such as flood control channels, utility corridors, residential/wildland areas. Incorporated into the design elements are creative utilization of local geology and plant materials with community-based input and added features of minimal cost and sustainable design. Of particular note have been the interest generated among fire departments looking at proactive planning alternatives to weed control and fire-prone landscapes in urban/wildland connection corridors, such as flood control channels. LBPs are now being considered for a number of solution-focused projects along the Foothills. Some of the potential site locations for LBPs would include: utility corridors, flood control and wash areas, drainage areas, city park buffer zones, etc.
  • Fire management is generally dictated by season, depending on safety and health, temperature, humidity, air quality, nesting seasons, etc. Preference for use of any fire/burn strategies would be incorporated as prescriptive burns in limited mosaic patterns with extensive backup fire management and fire department personnel/equipment.

Provide an accessible site and opportunities for outdoor physical activity: Each land area, parcel, or property has a unique Land Use Plan that often includes recreational opportunities.   Highly sensitive areas with endangered species and/or high biodiversity have minimal recreational components, typically including a species-viewing area, environmental education, and stewardship cleanup and planting projects.  Areas already impacted have more extensive recreational opportunities, including nature centers, multi-purpose trails of various lengths and difficulty, programming, fitness conditioning, and stewardship cleanup and planting projects for all ages.  Many areas contain trails and features for all accessibility ranges, including wheelchairs, and wellness components. Camping is limited, due to concerns about fire, animal, and other safety issues.  Other areas that are key linkage properties, or have good to high potential for recovery of native habitat, water resources, or restoration in general, may have limited recreational components, such as a trail with cautions and extensive monitoring/management.

Promote sustainable education and awareness: Through websites and nature center networking, extensive programming is being provided. This programming is having a positive impact based on long-term stewardship and watershed education, interactive presentations and participation, demonstrating greater and more sustainable outcomes.  

  • Workshops and customized notebooks designed for specific audiences give both flexibility and resourcefulness for sustainable education and awareness.
  • Signage varies as to location. Most signage in urban areas becomes a target for graffiti and vandalism.
  • New, user-friendly models of guides, books and publications, such as Wildflowers of the San Gabriel Mountains, have produced great interest and response.
  • Incentives are also utilized, such as caps, patches, and T-shirts, for some groups to keep coming back for more activities and projects with the conservancies. Such incentives also become identification and marketing devices as well for outreach and promotion.
  • Conservancy/university sponsored regional conferences, such as the War on Weeds/WOW Conferences of SGMRC with Cal Poly, also provide alternatives in education and outreach, bringing together stakeholders at minimal cost. Interestingly, people who probably would not ordinarily cross paths in working together on sustainable projects come together at the neutral ground of the university to learn and bond together. New community-based models have emerged to sustainably control weeds in trail and riparian areas of natural areas.
  • Scout and other youth groups are involved in projects, cleanups, planting, and restorations. A number of programs, activities, and workshops have been tested and are available through various outdoor education opportunities.

Construction Cost

Construction, acquisition, and restoration costs in implementation of the Plan vary from simple donations and two to three-figure costs to virtually millions of dollars. Where volunteer and community-based projects such as weed management, trail building, cleanup, and planting projects for watershed enhancements are planned, costs are usually minimal, but may range depending on the size of the project and scope of the work from $50 to $50,000, with many local businesses and companies donating materials, water, and food.

For restorations where drainage changes are made to restore historic flows to feed a vernal pool, for example, costs may range from $15,000 to an estimated $100,000, depending on volunteering, grants, and donations.

Other larger-scale restorations such as watershed riparian restorations, based on cost per acre, may run in excess of the current estimate of $110,000/acre.  In contrast, oak woodland restorations, depending on the number and size of plantings, are in the $80,000 to $90,000 range.

Watershed acquisitions for in perpetuity land, aquifer, stream, and open space protection are of the greatest regional need and the most costly in terms of watershed implementation for urban and urban interface areas.  Current fair market appraisal pricing for foothills properties is commonly set at $100,000/acre.  In spite of such high costs, SGMRC with other conservancies and partnering entities has been highly successful in attracting grants to fund and permanently protect more than 2,000 acres of foothills properties for watershed protection, which also protects and invests in future water supply.   For SGMRC, another 2,000 acres have been targeted to complete this high priority implementation of the watershed plan.  In contrast, the largest single land gift in the region to a conservancy was 130 acres of high quality chaparral habitat, which is continuing to be stewarded and managed in perpetuity for open space, watershed, habitat, and sensitive species.

Construction costs for nature centers and outdoor classrooms may run from lower cost modular buildings of $50,000 to permanent structures in the millions.  Such construction opportunities are best planned in partnership with established agencies, such as cities or counties for cost, outreach, and overall effectiveness.

Monitoring Information

Monitoring has increasingly emerged as a major benefit in restorations and other projects, but as a long-term cost investment for contingency and sustainability planning in order to assess positive and negative changes within project implementation. More commonly, the focus and reporting may include disturbances, re-planting, re-treatment, and/or new infestations of invasives. Current monitoring/reporting typically includes site visits two to three times per year with documentation and follow-up recommendations for action. In addition, monitoring plans have now been revised to as many as eight to 10 years, plus potential recommended re-trainings of managers if maintenance/management strategies are not effective. Such increases in monitoring per year and with added years will undoubtedly aid in the establishment and sustainability success of projects such as restorations.

As to details of monitoring processes, typically teams of as many as three from different scientific backgrounds/training, walk project sites and discuss status, progress of land, habitat, or restorations. Site-visit photos are taken for documentation, and written reports provide assessment and results with recommendations. Some monitoring documentation provides the basis for yearly reports to agencies, if requested. Such monitoring methods are vital in preventing erosion, halting habitat declines, and/ or giving documentation for restoration funding (or continuation of such funding) in a timely manner. With monitoring, exact locations of populations of sensitive or endangered species can now be tracked with precision and compared with other similar species populations.

Endangered species require by law unique and special care, maintenance, and management. Biodiversity requires that a comprehensive and exhaustive listing and location for each species be mapped (GIS/GPS). Ecotone management requires monitoring and management of the boundaries between/among different plant communities, as recommended by monitoring/management teams. Bio-indicators of environmental health could be any living species which shows disease, damage, invasiveness in a habitat area.Each habitat will have its unique set of bio-indicators to visibly point out habitat balance and health.

The fire management component, which has been underway over the last two years, focuses initially on data collection and monitoring. The monitoring plan is multifaceted and conducted by an integrated design and management team of biologists, watershed managers and LA County forest and fuel reduction specialists as well as county fire crews and units. Data collection includes biological surveys, archeological surveys, pre-fire/post-fire comparisons, and documentation using extensive photo sets in varied habitat conditions. Integrated methods used to address fire management will be monitored by both interns and university experts over a 10-year period, with feedback compared to areas not using integrated fire management programs. A similar 500-acre project in another city (Rancho Cucamonga) will be used as a comparative case study. The plan will be successful if bio-indicators show increased habitat health, increased water quality and quantity, including groundwater recharge, reduction in fire management costs, fewer fire hazards, and reduced air quality impairment.


Maintenance plans will focus on the removal and control of invasive plants, overall land management, trail maintenance and restoration of habitat in streamside or riparian areas. Each plan will be specific to the factors creating the threat or decline including the consultants, volunteers, materials, equipment, etc. to be incorporated into the seasonal/ weekly/ monthly/ yearly calendar. Most implementation will start with a plan developed by partnering entities and key resource people or consultants working directly with the SGMRC Team.

The Fire Management Planning/Projects (Projects) are unique in terms of proposing an alternative approach for fire in the ecology and resources of wildlands and wildland/urban interfaces. Instead of a focus on fire suppression only, the Projects utilize fire as a maintenance/ management alternative to reduce fire hazards/devastation and instead to promote fire enhancement and benefits in relation to water resource enhancement, habitat health and revitalization, and compatability to reduce overall urban fire hazards and increased safety. Fire, therefore, is looked at as a tool for management, instead of a threat to management of natural and wildlife/urban interface areas. As an additional benefit, invasives management will also be a positive outcome with these integrative approaches.

Overall, three general geographic/geologic regions in the 640 square miles can be typically assigned a dollar maintenance/management cost per acre. These regions would be: mountains, foothills, and valley.

  • Mountains estimated at $5,000/ acre (50 percent of land cover)
  • Foothills estimated at $15,000 (20 percent of land cover)
  • Valley estimated at $15,000/acre (30 percent are valley - streams and ridgelines, plus flat area).

Recovery and restoration of mountains and foothills

Issues/Constraints of the Site

  • Unique constraints include endangered species and biodiversity planning, as well as aquifer protection/enhancement, ecotone management, and study of bio-indicators of environmental health.
  • Communication, funding, and volunteer staffing are both the strength and weakness of programming for sustainable education and awareness. If all three are emphasized, the results are highly successful. Shortages in any of the three affect the other two by limiting successes. In general, long-term commitment and perseverance produce sustainable programming.

Lessons Learned

Numerous lessons have been learned that contribute to sustainable management and best management practices (BMPs) as adapted to specific properties or resources. Examples include:

  • The importance of using local plant stock for habitat restoration, understanding trail impacts through biodiverse areas, and the efficacy of mulch-based water conservation for habitat establishment were critical lessons learned.
  • Habitat management, water resources conservation and enhancement, fire management, etc. have increased significantly by local stewardship interaction with open space lands, restorations, and projects. In the past eight years since the plan was released, $40 million has subsequently been raised to address the plan goals, with over 200 volunteers to date in place to carry forth beneficial projects indefinitely.
  • Seed collection of local species/variants for plant propagation is increasingly important for fire recovery and habitat enhancement.


More project details


Project Consultants


  • California State Polytechnic University, Pomona, California (Cal Poly Pomona)
    Landscape Architecture Graduate Program
  • San Gabriel Mountains Regional Conservancy (SGMRC);
    Ann Croissant, Ph.D., President, Board of Directors; Ricardo Montijo, Board Member, Senior Biologist
  • Cal Poly Pomona, Graduate Landscape Architecture Principals (Masters Degree Committee Members): Kristina Barker, ASLA; Jeffrey Olson, ASLA; Philip Pregill, ASLA; Joan Woodward, ASLA

Design Team:

  • Cal Poly Pomona, Masters Degree Graduate Team: Doug Delgado, Jay Brown, Jeff Stevens, and Kibum Sung
    - Provided the defining study for SGMRC and the San Gabriel Valley, Foothills, River, Watershed (Reconnecting the San Gabriel Valley, 2000).

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