Guadalupe Creek Restoration Project
Guadalupe Creek is a principal tributary of the Guadalupe River. It originates in the
eastern foothills of the Santa Cruz Mountains and flows east and north to join the River
upstream of Almaden Lake, in the City of San Jose (Santa Clara County). The
Guadalupe Creek Restoration Project involves restoring coldwater anadromous fish
habitat and riparian vegetation along 1.7 miles of Guadalupe Creek between Almaden
Expressway and Masson Dam. Implementation of the Guadalupe Creek Restoration
Project will entail:

channel realignment (approximately 2,500 lf);

floodplain creation;

bank stabilization (including approximately 725 lf of bank protection
features);

instream habitat improvements; and

planting approximately 13,000 lf of shaded riverine aquatic (SRA) cover
and 6 acres of riparian vegetation.
Project Features Described by Reach
In Reach 1, the proposed project will emphasize planting existing surfaces, including
bars, and minimizing physical modifications to the channel and floodplain.
Instream structures—e.g., rootwads and other instream woody material (IWM), stream
barbs, boulders, and v-weirs—will be incorporated into the channel bed and banks to
control existing erosion, narrow the low-flow channel, provide cover and instream habitat
for fish, and improve hydraulic diversity while maintaining the low sinuosity of the
existing planform.
The planting program for Reach 1 will emphasize planting sycamores and other riparian
vegetation on floodplain and bar surfaces to create a strip of riparian vegetation along
the north bank, and to fill gaps in the existing riparian canopy. The bench at the toe of
the slope along Coleman Road will also be planted with riparian species. Oak woodland
species will be planted at relatively low elevations where soils are coarse and permeable
and contain less moisture. Immediately upstream from the Almaden Expressway Bridge,
planting areas will be tapered to ensure that the bridge opening is unobstructed, and
existing access to the bridge will be maintained to facilitate maintenance activities.
The existing planform of the creek will generally be maintained in Reach 2. Minor
modifications will be made to lower floodplains in most areas, except downstream from
the Meridian Avenue Bridge, where more extensive excavation will expand the floodplain
on the parcel owned by the City. This expansion will reduce the flow velocity in the main
channel while preserving a band of willows along the south bank. An existing sycamore
tree at the top of the bank will be removed to allow for the expansion of the floodplain.
An existing oak in the same area may also be removed.
Instream structures will also be installed in Reach 2. IWM will be used to improve bank
stability, to increase instream cover, and to increase channel complexity and hydraulic
diversity in the low-flow channel. Bank stabilization structures will be used on the bend
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upstream from Meridian Avenue to protect the maintenance road and improve instream
cover. Near the downstream end of Reach 2, bank stabilization measures will be
installed at the toe of the bank adjacent to Coleman Road.
Planting in Reach 2 will include establishing riparian vegetation on the lower floodplain
surfaces and higher slopes and terraces. Immediately upstream and downstream from
the Meridian Avenue Bridge, the planting areas will be tapered to ensure that the bridge
opening is unobstructed. Sycamore woodland species will be planted on the north side
of the creek immediately upstream from the bridge to ensure that the plantings do not
impede floodflows.
Project features proposed for Reach 3 will focus on modifying the existing channel and
floodplain to reduce the level of entrenchment, providing planting surfaces for riparian
vegetation, and increasing hydraulic diversity in the channel. Near the downstream end
of the reach, modifications will be made to the channel planform to extend the floodplain
and increase channel complexity and hydraulic diversity. These modifications will
generally follow the same meander pattern that now exists in the upstream portion of the
reach. Channel realignment will significantly expand the area suitable for planting
riparian vegetation. Two mature sycamores, located on artificially created mounds and
isolated from the active floodplain, will be removed to create additional floodplain
surfaces to reduce channel velocities. IWM will be added to stabilize the bed and banks,
to increase cover, and to increase channel complexity and hydraulic diversity. Woody
material will also be placed on the bar surfaces in Reach 3 to stabilize the bars and
provide additional planting sites.
The planting program in this reach will focus on planting riparian vegetation on expanded
floodplain surfaces, in areas where the channel has been relocated, and on sites created
by the installation of bank structures and placement of IWM on the backs of bars. Oak
woodland species will be planted on the higher surfaces to fill gaps in existing
vegetation.
In the downstream segment of the reach, significant SRA cover vegetation already exists
and fish habitat values are high. Minimal modifications will be made to the channel in this
portion of Reach 4. Woody material will be placed in an existing erosion cusp to protect
the maintenance road, shelter young riparian vegetation, and provide additional planting
sites.
Downstream from Percolation Pond 1, which serves as a settling basin for the
percolation pond system, approximately 350 feet of the existing maintenance road will
be shifted to the north to create a wider bench adjacent to the channel. This shift will
increase flood conveyance capacity and provide a buffer to protect the road from bank
erosion.
In the area adjacent to Percolation Pond 1, the channel will be relocated north to
reoccupy a historical channel alignment. Two existing sycamores may be affected by the
channel alignment. Approximately 600 feet of new channel will be created. This
realignment will require relocating the maintenance road approximately 10 feet to the
north, and filling the existing channel to create a new floodplain. Percolation Pond 1 will
not be modified. These actions will lengthen the channel and increase instream cover
and channel complexity. The channel alignment will use existing mature trees to shade
the new stream surface. Existing Phase 1 plantings affected by the channel realignment
will be transplanted to appropriate areas.
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In the upstream segment of Reach 4, the floodplain will be expanded. On the south side
of the channel, a broad lowered floodplain surface will be graded along the stream at the
edge of the Los Capitancillos Freshwater Wetland Mitigation Site. On the north side of
the channel, the width of the maintenance road will be reduced to 25 feet to create a
floodplain bench. In addition, some of the existing riprap along the north bank will be
removed.
The planting program in Reach 4 will focus on planting riparian vegetation and oak
woodland species on created surfaces. Along the south bank of the creek, existing
riparian vegetation upstream will be preserved. Additional project features that will be
implemented in Reach 4 include installing IWM to provide planting sites on bar surfaces
and installing rootwads and other structures to stabilize the outside banks of meander
bends and to create instream cover.
Bank Stabilization
Bank stabilization will be accomplished through the construction or installation of a
variety of measures designed to control erosion and improve habitat. These measures
include rootwads, log and rock barbs, and log cribwalls; project design prioritizes the use
of biotechnical techniques.
Instream Habitat Improvements
Proposed instream habitat improvements are designed to increase hydraulic complexity
and provide cover and resting habitat for native anadromous fish. A variety of restoration
techniques will be implemented, relying on a combination of woody materials, boulders,
and fill. Boulders will be used to increase habitat and hydraulic complexity along
channel banks, to create weirs and barbs, and to provide safe sites for the accumulation
of vegetation and other waterborne debris. Additional habitat improvements will include
the installation of rootwads, debris jams, off-bank branch and log cover, buried groins,
log toe bank structures, and wing deflectors.
Planting
Locally native SRA cover and riparian vegetation will be planted on floodplain and bar
surfaces. Five planting zones have been designated based on existing site conditions,
including flood recurrence interval, depth to groundwater, and soil characteristics.
Plantings will include cuttings, container stock, and site transplants. Both cuttings and
container stock will be placed in augered and backfilled holes. Cuttings will be planted
with one third of the cutting above finished grade; container stock will be planted at
grade and bermed to facilitate irrigation. Irrigation will be installed in have been
completed. Irrigation will consist of an automated bubbler system to ensure deep
watering of newly planted seedlings and transplants.
In seeded areas, plants will be removed by hand or spot herbicide methods. When
possible, native plant volunteers will not be removed.
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