1300 Clay Street, Suite 1000 | Oakland, California 94612 | www.terraphase.com File: CO-SanLeandro-AdaptationPlanMapping-18Sept24
September 18, 2024
Sheila Marquises
Public Works Director
City of San Leandro
San Leandro, California
sent via email to [email protected]
Subject: Change Order Request to Provide Additional Mapping Services, Collect Critical Asset Data, Evaluate Groundwater Elevation Data, Develop Community Outreach Materials, and Collaborate with Regional Stakeholders for the Shoreline Sea Level Rise Adaptation Plan, San Leandro, California
Dear Ms. Marquises:
Terraphase Engineering Inc. (Terraphase) is submi�ng this change order for addi�onal services to support the Shoreline Sea Level Rise Adapta�on Plan for San Leandro, California (Site), on behalf of the City of San Leandro (City; Client). The previously authorized scope of work and budget were presented in Terraphase’s proposal dated April 14, 2023, and as outlined in Schedule A of the Consul�ng Agreement between Terraphase and the City. This change order request was developed based on the discussion between Terraphase and the City during a mee�ng on December 6, 2023, regarding the mapping products prepared under the original scope of work, and addi�onal mee�ngs and email communica�on with the City. It is our understanding that the City would like to understand the poten�al impact to City assets from projected surface water inunda�on in years 2050 and 2100 using Mean Higher High Water (MHHW) and King Tide datums, as well as the influence of sea-level rise (SLR) on surface water inunda�on and groundwater rise/emergence for year 2070. The addi�onal mapping also includes mapping assets that were not iden�fied during the exis�ng scope of work. In addi�on, it is our understanding the City would like Terraphase to collect survey data for cri�cal assets where data may be lacking, conduct an evalua�on of groundwater eleva�on data to beter understand and fine tune es�mates of SLR-induced groundwater rise and emergence, develop outreach materials and messaging for use in Community Workshops that will be conducted by the City, and to conduct mee�ngs to collaborate with neighboring Operable Landscape Units (OLUs) to support adapta�on planning.
Since the previously authorized scope of work was issued, the California Sea Level Rise Science Task Force (CSLRTF) from the Ocean Protec�on Council (OPC) has released updated SLR guidance (CSLRTF 2024)1 that provides updated SLR projec�ons consistent with the best available science (Sweet et al. 1 California Sea Level Rise Guidance: 2024 Science and Policy Update. 2024. California Sea Level Rise Science Task Force, California Ocean Protec�on Council, California Ocean Science Trust.
September 18, 2024
Public Works Director
City of San Leandro
Change Order Request to Provide Additional Mapping Services, Collect Critical Asset Data, Evaluate Groundwater Elevation Data, Develop Community Outreach Materials, and Collaborate with Regional Stakeholders for the Shoreline Sea Level Rise Adaptation Plan
2022)2. The updated projec�ons for the high-risk scenario, which is the recommended scenario for SLR planning in California, are slightly lower than the previous projec�ons as follows:
Table 1 Comparison of OPC Projections
Year Former Projection
(feet)
Updated Projection
(feet)
2050 1.9 1.2
2070 3.5 3.0
2100 6.9 6.6
For consistency with the OPC guidance and to align with local and regional shoreline adapta�on efforts throughout the Bay Area, the proposed scope of work herein assumes use of the updated projec�ons for the addi�onal mapping products. Based on communica�on with the City, the exis�ng maps of surface water inunda�on and groundwater rise/emergence for years 2050 and 2100 will not be revised to incorporate the updated projec�ons.
A detailed cost es�mate for the revised scope of work is atached (Table 1).
Revised Scope of Work
The revised scope of work is presented as Tasks 1 through 6 below.
Task 1: Mapping Mean Higher High Water and SLR, Years 2050 and 2100 This task includes prepara�on of surface water inunda�on maps using a datum of Mean Higher High Water (MHHW) plus the SLR magnitudes for years 2050 and 2100 (1.2 and 6.6 feet, respec�vely). The MHHW datum will be established using the San Leandro Marina CA �dal gauge sta�on #9414688. These maps will be constructed using the same four map views of the City established for the exis�ng mapping products. The deliverables include 4 maps for year 2050 and 4 maps for year 2100, referred to as Daily Surface Water Inunda�on, as follows:
1. Daily Surface Water Inundation, 2050, Oyster Bay
2 Sweet, W.V., B.D. Hamlington, R.E. Kopp, C.P. Weaver, P.L. Barnard, D. Bekaert, W. Brooks, M. Craghan, G. Dusek, T.
Frederikse, G. Garner, A.S. Genz, J.P. Kras�ng, E. Larour, D. Marcy, J.J. Marra, J. Obeysekera, M. Osler, M. Pendleton, D.
Roman, L. Schmied, W. Veatch, K.D. White, and C. Zuzak, 2022: Global and Regional Sea Level Rise Scenarios for the United States: Updated Mean Projec�ons and Extreme Water Level Probabili�es Along U.S. Coastlines. NOAA Technical Report NOS 01. Na�onal Oceanic and Atmospheric Administra�on, Na�onal Ocean Service, Silver Spring, MD, 111 pp. htps://oceanservice.noaa.gov/hazards/sealevelrise/noaa-nos-techrpt01-global-regional-SLR-scenariosUS.pdf September 18, 2024
Public Works Director,City of San Leandro
Change Order Request to Provide Additional Mapping Services, Collect Critical Asset Data, Evaluate Groundwater Elevation Data, Develop Community Outreach Materials, and Collaborate with Regional Stakeholders for the Shoreline Sea Level Rise Adaptation Plan
2. Daily Surface Water Inundation, 2050, Mulford Gardens
3. Daily Surface Water Inundation, 2050, Marina Faire
4. Daily Surface Water Inundation, 2050, Heron Bay
5. Daily Surface Water Inundation, 2100, Oyster Bay
6. Daily Surface Water Inundation, 2100, Mulford Gardens
7. Daily Surface Water Inundation, 2100, Marina Faire
8. Daily Surface Water Inundation, 2100, Heron Bay
This task includes one mee�ng between Terraphase and the Client to present the mapping products.
The cost for this task is $5,659.
Task 2: Mapping King Tide and SLR, Years 2050 and 2100
This task includes prepara�on of surface water inunda�on maps using a datum of Highest Astronomical Tide (HAT) (also referred to as a King Tide) plus the SLR magnitudes for years 2050 and 2100 (1.2 and 6.6 feet, respec�vely). The HAT datum will be established using the San Leandro Marina CA �dal gauge sta�on #9414688. These maps will be constructed using the same four map views of the City established for the exis�ng mapping products. The deliverables include 4 maps for year 2050 and 4 maps for year 2100, referred to as King Tide Surface Water Inunda�on, as follows:
1. King Tide Surface Water Inundation, 2050, Oyster Bay
2. King Tide Surface Water Inundation, 2050, Mulford Gardens
3. King Tide Surface Water Inundation, 2050, Marina Faire
4. King Tide Surface Water Inundation, 2050, Heron Bay
5. King Tide Surface Water Inundation, 2100, Oyster Bay
6. King Tide Surface Water Inundation, 2100, Mulford Gardens
7. King Tide Surface Water Inundation, 2100, Marina Faire
8. King Tide Surface Water Inundation, 2100, Heron Bay
This task includes one mee�ng between Terraphase and the Client to present the mapping products.
The cost for this task is $5,659.
Task 3: Mapping Surface Water Inundation and Groundwater Rise, Year 2070 This task includes prepara�on of a comprehensive set of surface water inunda�on and groundwater rise and emergence maps for SLR at year 2070 (3.0 feet). The 2070 surface water inunda�on maps will be developed using the Base Flood Eleva�on (BFE) datum, consistent with the 2050 and 2100 maps prepared for the exis�ng scope of work; in addi�on, surface water inunda�on maps will be prepared using MHHW and the HAT (King Tide) datums for year 2070 as described for Tasks 1 and 2 above.
Groundwater rise and emergence maps for year 2070 will be developed using the Pathways Climate Ins�tute LLC (Pathways) and the San Francisco Estuary Ins�tute (SFEI) Shallow Groundwater Response to September 18, 2024
Public Works Director
City of San Leandro
Change Order Request to Provide Additional Mapping Services, Collect Critical Asset Data, Evaluate Groundwater Elevation Data, Develop Community Outreach Materials, and Collaborate with Regional Stakeholders for the Shoreline Sea Level Rise Adaptation Plan
Sea-Level Rise study, consistent with the exis�ng scope of work. The Pathways/SFEI data set that maps 36-inches (3 feet) of SLR rela�ve to their modeled baseline/current condi�ons will be used.
All maps will be constructed using the same four map views of the City established for the exis�ng mapping products. The deliverables include 16 maps iden�fied as follows:
1. Base Flood Elevation + SLR in 2070, Oyster Bay
2. Base Flood Elevation + SLR in 2070, Mulford Gardens
3. Base Flood Elevation + SLR in 2070, Marina Faire
4. Base Flood Elevation + SLR in 2070, Heron Bay
5. Daily Surface Water Inundation, 2070, Oyster Bay
6. Daily Surface Water Inundation, 2070, Mulford Gardens
7. Daily Surface Water Inundation, 2070, Marina Faire
8. Daily Surface Water Inundation, 2070, Heron Bay
9. King Tide Surface Water Inundation, 2070, Oyster Bay
10. King Tide Surface Water Inundation, 2070, Mulford Gardens
11. King Tide Surface Water Inundation, 2070, Marina Faire
12. King Tide Surface Water Inundation, 2070, Heron Bay
13. Depth to Groundwater, 2070, Oyster Bay
14. Depth to Groundwater, 2070, Mulford Gardens
15. Depth to Groundwater, 2070, Marina Faire
16. Depth to Groundwater, 2070, Heron Bay
This task includes one mee�ng between Terraphase and the Client to present the mapping products.
The cost for this task is $11,318.
Task 4: Collect Location and Elevation Data for Critical Assets This task includes collec�on of loca�on and eleva�on data for cri�cal assets that may not be adequately characterized with exis�ng data. Terraphase will collect the data with the Arrow Gold RTK GNSS Receiver3, a Global Posi�oning System (GPS) unit that uses rea-�me kine�c data from a global naviga�on satellite system. The horizontal accuracy of this unit is approximately one foot; for the ver�cal accuracy, the unit is within three feet.
This task also includes incorpora�ng the asset GPS data into the Geographic Informa�on Systems (GIS) database and mapping the assets on the exis�ng and proposed flood maps. This task includes labor and direct costs associated with electronic field data collec�on and travelling to the asset loca�ons. It is assumed up to ten assets will require measurements.
3 Arrow Gold Real-Time Kinetic Global Navigation Satellite System; Arrow Gold® RTK GNSS Receiver - Eos (eosgnss.com) September 18, 2024
Public Works Director,City of San Leandro
Change Order Request to Provide Additional Mapping Services, Collect Critical Asset Data, Evaluate Groundwater Elevation Data, Develop Community Outreach Materials, and Collaborate with Regional Stakeholders for the Shoreline Sea Level Rise Adaptation Plan
This task includes one mee�ng between Terraphase and the Client to iden�fy the assets requiring a survey.
The cost for this task is $14,076.
Task 5: Evaluate Available Groundwater Elevation Data
This task includes Terraphase review of groundwater monitoring program reports and groundwater modeling efforts in the East Bay that may provide informa�on that can be used to develop more realis�c depic�ons of how the groundwater response to SLR dissipates with distance from the shoreline.
Addi�onally, Terraphase will obtain and review available groundwater level data within and in the vicinity of the City of San Leandro and compare that informa�on to the baseline condi�ons (referred to as “current condi�ons”) used by the San Francisco Estuary Ins�tute (SFEI) to map groundwater rise and emergence. Terraphase will evaluate uncertainty associated with the known limita�ons and errors that exist with the SFEI baseline condi�ons and assess how that has influenced the groundwater rise and emergence mapping products for this project. The informa�on obtained from the data review and analysis of groundwater condi�ons will be used to beter define current groundwater levels and groundwater level trends due to seasonal clima�c condi�ons and �dal influence. This evalua�on will be used to refine conclusions regarding groundwater rise and emergence for the San Leandro study area.
This task includes prepara�on of a dra� technical memorandum and a final technical memorandum that incorporates one round of compiled comments from the City Stakeholder group. The memorandum will include a synopsis of the data and informa�on obtained from the reports and modeling efforts, will provide our analysis of current and future groundwater level trends, and an evalua�on of how SLRinduced groundwater rise may dissipate with distance from the shoreline.
The cost for this task is $24,370.
Task 6: Map Additional Assets
This task includes mapping assets iden�fied during the interviews conducted for the Background Report as listed on the asset inventory table emailed to the City on January 24, 2024. The task budget also includes an allowance to map up to 10 addi�onal assets iden�fied by the local Sogorea Te' Land Trust, which have not yet been provided to the City.
This task includes two mee�ngs between Terraphase and the Client to ensure all assets have been iden�fied. It is assumed that a�er the second mee�ng, the Client will provide a final list of assets for the mapping. This task also includes �me to obtain the data and informa�on to map the addi�onal assets to all exis�ng and proposed addi�onal mapping products.
The cost for this task is $8,172.
September 18, 2024
Public Works Director
City of San Leandro
Change Order Request to Provide Additional Mapping Services, Collect Critical Asset Data, Evaluate Groundwater Elevation Data, Develop Community Outreach Materials, and Collaborate with Regional Stakeholders for the Shoreline Sea Level Rise Adaptation Plan
Task 7: Develop Outreach Materials and Messaging
This task includes prepara�on of presenta�on materials and messaging to support community workshops and mee�ngs that focus on local and regional adapta�on strategies to mi�gate SLR-induced flooding. The messaging will include caveats regarding uncertain�es associated with the SLR projec�ons and the available surface water and groundwater data sets. The materials will include the goals and plans outlined in the San Franciso Bay Conserva�on and Development Commission (BCDC) One Bay Vision for regional adapta�on projects and other applicable neighboring and/or regional projects.
This task includes four mee�ngs between Terraphase and the Client to select the mapping products and develop the messaging. It is an�cipated the maps will provide context for the Community regarding daily inunda�on versus extreme weather events.
This task also includes Terraphase prepara�on for and atendance at three mee�ngs:
• One meeting with agencies the City is collaborating with. • One public workshop or community meeting.
• One City Council meeting.
This task also includes development of ques�ons and/or prompts to be used by the City during Community Workshops #1 and #2, and one agency work session to solicit input to develop the Shoreline Master Plan Concept and Dra� Master Plan. This work will be performed by Raimi + Associates (R+A), the Master Plan subconsultant for this project. In addi�on, this task includes produc�on of a one-page factsheet that will help explain the Plan, including the key adapta�on goals, policies, and strategies to the community. The factsheet will be translated into Spanish and can be distributed throughout the City of San Leandro to engage all residents. City staff will support the transla�on of the factsheet into addi�onal locally relevant languages.
The cost for this task is $30,466.
Task 8: Collaboration with Neighboring Operable Landscape Units This task includes preparing for and par�cipa�ng in mee�ngs between Terraphase, the City, neighboring OLUs (San Leandro and Alameda Creek), and applicable organiza�ons, including but not limited to:
• San Francisco Estuary Institute
• Bay Conservation and Development Commission
• San Leandro Bay/Oakland/Alameda Estuary Adaptation Group • East Bay Dischargers Authority
• Hayward Area Shoreline Planning Agency
The purpose of these mee�ngs is to ensure adapta�on plans priori�zed by the City are consistent with and done in collabora�on with neighboring OLUs. This task also includes other coordina�on or collabora�on tasks associated with adapta�on planning as determined by the City. It is assumed the September 18, 2024
Public Works Director,City of San Leandro
Change Order Request to Provide Additional Mapping Services, Collect Critical Asset Data, Evaluate Groundwater Elevation Data, Develop Community Outreach Materials, and Collaborate with Regional Stakeholders for the Shoreline Sea Level Rise Adaptation Plan
mee�ngs and other coordina�on/collabora�on tasks will be conducted consistent with the project �meline.
The cost for this task is $18,014.
Task 9: Project Management and Meetings
This task includes project management tasks including scope and budget review and tracking, invoicing, internal communica�on, and Client communica�on.
This task also includes R+A atendance at the public hearing to adopt the Master Plan.
The cost for this task is $16,052.
Cost Estimate
The total estimated costs are as follows:
Task Description Cost
1 Map MHHW + SLR, 2050 and 2100 $5,659
2 Map King Tide + SLR, 2050 and 2100 $5,659
3 Comprehensive Set of Maps, 2070 $11,318
4 Collect Location and Elevation Data for Critical Assets $14,382 5 Evaluate Available Groundwater Elevation Data $24,370 6 Map Additional Assets $8,172
7 Develop Outreach Materials and Messaging $30,466
8 Collaboration with Neighboring OLUs $18,014
9 Project Management $16,052
Total: $134,093
The total cost for all proposed additional tasks is $134,093. A detailed cost estimate is attached (Table 1). Terraphase proposes to complete this work on a time-and-materials basis. Terraphase will not exceed this authorization without prior written approval of the client.
September 18, 2024
Public Works Director
City of San Leandro
Change Order Request to Provide Additional Mapping Services, Collect Critical Asset Data, Evaluate Groundwater Elevation Data, Develop Community Outreach Materials, and Collaborate with Regional Stakeholders for the Shoreline Sea Level Rise Adaptation Plan
Schedule
Terraphase will start the proposed work upon approval to proceed. It is our understanding that the work will require approximately 11 months to complete.
Closing
We are grateful for the opportunity to offer our services on this important project. If you have any questions or comments regarding this submittal, please contact me at 617-947-3070 or by email at [email protected].
Sincerely,
for Terraphase Engineering Inc.
Tracy Roth, PG Lucas W. Paz, PhD, CPESC, QSD
Principal Hydrogeologist Principal Hydrologist
Attachments: Table 1 – Time-and-Materials Cost Estimate Acceptance of Proposal
The cost, specifications, and conditions outlined herein are satisfactory and are hereby accepted.
Terraphase is authorized to proceed with the work, as specified.
This proposal is hereby accepted by a duly authorized representative of the Client to whom it is addressed:
Signature: Date:
Printed Name:
Title:
Table 1 - Time and Materials Cost Estimate
Client: City of San Leandro
Qty Cost Qty Cost Qty Cost Qty Cost Qty Cost Qty Cost Qty Cost Qty Cost Qty Cost Qty Cost Senior Principal Hour 297.00 $ 10% 267.30 $ - $ - $ - $ - $ 4 1,069 $ - $ - $ - $ - $ 4 1,069 $ Principal Hour 278.00 $ 10% 250.20 $ 6 1,501 $ 6 1,501 $ 12 3,002 $ 20 5,004 $ 60 15,012 $ 10 2,502 $ 54 13,511 $ 72 18,014 $ 35 8,757 $ 275 68,805 $ Senior Associate Hour 259.00 $ 10% 233.10 $ - $ - $ - $ - $ - $ - $ - $ - $ - $ 0 - $ Associate Hour 240.00 $ 10% 216.00 $ - $ - $ - $ - $ - $ - $ - $ - $ - $ 0 - $ Senior Project Hour 225.00 $ 10% 202.50 $ - $ - $ - $ - $ - $ - $ - $ - $ - $ 0 - $ Project Hour 210.00 $ 10% 189.00 $ 22 4,158 $ 22 4,158 $ 44 8,316 $ 48 9,072 $ 40 7,560 $ 30 5,670 $ 28 5,292 $ - $ - $ 234 44,226 $ Senior Staff 2 Hour 194.00 $ 10% 174.60 $ - $ - $ - $ - $ - $ - $ - $ - $ - $ 0 - $ Senior Staff 1 Hour 177.00 $ 10% 159.30 $ - $ - $ - $ - $ - $ - $ - $ - $ - $ 0 - $ Staff 2 Hour 158.00 $ 10% 142.20 $ - $ - $ - $ - $ - $ - $ - $ - $ 16 2,275 $ 16 2,275 $ Senior Editor/ Senior Project Coordinator Hour 155.00 $ 10% 139.50 $ - $ - $ - $ - $ - $ - $ - $ - $ - $ 0 - $ Senior Technician Hour 145.00 $ 10% 130.50 $ - $ - $ - $ - $ - $ - $ - $ - $ - $ 0 - $ Staff 1 Hour 137.00 $ 10% 123.30 $ - $ - $ - $ - $ - $ - $ - $ - $ - $ 0 - $ Editor 2/Project Coordinator 2/Accountant 2 Hour 135.00 $ 10% 121.50 $ - $ - $ - $ - $ 6 729 $ - $ 6 729 $ - $ 8 972 $ 20 2,430 $ Technician 3 Hour 125.00 $ 10% 112.50 $ - $ - $ - $ - $ - $ - $ - $ - $ - $ 0 - $ Editor 1/Project Coordinator 1/Accountant 1 Hour 115.00 $ 10% 103.50 $ - $ - $ - $ - $ - $ - $ - $ - $ - $ 0 - $ Technician 2 Hour 106.00 $ 10% 95.40 $ - $ - $ - $ - $ - $ - $ - $ - $ - $ 0 - $ Technician 1 Hour 88.00 $ 10% 79.20 $ - $ - $ - $ - $ - $ - $ - $ - $ - $ 0 - $ Total Terraphase Labor $ 5,659 5,659 $ 11,318 $ 14,076 $ 24,370 $ 8,172 $ 19,532 $ 18,014 $ 12,004 $ 118,805 $ Raimi + Associates (expenses) Total 13,620.00 $ 13,620.00 $ - $ - $ - $ - $ - $ - $ 0.7298 9,940 $ - $ 0.2702 3,680 $ 1 13,620 $ 0 Total - $ - $ - $ - $ - $ - $ - $ - $ - $ - $ - $ 0 - $ Total Subcontractor Costs $ - - $ - $ - $ - $ - $ 9,940 $ - $ 3,680 $ 13,620 $ Total Other Direct Costs $ - - $ - $ - $ - $ - $ - $ - $ - $ - $ Direct Cost Handling 10% 10.0% - $ - $ - $ - $ - $ - $ 994 $ - $ 368 $ 1,362 $ Total Direct Costs $ - - $ - $ - $ - $ - $ 10,934 $ - $ 4,048 $ 14,982 $ Truck/Vehicle (day) Day 184.00 $ 184.00 $ - $ - $ - $ - $ - $ - $ - $ - $ - $ 0 - $ IPad and Electronic Field Data (day) Day 35.00 $ 35.00 $ - $ - $ - $ 5 175 $ - $ - $ - $ - $ - $ 5 175 $ Daily Consumables (includes gloves, ziplock bags and trash bags) Each 21.00 $ 21.00 $ - $ - $ - $ - $ - $ - $ - $ - $ - $ 0 - $ Field Health and Safety and Decon Supplies (daily fee) Day 30.00 $ 30.00 $ - $ - $ - $ - $ - $ - $ - $ - $ - $ 0 - $ Total Terraphase Equipment/Supplies (ERS) $ - - $ - $ 175 $ - $ - $ - $ - $ - $ 175 $ Mileage mile 0.655 $ 0.655 $ - $ - $ - $ 200 131.00 $ - $ - $ - $ - $ - $ 200 131.00 $ Total Travel Costs $ - - $ - $ 131.00 $ - $ - $ - $ - $ - $ 131.00 $ Total Estimated Project Unit Costs 5,659 $ 5,659 $ 11,318 $ 14,382 $ 24,370 $ 8,172 $ 30,466 $ 18,014 $ 16,052 $ 134,093 $ Task 2: Map King
Tide + SLR 2050,
2100
Task 3: Set of
Maps for 2070 TOTALS
Task 1: Map
MHHW + SLR
2050, 2100
Task 4: Collect
Location and
Elevation Data for
Critical Assets
Task 5: Evaluate
Available
Groundwater
Elevation Data
Task 6: Map
Additional Assets
Task 7: Outreach
Materials and
Messaging
Task 8:
Collaboration
with Neighboring
OLUs
Task 9: Project
Management and
Meetings
Travel Costs
Labor
Direct Costs
Subcontractor
Other Direct Costs
Terraphase Equipment/Supplies (ERS)
Category Units
2023
Standard
Rate
Discount Rate
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