Watershed Conservation Authority’s San Gabriel Mountains and Foothills Regional Open Space Acquisition Prioritization Plan commissioned a number of studies that clarify how biological, hydrologic, and cultural resources, human factors, fire threat, and resource management considerations should inform the Authority’s acquisition of additional conservation lands in the Wildland Urban Interface of the San Gabriel Mountains. An integral part of WCA's founding mission is to acquire and protect lands for watershed protection, conservation, natural open space, and recreational purposes.

San Gabriel Mountains and Foothills Regional Open Space Acquisition Prioritization Plan was initially conceived in 2016 by Watershed Conservation Authority and Trust for Public Land to guide WCA’s strategies for open space protection in the foothills. Since that time, extreme heat and drought, proliferation of invasive species, increased demand for recreational access, and the continuation of development in severe fire hazard zones, bring additional dimensions to this work. The ecosystem services provided by our rare remaining open space lands is as important as ever. Such ecosystem service include biodiversity, stormwater capture and infiltration to increase local water supplies and reduce downstream flooding, and improving water quality in surface water bodies. 

Trust for Public Land identified several dozen clusters of undeveloped parcels as candidates for conservation by considering aggregate size of parcel clusters, contiguity to other protected lands, real estate factors, and funding climate. These recommended parcels became the basis for additional studies that clarify how biological, hydrologic, and cultural resources, human factors, fire threat, and management considerations should affect WCA's priorities.

The San Gabriel Mountains and Foothills Open Space Acquisition Master Plan is currently being packaged along with additional interviews and analysis by WCA, into a condensed form for public sharing.

In 2024, WCA will present a series of online events to share the studies that contribute perspectives on the role of open space conservation in the San Gabriel Mountains Foothills. Online events will be supplemented by field excursions. A link to the schedule is available here.

In the meantime, the studies included are shared below:  

• Coarse scale biodiversity metrics that account for factors associated with biodiversity were developed by Psomas. Scoring of these metrics was based on public data, and many of the metrics are based on relatively stable factors that influence a parcel’s contribution to the goals of the study. (Percentage of native vegetation cover, parcel size, adjacency to protected land, presence or proximity to special status species). These parameters were scored and weighted as appropriate to assign priorities for property acquisition.
  
  
• On-the-ground “rapid field assessments” of potential priority parcels was conducted by Cooper Ecological Monitoring. These assessments add detail to the picture of biodiversity in the study area, and revealed recent trends as manifest in the landscape, and additional resources that should not be overlooked.
  
  
• Geomorphic and Hydrologic opportunities in priority parcels. Balance Hydrologics created a prioritization based on the presence of hydrologic features on parcel clusters under consideration that might be expected to contribute to regional watershed management goals including headwaters and water quality protection, infiltration potential, longitudinal connectivity, and presence of riparian areas, seeps, and springs.
  
  
• Existing Conditions and Restoration Opportunities in the San Gabriel River and Azusa Floodplain. Balance Hydrologics evaluated hydrologic and geomorphic factors that have potential to contribute to hydrologic restoration of the San Gabriel River mainstem, and to inform prioritization of open space acquisition.
  
  
• Aquatic habitat assessment in the San Gabriel River mainstem. Stillwater Sciences assessed the current channel and floodplain conditions to understand how opportunities to improve aquatic habitat should inform prioritization of acquisitions.
  
  
• Foothills Records Search and Sensitivity Analysis was conducted by Cogstone Resource Management. The records search included the original parcel clusters recommended by TPL as well as a ½ mile radius. Based on the results of this search Cogstone ranked the sensitivity of candidate parcels based on whether they have been previously surveyed for cultural resources, whether resources were found.
  
  
• Cultural Sensitivity of 118 Parcels Located in the San Gabriel Mountain Foothills, is a more in-depth cultural sensitivity analysis by Cogstone Resource Management which includes discussion of the project area’s cultural setting, Tongva ethnography, village, trade and exchange routes, and the need to recognize the traditional Tongva concept of Maxaax, a reciprocal relationship to the land.

WCA served as a client for UCLA Master of Urban and Regional Planning candidates Zachary Zeilman and Matthew J. Mello on capstone projects that examine fire in the Wildland Urban Interface with a specific focus on the foothills of the Eastern San Gabriel Mountains:

• Wildfire in the WUI: Building a Cost-Benefit analysis of Development Scenarios in Eastern LA County’s Wildland Urban Interface to reduce risk of Wildfire, by Zachary Zeilman.
  
  
• Living Alongside Wildfire: People and Climate colliding in the San Gabriel Valley, by Matthew J. Mello.