Task 1. Project Management and Coordination
Stillwater will provide project management and support including attending meetings
with SCRC and other Project team members (SCRC, UCSB, and City of Santa Clarita),
coordinating with UCSB for the field effort, and general project management duties.

Task 2. Vegetation Mapping
Stillwater will create a vegetation map in Geographic Information Systems (GIS) to
reflect conditions in the Santa Clara River floodplain and selected tributaries as
observed during Spring 2022 field surveys and during remote investigations using
satellite imagery (i.e., National Agricultural Inventory Program [NAIP] 2020). The Study
Area will be the active floodplain of the Santa Clara River from the Santa Clara River
Estuary in Ventura County to Soledad Canyon in Los Angeles County and the following
tributary extents: Castaic Creek to Castaic Lagoon, San Francisquito Canyon Creek to the
USFS boundary, Bouquet Canyon Creek to the USFS boundary, South Fork Santa Clara
River to the confluence of Pico and Lyon Canyon creeks, and Mint Canyon Creek to the
USFS boundary.
Initially, vegetation mapping will be informed by LiDAR including assessing extent of
active floodplain, relative elevation of low flow channel and canopy height. Where
available, Stillwater’s 2018 mapping (Stillwater 2019) will be updated to reflect changes
in Arundo cover and any large-scale changes to vegetation classification due to events
such as fire, drought stress or high flows. Where no existing vegetation mapping data
exists (i.e., Los Angeles County upstream of the confluence with Bouquet Canyon Creek),
desktop-based mapping will be performed to provide coarse-scale habitat mapping of
the active floodplain vegetation using NAIP 2020 imagery. Each map unit (i.e., polygon)
will be attributed with the percent cover of Arundo and other non-native species where
signatures are evident in imagery, including Eucalyptus species (Eucalyptus sp.),
Peruvian pepper tree (Schinus molle), and tamarisk species (Tamarix sp.). Figure 1 shows
the extent of 2018 vegetation mapping previously conducted within the Santa Clara
River floodplain (Stillwater 2019) and the proposed extent of additional mapping in the
Upper Santa Clara River in Los Angeles County.
A preliminary vegetation map will be prepared prior to the Field Verification Surveys
conducted by Stillwater and UCSB (Task 3) and revised to incorporate field observations
in the final map.