*NOT YET APPROVED*
1 ORDINANCE NO. _____
Ordinance of The Council of The City of Palo Alto Approving a Plan for Improvements to the
Palo Alto Baylands as part of the
Horizontal Levee Pilot Project
The Council of the City of Palo Alto does ORDAIN as follows:
SECTION 1. Findings. The City Council finds and declares that:
(a) Article VIII of the Charter of the City of Palo Alto and Section 22.08.005 of the Palo Alto Municipal Code (PAMC) require that, before any substantial building, construction, reconstruction or development is commenced or approved, upon or with respect to any land held by the City for park purposes, the Council shall first cause to be prepared and by ordinance approve and adopt a plan therefor.
(b) The Horizontal Levee Pilot Project (Project) is part of the Marsh Front Trail (Trail).
The Project site is located in the City’s Baylands, which is dedicated parkland (See PAMC §
22.08.020 et seq.) Based on the current habitat quality of the Project site, the location has been identified as in need of enhancements to better provide refugia for many species including the endangered Salt Marsh Harvest Mouse.
(c) The City of Palo Alto intends to authorize the construction of a horizontal levee pilot system that will enhance habitat, maintain public access, provide educational opportunities, provide regionally-beneficial information on nature-based sea level rise adaptation options, and beneficially reuse treated wastewater.
(d) The Plan of improvements shall comprise, as follows:
(1) The Project will construct a horizontal levee along Harbor Marsh and install along Embarcadero and Harbor Roads an underground treated wastewater pipeline for irrigation of the horizontal levee. The horizontal levee will be planted with various native plants to restore diverse transitional habitats including freshwater marsh, wet meadow, and riparian scrub. The Project will re -align a portion of the Trail as required to accommodate the horizontal levee and reconnect habitats . The Project will install educational signage and provide opportunities for public participation in community science activities such as photo-point monitoring of habitat restoration and water quality testing. (2) The Project will require temporary rerouting of a portion of the Marsh Front Trail and temporary traffic restrictions to a portion of Harbor Road to accommodate construction.
*NOT YET APPROVED*
2 (e) The Project described above and as otherwise depicted in the attached exhibit is consistent with recreation and conservation purposes
(f) The Council desires to approve the Plans for the Project described above and as depicted in Exhibit "A".
SECTION 2. The Council hereby approves the Plan for construction of the Horizontal Levee Pilot Project as described in this Ordinance.
SECTION 3. City of Palo Alto is the Lead Agency for the Project under the California Environmental Quality Act (CEQA) and finds that the Project is categorically exempt under CEQA Section 15333, Class 33 for small habitat restoration projects.
SECTION 4. This ordinance shall be effective on the thirty -first day after the date of its adoption.
INTRODUCED:
PASSED:
AYES:
NOES:
ABSENT:
ABSTENTIONS:
ATTEST:
____________________________ ____________________________ City Clerk Mayor
APPROVED AS TO FORM: APPROVED:
____________________________ ____________________________ Deputy City Attorney City Manager
____________________________
Director of Community Services
Palo Alto
Airport
Harbor
Marsh
Byxbee
Park
Palo Alto
RWQCP
SOURCE: USGS 7.5' Topographic Quadrangle (Mountain View, CA); ESA 2022 0 650 1,300
Feet
Palo Alto Horizontal Levee Pilot Project . D201801306
Figure 1
Project Location
Project Boundary
U:\GIS\GIS\Projects\18xxxx\D181306_Palo_Alto_Horiz_Levee\03_MXDs_Projects\PD\Fig1_ProjectLocation_rev parking.mxd
EXHIBIT A
Install pump in effluent
junction box and connect
to new effluent line
Palo Alto
RWQCP
Byxbee Park
Marsh Front Trail
H a r b o r
M a r s h
Palo Alto
Airport
SOURCE: ESRI 2021; ESA 2022
0 100 200
Feet
Palo Alto Horizontal Levee Pilot Project . D201801306
Figure 2
Project Components
Project Boundary
Project Component
Horizontal Levee Area
Access
Effluent Line in
Roadway
Equipment Staging Area
Contractor Parking Area
EXHIBIT A
,
,
,
,
,
,
,
,
,
,
,
,
8 10
12 6
8 10
8 10
10 10
10 10
6 10
SOURCE: ESRI 2021; ESA 2022
0 30 60
Feet
Palo Alto Horizontal Levee Pilot Project . D201801306
Figure 3
Draft Horizontal Levee Plan
Legend
Project Boundary
Major Contour 2'
Minor Contour 0.5'
Existing Overhead Power Lines
Demo Abandoned W4 Line
Demo 18-Inch Storm Drain
Preserve 18-Inch Storm Drain
Preserve 18-Inch Renzel Marsh
Pipeline
New 18-Inch Culvert
New 4-Inch Effluent Line
New Distribution Lateral
, , ,New Distribution Trench
Existing Renzel Marsh Intake
Structure
Remove Existing Trail
Brackish Marsh (Clear & Grub,
No Grading)
@
@@
@
@
@
@ @
Freshwater Marsh
Freshwater Swale
Relocated Marsh Front Trail
àààààà
à
àPerennial Wet Meadow
kk kk k
k
k
k
k
k
k
Riparian Buffer
ùù
ù ùù
ùùù
ùù
Riparian Scrub (Transition)
ÇÇÇÇÇÇÇÇÇÇÇÇ
Seasonal Wet Meadow
ûûûûûûûûûûûûûûûûûûûûûûûû
° ° °° ° ° Subsurface Treatment Zone
Upland (Levee and Staging Area
Seeding)
Palo Alto RWQCP
Harbor Marsh
Ridge Section A
Swale Section B
U:\GIS\GIS\Projects\18xxxx\D181306_Palo_Alto_Horiz_Levee\03_MXDs_Projects\PD\Fig3_LeveePlan.mxd Harbor Road
EXHIBIT A
DWG: P:\01 CAD\18xxxx\D20181306.00 - Palo Alto Horizontal Levee\09 CAD\PDF\2022-02-05_ConstructionPhasing\FigureBox_8.5x11Portrait.dwg USER: Marisa Landicho PLOT DATE: 2/18/2022 2:53:50 PM Figure 4Horizontal Levee SectionsPalo Alto Horizontal Levee Pilot Project . D201801306
ELEVATION
STATION
0 5
10 15
20 25
0 5
10 15
20 25
0+00 0+50 1+00 1+50 2+00 2+26
12'
BERM
30'
TREATMENT AREA
EMBARCADERO ROAD
8'
TRAIL
EL
12'
EL 10'
EL
9'
EL
8' MATCH GRADE
EL 7'±
2' THICK
SAND FILTER (NOTE 3)
EFFLUENT LINE
SEE MECHANICAL PLANS
OVER EXCAVATE
& PLACE 1' LAYER
OF COARSE
NATIVE MATERIAL
APPROX. (E) EDGE
OF MARSH @ EL 8'
EL 13'
3' THICK
DISTRIBUTION
TRENCH
SHT C06 DTL 1
HORIZONTAL LEVEE
DESIGN GRADE, TYP
BERM KEYWAY
COARSE MATERIAL (NOTE 4)
1' THICK SUBSURFACE
TREATMENT LAYER, TYP (NOTE 2)
EXISTING GRADE, TYP
1 1
1 1
1 15
3 1
130
1 ~15 1
~10
1 2
HABITAT SLOPE ~68' TO 93'
1 2
SWALE
(N) FENCE, TYP
(E) OH POWER
STA 0+55 EL UNK
A
-
TYPICAL SECTION - RIDGES/HIGH & WIDE
PROFILE SCALE: 1" = 10' H
1" = 5' V
ELEVATION
STATION
-2
0 5
10 15
20 25
-2
0 5
10 15
20 25
0+00 0+50 1+00 1+50 2+00 2+11
EMBARCADERO ROAD
12'
BERM
30'
TREATMENT AREA
8'
TRAIL
EL 11.5'
EL
9.5'
EL 9'
CONFORM TO
(E) TIDAL
CHANNEL
OVER EXCAVATE & PLACE 1'
LAYER OF FINE NATIVE MATERIAL
APPROX. (E) EDGE
OF MARSH @ EL 8'
EL 13'
2' THICK
SAND FILTER (NOTE 3)BERM KEYWAY
EXISTING GRADE, TYP
HORIZONTAL LEVEE
DESIGN GRADE, TYP
TOP OF BANK
(BEYOND)
BASE SWALE/
DEPRESSION
1 1
1 1
FINE MATERIAL (NOTE 4)
1' THICK SUBSURFACE
TREATMENT LAYER, TYP (NOTE 2)
1 15
3 1
1 20
1 15
1 15
1 2
HABITAT SLOPE ~68' TO 93'
SWALE
EFFLUENT LINE
SEE MECHANICAL PLANS
(N) FENCE, TYP
(E) OH POWER
STA 0+53 EL UNK
B
-
TYPICAL SECTION - SWALES & DEPRESSIONS
PROFILE SCALE: 1" = 10' H
1" = 5' V
1. SEGREGATE FINE AND COARSE MATERIAL ENCOUNTERED DURING EXCAVATION OF SITE TO SUBGRADE. DURING FILL OPERATIONS, PLACE COARSE MATERIAL ON THE RIDGES AND FINE MATERIALS IN THE SWALES.
2. SUBSURFACE TREATMENT LAYER COMPRISED OF A BLEND OF DRAIN ROCK AND COMPOSTED WOOD CHIPS.
3. SAND FILTER COMPRISED OF A BLEND OF SAND AND WOOD CHIPS.
4. COARSE AND FINE MATERIAL INCLUDES A BLEND OF NATIVE MATERIAL WITH COMPOSTED WOOD FINES.
5. FUTURE FLOOD CONTROL LEVEE MAY OR MAY NOT BE CONSTRUCTED, BUT THIS LAYOUT PLANS FOR ITS POTENTIAL SPACE SHOULD IT BE CONSTRUCTED.
6. ALL ELEVATIONS ARE ON NORTH AMERICAN VERTICAL DATUM 1988 (NAVD88).
NOTES
SEE FIGURE 5
HARBOR ROAD
HARBOR ROAD
DWG: P:\01 CAD\18xxxx\D20181306.00 - Palo Alto Horizontal Levee\09 CAD\PDF\2022-02-05_ConstructionPhasing\FigureBox_8.5x11Portrait.dwg USER: Marisa Landicho PLOT DATE: 2/18/2022 2:53:49 PM Figure 5Distribution DetailPalo Alto Horizontal Levee Pilot Project . D201801306 1A
- SECTION
DISTRIBUTION CONNECTION AND TREATMENT ZONE MATERIAL
SCALE: 1" = 2'
DISTRIBUTION
LATERAL, TYP
QUICK4 EQUALIZER 24 LOW
PROFILE INFILTRATOR, OR
APPROVED EQUAL
~0.5' SOIL CAP
FILTER FABRIC 1.5'± SOIL WITH
COMPOSTED
WOOD FINES
1.0' TREATMENT LAYER
DRAIN ROCK & COMPOSTED WOOD CHIPS
FILTER FABRIC
0.5' SAND AND WOOD CHIPS
~4.5' (VARIES)
NEW TRAIL
EFFLUENT SUPPLY LINE
SEE MECHANICAL PLANS
DISTRIBUTION BOX
SEE MECHANICAL PLANS
SCALE
0 FEET
1"=2'
2 1 2 4