Fort Bragg City Council
December 8, 2025

Water Distribution
System Master Plan
City of Fort Bragg
November 21, 2025
Water Distribution System Master Plan
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Contents
Executive Summary ........................................................................................................................................

Background ......................................................................................................................................... x Key Master Plan Components ............................................................................................................ x Capital Improvement Plan.........................................................................................................xi Capital Plan Funding...............................................................................................................xiii Environmental Compliance .....................................................................................................xiii Hydraulic Model Development ................................................................................................xiii Geotechnical, Environmental, and Climate Risk and Resilience ............................................xiv CHAPTER 1 Introduction................................................................................................................... 1

1.1 Master Plan Purpose & Goals................................................................................................... 1

1.2 The 1986 Master Plan............................................................................................................... 1

1.3 Water Distribution System......................................................................................................... 2

1.4 Water Supply............................................................................................................................. 2

1.5 Report Organization .................................................................................................................. 4 CHAPTER 2 System Mapping........................................................................................................... 5

2.1 Introduction................................................................................................................................ 5

2.2 GIS Conversion Approach......................................................................................................... 5

2.3 GIS Updates.............................................................................................................................. 5

2.4 Continued Maintenance ............................................................................................................ 6

2.5 Recommended Next Steps ....................................................................................................... 8 CHAPTER 3 Current & Projected Water Demand ............................................................................ 9

3.1 Existing Land Use ..................................................................................................................... 9

3.2 Historical Demands ................................................................................................................. 11

3.3 Water Duty Factors ................................................................................................................. 15

3.4 Future Land Use...................................................................................................................... 17

3.5 Potential Future Development Plans....................................................................................... 19

3.5.1 Georgia Pacific Mill Site ............................................................................................. 19

3.5.2 Future Annexation Areas ........................................................................................... 21

3.6 Demand Projections................................................................................................................ 22

3.6.1 Near-Term Demand Projections ................................................................................ 22

3.6.2 Buildout ...................................................................................................................... 24

3.6.3 Water Demand Projections Summary........................................................................ 27

3.7 Peaking Factors ...................................................................................................................... 28 CHAPTER 4 Hydraulic Model Development ................................................................................... 31

4.1 Software Selection .................................................................................................................. 31

4.2 GIS Integration ........................................................................................................................ 31

4.3 Model Input Data..................................................................................................................... 33

4.3.1 Water Treatment Plant ............................................................................................... 33

4.3.2 Storage Tanks ............................................................................................................ 33

4.3.3 Pump Stations ............................................................................................................ 33

4.3.4 Pressure Reducing Valves......................................................................................... 34

4.3.5 Water Demand Loading ............................................................................................. 34

4.4 Model Validation...................................................................................................................... 35 Water Distribution System Master Plan
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4.4.1 Steady State Validation.............................................................................................. 37

4.4.2 EPS Validation ........................................................................................................... 37

4.5 Scenario and Model Use......................................................................................................... 43

4.5.1 Field Surveying/Potholing .......................................................................................... 44

4.5.2 Hydrant Flow Tests .................................................................................................... 44 CHAPTER 5 Geotechnical, Environmental, and Climate Risks & Resilience................................. 45

5.1.1 Seismic Hazards ........................................................................................................ 46

5.1.2 Tsunamis.................................................................................................................... 48

5.1.3 Soil Corrosiveness ..................................................................................................... 49

5.2 Environmental Risk ................................................................................................................. 49

5.2.1 Flooding...................................................................................................................... 49

5.2.2 Fire ............................................................................................................................. 50

5.2.3 Extreme Weather Events ........................................................................................... 50

5.3 Climate Change Impact........................................................................................................... 51

5.4 Environmental Practices.......................................................................................................... 51

5.4.1 Water Efficiency ......................................................................................................... 51

5.4.2 Conservation .............................................................................................................. 53

5.4.3 Local Watershed Protection ....................................................................................... 55 CHAPTER 6 Water System Capital Improvement Program ........................................................... 56

6.1 Introduction.............................................................................................................................. 56

6.2 Ten-Year Capital Plan Overview............................................................................................. 56

6.3 Preliminary Engineering Reports ............................................................................................ 59

6.4 Planning Criteria...................................................................................................................... 59

6.4.1 Distribution System .................................................................................................... 59

6.4.2 Pump Station Criteria ................................................................................................. 60

6.4.3 Storage Criteria .......................................................................................................... 61

6.5 Existing System Capacity Analysis ......................................................................................... 62

6.6 Near-Term System Capacity Analysis .................................................................................... 68

6.7 Build-Out System Capacity Analysis....................................................................................... 68

6.8 System Renewal ..................................................................................................................... 72

6.8.1 Renewal Strategy....................................................................................................... 72

6.8.2 Pipe Condition Assessment ....................................................................................... 73

6.9 Risk Assessment..................................................................................................................... 74

6.10 Unit Costs................................................................................................................................ 75

6.10.1 Pipeline Unit Costs..................................................................................................... 76

6.10.2 Valve Unit Costs......................................................................................................... 77

6.10.3 Tank Unit Costs.......................................................................................................... 77

6.11 Other Capital Projects ............................................................................................................. 77

6.11.1 Capital Plan Updates.................................................................................................. 78

6.11.2 Sampling of Asbestos Pipe ........................................................................................ 78

6.11.3 CMMS Needs Analysis............................................................................................... 78

6.11.4 CMMS Acquisition and Implementation ..................................................................... 78 CHAPTER 7 Funding Opportunities................................................................................................ 79

7.1 Overview ................................................................................................................................. 79

7.2 Water Infrastructure Finance and Innovation Act (WIFIA) ...................................................... 80

7.3 U.S. Department of Housing and Urban Development Community Development Block Grants............................................................................................................................ 81 Water Distribution System Master Plan
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7.4 Economic Development Administration Public Works and Economic Adjustment Assistance Programs .............................................................................................................. 82

7.5 U.S. Department of Agriculture Water and Waste Disposal Loans and Grant Program ........ 82

7.6 Congressional Earmarks......................................................................................................... 83

7.7 State Revolving Funds ............................................................................................................ 83

7.8 Funding Recommendations .................................................................................................... 86 CHAPTER 8 CEQA Compliance ..................................................................................................... 89

8.1 Levels of Documentation under CEQA ................................................................................... 89

8.1.1 Exemptions................................................................................................................. 89

8.1.2 Initial Study................................................................................................................. 90

8.1.3 Environmental Impact Reports................................................................................... 90

8.2 Level of Effort for Environmental Compliance: Fort Bragg’s Water Enterprise CIP................ 92

8.2.1 Expected Notice of Exemptions (NOEs) for City CEQA Compliance ........................ 92

8.2.2 Environmentally Clearing Individual Projects............................................................. 94

8.2.3 Program Environmental Impact Report(s).................................................................. 96

8.2.4 Master Environmental Impact Report......................................................................... 96 CHAPTER 9 Asset Management .................................................................................................... 97

9.1 What is Asset Management? .................................................................................................. 97

9.2 Why is it Important for the City? .............................................................................................. 98

9.3 Asset Management Practices at the City ................................................................................ 99

9.3.1 Maintenance............................................................................................................... 99

9.3.2 Capital Planning ....................................................................................................... 100

9.4 Asset Management Improvement Recommendations .......................................................... 101

9.4.1 Maintenance Recommendations.............................................................................. 101

9.4.2 Capital Planning Recommendations........................................................................ 102

9.4.3 Technology Recommendations................................................................................ 102 CHAPTER 10 Conclusion & Summary of Recommendations ........................................................ 105 CHAPTER 11 References ............................................................................................................... 107 Water Distribution System Master Plan
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Tables
Table 1 – 10 Year Capital Improvement Plan...............................................................................................xi Table 2 – ADD and MDD Water Demand Projections for Existing, Near-Term, and Buildout ...................xiv Table 3 – Metered Water Consumption Data Based on Land Use Types.................................................. 15 Table 4 – Water Duty Factors for Different Land Use Types...................................................................... 16 Table 5 – Projected Water Demands for Near-Term Development Plans.................................................. 24 Table 6 – Projected Water Demands for GP Mill Site at Buildout............................................................... 26 Table 7 – Projected Water Demands for Undeveloped City Lots at Buildout............................................. 26 Table 8 – Projected Water Demands for Annexation Areas at Buildout..................................................... 27 Table 9 – Projected Water Demands Summary for Existing, Near-Term and Buildout Based on Various Land Use Categories ........................................................................................................ 27 Table 10 – ADD and MDD Water Demand Projections for Existing, Near-Term, and Buildout ................. 28 Table 11 – Maximum Day and Minimum Day Peaking Factors with respect to ADD for 2013 - 2022 ............................................................................................................................................... 29 Table 12 – Hourly Water Production Data for the Maximum Day in the Year 2022 ................................... 29 Table 13 – Selected Peaking Factors with respect to ADD........................................................................ 30 Table 14 – GIS Water System Facilities provided by City .......................................................................... 31 Table 15 – Storage Tank Modeling Data and Information.......................................................................... 33 Table 16 – Steady State Static and Residual Pressure Validation............................................................. 37 Table 17 – Ten-Year Capital Improvement Plan ........................................................................................ 57 Table 18 – Fire Flow Requirements............................................................................................................ 60 Table 19 – Storage Requirement for Existing, Near Term, and Buildout Scenarios .................................. 62 Table 20 – CIP Projects For Existing System............................................................................................. 63 Table 21 – CIP Projects For Buildout System............................................................................................. 69 Table 22 – Summary of AC Pipe Testing Results ...................................................................................... 74 Table 23 - Pipeline Unit costs ..................................................................................................................... 77 Table 24 - Valve Unit Costs ........................................................................................................................ 77 Table 25 – Interest Rates Effective April 1, 2025 ....................................................................................... 82 Table 26 – DWSRF Interest Rates ............................................................................................................. 84 Table 27 – DWSRF Disadvantaged Community Citeria ............................................................................. 84 Table 28 – DWSRF Principal Forgiveness Criteria..................................................................................... 85 Table 29 – DWSRF Schedule..................................................................................................................... 85 Table 30 – Potential Funding and Project Eligibility Matrix......................................................................... 87 Table 31 – Available Funding Summary ..................................................................................................... 87 Figures
Figure 1 – Service Area and System Map .................................................................................................... 2 Figure 2 – City’s Existing Land Use Designations ........................................................................................ 9 Figure 3 – Existing Land Use Distribution................................................................................................... 10 Figure 4 – City’s Existing Residential, Non-Residential, and GP Mill Site Land Use Distribution Consolidated .................................................................................................................................. 11 Figure 5 – City’s Monthly Production and Metered Water Demands from July 2018 to May 2021........... 12 Figure 6 – Historical Average Water Use by Customer Type..................................................................... 13 Figure 7 - Historical Average Consolidated Residential and Non-Residential Water Use ......................... 13 Water Distribution System Master Plan
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Figure 8 – Water Production versus Metered Water Consumption Comparison (note: the metered water data is based on the master service line list)....................................................................... 14 Figure 9 – City’s Buildout Land Use Categories ......................................................................................... 18 Figure 10 – GP Mill Site included in Proposed Rezoning, LCP Amendment 1-24 ..................................... 20 Figure 11 – Annexation Areas .................................................................................................................... 21 Figure 12 – Future Development Lots Within the City’s Existing Service Area.......................................... 23 Figure 13 – Buildout Development Lots...................................................................................................... 25 Figure 14 – Fort Bragg Existing Water Distribution System ....................................................................... 32 Figure 15 – East Fort Bragg Pressure Zone............................................................................................... 34 Figure 16 – Zones and Hydrants for Steady State Validation..................................................................... 36 Figure 17 – Adjusted EPS Validation Diurnal Patterns............................................................................... 38 Figure 18 – January Booster Station Discharge Pressure.......................................................................... 38 Figure 19 – January Booster Station Suction Pressure.............................................................................. 39 Figure 20 – January Pump Station Flow..................................................................................................... 39 Figure 21 – January Distribution Flow ........................................................................................................ 40 Figure 22 – January WTP Tank Level ........................................................................................................ 40 Figure 23 – July Booster Station Discharge Pressure................................................................................ 41 Figure 24 – July Booster Station Suction Pressure .................................................................................... 41 Figure 25 – July Pump Station Flow ........................................................................................................... 42 Figure 26 – July Distribution Flow............................................................................................................... 42 Figure 27 – July WTP Tank Level............................................................................................................... 43 Figure 28 - Quaternary Fault Map............................................................................................................... 47 Figure 29 - Fort Bragg Landslide Susceptibility .......................................................................................... 48 Figure 30 - Tsunami Hazard Area - Shaded............................................................................................... 49 Figure 31 – CIP Projects for Existing System............................................................................................. 65 Figure 32 – CIP Project P-1: Cedar Street Water Line Replacement......................................................... 66 Figure 33 – CIP Project P-2: North Fort Bragg Water Main Extension....................................................... 66 Figure 34 – CIP Project T-1: Tank 1 Replacement..................................................................................... 67 Figure 35 – CIP Project V-1: Oak Street Valves......................................................................................... 67 Figure 36 – CIP Project P-3: Noyo Center Water Line ............................................................................... 68 Figure 37 – CIP Projects for Buildout System............................................................................................. 70 Figure 38 – P-12 for Buildout System......................................................................................................... 71 Figure 39 – P-14 for Buildout System......................................................................................................... 71 Figure 40 - System Performance vs Investment Level ............................................................................... 73 Figure 41 - Asset Management Pyramid .................................................................................................... 98 Water Distribution System Master Plan
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Appendices
Appendix A. CAD to GIS Conversion
Appendix B. Geotechnical Evaluation of Seismic Safety Elements Related to Water Distribution Facilities
Appendix C. Climate Risk And Vulnerability
Appendix D. Software Selection Technical Memorandum
Appendix E. Risk Assessment Factors
Appendix F. 10-Year Capital Plan and Preliminary Engineering Reports Appendix G. AC Pipe Condition Assessment
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ACRONYMS AND ABBREVIATIONS
AACEI Association for Advancement of Cost Engineering International AC Asbestos Cement Pipe
ADD Average Daily Demand
AWWA America Water Works Association
BABA Build America, Buy America Act
CAD Computer-Aided Design
CALFIRE California Department of Forestry and Fire Protection CDBG Community Development Block Grants
CDFW California Department of Fish and Wildlife
CEQA California Environmental Quality Act
CGS California Geological Survey
CIP Capital Improvement Program
City The City of Fort Bragg
CMMS Computerized Maintenance Management System
CNDDB California Natural Diversity Database
CoF Consequence of Failure
DTSC Department of Toxic Substances Control
DAC Disadvantaged Community
DIP Ductile Iron Pipe
DPS Distinct Population Segment
DWSRF Drinking Water State Revolving Funds
EDA Economic Development Administration
EDS Energy Dispersive X-Ray Spectroscopy
EFBPZ East Fort Bragg Pressure Zone
EIR Environmental Impact Report
ENR CCI Engineering News-Record Construction Cost Index EPA Environmental Protection Agency
EPS Extended Period Simulation
ERDIP Earthquake Resistant Ductile Iron Pipe
ESA Endangered Species Act
ESRI Environmental Systems Research Institute
ESU Evolutionarily Significant Unit
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FEMA Federal Emergency Management Agency
FFY Federal Fiscal Year
FME Feature Manipulation Engine
GIS Geographic Information System
GP Georgia Pacific
GPR Green Project Reserve Funding
GPD Gallons per Day
GPM Gallons per Minute
HGL hydraulic gradient line
HUD U.S. Department of Housing and Urban Development
HWY 20 Highway 20
IIJA Infrastructure Investment and Jobs Act
IPaC Information for Planning and Consultation
IS Initial Study
ISO International Organization for Standardization
IUP Intended Use Plan
LoF Likelihood of Failure
LOI Letters of Interest
MDD Maximum Daily Demand
MESA Mendocino Emergency Services Authority
MG Million Gallons
MGD Gillion Gallons per Gay
MHI Median Household Income
MinDD Minimum Day Demand
MND Mitigated Negative Declaration
MWELO Model Water Efficient Landscape Ordinance
NEPA National Environmental Policy Act
NMFS National Marine Fisheries Service
NOE Notice of Exemption
NOFA Notice of Funding Availability
OPC Opinion of Probable Cost
O&M Operations and Maintenance
PE Polyethylene Pipe
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PEIR Program Environmental Impact Report
PHD Peak Hour Demand
PVC Polyvinyl Chloride Pipe
QA/QC Quality Assurance and Quality Control
Saas Software as a Service
SCADA Supervisory Control and Data Acquisition
SDAC Small Disadvantaged Community
SOC Statement of Overriding Considerations
SRF State Revolving Funds
TM Technical Memorandum
UN Utility Network
USDA United States Department of Agriculture
USFWS U.S. Fish and Wildlife Service
USGS United States Geological Survey
UWMP Urban Water Management Plan
WIFIA Water Infrastructure Finance and Innovation Act
WDMP Water Distribution Master Plan
WTP Water Treatment Plant
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EXECUTIVE SUMMARY
Background
The water distribution system includes 41 miles of pipeline, four storage tanks, one pump station, and one pressure zone. The oldest facilities were constructed in the 1960s and are approximately 65 years old or older, while newer sections are estimated to be 20 years old or newer. The City’s largest water main (20-inches in diameter) delivers treated water from the 2.2 million gallons per day (MGD) capacity, Fort Bragg Public Works Water Treatment Plant (WTP), and the City’s four aboveground storage tanks to an 18-inch-diameter trunk main in Sherwood Road/Oak Street and is then distributed to customers from a network of pipe ranging from four to 16 inches in diameter composed of primarily asbestos cement pipe (AC), but also some Polyvinyl Chloride Pipe (PVC) or other material.

The City’s water distribution infrastructure currently operates successfully with minimal breakages or service interruptions. However, the system is aging, and many factors like population, land use, and climate will change over time. The City anticipates a need to plan for overall system renewal, and investment in resilience and expansion. This 2025 update to the Water Distribution Master Plan (WDMP) will develop and document a transparent, data-driven, and repeatable capital planning process. The WDMP will identify and prioritize capital projects to promote water distribution system resilience, with adequate water facilities to meet current and future demand.

Key planning factors include:
• Evaluating hydraulic pressure, valve isolation, and looping dead ends. • Re-zoning and development of the City’s industrial areas. • Identifying strategies to improve system resilience in response to anticipating seismic, climate, and other environmental threats.

Key Master Plan Components
The development of this capital planning strategy is built on multiple actions, including:
• CHAPTER 2 – System Mapping - Development of GIS feature sets to support hydraulic modeling, risk analysis, and current and future capital planning • CHAPTER 3 – Current & Projected Water Demand - Current and future demand analysis • CHAPTER 4 – Hydraulic Model Development - Hydraulic model of the system • CHAPTER 5 - Geotechnical, Environmental, and Climate Risks & Resilience - Geotechnical, environmental, and climate risk and resilience assessment • CHAPTER 6 - Water System Capital Improvement Program - CIP plan including a pipeline replacement strategy
• CHAPTER 7 - Funding Opportunities - Analysis of potential funding opportunities Water Distribution System Master Plan
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• CHAPTER 8 - CEQA Compliance - CEQA compliance strategy • CHAPTER 9 – Asset Management - Asset management strategy and recommendations for implementation
Capital Improvement Plan
A more detailed version of Table 1 is provided in CHAPTER 6, showing the 10-year capital improvement plan for the water distribution system. Projects included represent priority capacity, operational, and asset renewal improvements needed to meet existing and future demands, facilitate system operations, and keep the current system performing at expected levels of service.

Table 1 – 10 Year Capital Improvement Plan
Priority
Ranking
CIP
ID Project Name
Total
Pipe
Footage
(FT)
Time
Frame
(years)
Risk
Score Category Escalated Project Cost
1 PS-1 Pump Station
Upsize - < 5 - Capacity or Fire Flow Deficiency $ 8,141,000 2 V-1 Oak Street Valves 930 < 5 1.746 Operational
Improvements $ 93,000
3 P-1
Cedar Street
Water Line
Replacement
4,248 < 5 1.646 Capacity or Fire
Flow Deficiency $ 3,357,000
4 T-1 Tank 1 Upgrade - < 5 0.988 Asset Renewal $ 8,955,000 5 P-2
North Fort Bragg
Water Main
Extension
2,144 < 5 0.98 Capacity or Fire
Flow Deficiency $ 1,384,000
6 PL-1 System RenewalPipe Replacement 5,000 < 5 - Asset Renewal $ 2,830,000 7 O-1 Opportunistic Pipe
Sampling - < 5 - Other $ 69,000
8 O-2 CIP Update - < 5 - Other $ 110,000
9 O-3 CMMS Needs
Analysis - < 5 - Other $ 39,000
Next 5 Year Sub-Total $ 24,978,000
10 P-7
East Laurel Street
Water Main
Replacement
539 5 to 10 2.194 Capacity or Fire
Flow Deficiency $ 354,000
11 P-3 Noyo Center
Water Line 4,018 5 to 10 2.018 Capacity or Fire Flow Deficiency $ 2,985,000 12 P-6
North Main Street
Water Main
Replacement
5,429 5 to 10 2.014 Capacity or Fire
Flow Deficiency $ 4,016,000
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Priority
Ranking
CIP
ID Project Name
Total
Pipe
Footage
(FT)
Time
Frame
(years)
Risk
Score Category Escalated Project Cost
13 P-13
East Alder Street
Water Main
Replacement
717 5 to 10 1.784 Capacity or Fire
Flow Deficiency $ 470,000
14 P-10
Chief Celeri Dr
Water Main
Replacement
1,362 5 to 10 1.622 Capacity or Fire
Flow Deficiency $ 951,000
15 P-4
Noyo Point Road
Water Main
Replacement
651 5 to 10 1.416 Capacity or Fire
Flow Deficiency $ 455,000
16 P-8 Maple Street
Water Main Loop 313 5 to 10 1.34 Capacity or Fire Flow Deficiency $ 206,000 17 P-5 East Elm Street
Water Main Loop 194 5 to 10 1.33 Capacity or Fire Flow Deficiency $ 145,000 18 P-9
East Chestnut
Street Water Main
Replacement
472 5 to 10 1.182 Capacity or Fire
Flow Deficiency $ 330,000
19 P-11
Spruce Street
Water Main
Replacement
1,330 5 to 10 1.156 Capacity or Fire
Flow Deficiency $ 873,000
20 PL-2 System RenewalPipe Replacement 5,000 5 to 10 - Asset Renewal $ 3,280,000 21 O-4 Opportunistic Pipe
Sampling - 5 to 10 - Other $ 80,000
22 O-5 CMMS Acquisition
& Implementation - 5 to 10 - Other $ 191,000
23 O-6 CIP Update - 5 to 10 - Other $ 127,000
5-10 Year Sub-Total $ 14,463,000
Total $ 39,441,000
Capacity & Fire flow Deficiency related capital projects were identified by evaluating current water demands, near-term water demand projections (over the next 10 years), and expected demands at buildout that includes development of the GP Mills site, five additional undeveloped lots within the City, APN: 01821029, APN: 01809002, APN: 01809016, APN: 01811303, and APN: 01811301 (See Section 3.6.1 and Figure 12), and the future annexation areas (See Figure 13).

Operational improvements are recommended to maintain or increase the City’s ability to efficiently manage the system. These projects are designed to enable the City to perform regular maintenance and repairs on the system while minimizing the impact on customers and the community Asset renewal projects include infrastructure replacement and rehabilitation of existing infrastructure to keep the current system operating as expected. These projects are focused on aging infrastructure and infrastructure that is in poor condition. An annual replacement rate of 1% Water Distribution System Master Plan
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has been established to be able to replace the entire system in the next 100 years (which is consistent with current industry standards).

Other capital projects include planned condition assessment efforts, and other studies to continue to evaluate environmental, geotechnical, and climate change risks and resilience opportunities.

Condition assessments will be used to plan and prioritize upcoming capital projects (such as pipeline replacements) and the environmental studies will help the City anticipate changes in environmental factors and adjust capital plans to address these changes in the future.

Capital Plan Funding
Chapter 7, Funding Opportunities, provides a summary of some of the grants and funding options from state and federal sources that may be considered for funding projects. Each funding program has specific requirements surrounding permits and project timelines. Each program’s process, timeline, and requirements should be reviewed within the context of the City’s overall goals, financial situation, project timelines, and debt policies.

It is important to note that funding levels and eligibility requirements are prone to yearly changes.

This Master Plan report provides initial funding guidance, but updated funding availability and program requirements should be reviewed before developing an application. Long-term, water rate increases may be needed to recover revenue for projects that do not closely align with grant priorities.

Environmental Compliance
The California Environmental Quality Act (CEQA) was passed in 1970 and was intended to:

1. Inform governmental decision makers and the public about potential, significant environmental effects of proposed activities.

2. Identify the ways that environmental damage can be avoided or significantly reduced.

3. Prevent significant, avoidable damage to the environment by requiring changes in projects through the use of alternatives or mitigation measures when the governmental agency finds the changes to be feasible.

4. Disclose to the public the reasons why a governmental agency approved the project in the manner the agency chose if significant environmental effects are involved.

CHAPTER 8 - CEQA Compliance outlines the recommended environmental review requirements for the projects in the capital plan.

Hydraulic Model Development
The table below can be found in CHAPTER 3 - Current & Projected Water Demand and summarizes the existing, near-term and buildout water demand projections for the City based on average daily demand (ADD) and maximum daily demand (MDD). See CHAPTER 3 for an explanation of how these projections were developed.

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Table 2 – ADD and MDD Water Demand Projections for Existing, Near-Term, and Buildout Description
Residential Nonresidential
Water
Loss
(mgd) (2)
Total
ADD
(mgd)
Total
MDD
(mgd) (3)
ADD (mgd) ADD (mgd)
Existing Usage (1) 0.428 0.156 0.11 0.58 1.01
Existing + Near Term Usage 0.440 0.165 0.11 0.61 1.05
Existing + Near Term + Buildout
Usage 0.717 0.641 0.24 1.36 2.35
(1) GP Mill site area not included in the existing and near-term projections since it will only have water demand during buildout.
(2) Water loss calculated assuming that water loss remains the same as 2021 average (i.e., 18%). (3) MDD water demand projection calculated based on the selected MDD:ADD peaking factor of 1.73.

Geotechnical, Environmental, and Climate Risk and
Resilience
The City’s infrastructure faces more challenges than just meeting fire flow and aging. The distribution system also faces geotechnical, environmental, and climate risks.

Geotechnical risks are related to the topography and geology of a location. The City is located on a seismically active, uplifted coastal terrace and faces key geotechnical risks such as:
• Seismic Risk – although there are no fault lines crossing the City’s service area, differential movement, especially at bridge crossings, may pose risks to the distribution system.

Mitigation strategies may include use of articulating joints or earthquake resistant ductile iron pipe (ERDIP) for highly critical infrastructure.
• Densification – Significant settlement due to soil spreading or groundwater fluctuation could damage the system.
• Landslides & Bluff Erosion – Differential settlement or pipe lengthening due to landslides pose a risk to the distribution system.
• Soil Corrosivity – Terrace deposits are acidic (corrosive) and become more so towards the coast.

Environmental Risks are risks stemming from natural hazards or contamination that can directly impact or require specific infrastructure. Key environmental risks include:
• Flooding/Extreme Weather Events - The City is susceptible to flooding and severe winter storms.
• Fire – Significant fires have occurred in Northern California in the last few years, and the City’s fire hydrant system is critical infrastructure for public safety • Chemically Impacted Sites – Several chemically impacted sites are located within the City of Fort Bragg. Many of these sites are identified as having been remediated to meet standards set forward by regulatory agencies. It should be noted that there may be residual chemically impacted soils that may require special testing and handling to determine material Water Distribution System Master Plan
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reuse or disposal. The Department of Toxic Substances Control (DTSC) GeoTracker website should be referenced during future system upgrades or rehabilitation projects.

Climate Risks are risks driven by long-term changes in climate patterns that may increase the frequency or severity of environmental risks. Key climate change impacts include:
• Hotter Temperatures – Hotter weather adds demand and stress to the water system and can exacerbate wildfire threat to infrastructure. Storage tanks may be vulnerable to wildfire. • Variability in Precipitation – Extreme weather like drought can threaten water availability and more frequent/more intense weather events may increase landslide risk and erosion. • Sea-Level Rise – Sea-level rise can increase risk of landslides and erosion and may also result in higher salinity within rivers.

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CHAPTER 1 INTRODUCTION

1.1 Master Plan Purpose & Goals
This 2025 update to the Water Distribution Master Plan (WDMP) develops and documents a transparent, data-driven, and repeatable capital planning process to provide the City of Fort Bragg (City) with a master plan and 10-year capital improvement plan that identifies and prioritizes improvements and other planning actions for the water distribution system. While there currently are not many issues with the water distribution system, the City anticipates that more focus and resources will be needed in the near term as the system continues to age. The WDMP will help the City identify and prioritize these needs before they become emergencies. Projects that are defined from these efforts will be used for the basis of annual capital planning in the coming years. The WDMP will identify and prioritize capital projects to promote water distribution system resilience, with adequate water facilities to meet current and future demand. In the development of the WDMP, the City weighed available budget with many factors, including aging infrastructure, technological advances, community growth, and seismic, environmental, and climate risk.

Key planning factors include:
• Evaluating hydraulic pressure, valve isolation, and looping dead ends. • Re-zoning and development of the City’s industrial areas. • Identifying strategies to improve system resilience in response to seismic, climate, and other environmental threats.
• Evaluation of existing infrastructure and planned renewal/replacement The master plan provides defensible justification, supporting data, a transparent process, and assesses impacts to the City if the projects are not completed. This will provide the City with a balanced view to compare these needed water distribution projects with other, more visible civil projects to support budget approval.

1.2 The 1986 Master Plan
The City’s previous master plan was finalized in April 1986 and was based on 1980 General Plan data that projected development through the year 2000. The purpose of the study and master plan was to evaluate several aspects of the water supply and distribution system, including present and future water supply sources; water treatment plant components; bypassing Newman Reservoir; physical improvement of existing sources; and computer simulation of the existing and future distribution systems using the University of Kentucky’s “Computer Analysis of Flow in Pipe Networks”. Many of the recommendations from the 1986 plan have been implemented.

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1.3 Water Distribution System
It is important to understand the boundaries of
what is addressed in the WDMP. The WDMP
draws its boundary downstream from the outlet of
the WTP and assesses the current state of and
primary threats to the use and integrity of the
treated water distribution system, which includes
41 miles of pipe, four storage tanks, one pump
station, and one pressure zone (Figure 1).

The oldest facilities were constructed in the
1960s and are approximately 65 years old or
older, while newer sections are estimated to be
20 years old or newer. A 20-inch-diameter water
main delivers treated water from the 2.2 million
gallons per day (MGD) capacity, Fort Bragg
Public Works Water Treatment Plant (WTP), and
the City’s above-ground storage tanks to an 18-
inch-diameter trunk main in Sherwood Road/Oak
Street. This 18-inch-diameter main reduces to a
10-inch-diameter main at Wall Street. There are
12-inch-diameter mains in Harold Street and
Redwood Avenue north of Oak Street and in the Southern section of the distribution system along Highway 20 near the Highway 20 Storage Tank.

The East Fort Bragg Pressure Zone (EFBPZ) is
located in the eastern portion of the City service area and is shown in Error! Reference source not found.. The EFBPZ includes elevations that are too high to be served via the gravity system and is served by a pump station located on Willow Street. The majority of the City’s water distribution system is composed of 6-inch- and 8-inch-diameter mains. Treated water storage tanks range in size from 1.47 MG to 1.62 MG.

1.4 Water Supply
Capital planning for water resources, including sources, reservoirs, and transmission lines upstream of the WTP, are not within the scope of the WDMP. However, understanding the context and components of the City’s water supply is important. Therefore, an overview of the City’s water supply and ongoing measures to address water resource needs are provided below.

The City receives its raw water from three main sources:
• Newman Gulch
• Waterfall Gulch
• Noyo River
Since 1994, most of the City’s water supply has been provided by diversions from the Noyo River.

The Noyo River experiences high salinity caused by tidal influence during late summer. The City has Figure 1 – Service Area and System Map
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a small desalination plant that has been intermittently operational since 2021 to treat the brackish water before it is processed through the City’s WTP prior to distribution. Newman Gulch and Waterfall Gulch are spring-fed tributaries to the Noyo River and Hare Creek, respectively, that divert water via gravity flow to the WTP. During drought years, the City relies on diversions from Waterfall Gulch to make up for shortages in its other supplies. This source of water has historically been less impacted by drought than the City’s other water supply sources. However, between 2015 and 2021, the City experienced a steady decline in available flow at Waterfall Gulch, making it a less reliable water supply source.

The Urban Water Management Planning Act of 1983 requires water suppliers that serve more than 3,000 connections or produce over 3,000 acre-feet of treated water annually to prepare a formal Urban Water Management Plan (UWMP). An UWMP evaluates and demonstrates the reliability of a supplier’s water resources. The City of Fort Bragg does not currently meet these thresholds and is therefore not required to maintain a formal plan.

In the absence of a formal UWMP, the City has implemented several measures to evaluate the adequacy and reliability of its raw water supply and storage. Examples of these efforts are outlined below.
• Water-Supply Model (2015) - In 2015, the City partnered with Lawrence & Associates to develop a Water-Supply Model which helps Fort Bragg evaluate water-supply scenarios by simulating how changes in demand, river flow, and new sources (like reservoirs or groundwater) affect availability. This model relies on historical hydrologic data from 1973 through 2015 and actual demand records and predicts future supply reliability under varying conditions, including drought.
• Summers Lane Reservoir (2016) - In 2016 the City constructed the 45 acre-ft Summers Lane Reservoir adjacent to Newman Gluch. The Summers Lane Reservoir is filled via the Waterfall Gulch source and serves as a hydraulic break for the pipeline. • Water Resource Capital Planning (2025) - The City is also undertaking studies to assess capital water resource options to improve the resiliency of the City's raw water supply. In January 2025, the City developed a preliminary engineering report outlining the plans for three 45-acre-foot reservoirs which would be connected to the existing raw water transmission system. The reservoirs would be filled with the City’s existing water rights via the existing transmission system, which currently feeds into the Fort Bragg Water Treatment Plant (FBWTP). And are planned to be built on parcels currently owned by the City.

The City will continue to monitor and evaluate the reliability of its raw water sources. While the climate change impact assessment included in this WDMP addresses some key factors affecting raw water supply, the other sections in this document remain focused on components of the treated water distribution system, as defined in Section 1.3 above.

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1.5 Report Organization
The following sections are provided in the WDMP:
• CHAPTER 1 Introduction – Describes the WDMP purpose and goals, provides an overview of the water distribution system, and describes the report organization. • CHAPTER 2 System Mapping – Discusses the development of the geographic information system (GIS) data needed to support hydraulic modeling and other master planning analyses.
• CHAPTER 3 Current & Projected Water Demand – Summarizes the development of current and future water demands needed to assess system capacity. • CHAPTER 4 Hydraulic Model Development – Presents the development of the hydraulic model and discusses the modeling results.
• CHAPTER 5 Geotechnical, Environmental, and Climate Risks & Resilience – Analyzes the current and future environmental risks associated with the water distribution system. • CHAPTER 6 Water System Capital Improvement Program – Presents the recommended capital projects and the 10-year capital improvement plan (CIP). Water System Capital Improvement Program
• CHAPTER 7 Funding Opportunities – Discusses potential funding opportunities and potential environmental compliance needs to implement the CIP.
• CHAPTER 8 CEQA Compliance – Presents the recommended level of effort to achieve environmental compliance.
• CHAPTER 9 Asset Management – Provides recommendations for the City to implement an asset management strategy to improve system reliability and optimize the City’s investment in infrastructure.
• CHAPTER 10 Conclusion & Summary of Recommendations – Summarizes the recommendations, conclusions, and findings of the master planning effort.

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CHAPTER 2 SYSTEM MAPPING

2.1 Introduction
The first step in the master planning effort was the evaluation of the City’s mapping resources (Computer-Aided Design (CAD) and Geographic Information System (GIS)) and their suitability for master plan hydraulic modeling analysis. This evaluation determined that the GIS required significant improvements in order to provide the necessary up-to-date water distribution infrastructure information needed to support the majority of the master planning analysis. Various systems of record for the water distribution system, sewer collection system, and stormwater collection system were combined and integrated into one standardized GIS Utility Network dataset.

The dataset was then reviewed and verified by the City to identify final corrections and accurate improvements. The standardized dataset was used as the foundation for the hydraulic model outlined in this master plan, provided the basis for many of the master planning analyses, and was the source for many of the maps and figures provided. Continued updates to the dataset will be incorporated in future asset management planning.

This section describes the process for development of the GIS datasets and provides recommendations for keeping the data accurate and up to date.

2.2 GIS Conversion Approach
One of the primary sources of data for the GIS was the existing CAD files maintained by the City.

These data files were converted into a geodatabase (GIS-compatible data file). The staging file geodatabase was created using a prebuilt data schema for water, sewer and storm utilities based on the industry standard for water utility networks (Environmental Systems Research Institute (ESRI) Solutions Utility Network). Applicable descriptions of how the GIS data was used are provided in the chapters below.

HDR used feature manipulation engine (FME) software to perform the conversion and introduce additional geometry improvement processes. Geometry processes were included to enable use in the hydraulic model and to allow accurate tracing in the utility network. The migrated data has been added to a Utilities ArcGIS Pro Project (aprx) file that is incorporated with the ESRI Solutions Utility Network map templates. Additional information and technical details are provided in Appendix A.

2.3 GIS Updates
Once the geodatabase was created, additional updates were performed to accurately portray current infrastructure conditions. Several updates to the GIS were made based on cross-checking the GIS with other data sources and additional review with City staff. These updates were necessary for the development of the hydraulic model and included as-built project information that was not present in the original CAD source file. Projects incorporated into the GIS include • Pudding Creek water main relocation project, 2022. This update included abandoning the old Pudding Creek water line crossing and adding the new water main crossing on the Highway 1 Pudding Creek bridge.

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• Water treatment plant upgrades, 2024. This update included revisions to the water main piping, valves, and meters during upgrades to Fort Bragg WTP. • Danco project updates, 2020. This update added the main service line additions and connection for the Plateau Housing Project.

2.4 Continued Maintenance
To ensure proper maintenance of the GIS system, a standard workflow should be established that helps the City keep the infrastructure data accurate and up to date. At the time of this Master Plan, the City’s authoritative spatial data is managed in AutoCAD and is supported by several maintainers variously proficient in AutoCAD and ArcGIS Desktop. Upon delivery of the GIS Utility Network Geodatabase, the GIS should become the authoritative source of spatial information for the Sewer, Water, and Storm Drain networks. HDR recommends the City identify personnel to maintain this data source. These maintainers and any users of the Utility Network dataset should be trained in the necessary elements of ArcGIS Pro and Utility Network data model use, maintenance, and editing.

Recommended training for City staff is provided in the section below. This training may be selfguided through ESRI Online courses or administered by HDR staff through virtual or in-person sessions.

To leverage the work associated with updating the City’s GIS data set, the City should plan to continue maintaining, updating and improving the data to support ongoing decision-making and future capital planning updates. The City should continually update the GIS data as the water distribution infrastructure is improved, replaced, and maintained. This will facilitate its use as the data source for management and analysis activities to support daily capital planning and maintenance decision-making, help to efficiently keep the hydraulic model up to date, facilitate integration with the City’s asset management systems, and provide for future integration with other enterprise systems (e.g. utility billing system).

Three potential options are provided to support the City’s operational needs for infrastructure management:

1. Option 1 - Desktop Only
This strategy would augment the CAD Technician’s existing capabilities, providing the ability to update and utilize the City’s Utility Network in a local file geodatabase, maintain integrated GIS systems, and export pdf production maps.

Benefits – Limited licensing costs, no need for additional staffing.

Limitations – Limited sharing capabilities, manual effort to export data and maps, City staff reliant on one person to get the information products they need.

2. Option 2 - Desktop and ArcGIS Online (AGOL)
This strategy is a hybrid approach between Options 1 and 3. The Desktop GIS file geodatabase would act as the City’s authoritative data source for water utilities but would integrate some data from the ArcGIS Online SaaS Portal. This strategy would allow City staff to access interactive web maps and applications in the office and in the field. A standard procedure would have to be established to publish GIS updates, but there would be less burden on GIS staff to export and produce maps, as City staff could rely on web mapping within the ArcGIS Online system as needed.

Benefits – Additional outreach and specific applications for City staff. Potential for direct Water Distribution System Master Plan
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integration opportunities.

Limitations – Licensing costs for ArcGIS Online, data sync process would still be needed for data updates between local file geodatabase and AGOL data displayed.

3. Option 3 - Desktop and ArcGIS Enterprise
This strategy represents the most robust option and is the most common strategy for utilities and medium sized local governments using ArcGIS Enterprise. This approach provides the greatest benefit for managing and maintaining data without the need to export data or maps but also requires more licensing and potentially more staffing. Users can access data and applications like option 2 but the GIS staff will not need to develop a sync procedure for web maps and applications. An enterprise database has many more capabilities than Desktop or ArcGIS Online, but these benefits need to be weighed against the overhead cost of having dedicated staffing and resources.

Benefits – synced desktop and web data, editing versioning, and integration capabilities.

Limitations – More overhead costs and staffing, additional licensing.

The GIS was populated using FME automation to extract spatial data from the provided CAD sources, primarily ACAD_Utility_September2022.dwg. The data was extracted from the identified CAD layers and parsed into the respective Utility Networks, with the primary goal of creating a data source for hydraulic modeling. The sources used for automated extraction were the layers with the following layer name prefixes:
• “Sewer-“
• “Water-“
• “Storm Drain-“
Network connectivity was established using the same automation processes followed by a manual review and editing. The primary goal of this process was to create a data source for the hydraulic modeling that supports development of the Master Plan. Consequently, not all of the detail of the original CAD sources were captured.

For example, the import processes captured not only feature geometry but also attribute information such as pipe material and diameter from CAD annotation based on proximity to those features. In some cases, the closest CAD annotation to a feature applied to a different feature. These types of inconsistencies were largely identified and corrected during hydraulic modeling, but some minor discrepancies like these may still exist.

Also, not all layers from the source CAD file were imported into (or even applicable to) the Water, Wastewater or Stormwater GIS. For example, the CAD source included many layers from historical city projects, and features in those layers may not have been imported during the automation process. Notably, the layer names prefixed with “Utility-“ contained unstructured information from many projects, but because of their unstructured format, were not amenable to automated conversion. These layers were used as reference to clean up and establish network connectivity, however there may be additional information in those layers that could be included in the GIS.

There is also a large amount of unstructured annotation contained in the CAD file that was not possible to import into GIS using automated processes.

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We recommend the City continue to update and edit the GIS. A systematic review of the GIS features and comparison with the CAD drawings would allow the capture of additional information from the CAD sources for display and analysis in the GIS.

We recommend the City maintain and utilize the GIS data as the primary source for water asset information going forward. This will facilitate its use as the data source for management and analysis activities such as updates to the hydraulic model, integration with the City’s asset management systems, and integration with utility billing systems.

2.5 Recommended Next Steps
The recommended next steps for maintenance of the GIS are:
• Select a GIS use strategy as outlined above.
• Training – Depending on the selected use strategy, training will be required for the CAD/GIS Technician, system users, and system administrators. No matter which strategy is selected, training should include instruction on general ArcGIS Pro use and maintenance, including editing and production workflows as well as specific processes to update the water network. • Computerized maintenance management system (CMMS) Integration – We recommend integration between the GIS and the City’s CMMS for water distribution assets. The City should establish workflows that provide repeatable standardized GIS/CMMS integration processes. Additional discussion is provided in CHAPTER 9.

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CHAPTER 3 CURRENT & PROJECTED

WATER DEMAND

3.1 Existing Land Use
The City occupies approximately 1,770 acres, divided into 17 land use categories as shown in Figure 2. There are some areas within the City’s sphere of influence that do not have a City designated land use category. These areas constitute the City’s near-term annexation areas except for the thin strip shaped area south of Pudding Creek Road. These annexation areas have been taken into consideration in the projection of the City’s near-term water demands. For the water demand analysis, the 17 land use categories were reduced to a total of nine categories (by combining coastal and inland) to improve visualization of the land use data.

Figure 2 – City’s Existing Land Use Designations
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Figure 3 shows the distribution of the nine aggregated land use categories based on percentage of total City area. The largest percent area in the City is occupied by the Georgia Pacific (GP) Mill Site (24% by area) followed by Low Density Residential (22% by area). It is worth noting that the GP Mill site spans an appreciable area in comparison to the residential and non-residential land uses (Figure 4). The City is working with the property owner who intends to develop the area at the GP Mill Site in the future.

Figure 3 – Existing Land Use Distribution
Very High Density
Residential
7% High Density
Residential
4%
Low Density
Residential
22%
Medium Density
Residential
4%
Suburban
Residential
1% Commercial
17%
Industrial
3%
GP Mill Site
24%
others
18%
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Figure 4 – City’s Existing Residential, Non-Residential, and GP Mill Site Land Use Distribution Consolidated
*Note that the land use category, “Other”, is excluded

3.2 Historical Demands
To quantify historical water demands, metered water usage data was obtained from the City spanning from July 2018 to May 2021. The information provided included WTP production, water user location, account number, serial number, meter manufacturer, model number, and meter size.

Figure 5 below shows the total WTP monthly production, metered water demands from July 2018 to May 2021 and the corresponding monthly water losses.

The City maintained an average monthly water production of approximately 22 million gallons (MG).

The peak monthly water production occurred in July 2019, reaching approximately 31 MG, while the lowest production level was recorded in February 2021, totaling approximately 17 MG. The City averaged approximately 23% water loss for the given time frame, with the highest water losses occurring during November 2019. The water losses for the City are above the national target for water losses (about 9-10%). However, average water losses for the City in 2021 (18%) indicate a declining trend in water losses. This declining trend may reflect the successful strategies that the City has taken to mitigate water losses. Potential sources for water losses can be water theft, water leaks, unmetered construction water consumption, or degradation in water meter accuracy.

Residential
35%
Non-Residential
42%
GP Mil Site
23%
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Figure 5 – City’s Monthly Production and Metered Water Demands from July 2018 to May 2021
Percent distribution of metered water use by land use category is shown in Figure 6. The largest metered water use category is Low-Density Residential with an average daily demand (ADD) of 41% (0.25 mgd) of the total ADD, followed by Commercial land use with an ADD of 20% (0.12 mgd) of the total ADD. Figure 7 shows the consolidated ADD into the residential and non-residential user types.

Residential ADD is 70% (about 0.43 mgd) of the total metered water demands, and non-residential ADD is 30% (0.16 mgd) of the total metered water demand. 0%
13%
25%
38%
50%
63%
75%
88%
100%
0 5
10 15
20 25
30 35
40 Jul-18 Jan-19 Jul-19 Jan-20 Jul-20 Jan-21
Volume (MG)
Water Loss (%)
Water Loss (%) Metered Water Consumption (MG) Water Production (MG) Water Distribution System Master Plan
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Figure 6 – Historical Average Water Use by Customer Type Figure 7 - Historical Average Consolidated Residential and Non-Residential Water Use The City provided georeferenced meter points in the form of GIS maps for the year 2017. Since the metered water consumption considered in this analysis is limited to July 2018 to May 2021, the May 2021 metered water consumption data was correlated with the 2017 georeferenced meter points to create a master meters list that is used for calculating water-use duty factors. While there was some loss of meter points and the associated water consumption data during the data correlation process due to changes in the parcel database, the loss of these data points does not materially affect the development of the City’s water use duty factors.

Very High Density
Residential
14%
High Density
Residential
4%
Low Density
Residential
41%
Medium Density
Residential
10%
Suburban
Residential
<1%
Commercial
20%
Industrial
5%
others
6%
Residential
70%
Non-Residential
30%
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This can be better visualized in Figure 8 below, which shows the water production data from the City’s WTP and the metered water production for the master meter points list resulting from the combination of georeferenced meter points data from 2017 and meter points list from May 2021.

Most data loss occurred from July 2018 to December 2019. Therefore, only metered water consumption from January 2020 to May 2021 was considered for further analysis.

Another observation from Figure 8 is that there is an offset between the metered water consumption data and water production data as visible from the mis-aligned peak in July 2020. Potential reasons behind this offset can be delayed measurement of metered water consumption or errors in measuring metered water consumption.

Figure 8 – Water Production Versus Metered Water Consumption Comparison (note: the metered water data is based on the master service line list) 0 5
10 15
20 25
30 35
40 Jul-18 Jan-19 Jul-19 Jan-20 Jul-20 Jan-21
Volume (MG)
Metered Water Consumption (MG) Water Production (MG)
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Table 3 below summarizes the metered water consumption based on various land use types for the City. The City averaged about 0.59 mgd of metered water usage from January 2020 to May 2021.

Table 3 – Metered Water Consumption Data Based on Land Use Types Land Use Type 2020 (gpd) 2021 (gpd) January 2020 – May 2021 Average (gpd)
Very High Density Residential 83,700 93,600 88,700
High Density Residential 28,000 26,900 27,500
Medium Density Residential 237,200 261,300 249,200
Low Density Residential 59,000 62,000 61,000
Suburban Residential 3,120 3,110 3,110
Central Busines District 45,900 54,800 50,300
General Commercial 35,900 43,200 39,600
Neighborhood Commercial 15,910 23,890 19,900
Office Commercial 3,700 4,190 3,940
Highway Visitor Commercial 100 400 300
Heavy Industrial 2,320 2,140 2,230
Light Industrial 10,300 11,800 11,000
Harbor District 0 0 0
Open Space 3,130 4,800 3,960
Parks and Recreation 6,250 4,330 5,290
Public Facilities and Services 200 220 210
Timber Resources Industrial 17,372 26,742 22,057
Total Residential 411,000 447,000 429,000
Total Non-Residential 141,100 176,500 158,800
Total 552,000 624,000 588,000

3.3 Water Duty Factors
Water duty factors are a representation of water use per land use category and can be calculated either in terms of gpd per unit area or gpd per service line. Duty factors are used in conjunction with future land use projections to develop future water demands. Existing land use categories and monthly metered water demands from January 2020 to May 2021 were used to calculate the water duty factors.

Table 4 below shows water duty factors that are calculated based on historical data. The calculated duty factors are used for demand projections. As shown in Table 4, most of the calculated duty factors were recommended for use in the projected water demand analysis. However, two calculated duty factors, High-Density and Medium-Density Residential land use, did not fall within the expected range. Based on typical land-use water consumption relationships, these duty factors typically fall Water Distribution System Master Plan
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between Very High Density Residential and Low Density Residential. Therefore, the high and medium- density duty factors were adjusted to align with the land use based duty factor trends.

There are several possible explanations for the inconsistencies in the calculated duty factors. One is that the land use designations may not accurately represent the current conditions. This is a common land use inconsistency as city planning agencies are not equipped to update and field verify new land use designations triggered by changes in occupancy. Additionally, there is also a possibility of inaccuracies associated with the geocoded assignment of water meters to the correct parcels.

Table 4 – Water Duty Factors for Different Land Use Types Customer Type Residential/ nonresidential
Calculated Duty
Factor
(gpd/ service line)
Calculated
Duty Factor
(gpd/ acre)
Recommended
Duty Factor
(gpd/ service line)
Duty Factor
(gpd/ acre)
Very High Density
Residential Residential 277 684 277 684
High Density
Residential Residential 196 442 257 668
Medium Density
Residential Residential 236 896 236 660
Low Density
Residential Residential 226 655 226 655
Suburban
Residential Residential 115 302 115 302
Central Business
District Non-Residential 305 991 305 991
General Commercial Non-Residential 283 422 283 422
Neighborhood
Commercial Non-Residential 186 336 186 336
Office Commercial Non-Residential 408 316 408 316
Highway Visitor
Commercial Non-Residential 227 212 227 212
Heavy Industrial Non-Residential 158 69 158 69
Light Industrial Non-Residential 227 212 227 212
Harbor District Non-Residential 995 4,672 995 4,672
Open Space Non-Residential 0 0 0 0
Parks and
Recreation Non-Residential 264 44 264 44
Public Facilities and
Services Non-Residential 189 32 189 32
Timber Resources
Industrial Non-Residential 71 0.5 71 1
Average Residential 210 596 210 593
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Customer Type Residential/ nonresidential
Calculated Duty
Factor
(gpd/ service line)
Calculated
Duty Factor
(gpd/ acre)
Recommended
Duty Factor
(gpd/ service line)
Duty Factor
(gpd/ acre)
Average NonResidential 276 609 316 607
Average 257 605 260 604

3.4 Future Land Use
Figure 9 shows the anticipated buildout condition for the City as depicted in the 2013 Inland Land Use, Development, and General Plan. This analysis includes projected demands for the future build out to the entire City sphere of influence, including areas not classified in the current land use categories shown in Figure 2. Most of these areas cover the rural residential areas located in the west and south of the City’s potable water service area. Other areas of potential growth include the Harbor District area in the south along the Noyo River.

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Figure 9 – City’s Buildout Land Use Categories
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3.5 Potential Future Development Plans
This section summarizes known potential future development plans used to project future water distribution system capacity needs.

3.5.1 Georgia Pacific Mill Site
The City is anticipating development at the GP Mill site, which covers about 300 acres (about 17% of the total existing service area). This area is located along the coast towards the western extents of the City. The City aims for a level and intensity of development on the GP Mill Site for commercial, industrial, and residential purposes that align with the existing development of the City. The GP Mill Site was originally slated for an area of about 400 acres. However, the City purchased 100 acres of area for coastal trails, 95 acres of which were purchased in 2010 and the remaining 5 acres in 2015.

The City’s proposed development of the Mill Site is shown in Figure 10. This land use is derived from Proposed Rezoning, LCP Amendment 1-24, that includes the Coastal Trail. and includes the planned Noyo Center development south of the water treatment plant.

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Figure 10 – GP Mill Site included in Proposed Rezoning, LCP Amendment 1-24 Water Distribution System Master Plan
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3.5.2 Future Annexation Areas
The City has a total of 8 annexation areas that are shown in Figure 11. Water demand for these annexation areas has been projected assuming that these areas are developed following the land use categories shown in Figure 9.

Figure 11 – Annexation Areas
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3.6 Demand Projections
To determine future capacity needs for the water distribution system, two scenarios were developed for analysis.
• Near-Term Development – Projected growth over the next 10 years that incorporates undeveloped lots and development plans specified by the City. Based on the growth rate of .5% per year, Mendocino College has been incorporated into the Near-Term Development.

The remaining parcels inside the City’s service area specified by the City have been incorporated into the Build-Out Scenario.
• Build Out – The Build-Out scenario expands on the near-term development scenario and includes the development of the GP Mill Site, five additional undeveloped lots within the City, APN: 01821029, APN: 01809002, APN: 01809016, APN: 01811303, and APN: 01811301 (See Figure 12), and the future annexation areas.

The demand projections for these scenarios are discussed below.

3.6.1 Near-Term Demand Projections
The City commissioned an Impact Fee Nexus Study in 2023, conducted by Lechowicz + Tseng Municipal Consultants. The study projects a future water demand of 1.14 mgd over the next 30 years. It should be noted that this study assumes a 14.4% of population growth within the next 30 years. In comparison, the current study by HDR assumes that the annexation areas grow at a rate of

0.5% (in terms of area) for the next 10 years. Based upon input from City Staff, near-term developments include two undeveloped lots to the south near the Mendocino College Coast Center, and four near-term specific development plans specified by the City. These developments are shown in Figure 12.

The undeveloped lots (APN: 01845036, APN: 01845041) were specified by the City as being developed in the near term. Demands for these lots have been projected assuming that these areas get developed following the land use categories shown in Figure 9. The four specific development plans are listed below:

1. A 69-unit housing project near the intersection of South Street and River Drive. This project was completed in the summer of 2022. However, it has been included in the near-term projections to capture its water demands because it was not operational during the metering activity.

2. An 83 Unit Multi-Family project with 1,000 SF of retail space and 2,450 SF of visitor serving accommodations at 1151 S. Main Street.

3. Grocery Outlet: This property is located near the intersection of South Franklin Street and South Street. It is a 16,157 square-foot, one-story, retail store with a 55-space parking lot.

4. Avalon Hotel: A 65-room inn contained within three separate, three-story buildings for a total area of 43,469 square feet. It consists of a restaurant (660 square feet) with 63 seats and a bar (818 square feet) with 40 seats located in one of the three buildings. Additionally, there is a 3,064 square-foot event center proposed as a separate single-story structure. The total lot area for Avalon Hotel is 3.65 acres.

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Near-term water demand projections for the City are provided in Table 5. The near-term developments add roughly 0.021 mgd of ADD to the City’s existing water demands (excluding water losses).

Figure 12 – Future Development Lots Within the City’s Existing Service Area Water Distribution System Master Plan
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Table 5 – Projected Water Demands for Near-Term Development Plans Description Land Use
Classification
Total Area
(acre)
Duty Factor
(gpd/acre)
Total ADD
(gpd)
Total Water
Loss (gpd) (1)
69-unit housing near
intersection of South
Street and River Drive
Very High Density
Residential 6.5 (2) 676 4,400 800
83 Unit Multi-Family
project with 1,000 SF of
retail space and 2,450 SF
of visitor serving
accommodations at 1151
S. Main Street
Mixed Use 0.34 676 230 50
Grocery Outlet General Commercial 0.37 422 160 30
Avalon Hotel (3) Highway Visitor
Commercial 3.65 196 7,020 1,270
Undeveloped City Lots
High Density
Residential 11.3 668 7,550 1,360
Highway Visitor
Commercial 10.1 196 1,980 360
Public Facilities and
Services 8.0 32 260 50
Grand Total 40.3 21,580 3,890
(1) 2021 average City water loss (18%)
(2) Water demand for 69-unit housing project calculated based on an estimated area of 6.5-acres. (3) The Avalon Hotel is expected to have a total of 65 rooms. Water demand for the Avalon Hotel projected 80 gpcd for the hotel guests and 90% return to the sewer. It is also assumed that the hotel has an average occupancy of 2 guests/unit and is 75% occupied on average.

3.6.2 Buildout
This section describes the water demand projections for buildout which includes GP Mill Site, , five additional undeveloped lots within the City, APN: 01821029, APN: 01809002, APN: 01809016, APN: 01811303, and APN: 01811301 (See Figure 12), and the future annexation areas., Buildout development lots are shown in Figure 13. As shown in the following tables, the ADD for the City is expected to grow by 0.744 mgd by buildout (excluding water losses).

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Figure 13 – Buildout Development Lots
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3.6.2.1 GP Mill Site
Projected demands for the GP Mill Site per land use type are listed in Table 6. Duty factors were applied to each specified land use in the development. The remaining area within the GP Mill Site will remain undeveloped at buildout and thus have no water demand assigned. The GP Mill Site development is expected to add a total of 0.0627 mgd at buildout (excluding water losses).

Table 6 – Projected Water Demands for GP Mill Site at Buildout Land Use Type Total Area
(acre)
Duty Factor
(gpd/acre)
Total ADD
(gpd)
Total Water
Loss (gpd) (1)
Central Business District 2.7 991 2,700 500
General Commercial 33.2 422 14,100 2,600
Heavy Industrial 21.0 69 1,500 300
High Density Residential 39.3 668 26,300 4,800
Highway Visitor Commercial 29.6 196 5,800 1,100
Light Industrial 36.2 196 7,200 1,300
Open Space 32.7 77 2,600 500
Parks and Recreation 65.5 44 2,900 600
Grand Total 260.1 62,700 11,300
(1) 2021 average City water loss (18%)

3.6.2.2 Undeveloped city lots
The City specified a total of five undeveloped lots that will be developed at buildout. These lots are:

APN: 01821029, APN: 01809002, APN: 01809016, APN: 01811303, and APN: 01811301. The City provided a list of undeveloped parcels that were likely to develop in the near term and acreage was selected to correspond to the recommended .5% per year growth rate. This included 5 lots in the Harbor Area near the Mendocino College Coast Center. Demands for these lots have been projected assuming that these areas will be developed following the land use categories shown in Figure 9. Projected water demands are listed in Table 7. The development of these specified lots is expected to add a total of 140 gpd at buildout (excluding water losses).

Table 7 – Projected Water Demands for Undeveloped City Lots at Buildout Land Use Type Total Area
(acre)
Total ADD
(gpd)
Total Water
Loss (gpd) (1)
General Commercial 4.3 1,810 340
High Density Residential 6.1 4,090 750
Low Density Residential 1.9 1,230 230
Very High Density Residential 1.7 1,170 220
Grand Total 14.0 8,300 1,540
(1) 2021 average City water loss (18%)
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3.6.2.3 Annexation Areas
Annexation areas 1 through 8 are expected to be fully developed at buildout. Demands for these lots have been projected assuming that these areas are developed following the land use categories in the City’s General Plan and shown in Figure 9. Existing water use data did not provide duty factors for agricultural and rural residential land use types. These land use types were assigned to have the same duty factor as low-density residential land use. Project water demands are listed in Table 8.

The development of the annexation areas is expected to add a total of 0.681 mgd at buildout (excluding water losses).

Table 8 – Projected Water Demands for Annexation Areas at Buildout Land Use Type Total Area
(acre)
Total ADD
(gpd)
Total Water Loss
(gpd) (1)
Harbor District 93.6 437,720 79,030
Open Space 5.8 0 0
Low Density Residential 357.4 235,310 43,380
Suburban Residential 18.6 5,720 1,130
Very High Density Residential 5.1 3,440 630
Grand Total 480.5 682,190 124,170
(1) 2021 average City water loss (18%)

3.6.3 Water Demand Projections Summary
A summary of water demand projections for the existing system, near-term developments, and buildout based on various land use categories is shown in Table 9. The ADD is expected to increase by 0.766 mgd as compared to the existing water demands by the end of the buildout planning horizon, not accounting for water losses.

Table 9 – Projected Water Demands Summary for Existing, Near-Term and Buildout Based on Various Land Use Categories
Land Use Type
Existing Average
Metered Consumption
(January 2020 – May 2021
Average Period)
gpd
Existing + Near Term
Water Projection
gpd
Existing + Near Term
+ Buildout Water
Projection
gpd
Very High Density Residential 88,200 92,600 97,210
High Density Residential 27,690 35,470 65,850
Medium Density Residential 61,120 61,120 61,120
Low Density Residential 250,710 250,710 487,250
Suburban Residential 3,140 3,140 8,860
Central Business District 50,650 50,650 53,300
General Commercial 39,880 40,040 55,880
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Land Use Type
Existing Average
Metered Consumption
(January 2020 – May 2021
Average Period)
gpd
Existing + Near Term
Water Projection
gpd
Existing + Near Term
+ Buildout Water
Projection
gpd
Neighborhood Commercial 2,010 2,010 2,010
Office Commercial 10,110 10,110 10,110
Highway Visitor Commercial 20,540 29,540 35,350
Heavy Industrial 3,970 3,970 5,430
Light Industrial 310 310 7,430
Harbor District 20,040 20,040 457,760
Open Space 0 0 2,520
Parks and Recreation 3,930 3,930 6,840
Public Facilities and Services 5,330 5,590 5,590
GP Mill Site (1) 230 230 (1) 230 (1)
Total (2) 588,000 610,000 1,364,000
(1) Water demand projections for the GP Mill site distributed to their respective land use categories for the buildout. (2) Water demand projections shown here do not account for water losses through the water distribution network.

Table 10 below summarizes the existing, near-term and buildout water demand projections for the City based on ADD and maximum daily demand (MDD).

Table 10 – ADD and MDD Water Demand Projections for Existing, Near-Term, and Buildout
Description Residential
ADD (mgd)
Nonresidential
ADD (mgd)
Water
Loss
(mgd) (2)
Total
ADD
(mgd)
Total
MDD
(mgd) (3)
Existing Usage (1) 0.428 0.156 0.11 0.58 1.01
Existing + Near Term Usage 0.440 0.165 0.11 0.61 1.05
Existing + Near Term + Buildout
Usage 0.717 0.641 0.24 1.36 2.35
(1) GP Mill site area not included in the existing and near-term projections since it will only have water demand during buildout.
(2) Water loss calculated assuming that water loss remains the same as 2021 average (i.e., 18%). (3) MDD water demand projection calculated based on the selected MDD: ADD peaking factor of 1.73.

3.7 Peaking Factors
2013 – 2022 daily water production data from the water treatment plant was used to calculate the peaking factors, as shown in Table 11. Average peaking factors from 2013 to 2022 were selected for this analysis.

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Table 11 – Maximum Day and Minimum Day Peaking Factors with respect to ADD for 2013 - 2022
Year
Average day water
production
Maximum day
water
production
Minimum day
water
production Maximum day
peaking factor
Minimum day
peaking factor
mgd mgd mgd
2013 0.78 1.23 0.40 1.57 0.52
2014 0.69 1.09 0.39 1.58 0.56
2015 0.68 1.15 0.35 1.71 0.51
2016 0.61 0.96 0.37 1.58 0.61
2017 0.64 1.03 0.28 1.59 0.43
2018 0.72 1.44 0.40 2.01 0.56
2019 0.78 1.55 0.50 1.99 0.64
2020 0.67 1.43 0.23 2.11 0.35
2021 0.61 0.96 0.30 1.57 0.49
2022 0.58 0.89 0.32 1.55 0.56
Average 0.68 1.17 0.35 1.73 0.52
Max 0.78 1.55 0.50 2.11 0.64
Min 0.58 0.89 0.23 1.55 0.35
The City also provided hourly water production data for the day corresponding to the maximum water production (i.e., July 1) in the year 2022. This data and the associated hourly peaking factor is shown in Table 12. A summary of the selected peaking factors is shown in Table 13.

Table 12 – Hourly Water Production Data for the Maximum Day in the Year 2022 Hour
Filtered Effluent Flows
gpm
00:00 137
01:00 136
02:00 135
03:00 134
04:00 133
05:00 132
06:00 132
07:00 562
08:00 1,012
09:00 1,011
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Hour
Filtered Effluent Flows
gpm
10:00 738
11:00 867
12:00 1,005
13:00 1,015
14:00 1,009
15:00 655
16:00 1,002
17:00 838
18:00 1,002
19:00 1,005
20:00 679
21:00 1,001
22:00 1,007
23:00 789
Maximum Hourly Flow 1,015
Average Daily Flow for the year2022 403
Maximum Hour Peaking Factor 2.52
Table 13 – Selected Peaking Factors with respect to ADD Description Maximum Day Minimum Day Maximum Hour
Selected Peaking Factor 1.73 0.52 2.52
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CHAPTER 4 HYDRAULIC MODEL

DEVELOPMENT

4.1 Software Selection
The City’s existing hydraulic model is in WaterGEMS format, from Bentley Systems. The attached Software Selection Technical Memorandum (Appendix D) evaluated commercially available water hydraulic modeling software. The recommendation from that tech memo (TM) was to use InfoWater Pro, from Autodesk as the hydraulic modeling software for this Master Plan.

4.2 GIS Integration
A water system GIS database was developed by converting the City’s existing CAD utility map (ACAD_Utility_September2022.dwg) into an ESRI geodatabase with Utility Network functionality (see CHAPTER 2). The water system facilities contained in the GIS data are listed in Table 14.

Table 14 – GIS Water System Facilities provided by City Water Lines
Water Mains
Service Lines
Water Junctions Fittings
Water Devices
Pump
Fire Hydrants
Valves (System/Service/Flow/Pressure)
Storage (Reservoir/Tanks)
Supply (Well/Treatment Plants)
Water Assemblies Backflow Assemblies
Using InfoWater Pro’s GIS Gateway, the GIS data was imported into the hydraulic model. Model input data for nonlinear facilities (i.e. pump stations and tanks) was obtained from the City and input into the hydraulic model. The hydraulic model provides an additional level of Quality Control and Quality Assurance (QA/QC) on the GIS data. Additional errors identified included network connectivity errors, such as “floating” system valves and pipeline diameter inconsistencies. These errors were rectified in the GIS, and the model was updated accordingly to reflect the updated GIS database.

The City provided a list of normally closed valves to HDR and pressure zone isolation was validated in the hydraulic model.

The final existing water distribution system model is shown in Figure 14.

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Figure 14 – Fort Bragg Existing Water Distribution System Water Distribution System Master Plan
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4.3 Model Input Data
This section describes inputs used in the hydraulic model.

4.3.1 Water Treatment Plant
The Fort Bragg Public Works WTP is located within the City’s Corporation Yard at 31301 Cedar Street. The plant was built in 1958 with a process upgrade in 1986 which made the plant capacity

2.2 MGD. The WTP is currently undergoing an upgrade project to improve efficiency. This upgrade project is set to be completed in spring 2026. The plant was modeled as a boundary node reservoir with a pump station to simulate finished water being pumped into the storage tanks at the same rate as City provided Supervisory Control and Data Acquisition (SCADA) information.

4.3.2 Storage Tanks
The existing water distribution system includes four storage tanks: three tanks at the WTP, and one near the Fire Station on Highway 20 (HWY 20). Modeling data and information for these tanks is included in Table 15. Tank elevation, maximum levels, and diameter were specified by the City.

Table 15 – Storage Tank Modeling Data and Information
Tank Name Model ID Location Elevation
(ft)
Maximum
Level (ft) Diameter (ft)
Storage
Volume
(MG)
Tank 1 STRG-6 WTP 183 39 80 1.47
Tank 2 STRG-7 WTP 183 39 80 1.47
Tank 3 STRG-8 WTP 183 39 84 1.62
HWY 20 Tank STRG-9 HWY 20 183 39 36 0.30

4.3.3 Pump Stations
The Willow St Pump Station is located on Willow Street near the C.V. Starr Community Center and serves the EFBPZ, which is a small, boosted zone generally serving the area north of the Noyo River and Willow Street to Oak Street and East of S. Lincoln Street. Figure 15 shows the pressure zone extents and pump station.

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Figure 15 – East Fort Bragg Pressure Zone

4.3.4 Pressure Reducing Valves
There are no pressure reducing valves in the existing water distribution system.

4.3.5 Water Demand Loading
Existing, near-term, and buildout water demands estimated for the City are described in section 3.6:

Demand Projections. These demands were processed in the GIS in order to load them into the hydraulic model. They were first assigned to point loads in the GIS and then spatially joined to junctions in the water system to determine total demand at each junction. These junction demands were then loaded into the hydraulic model.

4.3.5.4 Existing
Existing water demands were based on water meter data provided by the City. As such, point loads for existing demands were located at each water meter. These point loads were spatially joined to the existing junctions of the distribution system, and the total demand at each junction was loaded into the existing model scenario.

4.3.5.5 Near-Term
Near-term developments all lie within existing city limits and thus can be served by the existing water distribution system. These demands were loaded into the model in the same way as existing demands. Near-term point loads were spatially joined to the existing junctions of the distribution system, and the total demand at each junction was loaded into the near-term model scenario.

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4.3.5.6 Build-Out
Development in the GP Mill Site and annexation areas at buildout lie outside the existing water distribution system. A future hypothetical water system network was developed for the annexation areas and GP Mill Site so that buildout demands for the developments could be loaded into the model. This future system is shown in Figure 37. Point loads were developed for the parcels within the future annexation areas and the GP Mill Site redevelopment, then spatially joined to junctions in the buildout water system. Total demands at each junction were loaded into the buildout model scenario.

4.4 Model Validation
The existing model scenario was validated in both a steady state and extended period simulation (EPS). A steady state validation was performed to compare simulated results to field measurements recorded in the CAD drawing provided by the City. An EPS validation was performed to compare simulated results over a 24-hour period with SCADA data provided by the City.

For this validation, the existing water distribution system was divided into three different zones: the booster station pressure zone, the north distribution pressure zone, and the south distribution pressure zone. Figure 16 shows the zones examined in the steady-state validation.

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Figure 16 – Zones and Hydrants for Steady State Validation Water Distribution System Master Plan
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4.4.1 Steady State Validation
According to America Water Works Association (AWWA) mode validation guidelines, the hydraulic gradient line (HGL) predicted by the model should be within 5 to 10 ft (2.2 to 4.3 psi) of that recorded in the field. HDR model results match static pressures recorded in the field, shown in Table 16.

Table 16 also shows the calculated HGL at each hydrant, using elevation acquired from the United States Geological Survey (USGS) National Map GIS database. HGLs predicted by the model are within the range suggested by AWWA.

Residual pressures recorded in the field are likely erroneous and are omitted from Table 16. For accurate values, residual pressure should be recorded from neighboring hydrants.

Table 16 – Steady State Static and Residual Pressure Validation Hydrant ID Elevation (FT)
Static Pressure (PSI) HGL (FT)
HGL Delta Field
Reading
Model
Result
Field
Reading
Model
Result
FR-HYDRNT-1521 142.0 38 34.2 229.8 220.9 8.8
FR-HYDRNT-1577 133.9 70 67.4 295.6 289.6 6.0
FR-HYDRNT-1587 158.6 65 61.7 308.7 301.1 7.6
FR-HYDRNT-1581 151.2 68 64.9 308.3 301.1 7.2
FR-HYDRNT-1606 160.4 64 60.9 308.2 301.1 7.1
FR-HYDRNT-1383 75.3 64 62.1 223.1 218.7 4.4
FR-HYDRNT-1388 64.6 65 67.2 214.7 219.9 5.1
FR-HYDRNT-1450 118.8 45 43.7 222.7 219.7 3.0
FR-HYDRNT-1438 111.7 50 46.8 227.2 219.7 7.4

4.4.2 EPS Validation
Two EPS validation scenarios were conducted in the model – one comparing results to SCADA data dated January 2022, and another comparing results to SCADA data dated July, 2022. These dates represent a typical minimum and maximum day, respectively. Diurnal patterns were developed for the booster station zone and the combined distribution zone for each date, for a total of four diurnal patterns. These diurnals were adjusted to match field results. Adjusted diurnals are shown in Figure

17. January EPS validation results for the major pump station and facilities within the model are presented in Figure 18, Figure 19, Figure 20, Figure 21, and Figure 22. July validation results are shown in Figure 23, Figure 24, Figure 25, Figure 26, and Figure 27.

Figure 19 and Figure 24 show a 22.5 PSI pressure difference between model results and field observations, with field observations showing a greater head loss than the model indicates. The previous WaterGEMS model predicted the same HGL on the suction side as the InfoWater Pro model. This indicates that the field measurement is potentially inaccurate, which could be attributed to a bad reading on the suction side of the booster pump station. The other validation parameters fall within generally accepted industry standards for planning level validation.

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Figure 17 – Adjusted EPS Validation Diurnal Patterns
Figure 18 – January Booster Station Discharge Pressure

0.0 0.5

1.0 1.5

2.0 2.5

3.0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Factor
Hour
January Booster Zone January Distribution Zone
July Booster Zone July Distribution Zone
55 56
57 58
59 60
61 62
63 64
65 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Pressure (psi)
Hour
Field Result Model Result
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Figure 19 – January Booster Station Suction Pressure
Figure 20 – January Pump Station Flow
0 5
10 15
20 25
30 35
40 45
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Pressure (psi)
Hour
Field Result Model Result
0 20
40 60
80 100
120
140
160
180
200
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Flow (gpm)
Hour
Field Result Model Result
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Figure 21 – January Distribution Flow
Figure 22 – January WTP Tank Level
0 100
200
300
400
500
600
700
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Flow (gpm)
Hour
Field Result Model Result

37.5 37.7

37.9 38.1

38.3 38.5

38.7 38.9

39.1 39.3

39.5 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Level (ft)
Hour
Tank 1 Field Result Tank 2 Field Result Tank 3 Field Result Model Result Water Distribution System Master Plan
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Figure 23 – July Booster Station Discharge Pressure
Figure 24 – July Booster Station Suction Pressure
55 56
57 58
59 60
61 62
63 64
65 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Pressure (psi)
Hour
Field Result Model Result
0 5
10 15
20 25
30 35
40 45
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Pressure (psi)
Hour
Field Result Model Result
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Figure 25 – July Pump Station Flow
Figure 26 – July Distribution Flow
0 50
100
150
200
250
300
350
400
450
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Flow (gpm)
Hour
Field Result Model Result
0 100
200
300
400
500
600
700
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Flow (gpm)
Hour
Field Result Model Result
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Figure 27 – July WTP Tank Level

4.5 Scenario and Model Use
Several scenarios were developed by applying peaking factors to the average day demand (ADD) sets developed.
• A MDD scenario with a peaking factor of 1.73 was used in fire flow analyses to examine pressures and pipes velocities during fire flow conditions for deficiencies. Capital improvement projects were developed to address these deficiencies. • A Peak Hour Demand (PHD) scenario with a peaking factor of 2.52 was used to check velocities and pressures at peak hour conditions for deficiencies. • A Minimum Day Demand (MinDD) scenario with a peaking factor of 0.52 was used to examine water quality during minimum demands.

ADD, MDD, PHD, and MinDD scenarios were developed for the three stages of the water distribution system: existing, near term, and buildout. Improvement scenarios for each stage are developed by addressing the deficiencies identified in each scenario. The City’s updated water system model is used to perform the above hydraulic scenarios and develop the resulting water system CIP.

The hydraulic model provided to the City can be used for an operational analysis and capacity analysis tool. Specifically, the steady state runs are typically used to evaluate fire flow availability and the ability to provide service to future development and used to determine capacity needs. The EPS scenarios are typically used to evaluate operational strategies and the impacts of improvement

36.00 36.50

37.00 37.50

38.00 38.50

39.00 39.50
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Level (ft)
Hour
Tank 1 Field Result Tank 2 Field Result Tank 3 Field Result Model Result Water Distribution System Master Plan
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projects to affect system parameters (i.e. flow and pressure) over an extended period of time (typically 24 – 48 hours).

4.5.1 Field Surveying/Potholing
Through the development of the hydraulic model, calibration, and validation, field surveying and potholing were deemed to be unnecessary to improve the quality of the data and disturbance of pipelines were determined to present a high risk of potential damage.

4.5.2 Hydrant Flow Tests
Hydrant flow rates and pressures were provided for the majority of the hydrants on the City’s utility CAD map and additional hydrant flow testing was not required.

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CHAPTER 5 GEOTECHNICAL,

ENVIRONMENTAL, AND CLIMATE RISKS
& RESILIENCE
Evaluations of geotechnical and environmental risks, and climate change impacts to the water distribution system were conducted as part of the WDMP. Technical Memorandums were developed for each of these topics and are included as Appendix B and Appendix C, respectively. This section discusses the identified risks and recommendations for mitigation.

While most of the risks discussed in this section are long-term threats and do not require capital improvements over the next ten years, the following risks should be noted for more immediate action:

Seismic – Although the City is not in an active fault zone, it is in a seismically active area. Strong shaking can disrupt the soils and damage pipelines and other infrastructure. The City may incorporate mitigation strategies into their design specifications such as articulating joints for joints on rigid structures and using Earthquake Resistant Ductile Iron Pipe (ERDIP) in highly critical, seismically impacted infrastructure.

Unstable Soils – The City includes many steep slopes and bluffs, which typically contain weak and unstable soil, which could damage or destroy water distribution infrastructure. In addition to projectby-project evaluation of these hazards, the City may wish to periodically evaluate trends in repair or other maintenance activities to indicate soil instability.

Soil Corrosiveness – Soils in the City have been classified as acidic and become more acidic toward the ocean, which can shorten the useful life of buried steel and concrete infrastructure. The City may desire to implement a testing and inspection program to monitor the condition of infrastructure and to better understand the impact. Some testing was completed as part of this master plan and is further discussed in Section 6.8.2 Pipe Condition Assessment.

Wildfire – Fort Bragg is surrounded by areas of dense woodlands, which are designated as moderate to very high wildfire risk zones. Drought and climate change can exacerbate this risk. The most vulnerable water supply infrastructure are the treatment plant and storage tanks. In addition, pipelines can be damaged due to high heat. The City may study and/or update the wildfire vulnerability of their infrastructure to implement appropriate mitigation measures.

Drought – Drought is becoming an increasingly common challenge for the City due to climate change. The City is vulnerable to drought due to its reliance on surface water and the compounding impacts of seasonal saltwater intrusion in the Noyo River. The City is already implementing numerous mitigation measures to address this risk, including the completed desalination system, construction of new reservoirs, testing other desalination technologies, and implementing water conservation measures. These are discussed in more detail below.

Many of these risks are incorporated into the risk model used to evaluate and prioritize water infrastructure projects. The risk model is described in Section 6.9 Risk Assessment.

An assessment of the geotechnical and seismic safety elements related to water distribution facilities is fully documented in the report titled Geotechnical Evaluation of Seismic Safety Elements Related Water Distribution System Master Plan
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to Water Distribution Facilities. This report can be found in Appendix B. The following is a summary of the report’s findings.

The City is located on a seismically active, uplifted coastal terrace. The uplifted terrace has created a coastal bluff that ranges from 50 feet tall at Soldier Point to 85 feet tall at Pomo Bluffs State Park.

Surface elevation slopes gently upward towards the east, rising to approximately 400 feet, where the terrace meets the Coastal Range Mountains. Studies have identified that terrace deposits are acidic (corrosive) and become gradually more acidic closer to the ocean.

5.1.1 Seismic Hazards
Although the City is in a seismically active area, it is not within an established Earthquake Fault Zone, and the risk of fault surface rupture is low; however, strong ground shaking can impact the soils in the area. Densification of loose to medium-dense terrace deposits may occur in the river and creek channels or along the coastal bluff. The risk of liquefaction is judged to be moderate in the terraces and high in the river and creek channels and can occur in the event of strong ground shaking. Differential movement both vertically and laterally can damage the distribution pipes, especially at connections to structures like bridges.

The nearest fault zone, the Alquist-Priolo Earthquake Fault Zone, is associated with the San Andreas Fault system and is located approximately 6.5 miles West of the City’s boundary. The Maacama Fault zone is approximately 21 miles to the east of the City; the Mendocino Fracture Zone is approximately 60 miles to the NorthWest (Figure 28). The potentially active, Pacific Star Fault, is located to the NorthEast between the towns of Fort Bragg and Westport. All faults may cause earth shaking activity. The Pacific Star and Pudding Creek Faults were identified in 2006 and are reported as connecting to the San Andreas fault paralleling the Pacific Coast though they are not located within a special fault study zone.

The fault offset hazard in the City is very low. There are no Alquist Priolo Hazards Zones identified within or near the City (www.conservation.ca.gov). The City will be subject to strong ground shaking that could induce densification of loose to medium dense terrace deposits and slope movement within the steeply incised river and creek channels and along the coastal bluff. Loose, saturated cohesionless soils are susceptible to liquefaction, including sediments that have accumulated within and at the mouth of the coastal, river, and creek channels and potentially in eolian (windblown) derived terrace deposits that become saturated due to groundwater. The State of California Office of Emergency Services online MyHazard maps (myhazards.caloes.gov) does not identify Fort Bragg as having a mapped liquefaction zone; however, the risk of liquefaction is judged to be moderate in the terraces and high in the river and creek channels and could occur in the event of strong ground shaking.

The 1977 5.2 magnitude earthquake near Willits is the largest magnitude earthquake in the vicinity of the City, originating approximately 28 miles east of Fort Bragg. The City reported severe losses after the 1906 earthquake due to structural damage and fire. A 7.0 magnitude earthquake offshore Cape Mendocino occurred on December 12, 2024, approximately 90 miles NorthWest of Fort Bragg, with little damage reported in the City as a result. Strong ground shaking is likely for a large earthquake event along the North California Coast region on the Maacama fault zone east of the city, the San Andreas Fault west of the City, and the Mendocino Fracture Zone/Cascadia Thrust Zone off the Pacific Coast near Eureka, California. USGS estimates that there is a 64.92% chance of an earthquake with a magnitude greater than 5 to occur in the next 50 years.

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Source: USGS.maps.arcgis.com/apps
Figure 28 - Quaternary Fault Map
Mitigation strategies may include the use of articulating joints for entering rigid structures and the use of Earthquake Resistant Ductile Iron Pipe (ERDIP). ERDIP is often limited to sites deemed critical to the function of the water system in the event of a major earthquake The American Lifeline Alliance is a public/private alliance between the Federal Emergency Management Agency (FEMA) and the National Institute of Building Sciences. In 2005, they published Seismic Guidelines for Water Pipelines that provide extensive guidance for the design of water pipeline design in the seismic environment. Unstable Soil The presence of unstable soils on steep slopes, bluff retreat, and the presence of weak and/or unstable soils present a hazard to the water distribution system. Geographic trends of pipe breaks or leaks may indicate areas underlain by weaker soils. Figure 29 presents a ranking of the potential deep-seated landslide occurrence-based on rock strength and slope inclination from CGS Map Sheet 58. The darker color red indicates the higher potential risk. Rock strength in Mendocino County is generally ranked as moderate; therefore; the instability is a function of slope inclination ranging from 3 degrees to over 40 degrees, with rocks inclined 15 to 20 degrees or greater having the highest susceptibility (approximately equivalent to 27 percent grade or higher). Therefore, the susceptibility of landslides impacting the City water supply and distribution system or evacuation Water Distribution System Master Plan
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routes directly or from debris flows should be evaluated on a case-by-case basis. It should be noted that climate change may increase the risk of slope instability.

Figure 29 - Fort Bragg Landslide Susceptibility

5.1.2 Tsunamis
Tsunamis could impact coastal areas like Noyo Harbor and upstream areas of Noyo River, Pudding Creek, and Hare Creek. Sea level rise may raise river levels in the Noyo River and Hare Creek to above the 100-year flood level. In combination with sea level rise, a tsunami event could impact all three rivers/creeks and cause additional saltwater intrusion at the existing Noyo River raw water intake.

Tsunamis would impact the coastal areas, the Noyo Harbor and upstream areas of Noyo River Pudding Creek and Hare Creek (Figure 30).The Pacific Institute presents the effect of 55 inches of sea level rise on their Sea Level Rise Map of the Fort Bragg Quadrangle referenced above. The map shows that sea level rise will exceed the 100-year flood level within the Noyo River and Pudding Creek. The occurrence of tsunami(s) combined with sea level rise would impact the areas shown effected by sea level rise within the limits of Pudding Creek, Hare Creek, and the Noyo River including impacting existing raw water intakes along the Noyo River with salt water. The intakes have been impacted in the past with saltwater intrusion from high tides, and beginning in 2021 the City began using a desalination system to treat high salinity raw water from the Noyo River (Water Boards Media Release October 12, 2021).

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Source: cal OES MyHazard
Figure 30 - Tsunami Hazard Area - Shaded

5.1.3 Soil Corrosiveness
Soil reports, identified Fort Bragg’s surface soil as acidic, gradually becoming more acidic towards the ocean. Terrace deposit soils should be considered corrosive to steel and slightly corrosive to concrete. Specific testing and visual inspection of buried structures is recommended to provide a better understanding of corrosive activity to inform the City’s water system management.

5.2 Environmental Risk
Environmental risks related to water distribution facilities are detailed in the report titled Geotechnical Evaluation of Seismic Safety Elements Related to Water Distribution Facilities, prepared by HDR Engineering, Inc. and dated December 12, 2023. This report can be found in Appendix B. A summary of these risks is provided below.

5.2.1 Flooding
Flooding hazard is typically determined for a 100-year flood level using maps developed by the Federal Emergency Management Agency. The most recent FEMA flood maps for the Fort Bragg area were published in 2024 and show larger 100-year flood hazards than what is shown in the City’s 2008 Coastal General Plan. Because the distribution system is largely pressurized. Impact from flooding is primarily related to additional stresses from groundwater fluctuation.

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5.2.2 Fire
The City’s fire hydrant system is critical infrastructure for public safety. Significant fires have occurred in Northern California in the last few years and the ability to protect the City from structure fires and wildfire is important. The fire hydrant system is also critical after a large seismic event.

In 2025, the city adopted Ordinance XXXX-2025 to approve a map as recommended by the California Department of Forestry and Fire Protection, which delineates fire severity zones and local responsibility areas. The City is outside the jurisdiction of CALFIRE and the City itself is zoned as a local responsibility area.

5.2.3 Extreme Weather Events
In February 2023, the United States Department of Agriculture (USDA) declared Mendocino County a Disaster Area due to severe winter storms and flooding. Atmospheric rivers are defined by the National Oceanic and Atmospheric Administration (NOAA) as narrow atmospheric regions transporting water vapor out of the tropics. Atmospheric rivers can vary greatly in size and strength, the average atmospheric river carries an amount of water vapor roughly equal to the average flow of water at the mouth of the Mississippi River. An exceptionally strong atmospheric river can transport up to 15 times that amount. (To compare the amount of water transported by an atmospheric river and that have an equivalent flow as at the mouth of the Mississippi River. Atmospheric river events can have 15 times that amount. The Pineapple Express is a strong atmospheric river which brings moisture from the tropics near Hawaii to the west coast.

Rain events can induce slope instability and rapid slope movement and debris flows. One such event happened to the community of Rio Nido along the Russian River in 1998 and have also been linked to coastal landslides in 1962.

The Mendocino County Office of Emergency Services joint powers organization that includes the County of Mendocino and the incorporated cities within the county, serves as the coordinating agency for mutual aid services provided by fire departments, law enforcement agencies, and emergency medical service providers throughout the county. In addition, MESA reviews and makes recommendations regarding emergency operation plans for public and private institutions where preplanning for emergency procedures is advisable. Coordination of emergency services and planning guidelines is provided for situations including flood, wildland fires, structure fires, explosions, hazardous material spills, severe weather, and earthquakes. Chemically Impacted Sites A review of the DTSC GeoTracker website showed the locations of numerous identified chemically impacted sites that range from small underground storage tanks to large facility clean-up activities.

Many of the sites are identified as having closed files, meaning that the sites have been remediated to meet cleanup goals set forward by regulatory agencies. It should be noted that there may be residual chemically impacted soils at these sites that did not require removal but, should they be excavated, may require special testing and handling to determine material reuse or disposal. The GeoTracker site and associated data should be checked as part future system upgrade or rehabilitation projects to be aware of potential impacted sites.

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5.3 Climate Change Impact
A detailed discussion of climate change impact on the water distribution system is provided in a report titled Climate Risk and Vulnerability Assessment, prepared by HDR Engineering, Inc. and dated May 27, 2025. This report can be found in Appendix C.

Primary climate change impacts the water distribution system include:
• Hotter temperatures add demand and stress to the Water System, and exacerbate wildfire threat to infrastructure.
• Increasingly exaggerated variability in precipitation, including flooding and drought conditions, require varied and more adaptable water management (discussed further in Section 5.4: Environmental Practices).
• Sea Level Rise in addition to extreme precipitation events and drought, will increase the risk of landslides and erosion.

Additional at-risk infrastructure includes:
• Transportation: Bridges are at risk of flooding.
• Energy Systems: Transmission lines exposed to wildfire and could impact operations of water pump(s) for the water distribution syste.
• Water Treatment: The Water Treatment Plant is at the edge of wildfire susceptibility. • Critical Infrastructure: Fort Bragg Fire Station #2 is vulnerable to wildfire.

Water distribution assets that may benefit the most from implementing resilience strategies include:
• Mains: Landslides along creek banks.
• Storage Tanks: Vulnerable to wildfire.

5.4 Environmental Practices
Environmental Practices are actions that the City is either currently undertaking or actions that the City may consider when seeking to minimize their infrastructure’s impact to the environment. This section focuses on three key environmental practice topics: water efficiency, conservation, and local watershed protection.

5.4.1 Water Efficiency
The City has multiple ongoing water efficiency efforts. The projects summarized below include the Raw Water Line Replacement Project (Dewberry 2022), the Oneka Seawater Desalination Buoy Pilot Study (City of Fort Bragg 2025a), and the Reservoir Project (City of Fort Bragg 2025b).

The Raw Water Line Replacement Project (Dewberry 2022) is undertaking a critical infrastructure upgrade to improve the reliability and efficiency of an approximately two-mile section of its aging raw water delivery pipeline. With the existing pipeline nearing the end of its operational lifespan and experiencing frequent failures, replacement is essential to ensure a stable and resilient water supply for the community. To identify the most efficient and environmentally responsible route, the project Water Distribution System Master Plan
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team—including engineers, biologists, and environmental and geotechnical experts—assessed multiple project alternative options. These alternatives were evaluated based on engineering feasibility, environmental considerations, land use compatibility, cost, and other relevant factors.

While the construction activities will occur near aquatic habitats, assessments indicate that potential impacts to sensitive fish species such as steelhead and coho salmon will be minimal and can be effectively mitigated.

The Oneka Seawater Desalination Buoy Pilot Study (City of Fort Bragg 2025a) is designed to enhance the resilience and efficiency of the water supply system for Fort Bragg, in response to increasing water reliability concerns. Through grant money awarded by California Department of Water Resources, the City is piloting a new innovative wave-powered desalination system developed by Oneka Technologies. This system uses only ocean wave energy to convert seawater into potable water via reverse osmosis, offering a sustainable and energy-independent solution. A single “Iceberg” unit, capable of producing approximately 13,200 gallons of freshwater per day, will be tested for 12 months about 0.5 miles offshore. The pilot study will monitor system performance, energy efficiency, and potential environmental effects to inform a future utility-scale deployment aimed at securing a reliable, low-impact water source. The Iceberg unit’s offshore location was selected to avoid ecologically sensitive areas, using existing disturbed zones near the wastewater treatment plant’s outfall for pipeline routing. Designed with environmental safeguards, the unit features a fine mesh intake screen, low intake velocity, and passive brine discharge, reducing risks to marine life and avoiding sediment disruption. Environmental monitoring during the study will assess impacts on water quality and marine habitats, with results informing regulatory permitting and the potential expansion of this zero-emission, wave-powered desalination approach in Fort Bragg’s long-term water strategy.

The City is planning the development of the Reservoir Project (City of Fort Bragg 2025b) which includes three new 45-acre-foot water storage reservoirs. This project is intended to improve longterm water supply reliability and enhance drought resilience. These reservoirs will be located on a forested, City-owned property encompassing 582 acres adjacent to the existing Summers Lane Reservoir. Designed to capture and store water during periods of high flow—either by gravity from Waterfall Gulch or pumped from the Noyo River—the reservoirs will provide a dependable water source during dry months. This seasonal storage strategy helps maintain streamflow levels in summer, reducing pressure on aquatic ecosystems and protecting sensitive fish species. Water from the reservoirs will primarily be delivered to the City’s treatment plant via gravity, improving energy efficiency. The project will include supporting infrastructure such as a caretaker’s residence, a storage facility, parking, and pit toilets, all sited in previously disturbed areas to limit environmental disruption. The reservoir designs will be modeled after the existing Summers Lane facility, with depths reaching up to 18 feet and stable side slopes. Importantly, the dam and storage parameters are expected to remain below thresholds that would trigger oversight from the California Division of Safety of Dams. The site includes both redwood forest and rare Mendocino Cypress Woodland habitat, prompting the completion of preliminary biological assessments to inform reservoir placement and avoid impacts on sensitive natural resources. As part of the project’s development, an Environmental Impact Report (EIR) will be prepared in compliance with California Environmental Quality Act (CEQA), and close coordination between engineering and environmental consultants will be required. Environmental mitigation strategies will be implemented as needed. The City plans to preserve the remaining forested land as a future community forest, supporting both conservation and public access goals.

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In addition to the City's projects, new development and retrofitted landscape water efficiency standards are regulated by the Model Water Efficient Landscape Ordinance (MWELO). These ordinances aim to enhance water efficiency while also improving environmental conditions in urban areas. Landscapes should be recognized not only for their aesthetic value but also for their role in restoring habitat lost to development. Proper landscaping offers a variety of ecological benefits, including habitat restoration, climate change mitigation, energy and materials conservation, and improvements to public health and quality of life, all of which contribute to a more sustainable and resilient environment.

5.4.2 Conservation
This section describes species that have been identified as important for conservation and then describes some of the projects the City has been involved with to support conservation efforts for these species.

Several species within the region have been identified as priorities for conservation efforts by the California Natural Diversity Database (CNDDB) (2024), U.S. Fish and Wildlife Service (USFWS) (2025), and National Marine Fisheries Service (NMFS) (2025). A search of the region using the CNDDB Quickview Tool identified several species of special concern by the California Department of Fish and Wildlife (CDFW) (CNDDB 2025). CNDDB (2025) shows that Central California Coast Coho salmon (Oncorhynchus kisutch) is state listed as endangered. Species of special concern include Northern California distinct population segment (DPS) winter-run steelhead (Oncorhynchus mykiss), California Coastal Chinook salmon (Oncorhynchus tshawytscha), tidewater goby (Eucyclogobius newberryi), and Pacific Lamprey (Entosphenus tridentatus) (CNDDB 2025). Additionally, an Information for Planning and Consultation (IPaC) search (USFWS 2025) of the region, which does not include Endangered Species Act (ESA) listed fishes under NMFS jurisdiction, shows the tidewater goby listed as a federally endangered species with critical habitat located in the lower portion of Pudding Creek and in the lower portion of Virgin Creek. Additionally, the northwestern pond turtle (Actinemys marmorata) is proposed for official listing as threatened, however, there is no critical habitat. Although there is no additional critical habitat listed, the following list of ESA-listed non-aquatic species were generated by an IPaC search of the region (USFWS 2025):
• Birds
o Endangered Hawaiian Petrel (Pterodroma sandwichensis) o Endangered Short-tailed Albatross (Phoebastria albatrus) o Threatened Marbled Murrelet (Brachyramphus marmoratus) o Threatened Northern Spotted Owl (Strix occidentalis caurina) o Threatened Western Snowy Plover (Charadrius nivosus nivosus) o Threatened Yellow-billed Cuckoo (Coccyzus americanus) • Insects
o Endangered Behren's Silverspot Butterfly (Speyeria zerene behrensii) o Endangered Lotis Blue Butterfly (Lycaeides argyrognomon lotis) o Proposed Threatened Monarch Butterfly (Danaus Plexippus) Water Distribution System Master Plan
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• Flowering Plants
o Endangered Burke's Goldfields (Lasthenia burkei)
o Endangered Contra Costa Goldfields (Lasthenia conjugens) o Endangered Howell's Spineflower (Chorizanthe howellii) o Endangered Menzies' Wallflower (Erysimum menziesii)
o Endangered Monterey Clover (Trifolium trichocalyx)
o Endangered Showy Indian Clover (Trifolium amoenum)
The NMFS Species and Habitat App (NMFS 2025), shows the Central California Coast Coho salmon evolutionarily significant unit (ESU) is endangered and have critical habitat in Pudding Creek and Noyo River. The California Coastal Chinook salmon ESU is threatened and has critical habitat in Noyo River. Finally, the Northern California steelhead DPS is threatened and has critical habitat in Pudding Creek and Noyo River. NMFS (2025) also shows essential fish habitat for Chinook and coho salmon, as listed under the Magnuson-Stevens Act, in the region. All of these species are relevant when considering water use and water development projects as part of the Plan.

The City has been involved in multiple conservation efforts. City staff assisted in developing the Noyo River Watershed Enhancement Plan (CSCC 2007). The primary purpose of this plan was to identify and describe strategic management and restoration activities with a focus on vegetation, wildlife, and salmonids. CSCC (2007) describes the following conservation projects with the City as a contributor:
• South Fork Noyo River Sub-basin Road Related Sediment Reduction Project • Comprehensive Road Assessment in the South Fork Noyo River Sub-basin • Road Reshaping and Decommissioning in the South Fork Noyo River Sub-basin • Kass Creek/Little North Fork Noyo Large Woody Debris Coho Habitat Enhancement • Kass Creek/Little North Fork Noyo River Road Assessment • Little North Fork Noyo/Kass Creek Road Implementation • Sherwood Road Sediment Reduction Project
• Upper Noyo/North Fork Noyo Sub-basin Road Assessment
• Upper Noyo/North Fork Noyo Sub-basin Road Implementation Project • Otis Johnson Wilderness Park Restoration
• Noyo Watershed Alliance Organizational Support
• Coastal Salmonid Monitoring Program (Pudding Creek)
Note that many of these projects focus on sediment management as it relates to road networks within the Noyo River watershed and other nearby areas which are expected to benefit conditions for listed salmonids described above.

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5.4.3 Local Watershed Protection
The City receives its water from three main sources including the Noyo River and Newman Gulch which connects to the Noyo River. The third source is Waterfall Gulch which flows into Hare Creek south of Fort Bragg. Regional Water Board (2005) provides a summary of the Noyo River watershed and activities to assess and improve conditions for anadromous salmonids. Some of the topics reviewed include water quality and excessive sediment loading associated with logging, overgrazing, and road building. These impacts affect both anadromous fish populations and drinking water supply and efficiency.

As part of the CDFW Fisheries Restoration Grant Program, a fish passage barrier was removed from Newman Gulch in 2013 and post-treatment monitoring conducted in 2016 (CDFW 2016). This project aimed to improve fish passage in Newman Gulch by replacing a small, inadequate culvert with a roughened stream channel and a 45-foot prefabricated steel bridge. The new design was specifically intended to allow uninterrupted movement for Chinook salmon, coho salmon, and steelhead trout throughout all stages of their life cycles, granting access to approximately a quarter mile of upstream habitat for spawning and juvenile development. Both coho salmon and steelhead have been observed in Newman Gulch since the barrier was removed (CDFW 2016). The City plans to continue protecting local watersheds in this way as future projects are implemented, supporting both conservation and public access goals.

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CHAPTER 6 WATER SYSTEM CAPITAL

IMPROVEMENT PROGRAM

6.1 Introduction
This chapter provides a list of recommended improvements within the City’s water distribution system and summarizes the capital improvements and their associated planning level costs. The resulting CIP provides the proposed prioritization, timing, and sizing of the recommended improvements. As with any infrastructure planning assessment, the actual timing and sizing will be dictated by the realized impact of growth and the year-to-year increase in water demand in the water service area and future annexation areas. This chapter documents the following components of the capital planning process:
• Planning Criteria to identify deficiencies and size recommended improvements • Existing System capacity analysis
• Future system capacity analysis
• Risk analysis used for capital project prioritization • Recommended system improvements
• Descriptions, locations, and sizes of supply, pumping, storage, and major transmission/distribution system improvements
• Prioritized implementation schedule based on water demand projections, hydraulic modeling, and system performance analysis over the planning years • Planning level opinions of probable cost (OPC) of improvements through the planning period, including documentation of the cost basis for each type of project • Phased capital improvements plan

6.2 Ten-Year Capital Plan Overview
Table 17 below shows the 10-year capital improvement plan for the water distribution system. This table and a map illustrating all CIP project Physical locations can be found in Appendix F.

Project priority was assigned first by anticipated timeframe, then by maximum proximal risk score and included projects that address priority capacity, fire flow, operational, asset renewal, and other recommended improvements needed to meet anticipated future demands, facilitate system operations, and keep the current system performing at expected levels of service.

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Table 17 – Ten-Year Capital Improvement Plan
Priority
Ranking CIP ID Project Name Project Description Total Pipe Footage (FT) Project Driver Escalated Project Costa 1 PS-1 Pump Station Upsize Upsize Willow Street Pump Station capacity to 2,000 GPM. - Capacity or Fire Flow Deficiency $8,141,000
2 V-1 Oak Street Valves Addition of two isolation valves to 14-inch water main on Oak Street. 930 Operational Improvements $93,000
3 P-1 Cedar Street Water Line
Replacement
Replacement of Cedar Street water main. Increase 53 FT of 6-inch pipe diameter to 16-inch. Increase 4,195 FT of 8-inch pipe diameter to 16-inch.
4,248 Capacity or Fire
Flow Deficiency $3,357,000
4 T-1 Tank 1 Upgrade Replacement of Tank 1 at WTP. - Asset Renewal $8,955,000 5 P-2 North Fort Bragg Water
Main Extension
North Fort Bragg Water Main Extension. Place new 2,144 FT of 10-inch main. 2,144 Capacity or Fire Flow Deficiency $1,384,000 6 PL-1 System Renewal- Pipe
Replacement
Provision for additional projects to meet 1% annual system renewal goal, based on condition. 5,000 Asset Renewal $2,830,000 7 O-1 Opportunistic Pipe
Sampling Collect and test condition of 3-5 AC pipe samples per year. - Other $69,000 8 O-2 CIP Update Update capital project list every 5 years. - Other $110,000 9 O-3 CMMS Needs Analysis Evaluate Computer Maintenance Management Software (CMMS) Needs. - Other $39,000
Next 5 Year Sub-Total $24,978,000
10 P-7 East Laurel Street Water
Main Replacement Increase 6-inch pipe diameter to 8-inch 539 Capacity or Fire Flow Deficiency $354,000 11 P-3 Noyo Center Water Line
Upsize 1,500 FT of existing 4-inch main to 12-inch. Place new 2,500 FT of 12-inch main. Project pending start of Noyo Center Development.
4,018 Capacity or Fire
Flow Deficiency $2,985,000
12 P-6 North Main Street Water
Main Replacement
Increase 32 FT of 6-inch pipe diameter to 8-inch.

Increase 867 FT of 6-inch pipe diameter to 10-inch.

Increase 220 FT of 6-inch pipe diameter to 12-inch.

Increase 3,665 FT of 10-inch pipe diameter to 12-inch.

Increase 645 FT of 8-inch pipe diameter to 10-inch.
5,429 Capacity or Fire
Flow Deficiency $4,016,000
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Priority
Ranking CIP ID Project Name Project Description Total Pipe Footage (FT) Project Driver Escalated Project Costa 13 P-14 East Alder Street Water
Main Replacement Increase 6-inch pipe diameter to 8-inch 717 Capacity or Fire Flow Deficiency $470,000 14 P-10 Chief Celeri Dr Water
Main Replacement Increase 6-inch pipe diameter to 10-inch 1,362 Capacity or Fire Flow Deficiency $951,000 15 P-4 Noyo Point Road Water
Main Replacement Increase 6-inch pipe diameter to 10-inch 651 Capacity or Fire Flow Deficiency $455,000 16 P-8 Maple Street Water Main
Loop Install new 8-inch pipe 313 Capacity or Fire Flow Deficiency $206,000 17 P-5 East Elm Street Water
Main Loop Install New 12-inch Pipe 194 Capacity or Fire Flow Deficiency $145,000 18 P-9 East Chestnut Street
Water Main Replacement Increase 6-inch pipe diameter to 10-inch 472 Capacity or Fire Flow Deficiency $330,000 19 P-11 Spruce Street Water
Main Replacement Increase 6-inch pipe diameter to 8-inch 1,330 Capacity or Fire Flow Deficiency $873,000 20 PL-2 System Renewal- Pipe
Replacement
Provision for additional projects to meet 1% annual system renewal goal, based on condition. 5,000 Asset Renewal $3,280,000 21 O-4 Opportunistic Pipe
Sampling Collect and test condition of 3-5 AC pipe samples per year. - Other $80,000 22 O-5 CMMS Acquisition &
Implementation
Acquire and implement new CMMS. Only if recommended in
O-3 CMMS Needs Assessment. - Other $191,000
23 O-6 CIP Update Update capital project list every 5 years - Other $127,000 5-10 Year Sub-Total $14,463,000
Total $39,441,000
a Costs escalated for inflation (see Unit Costs)
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Projects categories are described as follows:
• Capacity & Fire flow Deficiency - capital projects identified by evaluating current water demands, near-term water demand projections, and expected demands at buildout over the next 10 years (development of the GP Mills site). Currently, the eight annexation areas are not expected to be developed within the next 10 years.
• Operational improvements are recommended to maintain or increase the City’s ability to efficiently manage the system. These projects are designed to enable the City to perform regular maintenance and repairs on the system while minimizing the impact on customers and the community.
• Asset renewal projects include infrastructure replacement and rehabilitation of existing infrastructure to keep the current system operating as expected. These projects are focused on aging infrastructure and infrastructure that is in poor condition. An annual pipeline replacement rate of 1% has been established (see section 6.8.1 Renewal Strategy) to plan for the incremental renewal of the entire system in the next 100 years (which is consistent with current industry standards). For the ten-year CIP, some portion of the 1% annual replacement rate has been accounted for through Capacity and Fire flow projects. Therefore, specific annual allocations have been reduced from the 1% target. This allocation has remained separate to account for unanticipated replacement needs due to condition or pipe failure.
• Other capital projects include planned condition assessment efforts, and other studies to continue to evaluate environmental, geotechnical, and climate change risks and resilience opportunities. Condition assessments will be used to plan and prioritize upcoming capital projects (such as pipeline replacements) and the environmental studies will help the City anticipate changes in environmental factors and adjust capital plans to address these changes in the future.

6.3 Preliminary Engineering Reports
Preliminary engineering reports are provided in Appendix F and have been developed for five of the highest priority projects described in the ten-year capital plan (P-1: Cedar Street Line Replacement, P-2: Noyo Center Water Line, T-1: Tank 1 Replacement, and V-1: Oak Street Valves, PS-1: Pump Station Upsize). These reports were designed to contain detail to support the environmental and funding process and include schedule, cost, mapping, project descriptions and design triggers.

6.4 Planning Criteria
Planning criteria are performance metrics and standards required to meet levels of service expected by customers, stakeholders, and regulators. Three scenarios, Existing, Near-Term (anticipated growth and improvements in the next decade), and Build-Out (long-range condition assuming full development) were modeled and compared against the performance criteria outlined in this section to identify needs and define necessary capital projects.

6.4.1 Distribution System
Distribution system criteria address system pressure and pipeline requirements. These criteria are established to ensure that the proposed distribution system will provide adequate, but not excessive, Water Distribution System Master Plan
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water pressure and the conveyance system can accommodate peak demands without excessive wear or energy usage. These criteria are not recommended to limit, for example, pipeline velocities during intermittent activity such as flushing.

6.4.1.7 Water Service Pressure Requirements
The water service pressure requirements recommended for this hydraulic analysis are as follows:
• Maximum desired pressure: 120 psi
• Maximum allowable pressure: 150 psi
• Minimum allowable pressure at peak flow: 40 psi
• Minimum allowable pressure with MDD plus fire flow: 20 psi To help provide standardization throughout the City, provide adequate fire flows and avoid excessive velocity and head loss within the distribution system, the following pipeline design criteria are also recommended:
• Minimum pipe size for new construction: 8 inch
• Maximum allowable velocity at peak flow: 7 feet per second (fps) • Maximum allowable velocity during fire flow conditions: 15 fps • Maximum desirable head loss at peak flow: 5 feet per 1000 feet • Maximum allowable head loss at peak flow: 10 feet per 1000 feet

6.4.1.8 Fire Flow Requirements
Fire flow requirements for different land use types were provided by the City. Table 18 lists fire flow requirements used in the capacity analysis
Table 18 – Fire Flow Requirements
Land Use
Minimum Flow
Required
(gpm)
Minimum Desired
Pressure
(psi)
Minimum Duration
(hrs)
Required Fire
Storage Volume
(MG)
Residential 1,000 20 2 0.12
Commercial 2,000 20 3 0.36
Industrial 3,000 20 4 0.72

6.4.2 Pump Station Criteria
Pump Stations should be sized to handle MDD in pressure zones with storage. The in-zone storage will handle the fluctuations between MDD and PHD in addition to providing the recommended fire flow volume.

For pressure zones with no in-zone storage, the pump stations should be sized to handle PHD plus fire flow demands, in the event that fire flow demand is required during the peak hour condition.

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All pump stations should be sized to handle the required flow with the largest pump on standby (i.e., firm capacity). If a pump station contains a dedicated fire pump, the fire pump can be included in calculating the firm capacity of the pump station.

The existing distribution system has one pump station, the Willow Street Booster Pump Station, serving the EFBPZ. The rest of the city is supplied by the WTP via gravity flow.

6.4.3 Storage Criteria
Treated water storage should be sized to provide the following storage components within each pressure zone:
• Operational Storage – The storage to moderate fluctuations during normal operations between supply and demand. Typically supply provides MDD with storage providing the difference between MDD and PHD.
• Fire Flow Storage – The storage volume required to provide fire protection in each pressure zone (See Table 18 – Fire Flow Requirements)
• Emergency Storage – The storage required to provide supply during emergencies within the City, when water supply is reduced or turned off.

6.4.3.9 Operational Storage
Under normal operating conditions, operational storage balances the difference between water supply (typically MDD) and daily variations in demand. Water is supplied to the City via the WTP.

Operational storage is pressure zone dependent and based on the ADD per pressure zone It is recommended that the City’s operational storage be sized to balance the difference between PHD and MDD supplied by the WTP. As discussed previously, the typical peak hour period is a 3- hour period occurring between the hours of 4 a.m. and 7 a.m. Assuming 3 peak hours of demand, the difference between peak hour and maximum day is:

𝑂𝑂𝑂𝑂𝑂𝑂𝑂𝑂𝑂𝑂𝑂𝑂𝑂𝑂𝑂𝑂𝑂𝑂𝑂𝑂𝑂𝑂 𝑆𝑆 𝑆𝑆 = � 3
24 ℎ 𝑜𝑜 𝑜𝑜� ∗ (𝑃𝑃𝑃𝑃𝑃𝑃 − 𝑀𝑀 )
= 0.125 ∗ (2.52 − 1.73) ∗ 𝐴𝐴
= 0.099 ∗ 𝐴𝐴

6.4.3.10 Fireflow Storage
Fire flow storage is pressure zone specific and is based on the largest fire flow required, based on land use, for each pressure zone. Since there is no storage in the booster station zone, the distribution zone needs to be able to handle fire flow in both zones. The distribution zone has industrial parcels with a 3,000 gpm for 4-hour requirement (i.e., 720,000 gallons).

𝐹𝐹 𝐹𝐹 𝐹𝐹 𝑆𝑆 𝑆𝑆 = 0.72 𝑀𝑀𝑀𝑀
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6.4.3.11 Emergency Storage
Emergency storage, similar to operational storage, is pressure zone dependent and based on the ADD per pressure zone. Typically, water municipalities can respond to and mitigate outages within 1 day, which suggests that 1 average day be reserved for emergency storage. Since the City has a water treatment source and is not dependent on imported water or supply from a neighboring utility, it is important to balance the required level of emergency storage with the potential for adverse water quality issues stemming from excess storage. Therefore, 1 * ADD is recommended for the emergency storage component.

𝐸𝐸𝐸𝐸 𝐸𝐸𝐸𝐸 𝑆𝑆 𝑆𝑆 = 1 ∗ 𝐴𝐴

6.4.3.12 Recommended Storage Criteria
System-wide total treated water storage requirements for existing, near term, and buildout are summarized in Table 19. The City currently has 4.95 MG of treated water storage, and thus no additional treated water storage is required.

Table 19 – Storage Requirement for Existing, Near Term, and Buildout Scenarios Existing Near Term Buildout
Total ADD (gpm) 482 500 1,109
Total ADD (MG) 0.69 0.72 1.60
Operational Storage (MG) 0.07 0.07 0.16
Fire Flow Storage (MG) 0.72 0.72 0.72
Emergency Storage (MG) 0.69 0.72 1.60
Total Storage Required (MG) 1.48 1.51 2.48
Total Storage Available (MG) 4.95 4.95 4.95
Additional Storage Needed (MG) None None None

6.5 Existing System Capacity Analysis
Existing conditions represent current system performance based on available data and known infrastructure. This scenario identifies immediate deficiencies or constraints that require capital improvements. These improvements include increasing the current capacity of the fire pump at the Willow St. Pump Station from 1,000 GPM to 2,000 GPM, and a series of projects either specified by the City or developed by HDR to address fire flow capacity deficiencies. Fire flow deficiencies were examined in the distribution pressure zone in MDD conditions, and in the booster station pressure zone in PHD conditions. This is because the booster station zone has no storage to provide for the difference in demand between max day and peak hour, the pumps at the booster station must be able to provide fire flow plus the maximum demand required, which could occur at MDD.

CIP projects for the existing system are described in Table 20 and shown in Figure 31. The City specified four CIP projects for the existing system. These projects are shown in Figure 32, Figure 33, Figure 34, and Figure 35. Improvements identified by the hydraulic model were given a lower priority than those specified by the city. Improvements to existing pipes (i.e. upsizing) were prioritized over Water Distribution System Master Plan
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the addition of new pipes. Lower priority projects were ranked by total risk followed by the enhanced level of fire flow improvements addressed by the project.

Table 20 – CIP Projects For Existing System
CIP
Scenario
CIP
ID Project Name Project Description Total Pipe Footage (FT) Time
Frame
Existing PS-1 Pump Station Upsize Upsize Willow Street Pump Station capacity to 2,000 GPM - <5 years
Existing P-1 Cedar Street Water
Line Replacement
Replacement of Cedar Street water
main. Increase 53 FT of 6-inch pipe
diameter to 16-inch. Increase 4,195
FT of 8-inch pipe diameter to 16-
inch.
4,248 < 5 years
Existing P-2 North Fort Bragg Water
Main Extension
North Fort Bragg Water Main
Extension. Place new 2,144 FT of
10-inch main.
2,144 < 5 years
Existing P-4
Noyo Point Road
Water Main
Replacement
Increase 6-inch pipe diameter to
10-inch 651 5 - 10 years
Existing P-5 East Elm Street
Water Main Loop Install New 12-inch Pipe 194 5 - 10
years
Existing P-6
North Main Street
Water Main
Replacement
Increase 32 FT of 6-inch pipe
diameter to 8-inch.

Increase 867 FT of 6-inch pipe
diameter to 10-inch.

Increase 220 FT of 6-inch pipe
diameter to 12-inch.

Increase 3,665 FT of 10-inch pipe
diameter to 12-inch.

Increase 645 FT of 8-inch pipe
diameter to 10-inch.
5,429 5 - 10
years
Existing P-7
East Laurel Street
Water Main
Replacement
Increase 6-inch pipe diameter to 8-
inch 539 5 - 10 years
Existing P-8 Maple Street Water
Main Loop Install new 8-inch pipe 313 5 - 10
years
Existing P-9
East Chestnut Street
Water Main
Replacement
Increase 6-inch pipe diameter to
10-inch 472 5 - 10 years
Existing P-10
Chief Celeri Dr
Water Main
Replacement
Increase 6-inch pipe diameter to
10-inch 1,362 5 - 10 years
Existing P-11 Spruce Street Water
Main Replacement
Increase 6-inch pipe diameter to 8-
inch 1,330 5 - 10 years
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CIP
Scenario
CIP
ID Project Name Project Description Total Pipe Footage (FT) Time
Frame
Existing P-13
East Alder Street
Water Main
Replacement
Increase 6-inch pipe diameter to 8-
inch 717 5 - 10 years
Existing T-1 Tank 1 Replacement Replacement of Tank 1 at treatment plant - < 5 years
Existing V-1 Oak Street Valves
Addition of two 10-inch isolation
valves and one 18-inch isolation
valve to water main on Oak Street.
930 < 5 years
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Figure 31 – CIP Projects for Existing System
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Figure 32 – CIP Project P-1: Cedar Street Water Line Replacement Figure 33 – CIP Project P-2: North Fort Bragg Water Main Extension Water Distribution System Master Plan
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Figure 34 – CIP Project T-1: Tank 1 Replacement
Figure 35 – CIP Project V-1: Oak Street Valves
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6.6 Near-Term System Capacity Analysis
Near-Term Conditions reflect system demands and improvements expected in the short-term planning horizon (e.g. 5-10 years). It incorporates committed developments and known growth. The addition of near-term demands to the system does not trigger additional fire flow related system improvements. However, the City identified one CIP project, the Noyo Center Water Line, to be developed in the near-term to serve the proposed Noyo Center, shown in Figure 36. This project would be pending the start of Noyo Center Development. It is anticipated that a fair share of the cost of this project will be borne by the developer.

Figure 36 – CIP Project P-3: Noyo Center Water Line

6.7 Build-Out System Capacity Analysis
Build-Out conditions reflect long-range planning needs, incorporating the development of the GP Mill Site and the future annexation areas (Figure 37). It should be noted that annexation is not likely to occur within the next 20 years. Annexation Area 6 is unlikely to be developed in a way that would impact sewer and water because it’s in a low-lying, heavily forested area. If Annexation Area 6 does develop, it would need to be evaluated at that time. System improvements would be required to address these additional demands and provide the level of service established in the Planning Criteria.

Figure 37, Figure 35, and Figure 36 and Table below show the improvements to the system (P-12 and P-14) required to meet buildout demands and associated planning and design criteria. These improvements are not included in Table 17 – Ten-Year Capital Improvement Plan as the additional demand would be introduced beyond the planning horizon.

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Table 21 – CIP Projects For Buildout System
Priority
Ranking CIP ID Project Name
Total Pipe
Footage
(FT)
Time
Frame
(years)
Risk
Score Category Project Description
24 P-12
Dana Street
Water Line
Replacement
1200 > 10 - Capacity or Fire
Flow Deficiency
Increase 6-
inch diameter
to 10-inch
25 P-14
South Harbor
Drive Water Line
Extension
580 > 10 - Capacity or Fire
Flow Deficiency
Install New
12-inch Pipe
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Figure 37 – CIP Projects for Buildout System
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Figure 38 – P-12 for Buildout System
Figure 39 – P-14 for Buildout System
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6.8 System Renewal
In addition to the current and future capacity analysis, another key component informing required capital improvement is the need for the proactive renewal of aging infrastructure. All infrastructure ages and deteriorates over time and requires rehabilitation or replacement for the City to continue to provide a consistent level of service to its customers. In general, the water distribution system is in good shape and aside from one tank project, no individual pipelines have been identified for immediate replacement based on condition. However, most of the system is reaching or has exceeded its expected useful life and will eventually require replacement or rehabilitation.

This section develops and presents a pipeline replacement program strategy for the City. The intent of the program is to leverage pipeline condition and risk scoring information to minimize system interruptions over time and implement the program affordably while meeting industry performance standards.

6.8.1 Renewal Strategy
An annual pipe replacement rate of 1% is recommended based on a benchmark comparison of the City’s break data with break rates from other utilities. This rate of renewal, replacing approximately half a mile of pipe each year, results in full system replacement approximately every 100 years.

A break rate is defined as the average annual number of breaks per 100 miles of pipe, whereas a replacement rate represents the percentage of the entire pipe system replaced each year. The break rate for Fort Bragg was calculated using the formula below, and is expressed as breaks per year per 100 miles of pipe:

Break Rate = (Breaks Across Range / Year Range) / (Miles of Pipe / 100) From the available break history data, Fort Bragg has experienced 13 breaks over the last 14 years.

For a 41-mile system, this equates to 2.3 breaks per year per 100 miles. Figure 40 shows how this break rate falls in the low range of benchmarked utilities (dashed line).

While the City’s current break rate is low, this rate should be anticipated to increase as the system continues to age. The American Water Works Association (AWWA) reports the average estimated service life for AC pipes is 75 to 105 years and 70 years for PVC pipe. City records indicate that approximately 20% of the system is 65 years old or older. 60% of the system is approximately 45 years old, and 22% of the system is 20 years old or newer. This means that by AWWA standards, 20% of the system is either at or expected to reach its anticipated expected useful life within the next 10 years. By establishing an annual recommended replacement rate, Fort Bragg can shift their investment strategy from reactive to proactive, which will limit unexpected impacts to critical customers and allow the City to progressively invest in system renewal, keeping investments and capital effort sustainable over time.

Figure 40 below illustrates the benchmark analysis comparing a 1% and 0.5% annual replacement rate against 26 benchmarked water utilities. The upper left side of this chart represents a higher level of service focus (i.e. a more proactive approach) and the lower right side represents a strategy that is near-term cost-focused (i.e. a more reactive approach). This benchmark assessment evaluated a

0.5% and 1% replacement rate for the City as shown by the two orange dots plotted at the City’s calculated break rate of 2.3 breaks per year per 100 miles of pipe. While the City may benefit from a Water Distribution System Master Plan
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replacement strategy of 0.5% per year, which could offer a more cost-effective approach while still aligning with a higher level of service, at this rate, the entire system would only be replaced every 200 years, in contrast to a 100-year renewal cycle achieved with a 1% annual replacement rate.

The 1% rate equates to replacing approximately 0.5 miles of pipeline per year. The more aggressive, 1% rate is recommended for the 10-year planning period as a portion of the system is either approaching or past its expected useful life. This rate may serve as a planning benchmark for the City’s annual capital improvement budget and could be grouped in the form of larger projects on a multi-year cycle, such as every three to five years.

Figure 40 - System Performance vs Investment Level
This rate may be used for capital planning purposes, but it does not indicate which pipes should be prioritized for replacement. The City may consider several factors when deciding which pipes to replace and the replacement schedule. Factors to consider are:
• Water distribution pipe risk score
• Pipes shown to be in poor condition through opportunistic laboratory testing • Upsizing recommendations based on hydraulic modeling
• New valve installation recommendations
• Other civil projects where water mains will need to be excavated or exposed

6.8.2 Pipe Condition Assessment
While a comprehensive condition assessment of the distribution pipelines was not a component of this Master Plan, some opportunistic testing of asbestos cement pipe was completed on pipe Water Distribution System Master Plan
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samples that were recently removed from the system during routine maintenance activities. The testing indicates the level of corrosion of the concrete in the pipe wall.

The purpose of this effort was to demonstrate the effectiveness of developing a cost-effective, ongoing pipe sampling program to test pipe condition whenever the pipe is exposed for maintenance or service purposes. A line item for continual pipe testing is provided in the current capital plan.

Testing results (Tremaining), where T=pipe wall thickness are categorized based on the following condition categories.
• Very Poor (<55)
• Poor (55-70%)
• Moderate (70-76%)
• Good (76-83%)
The results for the three opportunistic test samples are listed in Table 22 below.

Table 22 – Summary of AC Pipe Testing Results
Sample ID Sample Date Diameter
(in)
Approx. RUL
(%)
Pressure
(psi) Tremaining Condition
AC-1 8/1/2024 6 45 ~57 55% Poor (55-70%)
AC-2 1/11/2024 6 45 ~25 63% Poor (55-70%)
AC-3 4/25/2024 8 >50 ~24 64% Poor (55-70%)
Appendix G describes the testing process and provides greater detail on how to interpret these results. Pipes categorized as being in ‘poor’ condition like the samples above are not necessarily more likely to break when operating under standard conditions. However, should these pipes experience pressure surges, these pipes are more likely to break and may be more difficult to repair.

6.9 Risk Assessment
Risk assessment was used to prioritize capital improvement decisions in this Master Plan. A risk model was developed to assign a relative risk score to each water main, based on:
• Likelihood of Failure (LoF) How likely a pipe is to fail, based on factors like pipe age, break history, and seismic/geologic risk.
• Consequence of Failure (CoF) The impact of a pipe’s failure, particularly for critical customers, high demand areas, or hard-to-access locations.

The risk model provides each pipe a numerical risk score, quantifying the risk factors relative to the other pipes in the system. The factors used for LoF and CoF represent indirect evidence of the reliability and criticality of each pipe, however none of these factors provide direct evidence of pipe condition. Therefore, the risk model should be used to prioritize assessment and rehabilitation work but should not be relied upon as direct evidence that a rehabilitation action is needed. Additional assessment will be needed to determine the true condition of any given asset.

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Examples of how the risk model can be used are:
• Prioritizing existing capital projects – When two or more projects are proposed (e.g. valve installation, pipeline expansion or enlargement) the risk model can be used to break a tie when other considerations are equal. If all other considerations are equal and one or more projects must be delayed, the pipe segment with the lowest risk score can be differed because the risks are comparatively lower.
• Prioritizing condition assessment – One of the programs initiated during this master plan is the testing of asbestos cement pipeline walls to determine the residual calcium remaining.

This is a good indicator of pipeline condition. The risk model can be used to determine where to sample next. This enables the City to focus on the higher risk pipes and mitigate issues that indicate a high consequence of failure.
• Prioritizing maintenance – Maintenance staff frequently prioritize between multiple demands on their time. Using the risk model to determine what maintenance activities should be done first enables the City to make risk-based maintenance decisions.

The risk model can also be continually improved as the City collects more data, learns more about the system and implements system changes. Periodically the model should be evaluated against additional information to determine if it should be updated. If there are additional pipeline breaks, it would be useful to look at the risk model to see if the risk results are consistent with the conditions that caused the break. If additional asbestos testing is completed, it can be compared with the model results. As new infrastructure is added or replaced, the model can be updated to accurately reflect current conditions.

6.10 Unit Costs
This section discusses the unit costs used to develop the opinions of probable cost (OPC) for each of the recommended improvements described in the following sections. Unit costs and OPCs are based on information known at this time (e.g., system needs, projected growth rates, development patterns). Costs are order of magnitude, planning level costs and consist of construction costs; engineering, legal, and administrative costs; and expenditures for land acquisition. The OPCs are intended to assist in budgeting for the implementation of the CIP.

It should be noted that OPCs for projects vary depending on the phase of the project when they are developed, which determines the level of detail and the expected accuracy of the estimate. The Association for the Advancement of Cost Engineering International (AACE International) Recommended Practices, specifically Document No. 18R-97, outline typical cost estimate accuracy based on the overall status of the project. The cost estimates for the improvements discussed herein should be considered Study (Estimate Classification 4) level estimates with an expected accuracy of +50 to -30 percent. OPCs should be verified and updated during the pre-design phase of each project.

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Project costs in the ten-year capital plan overview have been adjusted for inflation using Engineering News-Record’s (ENR) Construction Cost Index (CCI). The ENR CCI is computed from prices of construction material and labor and is based on a value of 100 in the year 1913 and escalated each year. Cost data in this report are based on the 2024 ENR CCI (20-city average) of 11,455. Future CCI was projected using the formula for compound growth (see formula below) and assuming an annual escalation rate of 3%.

𝐹𝐹 𝐸𝐸𝐸𝐸𝐸𝐸 𝐶𝐶𝐶𝐶𝐶𝐶 = 𝐵𝐵 𝐶𝐶𝐶𝐶𝐶𝐶 ∗ (1 + )𝑛𝑛
𝐵𝐵 𝐶𝐶𝐶𝐶𝐶𝐶 (2024) = 11,455
= 𝐴𝐴 𝐸𝐸 𝐸𝐸
= 𝑛𝑛 𝑜𝑜 ℎ
Project cost data presented in this report was adjusted using the ratio of the future CCI to the base (2024) CCI (see formula below). Projects were adjusted for the mid-point of their respective timeframes. For example, projects identified for the next 5 years were adjusted for 2027 dollars and projects identified for the five-to-ten-year range were adjusted for 2032 dollars.

𝐴𝐴𝐴𝐴𝐴𝐴 𝐴𝐴 𝑃𝑃 𝐶𝐶 = 2025 𝑃𝑃 𝐶𝐶 ∗ 𝐹𝐹 𝐸𝐸𝐸𝐸𝐸𝐸 𝐶𝐶𝐶𝐶𝐶𝐶
𝐵𝐵 𝐶𝐶𝐶𝐶𝐶𝐶
Construction costs are intended to cover the material, equipment, labor, and services necessary to build the proposed project. Prices used in this study were obtained from budgetary prices provided by vendors, as well as a review of construction costs from projects in the region, similar recent master plans in the region, cost estimating guides, and other pertinent sources of construction cost information.

Facility costs (e.g., pump station improvements) include allowances for site work, soil conditions, site piping, mechanical/HVAC, electrical, and instrumentation and control. Linear project costs (e.g., pipeline costs) include allowances for fittings and for incidental items such as dewatering, erosion control, traffic control, utility coordination and mitigation, and concrete removal and replacement.

Engineering, legal, and administrative services may include items such as preliminary investigations and reports, site and route surveys, geotechnical and foundation explorations, preparation of design drawings and specifications, engineering services during construction, construction observation, sampling and testing, start-up services, legal fees, financing fees, and administrative costs. The costs presented in this report include a 29 percent allowance, based on input from the City for design (12%), permitting (2%), and construction management (15%), and a 20% contingency.

6.10.1 Pipeline Unit Costs
Water pipeline unit costs include material costs, asphalt demolition, pipe demolition, and trench repair, in addition to the allowances and contingencies discussed above. Pipeline unit costs assume a material of C900 PVC pipe. Pipeline unit costs are provided in Table 23.

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Table 23 - Pipeline Unit costs
Diameter Construction Design
(12%)
Permitting
(2%) CM (15%) Contingency (20%) Total/LF
4" $288.62 $34.63 $5.77 $43.29 $57.72 $430.04
6" $314.17 $37.70 $6.28 $47.13 $62.83 $468.11
8" $347.49 $41.70 $6.95 $52.12 $69.50 $517.76
10" $369.60 $44.35 $7.39 $55.44 $73.92 $550.70
12" $395.27 $47.43 $7.91 $59.29 $79.05 $588.95
14" $420.56 $50.47 $8.41 $63.08 $84.11 $626.63
16" $442.03 $53.04 $8.84 $66.30 $88.41 $658.62
18" $481.20 $57.74 $9.62 $72.18 $96.24 $716.99
20" $525.94 $63.11 $10.52 $78.89 $105.19 $783.65
24" $616.40 $73.97 $12.33 $92.46 $123.28 $918.44
30" $924.40 $110.93 $18.49 $138.66 $184.88 $1,377.36
36" $1,063.08 $127.57 $21.26 $159.46 $212.62 $1,583.99
42" $1,368.70 $164.24 $27.37 $205.31 $273.74 $2,039.36
48" $1,534.56 $184.15 $30.69 $230.18 $306.91 $2,286.49

6.10.2 Valve Unit Costs
Valve unit costs include material costs, asphalt demolition, pipe demolition, and trench repair, in addition to the allowances and contingencies discussed above. Pipeline unit costs assume a material of C900 PVC pipe. Valve unit costs are provided in Table 24.

Table 24 - Valve Unit Costs
Description Construction Design (12%) Permitting
(2%) CM (15%) Contingency (30%) Total/LF
8" Gate Valve $9,049.85 $1,085.98 $181.00 $1,357.48 $1,809.97 $13,484.28 10" Gate Valve $9,382.85 $1,125.94 $187.66 $1,407.43 $1,876.57 $13,980.45 12" Gate Valve $11,049.85 $1,325.98 $221.00 $1,657.48 $2,209.97 $16,464.28

6.10.3 Tank Unit Costs
Tank unit costs are based upon recent bids received on similar tank projects. Tank unit costs assume a construction cost of $3.67 per gallon of storage and include the allowances and contingencies discussed above.

6.11 Other Capital Projects
This capital plan includes non-construction related projects that enable the City to continue to improve and refine capital planning and maintenance moving forward. These capital program- Water Distribution System Master Plan
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related projects are necessary for the City to respond to changing conditions, priorities, and requirements to meet customer, regulatory, and stakeholder needs over time. This section describes these projects that are included in Table 17 – Ten-Year Capital Improvement Plan (Projects O-1 through O-6).

6.11.1 Capital Plan Updates
It is recommended that the City update its 10-year capital plan at least every five years to adapt to changing conditions and update the need, timing, priority, and funding of identified CIP projects.

This project provides budget for those updates. Key activities to be performed include updating the development of current and projected water demands, verification of hydraulic model accuracy, updating the risk model, and revising/extending the ten-year capital plan as appropriate.

6.11.2 Sampling of Asbestos Pipe
As discussed above, under System Renewal, the City should consider an annual budget for continual testing of asbestos cement pipe to assess the condition of the buried pipelines. The sampling will be opportunistic, meaning that a sample for testing will be obtained when the pipe needs to be exposed for maintenance or service. This cost-effective strategy will enable the City to identify corroded pipes and prioritize them for replacement before failure.

6.11.3 CMMS Needs Analysis
This section provides an overview of asset management and how it may be applied to enhance the City’s maintenance and capital planning process for the water distribution system. Part of this assessment includes a discussion of the current use of the computerized maintenance management system (CMMS) and opportunities for improvement. One of the observations from this analysis is that the CMMS is underutilized at the City and that it is not properly configured to meet the maintenance management needs for maintaining the water distribution and wastewater collection system. It is recommended that the City perform a needs analysis to identify what the CMMS needs to be able to do to most effectively support infrastructure maintenance. This will enable the City to evaluate the capabilities and deficiencies in the current CMMS system and develop a plan for improvement or replacement.

6.11.4 CMMS Acquisition and Implementation
Should the City decide to replace the current CMMS (see the CMMS Needs Analysis discussion above) this project provides the budget to select and implement a new system. Activities anticipated include development of system requirements and a request for proposal to solicit potential solutions, an evaluation process to select a viable system, and a budget for a standard, high-level implementation process for system setup and configuration, system validation, and user training.

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CHAPTER 7 FUNDING OPPORTUNITIES
This section discusses the various funding opportunities and strategies that are available to the City and how they might be applied to the projects presented in the ten-year capital plan.

7.1 Overview
This section provides a summary of some of the grants and funding options from state and federal sources that may be considered for funding projects listed in section 6.2, Ten-Year Capital Plan Overview, above. No opinions or recommendations on debt or financing structures are provided as these decisions need to be made in the context of the City’s financial situation, long-term financial plans, project costs, and funding available during the respective application period(s).

Significant recent changes have occurred in water infrastructure programs based on the new funding priorities of the Trump Administration. Since the passage of the Infrastructure Investment and Jobs Act (IIJA), the federal government has prioritized funding allocations for projects focused on resiliency, climate change, sustainability and green infrastructure. New federal priorities have transitioned to expanding and improving U.S. energy infrastructure. While there is still water infrastructure related funding available through IIJA, strategically aligning projects to specific programs and new federal priorities is an important next step to improve the likelihood of project funding and reduce the time and costs of applying to multiple programs.

In general, most funding programs cover construction costs as well as development phase activities, including preliminary engineering work and environmental document preparation, acquisition of property, legal work, and engineering design including permit fees. Costs incurred prior to a funding award may be covered, depending on the program-specific restrictions. Federal funding programs will have additional requirements—such as Davis-Bacon prevailing wages, Build America, Buy America Act or American Iron and Steel provisions, adherence to federal procurement (including Brooks Act), environmental review, etc.—as part of assistance agreements.

Timing wise, it is important to consider applying to these programs as early as practical since engineering and environmental review documents must be prepared and reviewed prior to commencing with construction. Preparing applications early leaves time for drafts to be reviewed by agency partners and proper permit acquisition prior to deadline requirements. Since each funding program has specific requirements surrounding permits and project timelines, the individual program’s process, timeline, and requirements should be reviewed within the context of the City’s overall goals, financial situation, project timelines, and debt policies. The following programs have been identified as potential funding sources for projects listed in the Master Plan and are summarized herein:

Water Infrastructure Finance and Innovation Act (WIFIA) • Community Development Block Grants (CDBG)
• U.S. Department of Agriculture Water and Waste Disposal Loans and Grants • Economic Development Administration (EDA) Grants
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• Congressional Earmarks
• State Revolving Funds (SRF)

7.2 Water Infrastructure Finance and Innovation Act
(WIFIA)
WIFIA is a long-term, supplemental loan program administered by the Environmental Protection Agency (EPA). This program is intended to move projects forward that need additional funding beyond the capacity of other funding programs (e.g., SRFs). WIFIA can provide direct loans and loan guarantees to eligible borrowers for water infrastructure projects. WIFIA can only fund 49 percent of project costs; other funding sources must be obtained for the other 51 percent. If other funding sources include other federal programs, the total federal involvement is limited to 80 percent.

Most water-related infrastructure projects are eligible under WIFIA. All SRF eligible projects eligible under WIFIA. In addition to general costs associated with a project, WIFIA loans can also include debt issuance reserve funds and debt issuance costs.

Highlights of WIFIA:
• $7.5 billion in available funding until fully
expended
• Funding available for 49% of project
• No more than 80% from federal sources
• $5 million project minimum for communities of
25,000 or less
• Interest based on U.S. Treasury securities
• Maturity up to 35 years
• Debt payments can be sculpted
• Defer payments up to 5 years after
substantial completion
• If invited to apply after submittal of letter
of interest, application fee is $100,000
(large communities) or $25,000 (small
communities)
• Credit assurance review fee is typically
$100,000–300,000 (application fee is
credited)
• Service fees do apply for the life of the
loan (+/- $8,000–26,000 per year)
WIFIA is typically used for larger projects with a minimum project size of $20 million. Similar projects 6in a capital improvement plan (CIP) can be combined to form one larger project to meet the minimum project size or to simplify the overall process by having one loan instead of multiple loans if the projects will be constructed over a limited timeframe (i.e., EPA suggests a 5-year period).

The interest rate on WIFIA loans is based on U.S. Treasury securities and may be lower than bonds (depending on maturity, ratings, and market). One advantage of WIFIA financing is the ability to defer repayment of principal and interest for 5 years after substantial completion of the project.

Another potential advantage of WIFIA financing is the ability to negotiate the repayment terms. For example, U.S. Treasury rates at longer debt maturities may be much lower than other market debt instruments at the same maturity when compared to shorter term debt where the spread may be less. At shorter maturities, the spread between private market rates and U.S. Treasury rates may not be enough to provide a significant benefit. By issuing debt at a shorter maturity in the private market (for the 51 percent of costs that WIFIA will not cover) and then pushing WIFIA debt to a longer Water Distribution System Master Plan
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maturity (e.g., 30–35 years), sculpting repayments may provide a potential interest saving versus issuing both sources of debt at equal, longer maturities. However, bond markets and the U.S.

Treasury securities market can vary significantly, and somewhat independently, year to year. WIFIA debt can be prepaid without penalty.

EPA accepts Letters of Interest (LOI) on a rolling basis from the date listed in the Notice of Funding Availability (NOFA). Prospective borrowers can submit a LOI for review by EPA on a rolling basis from the date listed in the NOFA until the earlier of (1) the commitment of all available funding made available for that round or (2) publication of a subsequent notice cancelling or overriding the current NOFA. A rolling selection process allows EPA to provide year-round access to WIFIA funding and quicker selection decisions to prospective borrowers. The LOI is essentially a pre-application that EPA reviews and prioritizes against other LOIs. If the project is prioritized within the funding range, EPA will invite the prospective borrower to make a formal application (the application $100,000 fee is then due). Prospective borrowers must submit a formal application within a year of the invitation to apply.

For example, if the City combined all the proposed near term improvement projects including the Cedar St. line replacement, Oak St. valves, Noyo water liner, and tank replacement into a single fundable water transmission project, the consolidated projects may be eligible for WIFIA funding under a single loan. The advantage of having all projects under a single loan would be securing funding for all the near-term projects. However, including all projects under a WIFIA loan would require every near-term project to be federally compliant with regulations including the National Environmental Policy Act (NEPA) and the Build America, By America Act (BABA). Adherence to federal environmental and sourcing requirements could increase the cost of projects, especially if it is difficult to source materials domestically based on BABA requirements. BABA compliance can increase the timing required for project planning and approval. WIFIA funding should primarily be used for projects with flexible implementation and construction timelines when possible.

7.3 U.S. Department of Housing and Urban Development
Community Development Block Grants
The U.S. Department of Housing and Urban Development (HUD) provides annual funding to states, cities, and counties to stimulate the development of urban communities. In California, annual funding allocations are administered by the California Department of Housing and Community Development.

Based on Federal and State requirements, eligible projects must benefit low- and moderate-income persons, aid in the prevention of extreme poverty areas, or meet an urgent need. Eligible nonentitlement applicants in California include cities with populations below 50,000 or counties with a population of less than 200,000. One of the eligible activities under the program are public improvements including water and wastewater system updates. For public facilities projects to be eligible, the improvement must directly benefit a disadvantaged community.

Based on recent U.S. census data, Fort Bragg has a median household income that is below the state average and a higher population of person in poverty when compared to the state average.

Based on these statistics, valve and water line replacement projects may qualify for HUD funding if Fort Bragg can present a compelling case that improvements are needed to serve portions of the City with moderate income levels. Portions of the Noyo Center water line project may be eligible if it serves future developments that will address local housing needs. Fort Bragg should consider reaching out to the California Department of Housing and Community Development to discuss Water Distribution System Master Plan
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proposed water conveyance projects and how they align with the department’s future funding priorities.

7.4 Economic Development Administration Public Works
and Economic Adjustment Assistance Programs
The Economic Development Administration (EDA) awards grants for projects that advance economic development. Special consideration is given to projects that incorporate EDA priorities, including workforce development. Eligible projects include acquisition and improvement of land for public works use, water and sewer improvement projects, and other construction and pre-construction improvements that assist with community economic development. For the current funding cycle, EDA was appropriated $121.5 million for the public works program. Historically, the average grant award has been $1.4 million, but EDA expects awards in the current cycle to range between $600,000–5,000,000. The program has cost-match requirements, that vary depending on the community’s relative needs.

The Noyo water line project may qualify for EDA grant funding if the City can show that the project will serve new developments and industries needed for local economic development. EDA’s primary mission is to fund projects in communities that are experiencing economic stress due to loss of industry. Fort Bragg projects align with EDA priorities because the City’s economy was built on timber and logging. With the recent reduction in lumber milling, the City could make a compelling case that it would benefit from funding due to economic challenges from loss of industry.

7.5 U.S. Department of Agriculture Water and Waste
Disposal Loans and Grant Program
The United States Department of Agriculture (USDA) allocates funding for clean drinking water, sanitary sewer disposal, and stormwater drainage for households in eligible rural areas through Water and Waste Disposal Grants. Most state and local governmental agencies are eligible for funding. Eligible service areas include rural areas with populations of 10,000 or less and tribal lands in rural areas. Funding is available in the form of long-term, low-interest loans with up to a 40-year payback period. It should be noted that interest may be set at market rates for counties with a high median household income (MHI). A cost-benefit analysis should be used to evaluate if a USDA loan would be worth applying for when compared to water revenue bonds. To qualify, Fort Bragg must propose projects that expand services to very small, rural parts of the town. Eligible activities include legal and engineering fees, acquisitions, start-up operations and maintenance, interest incurred during construction, and the purchase of facilities to expand service. Potentially applicable interest rates are shown in Table 25.

Table 25 – Interest Rates Effective April 1, 2025
Financial Status Interest Rate
Poverty 2.500%
Intermediate 3.375%
Market 4.250%
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Fort Bragg qualifies as a small and rural community based on the USDA’s eligibility criteria of providing loans to populations of 10,000 or less. For large projects including the tank replacement at the water treatment plant, the low interest rates offered by the USDA may offer some cost savings over the lifetime of the project when compared to market interest rates. USDA loan funding should primarily be used to fund larger projects that cannot be funded primarily through rate revenues and reserves.

7.6 Congressional Earmarks
Earmarks are direct congressional funding for a specific local project. Earmarks are administered through federal agencies and projects must qualify based on established program requirements.

Earmarks are not merit based and circumvent the traditional grant application process. Earmarked projects are selected for funding and then follow an application process to ensure projects meet agency/program guidelines. Accessing earmark funding requires direct support from a congressional representative. To receive earmark funding, the utility needs to have a strong connection to a congressional representative and have direct meetings to present the value of the project to the state/county/community.

Future SRF funding may be reduced significantly due to allocations of funding to earmarks. In the 2024 House Appropriations Bill for SRF funding, the Appropriations Subcommittee approved an appropriations bill that allocated 46% of drinking water state revolving funds (DWSRF) funding as congressional earmarks. The amount of funding distributed to each state is determined through a formula after all earmarked funding has been removed. Annual funding allocations through the SRF program in FY2025 were significantly lower compared to previous years. In FY2026, congress elected not to earmark SRF funding and the entirety of the SRF allocations will be allotted to the states. However, the trend of earmarking funds from the SRF programs may continue in the future. If Fort Bragg has a high priority project, it could consider reaching out to a congressional representative about earmark funding for the project. Earmarked funding could result in significant saving for the City if awarded.

7.7 State Revolving Funds
SRF programs are low-interest, revolving loan programs administered by the state with EPA oversight. There are two SRF programs: the Clean Water SRF and the Drinking Water SRF (DWSRF). The DWSRF distributes funding annually for drinking water utility projects and infrastructure improvements. Examples of eligible projects include treatment facility upgrades, rehabilitation of wells or development of sources to replace contaminated sources, and transmission and distribution improvements. SRF requirements in many states, including California, are a mixture of federal and state-level requirements based on state law or state management preferences.

For example, federal statutes limit additional subsidization to disadvantaged communities (DACs), but the state SRF will have discretion on how a disadvantaged community is defined for their state program. The California DWSRF program is administered by the California Water Board and operates as a direct local loan program. Based on federal regulations, states must set interest rates for loans below market rates. The California Water Board set interest rates at 1.9% for 2025. Loan repayment periods are typically less than 30 years but a maximum term of 40 years. The DWSRF interest rates for specific funding allocations in federal fiscal year (FFY) 2024/2025 are provided in Table 26.

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Table 26 – DWSRF Interest Rates
Base Program Principal Forgiveness Principal forgiveness (equivalent to a grant and referred to as a grant in some cases by the SRF program) is available in the base program to help small and disadvantaged communities fund water infrastructure projects. These are applied to applicants that intend to obtain an SRF subsidized loan.

Entities meeting the criteria for financial hardship consideration may be eligible for reduced interest rates and loan principal forgiveness. Principal forgiveness eligibility is predominantly based on the medium household income (MHI) of the community a water system serves. The size of the population served also contributes to the interest rates or loan forgiveness awarded for a project.

The types of projects eligible for forgiveness either address a public health order or a drinking water emerging contaminant. Some forgiveness is also available for projects eligible for Green Project Reserve funding (GPR) with a sustainability factor. GPR funding is reserved for projects that utilize green infrastructure, create energy saving, or have some environmental benefits. The DWSRF DAC criteria and principal forgiveness criteria is provided on Table 27 and Table 28, respectively.

Table 27 – DWSRF Disadvantaged Community Citeria
Disadvantaged Community Definitions
Disadvantaged Community= MHI 80% or Less of State Annual MHI Disadvantaged Community (DAC) MHI <80% statewide MHI
Small Community <3,300 connections or <10,000 people
Expanded Small Community 3,3000-6,600 connections or 10,000 – 20,000 people Medium DAC 20,000 – 100,000 people and a MHI< 80% state MHI Loan Community Type Interest Rate Loan Forgiveness
Planning
<3,300 connections or
<10,000 persons
<80% of state MHI
N/A Up to 100%
Forgivable Loans Small DAC N/A Up to 100%
Repayable
Construction
Small SDAC with Water
Rates >=1.5% MHI 0.00% Interest Up to 100%
Expanded Repayable
Construction
Small DAC or Expanded
Small DAC/SDAC
½ General Obligation
Bond Rate N/A
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Table 28 – DWSRF Principal Forgiveness Criteria
Construction Grants and Principal Forgiveness
Type of Community Residential Water Rates
as a % of MHI
% of Total Eligible
Project Cost
Max Amount Per
Connection
Small DAC/SDAC; Eligible NTNC
That Serves a Small DAC/SDAC;
Expanded Small DAC/SDAC; or
Small Non-DAC with MHI < 150% of
Statewide MHI
N/A Up to 100% $80,000
Medium DAC >=1.5% Up to 50% $40,000
After an initial review, Fort Bragg may meet the disadvantaged community requirements. The 2022 census lists Fort Bragg’s MHI as $47,662 which is 52% of the state MHI of $91,551. The City’s population in 2022 was 6,919 which is also below the small community definition of having a population of 10,000 or less. Depending on the project Fort Bragg may be eligible for principal forgiveness/grant funding through the state SRF program. It is recommended to City confirm its eligibility with a State Water Board representative. The DWSRF application and funding schedule is provided in Table 29.

Table 29 – DWSRF Schedule
Historical Schedule of Annual Water Board SRF Milestones Submit Capitalization Grant Applications to the U.S. EPA June Draft Intended Use Plan (IUP) and Draft Supplemental IUPs Posted for Public Comment June Board Workshop July
Deadline for Public Comments on Draft IUP and Draft Supplemental IUPs Late July State water Board Considers IUP and Supplemental IUP at Regularly Scheduled Meetings August Receive Capitalization Grant Agreements from the U.S. EPA October All the near-term CIP projects would likely qualify for SRF funding. The City should prioritize applying for SRF funding with projects that have the greatest societal benefit. Projects that serve disadvantaged portions of the community and improve public safety will score highest on the SRF scoring criteria. Additionally, the City should apply for projects where other alternative funding sources are not available. The Noyo Center water line may be partially funded through developer agreements. Therefore, projects like the Cedar St. water line replacement, Oak St. valves and the tank replacement should be prioritized when applying for SRF funding.

The SRF process should be started early in the project schedule, particularly if bond supported loans are needed. In California, application packages including environmental reviews should be completed in the spring to be eligible for the upcoming fiscal year. If projects are selected and placed on the state’s intended use plan, it may take a year or more for contracts to be approved and for the project to receive funding. If the City intends to use SRF funding for any proposed projects, it is suggested that conversations with Water Board officials begin approximately a year and a half before project funding is needed. It should also be noted that eligibility for SRF funding is contingent on completion and approval of environmental reviews before the start of any construction activities.

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7.8 Funding Recommendations
As outlined in the Fort Bragg Master Plan, some of the City’s water infrastructure including the Cedar St. water line and Noyo Center Water line need to be upsized to properly serve portions of the City and provide adequate fire flow. Other treatment facility components including a storage tank are aging and in need of replacement. Installing and improving the City’s water conveyance infrastructure would be a significant undertaking and the City should develop an initial funding plan to evaluate how it could pay for new and improved water infrastructure. Table 26 outlines the funding mechanisms described in this section and what near term CIP projects may be eligible based on eligibility requirements. One or several of these programs and strategies could be utilized when considering how to fund long-term CIP projects. Additionally, Table 27 describes the current available funding levels and type of funding mechanisms for each program that has been identified as a potential funding mechanism for Fort Bragg. It is important to note that funding levels and eligibility requirements are prone to yearly changes. The tables below provide initial funding guidance, but updated funding availability and program requirements should be reviewed before developing an application.

Long-term, water rate increases may be needed to recover revenue for projects that do not closely align with grant priorities. For other projects that serve new development areas like the Noyo water Line, developer agreements should be leveraged when possible. This will allow the City to focus its attention on applying for other improvement projects like water line replacements and tank upgrades.

It is best practice to conduct a rate study every five years to project revenue requirements based on anticipated increases in operations and maintenance (O&M) costs. For larger system improvement and expansion projects beyond localized sewer main extensions, long-term debt like SRFs, WIFIA, and Water Revenue Bonds will likely provide more support than many of the grant programs that are more prone to year-to-year budget decisions. For treatment capacity expansions and infrastructure modernization projects over $20 million, WIFIA loans could be considered. All the near-term CIP projects including the Cedar St. Water Line Replacement, Oak St. valves, Noyo water line, and tank replacement could also be combined into a single application for WIFIA as a larger water transmission improvement project. Although current WIFIA interest rates are not as competitive as they were previously, the ability to defer principal payments and sculpting repayments is worth consideration. Programs like WIFIA will only fund new infrastructure projects, long-term maintenance and repairs should predominantly be funded using water rate revenue when possible. Mid-sized projects like the Cedar St. water line and Oak St. valves could be funded through a combination of rate increases, and SRF funding.

The loan process should be started early whenever possible, and efforts in capital improvement planning can aid this process. When planning for future land use changes, capital improvement planning with funding programs in mind is important in securing funding and allowing for a quick response when additional funding opportunities arise. When developing a funding strategy, it is helpful to develop a long-term plan which includes project milestones and how they line up with funding application deadlines. Developing a long-term funding plan would allow the City to apply for program funding early, providing adequate time for necessary environmental and compliance reviews that can create project delays and delay funding awards.

As described in the grants section, some grant funding is available that may cover the cost of system expansions that service low income and disadvantage communities. Based on U.S. Census and SRF criteria, Fort Bragg qualifies as a low-income disadvantaged community. The City’s Water Distribution System Master Plan
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disadvantaged status can be leveraged when applying to programs like HUD Community Development Grants and the EDA Public Works and Economic Adjustment Assistance Program.

When applying for grants, projects that improve transmission or serve disadvantaged parts of the City should be prioritized. For EDA funding, the Noyo Center water line may be eligible if the City can show that it will serve new developments that are needed for local economic development.

New Federal funding priorities have made grant funding levels more uncertain. Some annual funding programs have temporarily paused or halted funding allocations all together. With uncertainty regarding the future of some federal grant programs, the City should not rely on grants as the primary mechanism of project funding but monitor funding notices and maintain communication with funding agencies to learn about updates to grant funding availability as soon possible to maximize the potential for these outside funding sources. Project planning, initial environmental reviews, and early engineering designs should be developed as soon as possible. Starting to plan early will assist with the development of grant applications that will have limited application windows when notices of funding availability are posted. A correlation of the City’s water system CIP and potential funding source eligibility is provided in Table 30. A summary of the criteria associated with the potentially applicable funding sources is provided in Table 31.

Table 30 – Potential Funding and Project Eligibility Matrix CIP ID Project Name WIFIA HUD CDBG EDA Public
Works
USDA Loans
and Grants EPA SRF
P-1 Cedar Street Line
Replacement X X X
V-1 Oak Street Valves X X X
P-2 North Fort Bragg
Water Main Extension X X X
T-1 Tank 1 Replacement X X X
Table 31 – Available Funding Summary
Source Funding Type Available $a Notes
WIFIA Long-Term Loan
49% of eligible projects
over $20M and $5M for
small communities
• Interest rate based on U.S.

Treasury Securities
• Maturity up to 35 years
• Sculpted debt
• Letters of Interest on a rolling
basis
DWSRF Loan/Some Grant
Funding Available $391M
• Low interest for 20-year maturity
• Available $ = CA FY25 funding
allocation
• Amount of funding likely to
decline after 2026
• Broad eligibility
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Source Funding Type Available $a Notes
HUD Community
Development Block
Grants
Grant 2025 Allocation not
announced
• Funds allocated to state, city,
and county
• Project must resolve a problem
that will help revitalize the
community
• Short project completion window,
24 months
EDA Public Works and
Economic Adjustment Grant $30 million
• Must promote economic
development in disadvantaged
areas
• Percent match requirements
depending on disadvantaged
status
USDA Water and
Wastewater Loans and
Grants
Predominately loans
and some grants
Varies based on
annual funding
allocations
• Projects must serve rural
communities (population less
than 10,000)
• Interest rates vary based on
communities disadvantaged
status
• Up to 40-year payback period
aAvailable funds provided in 2025 dollars
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CHAPTER 8 CEQA COMPLIANCE
The California Environmental Quality Act (CEQA) was passed in 1970 and as defined in CEQA Guideline 15002 General Concepts subsection a, is intended to:

1. Inform governmental decision makers and the public about potential, significant environmental effects of proposed activities.

2. Identify the ways that environmental damage can be avoided or significantly reduced.

3. Prevent significant, avoidable damage to the environment by requiring changes in projects through the use of alternatives or mitigation measures when the governmental agency finds the changes to be feasible.

4. Disclose to the public the reasons why a governmental agency approved the project in the manner the agency chose if significant environmental effects are involved.

CEQA governs public actions and does not apply to private actions unless the action involves governmental participation, funding, or approval (CEQA Guidelines 15002 (c)). Such actions are referred to as “Projects”, and the definition of a Project has been refined by court decisions.

Complying with CEQA involves evaluating potential impacts from the proposed Project on the natural and human environment. These impacts cover a broad range of more than twenty resources, including but not limited to air quality, biological resources, transportation, recreation, and wildfire threat.

As a planning process, CEQA should be started at the earliest feasible time in Project development, but late enough so that they provide meaningful information in the environmental analysis (CEQA Guidelines 15004).

8.1 Levels of Documentation under CEQA
The level of review a project is subject to under CEQA varies based on the expected impacts from that project. Once established as a project that is subject to CEQA review, there are three general levels of review under which a project may be considered: Exemption, Initial Study (IS), and Environmental Impact Report (EIR). These review levels are briefly discussed below, with a focus on opportunities they present for streamlining the review process and their vulnerabilities to legal challenges.

8.1.1 Exemptions
Two types of exemption exist under CEQA. Statutory Exemptions are exempt by law. Categorical Exemptions are classes of projects that have been found to have less than significant environmental impacts. Statutory Exemptions are listed in Article 18 of the CEQA Guidelines (Sections 15260 to 15285), and Categorical Exemptions are detailed in Article 19 (Sections 15300 to 15333). The degree of exemption varies between completely exempt, exempt from part of CEQA’s requirements, or exempt just to the timing of CEQA compliance.

Categorizing a project as exempt from CEQA can simplify regulatory requirements, however there are significant limits to how exemptions may be employed. There are many conditions that provide exceptions to exemptions, for example the presence of a scenic highway, or of critical habitat for a Water Distribution System Master Plan
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species of special concern could override the applicability of categorical exemptions under classes 3, 4, 5, 6, and 11.

Further, the empowering statute for CEQA, California Public Resources Code Division 13, Section 21159.27, includes a prohibition against ‘piecemealing’. Piecemealing is first defined in Bozung v.

Local Agency Formation Com. (1975) which states:
• Environmental considerations do not become submerged by chopping a large project into many little ones – each with a minimal potential impact on the environment – which cumulatively may have disastrous consequences.

Laurel Heights Improvement Assn. v., Regents of University of California (1988) refined this discussion by providing the following test:
• We hold that an EIR must include an analysis of the environmental effects of future expansion or other action if: 1) it is a reasonably foreseeable consequence of the initial project; and 2) the future expansion or action will be significant in that it will likely change the scope or nature of the initial project or its environmental effects.

To summarize, the analysis of a project that is contingent upon another project being completed is not adequate without the inclusion of analysis of that project. Use of multiple exemptions to reduce paperwork within a project may seem appealing, however such use can create a significant effect on the environment and make the projects vulnerable to legal challenges.

Many other cases have tested this level of review; however, Laurel Heights remains the benchmark for evaluation of whether a project is part of a larger endeavor that has been piecemealed. The piecemealing question and test is an important consideration when evaluating the use of exemptions for implementation of a large, long-term program.

8.1.2 Initial Study
Projects that are not Statutorily or Categorically exempt from CEQA, often start with an environmental review through the preparation of an Initial Study (IS). If the IS identifies no significant impacts, the project may adopt a Negative Declaration and proceed with implementation. If the IS identifies significant impacts, but the impacts can be reduced to a less than significant level through mitigation then the project may adopt a Mitigated Negative Declaration (MND) and proceed. Projects with significant impacts that cannot be mitigated to less than significant levels must be evaluated in an Environmental Impact Report (EIR).

8.1.3 Environmental Impact Reports
An EIR is recognized as the ‘gold standard’ of CEQA documentation and analysis within an EIR requires substantial evidence. EIRs must evaluate the impacts of a proposed Project, alternatives to the proposed Project that can feasibly accomplish the Project’s objectives and may reduce environmental impacts, and mitigation measures that may be used to reduce Project impacts to a less than significant level. EIRs include a period of public review, during which public agencies and individuals may provide comments on the adequacy and accuracy of the document.

Ideally, an EIR will identify an environmentally superior alternative that is feasible and accomplishes the Project’s goals while causing no significant and unavoidable impacts. However, often an EIR Water Distribution System Master Plan
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identifies and evaluates an alternative that is feasible, meets the Project’s objectives, avoids and minimizes some impacts but still results in some significant impacts. In this instance, the lead agency may still certify the EIR and pursue their preferred alternative through the publication of a Statement of Overriding Considerations (SOC) as part of their decision making.

There are several types of EIR, intended to provide an opportunity to streamline the process and facilitate environmental review and CEQA compliance. These include a Project EIR, Staged EIR, Program EIR, and Master EIR. This section will not address Staged EIRs as they are less appropriate for city-wide, or district wide projects.

8.1.3.13 Project EIR
The Project EIR is the most common of EIR types. These evaluate the impacts of a specific Project and focus on changes in the environment that would result from the Project. Such analysis must include all elements of the Project including planning, construction, and operation (CEQA Guidelines 15161).

8.1.3.14 Program EIR
A Program EIR is defined in CEQA Guidelines 15168:
(a) General. A program EIR is an EIR which may be prepared on a series of actions that can be characterized as one large project and are related either:
1) Geographically,
2) As logical parts in the chain of contemplated actions, 3) In connection with issuance of rules, regulations, plans, or other general criteria to govern the conduct of a continuing program, or
4) As individual activities carried out under the same authorizing statutory or regulatory authority and having generally similar environmental effects which can be mitigated in similar ways.

A Program EIR has multiple advantages in streamlining complicated projects and subsequent review, as the document can be relied upon for related projects. This reduces repetitive analysis, broadens consideration of cumulative impacts, considers a wider range of alternatives before the lead agency has committed to a specific course, and can reduce paperwork. A program EIR also allows other activities to be performed under its auspices, assuming no substantial changes have occurred to the project, the circumstances under which it is undertaken, or new information is discovered (CEQA Guidelines 15168(c)). A project that is not specifically included in the scope of a Program EIR will not be evaluated under PRC 2166’s deferential standard of review but may be included under the fair argument standard. This has been successfully defended in court (Friends of the College of San Mateo v. San Mateo County (2016)) and provides a less rigorous standard of review than a new EIR.

8.1.3.15 Master EIR
A Master EIR evaluates the cumulative, growth inducing, and irreversible significant impacts on the environment of subsequent projects. It is intended to streamline review of subsequent projects for Water Distribution System Master Plan
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the classes laid out in CEQA Guidelines section 15175. The following list omits those sections that would not be relevant to utilities redevelopment or rehabilitation within Fort Bragg:

1. A general plan, or component update, element, amendment, or specific plan

2. Public or private projects that will be carried out or approved pursuant to, or in furtherance or, a redevelopment plan

3. A project that consists of smaller individual projects which will be carried out in phases

4. A rule or regulation which will be implemented by later projects

5. Projects that will be carried out or approved pursuant to a development agreement Of particular note in regards to the preparation of a Master EIR for use in streamlining a Capital Improvement Program, CEQA Guideline 15176 (b)(4) states that a Master EIR shall include a description of anticipated subsequent projects within the scope of the Master EIR including a capital improvement program that governs the submission and approval of subsequent projects, or an explanation as to why practical planning considerations render it impractical to identify any such program or scheduling or other device at the time of preparing the Master EIR.

Tiering under CEQA
Tiering is defined under CEQA Guidelines Section 15152 (a) • “Tiering” refers to using the analysis of general matters contained in a broader EIR (such as one prepared for a general plan or policy statement) with later EIRs and negative declarations on narrower projects; incorporating by reference the general discussions from the broader EIR; and concentrating the later EIR or negative declaration solely on the issues specific to the later project.

As such, Tiering can be applied to streamline environmental review in projects that follow from and are largely covered by a precedent environmental document, including a Master EIR; however, when Tiering a CEQA document from another one, if the precedent document includes an SOC, any document Tiering off of it will need to adopt another SOC, as established by Communities for a Better Environment v. California Resources Agency (2002). Establishing the intent and coverage of a Master EIR is important in calibrating the document’s scope, and when done effectively they simplify CEQA compliance, reduce paperwork, and manage many of the sorts of constituent projects that may be otherwise exempt or ministerial, without opening them to a meaningful piecemealing challenge.

8.2 Level of Effort for Environmental Compliance: Fort
Bragg’s Water Enterprise CIP

8.2.1 Expected Notice of Exemptions (NOEs) for City CEQA Compliance
Some projects and improvements in the WDMP may be covered by a Categorical or Statutory exemption and be exempt from evaluation under CEQA. Statutory exemptions were recently expanded by Senate Bill 131, passed on June 30 of 2025. Exemptions expected to be useful in the CIP complying with CEQA are listed below.

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Statutory Exemptions
• CEQA Statutes Section 21080.47 includes exemptions from CEQA for certain community water systems. As noted above, these exemptions were expanded due to Senate Bill 131.

Despite these expansions there are still some additional requirements that will need to be observed to make use of this exemption. The project must meet the following conditions:
o Does not affect wetlands as defined in the United States Fish and Wildlife Service Manual 660 FW 2 (June 21, 1993), or an environmentally sensitive habitat area within the coastal zone, as defined in Section 30107.5.
o Unusual circumstances do not exist that would cause a significant effect on the environment.
o Is not located on a hazardous waste site that is included on any list compiled pursuant to Section 65962.5 of the Government Code.
o Does not have the potential to cause a substantial adverse change in the significance of a historical resource.
o The construction impacts are fully mitigated consistent with applicable law. o The cumulative impact of successive reasonably anticipated projects of the same type as the project, in the same place, over time, is not significant.

None of these exceptions are expected to apply to projects within the City of Fort Bragg and covered by the Inland General Plan. If any of these exceptions are found to be applicable to a specific project proposed by the CIP, that project would require further evaluation to confirm applicability and before it could be implemented.
• CEQA Statutes Section 21080.21: Public Right-of-Way Projects less than One Mile in length.

Categorical Exemptions
• Class 2 Replacement or Reconstruction (c) On-site replacement of utility systems and/or facilities involving negligible or no expansion of capacity.

Categorical Exemptions do not apply to all projects. Projects that would normally be exempt from CEQA under one of these classes are excepted if:
• The project is located in a particularly environmentally sensitive area, where a normally insignificant impact may be substantial.
• Multiple projects of the same type in the same place would cause a significant cumulative impact over time.
• The project would result in a significant effect, due to unusual circumstances. • The project may result in damage to scenic resources. • The project would be located on a list of hazardous waste sites compiled under Section 65962.5 of the Government Code.
• The project would cause a substantial adverse change to a historical resource.

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8.2.2 Environmentally Clearing Individual Projects
This section evaluates CEQA clearance on a project-by-project basis. The updates to CEQA Statutes Section 21080.47 from SB 131 expand the exemptions available to streamline CEQA compliance for projects within the City of Fort Bragg that are in existing public rights-of-way and also in areas covered by the Inland General Plan.

CIP Projects that qualify for CEQA exemption under CEQA Statutes Section 21080.47 The following definitions from the revised CEQA Statutes Section 21080.47 establish the foundation for compliance with CEQA.
• Small Community Water System – A Community Water System is defined in the PRC as a public water system that serves at least 15 service connections used by yearlong residents, or that regularly serves at least 25 yearlong residents within the area served by that system.

It qualifies as a “small” system if that system serves no more than 3,300 service connections, or a yearlong population of no more than 10,000 persons. o According to 2023 American Community Survey Data (U.S. Census Bureau 2023), the City of Fort Bragg has a population of 7,001. As such, it falls between 25 yearlong residents and serves no more than 10,000 yearlong persons, thereby qualifying as a Small Community Water System.
• Disadvantaged Community - a community with an annual median household income that is less than 80 percent of the statewide annual median household income. o According to 2023 American Community Survey Data (U.S. Census Bureau 2023), the City of Fort Bragg has a median household income of $53,580. Median household income for the state of California in the same survey is $96,334. This puts the City of Fort Bragg’s median household income at 56 percent of that of California, less than the 80 percent threshold that qualifies as disadvantaged.
• These points together demonstrate that, by definitions set forth in CEQA Statutes Section 21080.47, the City of Fort Bragg’s water system qualifies as a “small, disadvantaged community water system”.
• Project - under CEQA Statutes Section 21080.47 certain specific infrastructure elements are defined as a project. The most salient to the City of Fort Bragg’s CIP are listed below:
o Drinking Water Storage Tanks with a capacity of up to 250,000 gallons, o Booster pumps and hydropneumatics tanks,
o Pipelines of less than three miles in length in a road right-of-way, o Water service lines,
o Minor drinking water system appurtenances, including, but not limited to, system and service meters, fire hydrants, water quality sampling stations, valves, air releases and vacuum break valves, emergency generators, backflow prevention devices, and appurtenance enclosures.
• Note that CEQA Statutes Section 21080.47 specifically excludes “Facilities that are constructed primarily to serve irrigation or future growth”.

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As Fort Bragg’s system fits the statutory definition of a small, disadvantaged community water system and many projects included in the CIP are pipelines within existing road right-of-way, or otherwise included in the statutory definition of “project” outlined above, these projects are presumed exempt from CEQA, absent any of the exceptional circumstances outlined under Statutory Exemptions in Section 8.2.1. These projects include: The Willow Street Pump Station Upsize Project (PS-1), Oak Street Valves Project (V-1), Cedar Street Water Line Replacement Project (P-1), System Renewal-Pipe Replacement Project (PL-1), East Laurel Street Water Main Replacement Project (P-2), North Main Street Water Main Replacement Project (P-6), East Alder Street Water Main Replacement Project (P-13), Chief Celery Dr Water Main Replacement Project (P-10), Noyo Point Road Water Main Replacement Project (P-4), Maple Street Water Main Loop Project (P-8), East Elm Street Water Main Loop Project (P-5), East Chestnut Street Water Main Replacement Project (P-9), Spruce Street Water Main Replacement Project (P-11), and System Renewal-Pipe Replacement Project (PL-2).

Should any circumstance listed as an exception to 21080.47 listed in section 8.2.1 arise during project planning or implementation, additional evaluation may be required. Otherwise, to demonstrate and record Project compliance with a Statutory Exemption under CEQA, the City would need to file a Notice of Exemption with the State Clearinghouse and Mendocino County.

CIP Projects not covered by CEQA Statutes Section 21080.47:

The CIP Projects that do not meet the CEQA Statutes Section 21080.47 Exemption conditions include the Tank 1 Upgrade Project at the treatment plant, the North Fort Bragg Water Main Extension Project, and the Noyo Center Water Line Project. These three Projects are discussed below.

The North Fort Bragg Water Main Extension Project (P-3) would install 2,144 feet of new water main, to serve future growth. The proposed alignment is within the right-of-way of Highway 1. As such, the North Fort Bragg Water Main Extension falls under the exemption in CEQA Statutes Section 21080.21, “…any project of less than one mile in length within a public street or highway or any other public right-of-way for the installation of a new pipeline…”. Therefore, implementation of P-3 would be exempt from CEQA. To demonstrate and record Project compliance with this Statutory Exemption under CEQA, the City would need to file a Notice of Exemption with the State Clearinghouse and Mendocino County.

The Tank 1 Upgrade Project (T-1) at the treatment plant exceeds 250,000 gallons of capacity and therefore would not be exempt under CEQA Statutes Section 21080.47 or any other Statutory Exemption. The Project is, however, Categorically Exempt under a Class 2 exemption for replacement of a facility on-site with no expansion in capacity. To demonstrate and record Project compliance with this Categorical Exemption under CEQA, the City would need to file a Notice of Exemption with the State Clearinghouse and Mendocino County.

The Noyo Center Water Line (P-2) is located in the Coastal Zone and would require additional investigation before it could be properly evaluated under CEQA Statutes Section 21080.47, furthermore this project is intended to serve future growth, and as such is specifically excluded from that exemption. The Noyo Center Water Line does not exist within a public right-of-way and therefore is not exempt under CEQA Statutes Section 21080.21. An Initial Study or EIR would likely need to be prepared before the Noyo Center Water Line could be implemented.

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8.2.3 Program Environmental Impact Report(s)
There are multiple ways that the City could scope the development of one or more Program EIRs. A Program EIR could potentially address all WDMP projects. A Program EIR could be focused to present mitigation as necessary to reduce impacts during construction within the right-of-way and to lessen or avoid impacts to Air Quality, Noise, Utilities, Public Services, Transportation and other resources. In the event of multiple Program EIRs being prepared it would be possible to focus them more tightly by expansion area, for example, the Noyo Water Line and the North Fort Bragg Water Main Extension Project could be combined. Once more information is available for the proposed projects, the determination if a Program EIR would be the appropriate level of documentation could be answered. The preparation of a Program EIR that could present general mitigation for projects that share certain characteristics (such as those that could be implemented entirely within existing right-of-way) would significantly streamline future environmental review.

Developing a Program EIR capable of encompassing all projects in the CIP may be difficult, and considering the expansion of exemptions represented by SB 131 may not be necessary or required.

The only project the CIP includes that is not expected to be exempt from CEQA is the Noyo Water Line Project. If a plan to redevelop the area surrounding the Noyo Water Line Project is to be developed, a Program EIR to support that the entirety of that project may be beneficial.

8.2.4 Master Environmental Impact Report
The development of a Master EIR for the City’s Capital Improvement Program would include a discussion of environmental and regulatory constraints. Incorporation of this discussion into the compliance effort for any project that fits within the parameters of the Master EIR would significantly reduce, and potentially eliminate, environmental analysis for subsequent projects. As a Master EIR is intended as a document to tier from, rather than incorporate the majority of a program, fewer project specifics are required than with projects covered under a Program EIR. This reduces repetition and revision of project elements in the event that a project description changes.

Due to this general flexibility a Master EIR could be used to tier to other projects that may not be considered at the time the Master EIR is prepared. A sufficiently broad Master EIR could, for example, be used to partially analyze projects forwarded by the Wastewater and Broadband enterprises of the City’s CIP. A project that doesn’t fall under the scope of a Master EIR would require additional analysis, however, the work done in the Master EIR could still be applied to reduce future necessary analysis.

The versatility of a Master EIR could also be extended to operate anywhere within the project area, whether the project site in question would be covered under the Inland General Plan or the Coastal General Plan. The inclusion of a section that discusses the additional regulatory elements of the Coastal General Plan would further simplify analysis of subsequent projects and may minimize the level of environmental review and compliance for each covered project.

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CHAPTER 9 ASSET MANAGEMENT
This section provides an evaluation of the City’s current asset management practices and provides prioritized future recommendations for improving asset management practices to track, evaluate, and replace aging infrastructure. It will define and discuss asset management strategies, provide an overview of current asset management practices in the City to support water distribution infrastructure, and will provide recommendations for improvement.

9.1 What is Asset Management?
Asset management is a framework that enables an organization to effectively manage their assets across the asset life cycles (acquisition, operation, disposal) in a sustainable and consistent way to get the most value from the asset while meeting the organization’s objectives and performance expectations. Asset management provides methods to make data-driven decisions which increases transparency to customers and stakeholders, provides consistency in decision-making, and presents a common language and strategy that facilitates communication and buy-in among management and staff.

Asset management is based on measurable asset data that describes:
• What assets do the organization own?
• Where are they located?
• What is their condition?
• How are they performing?
• What needs to be done to keep them performing?
• What has been done in the past?
Decisions made using asset management include both maintenance actions and capital improvements to the organization’s infrastructure. The decisions need to align with the overall organization mission, values, and performance measures. This alignment includes:
• Developing a common understanding of how asset management contributes to business. • Creating processes that address overall organizational needs with the realities of day-to-day management and operation of the infrastructure.
• Provides structure for consistent decision-making and values at all levels of the organization. • Implements process that collect, analyze and manage relevant data and technology systems.
• Provides a strong focus on risk management.

A typical asset management framework is illustrated in Figure 41. The pyramid shows several important asset management relationships and how they build on each other as they move up the pyramid. The foundation of this framework is asset data. Asset data is generated organizationally by field staff and analysts and provides an on-going means to measure the condition and performance of the infrastructure. These data are first used for tactical, day-to-day decisions. At Water Distribution System Master Plan
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high levels in the pyramid, the data is analyzed for more strategic decisions which are typically made by management and executives. The highest levels in the pyramid create alignment with the organization’s mission, goals, and performance expectations.

With organizations that have thousands of assets, limited resources, and competing needs, it is imperative that risk is factored into decisions. A risk framework can be established that enables the organization to determine where the biggest risk is to their expected levels of service, and what investments will provide the biggest return on risk reduction.

Figure 41 - Asset Management Pyramid

9.2 Why is it Important for the City?
There is ample evidence that implementing an asset management program provides several benefits, including improving service levels, reducing costs, and increasing staff motivation. An Asset Management Program will move the City towards a more proactive maintenance management process and establish best practices for developing capital and operating budgets International Organization for Standardization (ISO) 55000 states that “Organizations have achieved improvements in service level and system reliability between 5-25% and sustained total cost reductions of between 20-40%, along with better employee motivation and productivity, greater customer satisfaction and increased confidence from regulators and other external stakeholders.” Recent surveys by the American Water Works Association show that over one third of surveyed water utilities are using a robust asset management program to prioritize their capital and operational/maintenance investments. 62% of the surveyed agencies use asset management plans Water Distribution System Master Plan
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to manage infrastructure maintenance instead of reactively responding to wastewater pipeline and equipment failures (American Water Works Association, “AWWA Utility Benchmarking: Performance Management for Water and Wastewater,” 2019).

Specifically, asset management strategy provides many benefits including:
• Maximizing investment in City infrastructure by optimizing the useful life of each asset. • Providing a data-driven, transparent, and repeatable capital improvement process. • Improves alignment of resources to maintain or improve utility performance. • Provides for risk-based decision-making.
• Offers a framework and vocabulary that improves transparency, communication, and decision-making throughout the organization.

Asset management is not a “one size fits all” proposition. A comprehensive asset management program will apply can impact the whole agency, aligning how it is organized, developing policies, processes, and procedures around asset maintenance and capital planning. Others selectively apply specific asset management techniques and tools to certain aspects of their operations. The City does not currently have a comprehensive asset management program, however, they do apply some asset management strategies to maintenance and capital planning. Additional practices and recommendations are discussed below that will complement the City ‘s current practices and facilitate decision-making.

9.3 Asset Management Practices at the City
This section describes the current work practices in place for performing asset maintenance and for capital planning.

9.3.1 Maintenance
Work practices for performing maintenance can be divided into several parts: These are typically planning and scheduling, work assignment, and work completion. The maintenance management work process is the same for both the water distribution system and the wastewater collection system. Both are handled by the same field staff and Maintenance Lead. There are several ways that maintenance work is identified and initiated. Some of the most common ways are:
• Unscheduled work, such as leaks and repairs, are reported to the Maintenance Lead. • New water connections are provided by City Hall to the Maintenance Lead via a paper work order. The Maintenance Lead assigns the work to appropriate staff and attaches the paper work order to an electronic work order in Asset Essentials. • Programmatic maintenance, such as flushing or valve turning, is done on a regular basis.

These are scheduled by the Operations Manager and tracked in a spreadsheet. • Collection system cleaning is done on a regular basis. These are scheduled by the Operations Manager and tracked in a spreadsheet.

Work planning and scheduling are managed through a whiteboard. All maintenance work is listed on the whiteboard until it is completed.

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Work assignments are allocated by the Maintenance Lead daily. Regular coordination meetings are held early morning to provide assignments, coordinate, and discuss the necessary work.

Once work has been assigned, it is the responsibility of the field staff to prioritize and complete their assignments. As work is completed, the field staff will take relevant notes and pictures to capture what work was performed but these are not recorded permanently except for the programmatic maintenance and the collection system cleaning. Critical details related to new service connections are recorded and passed on to City Hall. Field staff will brief the Maintenance Lead on work completed at the end of each day, who will update his maintenance notes accordingly, and may plan for future work, if necessary. All tasks tracked in Asset Essentials are closed and marked completed in the CMMS system. Coordination of maintenance work throughout the year is managed verbally between the Operations Manager and the Maintenance Lead.

9.3.2 Capital Planning
Capital planning for the City is done on an annual basis. Most of the capital planning has focused on the water and wastewater treatment systems or other civil infrastructure and not on the water distribution or wastewater collection systems due to more urgent needs in the last several years.

When capital projects are identified for the distribution or collection systems it is usually triggered by an urgent issue, new regulation or litigation, or a new opportunity related to work being performed by other agencies. New potential projects can be identified by the Lead Operator or Operations Manager.

When a new project is identified, it is entered into the budget spreadsheet. The project will then be assigned to a staff member to research. The staff member responsible will update the description, justification, estimated cost, and general schedule for the project. All new projects are assigned to staff members for development of project plans based on new and existing priorities.

Once the project budget spreadsheet has been updated, the projects will be reviewed by the Operations Manager, Assistant Director of Engineering Division, Public Works Director, and City Manager. Projects are prioritized and scheduled based on several factors including factors impacting project construction, potential for grant funding, customer/stakeholder impacts, and/or City Council concerns.

The proposed capital plan is submitted to the City Council for review and approval at the June budget session. The City Council then reviews the plan and approves it if no changes are identified.

As mentioned above, most capital planning work for water or wastewater infrastructure has been focused on treatment facilities where the most urgent needs have been identified. There are not very many issues with the current water distribution or collection system infrastructure, but the City anticipates that more focus and resources will be needed in the near term as the systems continue to age. The current efforts to develop a master plan and ten-year capital plan for both the water distribution and wastewater collection systems will help the City identify and prioritize these needs before they become emergencies. Projects that are defined from these efforts will be used for the basis of annual capital planning in the coming years. The capital planning effort is based on current asset information and includes hydraulic modeling, condition assessment, and development of a risk model to facilitate prioritization. The master plans will provide defensible justification, supporting data, a transparent process, and assess impacts if the projects are not completed. This will provide Water Distribution System Master Plan
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the City with a balanced view to compare these projects with more highly visible civil projects for budget approval.

9.4 Asset Management Improvement Recommendations
There are several actions that the City can take to incorporate asset management best practices into the maintenance and capital planning process. This section provides recommendations to help the City align its water system maintenance and capital planning work processes with asset management best practices. The recommendations include a suggested priority to indicate which ones will provide the highest value in achieving this goal. Priorities are categorized as follows:
• High – Recommendation should be started as soon as possible and should be completed in the next two to three years.
• Medium – Recommendation should be completed in the next five years. • Low – Recommendation should be completed within the next five to ten years.

These recommendations reflect best practices and standards for asset management implementation that other agencies have applied successfully to improve utility performance. They have been selected and presented here because they would enable the City to increase asset management knowledge and maturity based on current work practices in place. Implementing these recommendations would help the City achieve the benefits described above. Some of the recommendations work best if implemented together, and some can be implemented successfully individually. The City should consider each of the recommendations and determine whether or not implementation will be cost-effective and provide sufficient value.

9.4.1 Maintenance Recommendations
• [High] Establish an asset data management specification that describes the critical information needed for maintenance management, including data requirements, staff roles and responsibilities, and standard work processes. Note that this recommendation is provided in the current ten-year plan.
• [High] Identify critical assets in the asset inventory to assist in prioritization. • [Medium] Maintain a central asset inventory and repository of maintenance activities, history, and plans (e.g. a CMMS). This will facilitate maintenance planning, assist with troubleshooting and decision-making, and provide more insight into maintenance needs for more cost-effective maintenance.
• [Medium] Capture labor and materials as appropriate on work orders, service requests, and inspections. Typically, the most valuable information that a CMMS provides is data about repair history, the effort involved, and parts used. This enables O&M management to make more informed maintenance decisions, determine if O&M needs are being appropriately addressed, and assess maintenance performance. Information on the amount of labor and materials needed to complete maintenance work is essential. • [Medium] Maintain an easily accessible maintenance history that can be accessed by maintenance staff for maintenance planning and troubleshooting.

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• [Medium] Build data quality control process into all workflows. It is not uncommon to introduce errors or data gaps when making updates to data. To address this, it is important that all data updates undergo a quality review process to catch errors or omissions. By building quality control work practices into data management, errors will be quickly identified and corrected, which will promote high confidence and reliability among data users. • [Low] Document job plans, tasks, and procedures in an electronic format to preserve institutional knowledge about maintenance needs and to provide maintenance consistency. • [Low] Implement the use of mobile technology to capture work in the field and access key information from GIS/CMMS. Most CMMSs provide useful tools to support capturing inspection and work order information electronically on tablets or cell phones while in the field. Many systems today are able to work “offline” in areas where cell coverage is unreliable.

9.4.2 Capital Planning Recommendations
• [High] Internalize the tools and processes developed for this Master Plan so that the City can continue to use it for capital planning. Establish procedures to regularly update asset data over time so that the capital priorities continue to align with the City’s changing needs over time. Key elements are the hydraulic model, GIS, and asset risk model. Details on these technological elements are provided below.
• [High] Continue to perform opportunistic asbestos testing of pipe samples to measure remaining wall thickness of the asbestos pipe. Energy Dispersive X-Ray Spectroscopy (EDS) uses mass spectroscopy to measure remaining carbon through a cross section of pipe. This provides direct evidence of pipe condition and can be used to prioritize pipe replacement. The use of EDS testing for the City is discussed in section 6.8.2: Pipe Condition Assessment and a line item for continual opportunistic testing is provided in the ten-year CIP (see section 6.11.2: Sampling of Asbestos Pipe) • [Low] Periodically update the pipeline risk model as more information is collected about the system. Evaluate the asbestos sampling results and compare them to the risk model results to add or replace risk model factors.
• [Low] Establish a regular cycle for master planning and 10-year CIP development.

9.4.3 Technology Recommendations
Recommendations for each of the technological components are provided below.

9.4.3.16 CMMS Recommendations
• [High] Develop a requirements analysis to document CMMS needs for water distribution as well as other divisions within the City. This will define the minimum requirements that the CMMS system needs to fulfill. These requirements can be used to either improve the existing CMMS for more consistent and comprehensive use or to help determine if a new system is needed. This recommendation is included in the ten-year capital plan. • [High] Specific functionality that should be implemented based on initial discussions with the City includes;
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o Integration of GIS features into the CMMS to facilitate use by Water Distribution. o Develop or modify work order templates that support the water system maintenance activities.
o Identify and develop standard reports that will support maintenance and capital planning. o Develop the capability to attach the appropriate water distribution assets to work orders to facilitate evaluation of maintenance history.
• [High] Assign a staff member to be the CMMS system owner. They will be responsible for working with the Operations Manager to keep the system updated, support planning and scheduling of maintenance work, help users with access and functionality, develop standard reports, and perform specific as-needed data analysis. They will also keep the asset inventory up to date as infrastructure components are replaced. • [Medium] All maintenance work should be recorded and maintained in the CMMS. The CMMS should be the system of record for all maintenance work. Consolidating all maintenance data and documentation into one system makes it easier to maintain, minimizes errors and discrepancies, and increases staff confidence in the accuracy and usefulness of the system. Data may be extracted and shared with other systems or further processed with other tools, but the CMMS should be the authoritative data source for maintenance data.
• [Low] Develop standard reports to be used across the department. A key strategy for successful CMMS implementation and return on investment is to maximize the use of the data and information collected. The most common and obvious uses for the data are for the O&M staff to use it for identifying maintenance requirements and maintenance history for troubleshooting, and for O&M management to use it for planning, understanding maintenance trends, and for daily decision-making. However, there are many other uses for the data as well. For example, Engineering can use trends in unscheduled maintenance and repair to prioritize capital planning, and Department management can use key performance indicators (such as percent of system flushed) to gauge how well the Department is meeting expected service levels.

9.4.3.17 GIS Recommendations
• [High] Select a GIS implementation strategy as outlined in CHAPTER 2: System Mapping. • [High] Assign a system owner to manage the water distribution GIS data. The City will realize the most benefit from its investment in GIS if it is regularly used for planning and decision-making. This requires accurate and up-to-date asset data and the ability to keep the GIS linked with the CMMS for current maintenance history. Without a focused effort on data maintenance, users will lose confidence in the data in the GIS, making it unreliable and requiring more effort to validate the work products and results. • [High] Establish a GIS update process. As the City completes maintenance and replacement of water mains and other maintenance or capital projects, it is essential that the information get updated in GIS in a timely manner. This will potentially impact other maintenance and inspection activities.
• [Medium] Integrate the GIS with the City’s selected CMMS. The GIS can function as the system-of-record for the City’s linear assets (i.e., assets outside of the treatment plants).

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These assets should be imported into the CMMS and a procedure established to keep them synchronized. This will allow maintenance and capital planning activities to be linked to linear assets as well as vertical (plant) assets, providing the foundational element for asset management.
• [Low] Consider leveraging the new Utility Network to develop a valve isolation function to identify valves to close and customers affected when pipes need to be isolated for repairs. A valve isolation application is available from ESRI for water system utility networks and can be configured to identify the valves to be turned to isolate a pipe for repair. It may also identify customers who will be affected.

9.4.3.18 Hydraulic Model Recommendations
• [Medium] The hydraulic model is linked to the GIS database through InfoWater Pro’s GIS Gateway. The model should be updated at routine intervals, as required. It is recommended that the model be updated at least every 5 years to coincide with Master Plan update intervals or updated after a significant capacity improvement is constructed. This recommendation is included in the ten-year capital plan under Capital Plan Updates. See section 6.11.1: Capital Plan Updates for additional discussion.

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CHAPTER 10 CONCLUSION & SUMMARY OF

RECOMMENDATIONS
Similar to many communities throughout the country, the City of Fort Bragg’s water distribution system faces the challenge of dealing with aging infrastructure to maintain system reliability.

Approximately 90% of the system is constructed from asbestos cement (AC) and polyvinyl chloride (PVC) pipe materials, with estimated useful lives of 75 to 70 years, respectively, depending on environmental conditions. Since the oldest segments installed in the 1960s are now over 65 years old, the City is faced with the challenge of implementing a proactive pipeline replacement program.

Currently, the City has not experienced many water distribution system issues. However, the City anticipates that more focus and resources will be needed in the near term to maintain the system as it continues to age. This 2025 update to the Water Distribution Master Plan will help the City identify and prioritize these needs in an effort to improve system reliability to minimize emergency conditions. This plan provides a transparent, data-driven, and repeatable capital planning process that identifies and prioritizes improvements and other planning actions for the water distribution system.

The system is generally well-sized for current needs based on hydraulic modeling analysis. Several areas of the City have been identified that could benefit from capacity or fire flow improvements.

These are included in the Capital Improvement Plan (CIP), prioritized first by City-designated importance and then by the risk assessment score developed in this Master Plan.

Key capacity enhancements and fireflow improvement projects include:
• PS-1: Upgrading the fire pump at the Willow Street Pump Station from 1,000 GPM to 2,000 GPM.
• P-1 through P-13: Distribution improvements to address capacity and fire flow needs.

The proposed Noyo Center development is the only known near-term project expected to increase system demands beyond the existing system capacity. The anticipated capacity improvement (P-3) has been included in the 10-year CIP, pending the start of the Center’s development.

Project V-1 (Oak Street Valves) was identified to provide recommended additional redundancy and operational improvement for the existing system. In addition, Tank 1 (T-1) was assessed to be in poor structural condition and is recommended for replacement as a high-priority project. While the current storage capacity is adequate for existing and near-term demand scenarios, the Tank 1 improvements will provide additional value to both current and future customers.

In the area of water supply resiliency, increasing occurrences of drought, as well as high-salinity and sea-level rise at surface water intakes and declining spring water availability highlight the need for continued evaluation of alternative supply sources. While desalination pilot projects are underway, further assessment is beyond the scope of this Master Plan but should continue to be studied.

Future intake location changes or source development should consider California Department of Fish and Wildlife regulations.

Given the system’s age, this Master Plan recommends a pipe sampling plan and an allocation for an annual replacement target. Three asbestos cement pipe samples from recently replaced distribution Water Distribution System Master Plan
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mains were analyzed for remaining wall thickness as part of this master plan study. All three samples were classified as being in "poor" condition. While “poor” condition does not necessarily indicate imminent failure, it does suggest increased vulnerability during high-pressure or surge events and may make pipe repair in the event of a break more difficult, often leading to prolonged outages if the potentially fragile neighboring pipes fail to support the required repairs.

While there are very few leaks identified in the system, much of the system’s pipeline network is old and has reached or exceeded its expected useful life. The City should consider investing in an ongoing pipe replacement program (PL-1) to manage future break rates and affordably renew its aging infrastructure.

Based on benchmarking several California utilities, a 1% annual replacement rate is recommended and has been included in the CIP. The City may implement this recommendation annually or develop replacement projects at longer intervals but should make continual progress on pipeline replacement to avoid larger (and costlier) emergency repairs that impact larger areas of the City.

Specific pipe segments beyond the targeted capacity-related replacements have not been identified due to limited data on actual pipe condition. As such, pipes selected for replacement should be fully investigated to verify that they are good candidates for replacement prior to starting the work.

Additional pipe sampling and condition assessment will facilitate this process, and the pipe risk model developed for this Master Plan may be used to prioritize sampling. These considerations have all been incorporated into the CIP.

Additional asset management recommendations include:
• Updating the CIP every five years to reflect new data, priorities, and condition assessments (O-2 & O-6).
• Evaluating and improving the City's Computerized Maintenance Management System (CMMS) to enhance maintenance tracking and planning (O-3 & O-5).

Following City Council review, this Master Plan and CIP will be incorporated into the City’s annual budgeting process. To support project implementation, project sheets have been developed, and project funding eligibility has been assessed for four of the highest priority projects (P-1: Cedar Street Line Replacement, P-2 North Fort Bragg Water Main Extension, T-1: Tank 1 Replacement, and V-1: Oak Street Valves). Environmental review requirements are outlined in the CEQA section of this report.

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CHAPTER 11 REFERENCES
Anderson Valley Advertiser (AVA). 2015. Mendocino County’s Daily Newspaper. Why the Hare Creek shopping center should not be built. Available online at:
https://theava.com/archives/48440?utm_source=chatgpt.com#7. Accessed on May 9, 2025.

California Department of Fish and Wildlife (CDFW). 2016. Newman Gulch Fish Passage Barrier Removal. Fisheries Restoration Grant Program – Restoration Project Case Study.

P1110303. Available online at:
https://www.calfish.org/Portals/2/Programs/MESHR/docs/P1110303_NewmanGulch_Cas eStudy.pdf.

California Natural Diversity Database (CNDDB). 2025. California Department of Fish and Wildlife.

Available online at: https://wildlife.ca.gov/Data/CNDDB.

City of Fort Bragg. 2025a. Oneka Seawater Desalination Buoy Pilot Study. Public Works – Current Public Works Projects.

City of Fort Bragg. 2025b. Reservoir Project. Public Works – Current Public Works Projects.

Available online at:
https://fortbraggca.gov/departments/public_works/current_public_works_projects/reservo ir_project.php
California State Coastal Conservancy (CSCC). 2007. Noyo River Watershed Enhancement Plan.

Available online at: https://westcoastwatershed.com/wpcontent/uploads/2020/04/NoyoWEP_final_0807_reduced_file_all.pdf.

Dewberry Engineers, Inc. (Dewberry). 2022. City of Fort Bragg Raw Water Line Replacement Project. Initial Study/Mitigated Negative Declaration. State Clearinghouse No. 2022030742. Submitted to City of Fort Bragg Public Works Department. Available online at:
https://webgen1files1.revize.com/fortbraggtmpca/Documents/Departments/Public%20Wo rks/Publications/Initial%20Study%20%20Mitigated%20Negative%20Declaration.pdf?t=2 02508040915220&t=202508040915220
North Coast Regional Water Quality Control Board (Regional Water Board). 2005. Watershed Planning Chapter. Section 2.3.5 - Noyo River Watershed. Available online at:
https://www.waterboards.ca.gov/northcoast/water_issues/programs/wpc/11noyosec2.pdf.

U.S. Census Bureau (2023). American Community Survey 5-year estimates. Retrieved from Census Reporter Profile page for Fort Bragg,
CA http://censusreporter.org/profiles/16000US0625058-fort-bragg-ca/, 11/10/2025.

United States Department of the Interior, Fish and Wildlife Service (USFWS). 2025. Information for planning and consultation (IPAC). Available online at:
https://www.fws.gov/service/information-planning-and-consultation. Accessed on November 19, 2025.

Water Distribution System Master Plan
City of Fort Bragg
December 3, 2025 | 108
United States Department of Commerce, National Oceanic and Atmospheric Administration, National Marine Fisheries Service (NMFS). 2025. Species and Habitat App. Available online at: https://www.fisheries.noaa.gov/resource/map/species-and-habitat-app.

Accessed on May 9, 2025.

Water Distribution System Master Plan
City of Fort Bragg
Appendix A. CAD to GIS Conversion
Appendix A – CAD to GIS Conversion
Data Conversion Workflow Process & Database Schema Design Introduction
The City of Fort Bragg (City) manages and maintains a water distribution system, sewer collection system, and stormwater collection system. To modernize and add analytical capabilities, HDR converted the existing Fort Bragg Systems of record, which are stored in both CAD and GIS formats, into one standardized GIS Utility Network dataset. The standardized data set will serve as the system of record for Fort Bragg Utilities being used as the source for hydraulic models, incorporate into asset management, and provide a common reverence for City staff in the office and in the field.

GIS Conversion Approach
To begin, HDR created a staging file Geodatabase that includes a prebuilt data schema for Water, Sewer and Storm Utilities using the industry standard GIS. The conversion process involved identifying the aspects of both CAD and GIS that we want to convert to the standardized model. Fort Bragg has been updating the CAD file more frequently and the CAD file was identified as the best spatial source, so the CAD geometry is being used for the locational data. There were some attributes such as feature ID’s that are important to maintain for specific features (Hydrants) and in those cases their additional fields have also been added. To perform the conversion and add in some additional geometry improvement processes HDR used FME software. Geometry processes were included to enable use in the hydraulic model and to enable accurate tracing in the utility network these processes included:
• Added surface elevations to z values and in the attribute tables for point features • Snap valves to mainlines
• Splitting mainlines at valve locations
• Adding tap fitting locations on mainlines (complex edges) and associating to Meter points • Joining attributes from GIS features
• Correctly tagging asset categories such as hydrant service lines and valves The migrated data has been added to a Utilities GIS ArcGIS Pro Project (.aprx) file that is incorporated with the Esri Solutions Utility Network map templates. 2D and 3D map templates have been configured with saved configured traces configured including:
• Subnetwork trace (system)
• Subnetwork Controller
• Downstream
• Upstream
• Isolation
• Shortest Path
The Utility Network APRX also includes saved diagram and map export templates.

Similar methodology was used for Sewer and Stormwater systems. Sample images of the migrated data in the Utility Network are provided below.

We have included the Utility Network Schema in electronic (.xls) format as an electronic attachment to this repot.

Image 1: Initial CAD (black) and GIS (blue) Geometry
Image 2: Migrated Data Mainline Splits at Valve Locations Image 3: Added Taps and Association Lines to Meter Points Image 4: Subnetwork Trace
Image 5: Water Isolation Trace
GIS Database Schema
HDR has used the standard Utility Network Data Models for conversion from CAD to GIS. FME was used to convert the CAD linework into GIS features as well as convert annotation into feature attributes. The attribution included diameters, materials, and Asset ID’s. HDR also included ownership information for assets that are managed and maintained vs other features that are managed by external parties such as Caltrans for Stormwater. Below is a list of current data layers (feature classes) used in GIS.

Water
Water Device – Used for most water point assets that are not lines or fittings and includes the following data groupings.
• Pump
• Hydrant
• System Valve
• Service Valve
• Flow Valve
• Pressure Valve
• Station
• Blowoff
• Storage
• Supply (Treatment Plant, Network Source)
• Service Meter
Water Junction – Used for fittings
• Misc Types (Tee, Tap, Elbow, etc.)
Water Line – Includes Mains and Service lines.
• Water Main – (Transmission, Distribution)
• Service – Includes Asset Types for (Residential, Commercial, etc.) Water Network (Subnet line) – UN generated aggregation created using Update Subnetwork tool Sewer
Sewer Device – Used for most sewer point assets that are not lines or fittings and includes the following data groupings.
• Cleanout
• Controllable Valve
• Service Valve
• Backflow Preventer
• Manhole
• Treatment (Network Source)
• Service Connection
Sewer Junction – Used for fittings
• Misc Types (Tee, Tap, Elbow, etc.)
Sewer Line – Includes Mains and Service lines.
• Gravity Main – (Collector, Interceptor)
• Force Main
• Lateral – Includes Asset Types for (Residential, Commercial, etc.) Sewer Network (Subnet line) – UN generated aggregation created using Update Subnetwork tool.

Stormwater
Stormwater Device – Used for most sewer point assets that are not lines or fittings and includes the following data groupings.
• Catch Basin
• Outlet (Network sources)
• Manhole
Stormwater Junction – Used for End walls.

Stormwater Line
• Pipe (Gravity, Force, Perforated)
• Culvert
• Open Channel – used for natural channels and ditches that participate in the overall stormwater network
Stormwater Network (Subnet line) – UN generated aggregation created using Update Subnetwork tool.

Basins – Basins polygons for the Stormwater network has been digitized and included.

Structures
The water data also includes structure layers for assets that support the individual domain networks.

Structure Junction – Vaults
Structure Lines – Casings
Structure Area – Boundaries for assets such as pump stations and treatment plants.

Detailed Database Schema Definition
A detailed database schema definition is included as an attached Microsoft Excel Spreadhseet, UN_Schema_All_Domains.xls. This includes detailed definitions of the following Utility Network geodatabase elements:
- A tab for each feature class
- All attribute field names and aliases
- Attribute field data types
- Attribute field domains (where applicable)
- Default attribute values
Name

OBJECTID
SHAPE

ASSETGROUP

ASSETTYPE

ASSOCIATIONSTATUS

ISSUBNETWORKCONTROLLER

ISCONNECTED

SUBNETWORKCONTROLLERNAME

TIERNAME

TIERRANK

TERMINALCONFIGURATION

GLOBALID
SystemSubnetworkName

SUPPORTEDSUBNETWORKNAME

SUPPORTINGSUBNETWORKNAME
IsolationSubnetworkName
diameter
secondarydiameter
pressure
designtype
normalstatus
presentstatus
additionaldetails
designinfo
operable
name
installdate
assetid
accountid
ownedby
maintby
additionaldevice
notes
symbolrotation
lastmaint
lifecyclestatus
inservicedate
retireddate
spatialsource
spatialconfidence
manufacturer
operator
actualInsideDiameter
Alias Type
Object ID OID
Shape Geometry
Asset group Integer
Asset type SmallInteger
Association status SmallInteger
Is subnetwork controller SmallInteger
Is connected SmallInteger
Subnetwork controller name String
Tier name Integer
Tier rank Integer
Terminal path String
Global ID GlobalID
System Subnetwork Name String
Supported subnetwork name String
Supporting subnetwork name String
Isolation Subnetwork Name String
diameter: Diameter, Diameter 1, Height, Inlet Diameter, Pipe Diameter, Weight Double secondarydiameter: Diameter 2, Nozzle Diameter, Outlet Diameter, Width Double pressure: Amperage, Pressure, Rated Pressure, Volume Double designtype: Anode Count, Design Type, Manufacturer, Pump Type, Test Wire Count, Valve Ty SmallInteger Normal Status SmallInteger
Present Status SmallInteger
additionaldetails: Clockwise to Close, Cooling Method, Critical, Material SmallInteger designinfo: Anode Depth, Rated Flow, Turns to Close, Voltage Double Operable SmallInteger
Name String
Install Date Date
Asset ID String
Account ID String
Owned By SmallInteger
Maintained By SmallInteger
additionaldevice: Additional Device, Has Bypass, Internal Meter, Metered SmallInteger Notes String
Symbol Rotation SmallInteger
Last Maintenance Date
Lifecycle Status SmallInteger
In-Service Date Date
Retired Date Date
Spatial Source SmallInteger
Spatial Confidence SmallInteger
Manufacturer SmallInteger
Postindicator Valve SmallInteger
actualInsideDiameter String
Length Domain Default Nullable Editable
TRUE
0 TRUE
0 TRUE
0 0
2 2000 Unknown
0 0
128 Default TRUE
2000 Unknown
2000 Unknown
2000 Unknown
2000 Unknown

TRUE TRUE

TRUE TRUE

TRUE TRUE

TRUE TRUE
Pipeline_Valve_Status TRUE TRUE
Pipeline_Valve_Status TRUE TRUE

TRUE TRUE

TRUE TRUE
Boolean 1 TRUE
64 TRUE TRUE

TRUE TRUE
64 TRUE TRUE
50 TRUE TRUE
Asset_Owner 1 TRUE TRUE
Asset_Manager 1 TRUE TRUE

TRUE TRUE
2000 TRUE TRUE
Symbol_Rotation TRUE TRUE

TRUE TRUE
Lifecycle_Combined 0 TRUE

TRUE TRUE

TRUE TRUE
Spatial_Source TRUE TRUE
Spatial_Confidence TRUE TRUE

TRUE TRUE

TRUE TRUE
8 TRUE TRUE
Water Distribution System Master Plan
City of Fort Bragg
Appendix B. Geotechnical Evaluation of Seismic
Safety Elements Related to Water Distribution
Facilities
Geotechnical Evaluation
of City of Fort Bragg
Seismic Safety Elements
Related to Water
Distribution Facilities
Fort Bragg Distribution System
Master Plan
City of Fort Bragg
April 1, 2025
City of Fort Bragg | Geotechnical Evaluation of City of Fort Bragg Seismic Safety Elements related to Water Distribution Facilities
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i
Table of Contents
1 Executive Summary ................................................................................................................... 1

1.1 Scope................................................................................................................................... 1

1.2 Topography and Geology..................................................................................................... 1

1.3 Emergency Access .............................................................................................................. 2

1.4 Risks to Water Supply and Distribution ................................................................................ 2

1.5 Geologic Hazards................................................................................................................. 3

1.6 Other Geologic Related Concerns ....................................................................................... 4

1.7 Non-Geologic Hazards......................................................................................................... 5

1.8 Areas of Concern for Rehabilitation of Water Distribution Facilities ..................................... 6

1.9 Recommended Future Actions............................................................................................. 6 2 Introduction ................................................................................................................................ 8 3 Approach.................................................................................................................................... 8 4 Background................................................................................................................................ 9 5 Topography and Geology......................................................................................................... 11

5.1 Mapped Units ..................................................................................................................... 12 6 Emergency Access .................................................................................................................. 17 7 Water Supply and Distribution.................................................................................................. 17 8 Geotechnical Conditions Assessments.................................................................................... 18

8.1 Geologic Hazards............................................................................................................... 20

8.2 Other Geologic Related Concerns ..................................................................................... 26 9 Areas of Concern for Rehabilitation of Water Distribution Facilities ......................................... 30

9.1 Densification and Liquefaction ........................................................................................... 31

9.2 Corrosivity .......................................................................................................................... 31

9.3 Groundwater ...................................................................................................................... 32

9.4 Seismic Response ............................................................................................................. 32

9.5 Bluff Erosion....................................................................................................................... 32 10 Recommended Future Actions................................................................................................. 32 11 Limitations................................................................................................................................ 34 12 References............................................................................................................................... 34 Attachment A – Summary of Geotechnical Conditions Depicted by City-Provided Geotechnical Reports.............................................................................................................................................. 36 Attachment B – NCRS Soil Survey Map and Select Data ................................................................. 43 City of Fort Bragg | Geotechnical Evaluation of City of Fort Bragg Seismic Safety Elements related to Water Distribution Facilities
Draft Technical Memorandum
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ii
List of Figures
Figure 1 – City of Fort Bragg Water Distribution System Schematic (no scale) ................................ 10 Figure 2 – Area Topography ............................................................................................................. 11 Figure 3 – Excerpt Geologic Mapping by Durham, 1979................................................................... 14 Figure 4 and Figure 5 – Excerpt from Noyo Watershed Mapping Relative Landslide Potential with Geology and Geomorphic Features (Manson et Al. 2001) ................................................................ 15 Figure 6 – Postulates Path of Historical Drained Beneath the City (No Scale).................................. 16 Figure 7 – Location Map – Reference Geotechnical Investigations .................................................. 19 Figure 8 – Quaternary Fault Map (Source USGS.maps.arcgis.com/apps)........................................ 21 Figure 9 – Tsunami Hazard Area - Shaded (source Cal OES MyHazard)......................................... 22 Figure 10 - Relative Slope Instability in the Fort Bragg Area (After CGS Map 58, 2011) .................. 30 List of Tables
Table 1 – Geotechnical Reference Provided by City of Fort Bragg by Area...................................... 23 City of Fort Bragg | Geotechnical Evaluation of City of Fort Bragg Seismic Safety Elements related to Water Distribution Facilities
Draft Evaluation
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1 1 Executive Summary

1.1 Scope
HDR has been retained by the City of Fort Bragg (City) to develop a water distribution system master plan. The purpose of this memorandum is to:
• Provide input on the geotechnical section of the Seismic Safety Components of the General Plan as they relate to the water distribution system,
• Develop a high-level summary description of geotechnical and geologic conditions within the City’s area of influence, and
Provide discussion regarding critical elements of the analysis of six geotechnical studies for City and private development projects, provided from the City representing subsurface conditions in different areas across the City, and geotechnical data available online related to the former Georgia-Pacific Lumber Company site closure. The study did not include an exhaustive investigation of applicable geotechnical reports that may be contained in City records and does not provide a site-specific seismic hazard analysis. This Executive Summary should not be referenced alone as it is a summary and does not contain specific discussions and details provided in the body of the report.

The data and discussion presented in this memorandum are organized as follows:
• Topography and Geology
• Emergency Access
• Water Supply and Distribution System
• Geotechnical Condition Assessment
• Geologic and Non-Geologic Hazards
• Areas of Concern for Rehabilitation of Water Distribution Facilities • Limitations
HDR’s review of the subsurface conditions as described in the provided reports is briefly summarized in Attachment A. Although some portions of this memorandum may include discussions on climate change, a separate report is being prepared by HDR addressing climate change implications.

Although the memorandum was prepared specifically as part of the water distribution master planning effort, it is applicable to other City agencies responsible for infrastructure such as the stormwater and sewer system.

1.2 Topography and Geology
The City is located on an uplifted terrace along the California Pacific North Coast. The uplifted terrace has created a coastal bluff that is approximately 50 feet tall at Soldier Point near the existing City’s Wastewater Treatment Plant and 85 feet tall at Pomo Bluffs State Park. Site grades slope gently upward towards the east to approximately El. 400 feet where the terrace meets the western edge of the Coastal Range Mountains. A high-level discussion of the City topography and mapped City of Fort Bragg | Geotechnical Evaluation of City of Fort Bragg Seismic Safety Elements related to Water Distribution Facilities
Draft Technical Memorandum
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2 geology is provided in the memorandum based on review of available published information. Review of other geotechnical studies contained in the City files could be a benefit to better understand subsurface conditions that could impact the water distribution (or other) system. Former creek channels may be present beneath the City that became obscured as the terraces were uplifted.

1.3 Emergency Access
Subsurface conditions and the response to strong seismic shaking or a large storm event can impact City features such as vehicle access. The main vehicle access (and emergency evacuation/access routes) into and out of the City is Highway 1, which includes bridges that cross Hare Creek, Noyo River, and Pudding Creek (from south to north). If these bridges were damaged during a seismic event or a large storm event, such as an intense storm washing out the bridge approaches or a tsunami damaging the bridge foundations, access would be limited. Highway 1 provides the main emergency access in and out of the City over bridges maintained by California Department of Transportation (Caltrans). Caltrans reports that the Noyo and Pudding Creek bridges have undergone seismic structure upgrades and plans to perform Hare Creek Bridge seismic structure upgrades in the future. In addition, the 2020 Medocino County Hazard Mitigation (MCHMP) plan identifies slope failure and wildfire risk as having highly likely and critical impact on the city of Fort Bragg while earthquake would be an extreme risk though it is a less likely hazard (see figure 2-2, City of Fort Bragg Risk Assessment, MCHMP Vol 2 2020), both briefly discussed in subsequent sections of this report.

1.4 Risks to Water Supply and Distribution
The City water supply system, described in the memorandum, consists of water collection points, treatment facilities and storage structures, and distribution system interconnected by pipelines. The water main line system connects the storage system to the end user and these pipelines likely have additional structural connections to a network of smaller diameter pipes forming the distribution system. Each part of the system is subject to geologic hazards including strong seismic shaking, seismic-induced differential movement at connections, seismically induced ground settlement and, potentially, ground failure. Also, soil chemistry can cause corrosion to steel and concrete materials.

Each needs to be evaluated based on site-specific conditions and in accordance with the appropriate design code.

Distribution piping itself can be at risk due to many geotechnical causes, such as:
• Corrosive soils that weaken the pipe itself
• Differential settlement or pipe lengthening due to land sliding, bluff retreat, soil densification, or liquefaction resulting in large magnitude settlements or lateral spreading, static settlement due to change of overburden or imposed loads, or hydro-compression due to changes in saturation
• Differential movement during earthquake, such as at service or distribution connections like large maintenance holes or bridge crossings
Also, the City fire hydrant system must be operational for small and large seismic events and wildfires.

City of Fort Bragg | Geotechnical Evaluation of City of Fort Bragg Seismic Safety Elements related to Water Distribution Facilities
Draft Technical Memorandum
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3 1.5 Geologic Hazards

1.5.1 Seismicity
The City of Fort Bragg is in an area that is known for seismic activity; however, the City is not within a currently established State of California Earthquake Fault Zone for surface fault rupture hazards and there are no known active fault traces in the immediate project vicinity. The following active faults are located within 60 miles of the City
• North San Andreas Faults System – 6.5 miles west
• Maacama Fault Zone – 21 miles east
• Mendocino Fault Zone – 60 miles north
The Pacific Star Fault is a recently identified potentially active fault located northeast of the City as is the Pudding Creek Fault. They are reported as being connected to the San Andreas Fault but have not been located in the State of California Special Studies Zone. USGS estimates that there is a

64.92% chance of an earthquake with a magnitude greater than 5 to occur in the next 50 years.

1.5.2 Fault Offset, Strong Ground Motion, Liquefaction and Tsunami Impacts The fault offset hazard in the City of Fort Bragg is very low. There are no Alquist Priolo Hazards Zones identified within or near the City (www.conservation.ca.gov). The City will be subject to strong ground shaking that could induce densification of loose to medium dense terrace deposits, and slope movement within the steeply incised river and creek channels and along the coastal bluff. Loose, saturated, cohesionless soils are susceptible to liquefaction, including sediments that have accumulated within and at the mouth of the coastal, river, and creek channels and potentially in eolian (windblown) derived terrace deposits that become saturated due to groundwater.

The State of California Office of Emergency Services online MyHazard maps (myhazards.caloes.ca.gov) does not identify Fort Bragg as having a mapped liquefaction zone; however, the risk of liquefaction is judged to be moderate in the terraces and high in the river and creek channels and could occur in the event of strong ground shaking.

Tsunamis would impact the coastal areas, the Noyo Harbor, and upstream areas of Noyo River, Pudding Creek, and Hare Creek. The Pacific Institute has prepared a graphic showing the effects of a 55-inch sea level rise and the effect combined with a tsunami. Sea level rise would raise river levels in Noyo River and Hare Creek to above the 100-year flood level. Sea level rise combined with a tsunami would impact all three river/creeks and cause saltwater intrusion to the existing raw water intake on the Noyo River. Recent high tides have also caused saltwater intrusion and impacted the raw water intake.

1.5.3 Non-seismic Hazards
Non-seismic hazards include presence of unstable soils on steep slopes, continued bluff retreat, and presence of weak and/or unstable soils.
• The presences and mitigation, if required, would be determined on a project-specific investigation/basis. It would be beneficial to document the past performance of the water distribution system (Geographical information System [GIS], mapping, and tabular format), City of Fort Bragg | Geotechnical Evaluation of City of Fort Bragg Seismic Safety Elements related to Water Distribution Facilities
Draft Technical Memorandum
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4 including areas of past pipe repairs/leak/breaks and areas of known surface (street pavement and hardscape) distress to identify areas that may be underlain by weaker soils.

A more detailed description of the regional geology and the near-surface geology and surface conditions is included in the body of this document. Of particular importance is that groundwater conditions documented in the reference reports represent conditions observed at the time of investigation and are generally poorly understood. Groundwater (at depth) and near-surface perched groundwater are two different groundwater occurrences and both have been reported. Additional groundwater investigations would be required to better understand the current temporal variations in groundwater at a specific site within the City’s area of influence. The assumptions related to groundwater levels have a significant impact on the occurrence of liquefaction induced by strong ground shaking and the values reported in the different documents should not be relied on for future projects.

The Georgia-Pacific Site cleanup documentation provides detailed maps showing groundwater conditions west of Highway 1 in the central portion of the City Coastal Area. The City of Fort Bragg has recently began to track shallow groundwater condition for the stormwater and water projects in the city.

1.6 Other Geologic Related Concerns

1.6.1 Mineral Resources
The Fort Bragg General Plan does not identify any locally important mineral resource recovery sites or sites being utilized for Surface Mining and Reclamation Act (SMARA) activities.

1.6.2 Corrosion
Limited studies have identified that the terrace deposits are acidic and have cation exchange capacity, being more acidic closer to the ocean.

The terrace deposit soils should be considered corrosive to steel and slightly corrosive to concrete unless specific testing is performed or the performance of buried structures can be determined from visual inspection. A testing standard should be developed for all corrosion testing so that a “Zone” database can be developed by the City to aid in their management of the water system.

1.6.3 Erosion
Removal of vegetation and redirection of surface water could induce erosion on any area of the City.

Care must be taken to restore disturbance to reduce the risk of developing areas of concentrated surface water flow that could induce erosion. Care must be taken to install trench dams along lengthy pipelines and in elevation transitions so that the pipeline trench does not act as collection, drawing and redirecting concentrated seepage to the trench outlet causing ground saturation and potential slope failure and erosion.

City of Fort Bragg | Geotechnical Evaluation of City of Fort Bragg Seismic Safety Elements related to Water Distribution Facilities
Draft Technical Memorandum
2365 Iron Point Road, Suite 300, Folsom, CA 95630-8709
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5 1.7 Non-Geologic Hazards

1.7.1 Flooding
Flooding hazard is typically determined for a 100-year flood level for insurance purposes using maps developed by the Federal Emergency Management Agency (FEMA). The FEMA updated flood maps for the Fort Bragg area are dated as being published in 2017 and show larger 100-year flood hazard than shown in the Coastal General Plan Map. The Inland Zone General Plan includes Map SF-3 Tsunami Inundation Map and Map SF-4 100-year Sea Level Rise Inundation Area, which is the Pacific Institute map previously referred to as an additional source document for this memorandum.

The most recent FEMA Flood Mapping and the Pacific Institute mapping of sea level rise are recommended as references for assessing flooding impacts.

1.7.2 Fire
The City’s fire hydrant system is critical infrastructure for public safety. Significant fires have occurred in Northern California in the last few years and the ability to protect the City from structure fires and wildfire is important. The fire hydrant system is also critical after a large seismic event.

In 2022, California Department of Forestry and Fire Protection (CALFIRE) published maps depicting Fire Hazard Severity Zones for Mendocino County as part of the Fire and Resource Assessment Program. The City is outside the jurisdiction of CALFIRE and the City itself is zoned as a local responsibility area (LRA). The Fire Hazard Zone Severity Viewer is no longer available online . The MCHMP does include earlier viersions of these maps that show the area south and east of the Noyo River zoned as Very High risk and the area north and east of the City as Moderate risk. High risk zones are located east of the City on the north side of the Noyo River and east of the north Coastal Area. The south Coastal Area is located in a Moderate risk zone west of Highway 1 and in the lower elevations east of Highway 1.

1.7.3 Extreme Weather Events
In February 2023, the United States Department of Agriculture USDA) declared Mendocino County a Disaster Area due to severe winter storms and flooding. The occurrence of heavy storms and storm events characterized as Atmospheric Rivers, defined by National Oceanic and Atmospheric Administration (NOAA) as long narrow regions in the atmosphere that transport most of the water vapor out of the tropics that have an equivalent flow at the mouth of the Mississippi River and exceptionally strong events can have 15 times that amount. The Pineapple Express is a strong atmospheric river bringing moisture from the tropics near Hawaii to the west coast. The rain events can induce slope instability and rapid slope movement and debris flows.

The ranking of deep-seated landslide susceptibility is presented on California Geological Survey (CGS) Sheet 58 that show the areas to the east and along the incised channel banks having the highest potential for slope instability and deep-seated sliding. The susceptibility of landslides impacting the City water supply and distribution system or evacuation routes directly or from debris flows should be evaluated on a case-by-case basis. It should be noted that climate change may increase the risk of slope instability.

City of Fort Bragg | Geotechnical Evaluation of City of Fort Bragg Seismic Safety Elements related to Water Distribution Facilities
Draft Technical Memorandum
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6 1.7.4 Chemically Impacted Sites
A review of the DTSC GeoTracker website showed the locations of numerous identified chemically impacted sites that range from small underground storage tanks to large facility clean-up activity.

Many of the sites are identified as having closed files, meaning that the sites have been remediated to meet cleanup goals set forward by regulatory agencies. It should be noted that there may be residual chemically impacted soils at these sites that did not require removal but, should they be excavated, may require special testing and handling to determine material reuse or disposal. The GeoTracker site and associated data should be checked as part future system upgrade or rehabilitation projects to be aware of potential impacted sites.

1.8 Areas of Concern for Rehabilitation of Water Distribution Facilities The following geotechnical factors should be considered when addressing water distribution design or rehabilitation.
• Densification and Liquefaction
• Corrosivity
• Seismic Response
• Bluff Erosion

1.9 Recommended Future Actions
To better understand geologic risk to specific portions of the water distribution system, a more detailed understanding is needed at the location of critical components of the system. Specifically, the following should be determined:
• The peak ground acceleration based on current code requirements, typically expressed as the design earthquake return period. Depending on the age of the facility, the current design code may be different than what was used at the time the component was designed and constructed.
• The thickness of fill and/or terrace deposits at the site, the depth to bedrock and an understanding of the groundwater depth and seasonal fluctuation. Past geotechnical investigations associated with the original design of the component/facility, or a report prepared for an adjacent property combined with review of the as-built grading plans would typically provide data regarding the site soil stratigraphy and depth to bedrock.

Understanding groundwater conditions below the site would likely require additional study, discussed below. This information is required as input into a seismic vulnerability assessment for understanding the potential for seismic densification or vertical or lateral deformation because of liquefaction, if potentially liquefiable soils are present at the specific site.
• Mapping of areas of slope instability along pipeline corridors and within 300 feet of a component or facility at a local scale will provide the input to assess the current hazards slope instability pose to the facility as well as allow comparison for changes in the risk, specifically after major storms/flood events or a large seismic event. Each specific area of concern should be mapped at a scale of 1 inch = 50 feet and fixed reference points set, such as rebar hubs setback (above) the area of instability in readily accessible areas that can be City of Fort Bragg | Geotechnical Evaluation of City of Fort Bragg Seismic Safety Elements related to Water Distribution Facilities
Draft Technical Memorandum
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7 used to easily identify changes visually and hand measurement. Each location will need to be assessed on a case-by-case basis to establish the limits of mapping and location and number of reference points. Use of fixed features such as a fence, fire hydrant, or street curb may not be sufficient as they can be modified or damaged over time.

The depth to bedrock could be evaluated by performing limited geophysical surveys (seismic refraction) that is a non-invasive and lower cost method of field investigation. The geophysical surveys, in combination with other geotechnical or environmental investigation reports that the City has, could provide the level of detail required without the expense of drilling soil borings.

Understanding the depth of groundwater and fluctuation over time could require installation of a strategically placed monitoring well or wells to understand the source and direction of groundwater flow and the effects of rainwater and irrigation infiltration. An initial widely spaced grid of wells could be established and monitored semi-annually to quarterly to develop an understanding of groundwater behavior. The wells could be supplemented if an areas data seems erratic of if additional detail is desired.

Planning for such a study should be proceeded by a desktop study reviewing available data contained in City files and interviewing local civil/geotechnical and geological consultants familiar with area soil and geologic conditions that may bring specific knowledge from past experience within the City limits. All the groundwater, soil, and bedrock depth and slope instability data can then be collected in a geographic information system (GIS) and reviewed to determine where more detailed study would be warranted. The information would need to be reviewed and updated to provide a living document that can be used by all City departments for planning and risk assessment.

City of Fort Bragg | Geotechnical Evaluation of City of Fort Bragg Seismic Safety Elements related to Water Distribution Facilities
Draft Technical Memorandum
2365 Iron Point Road, Suite 300, Folsom, CA 95630-8709
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8 2 Introduction
HDR has been retained by the City of Fort Bragg (City) to develop a water distribution system master plan. The purpose of this evaluation is to:
• Provide input on the geotechnical section of the Seismic Safety Components of the general plan as it relates to the water distribution system,
• Develop a high-level summary description of geotechnical and geologic conditions within the City’s area of influence, and
• Provide discussion regarding critical elements of the water supply system that should be considered as part of master planning and future distribution system maintenance/rehabilitation efforts.

This study is limited to review of the City’s existing general plans for the Inland and Coastal Zones, review of available published geotechnical and geologic information, review of six geotechnical studies for City and private development projects provided from the City representing subsurface conditions in different areas across the City, and geotechnical related data available online related to the former Georgia-Pacific Lumber Company site closure. This is not an extensive review of all potentially available geotechnical reports or related documents that may be contained in the City’s records or from local consultants, which is beyond the scope of this study. This evaluation also does not provide specific geotechnical hazards assessments for the specific components of the water distribution system. The scope of site-specific hazards assessments would need to be developed after a detailed review of each specific component which has not been performed for this evaluation. 3 Approach
The data and discussion presented in this evaluation are organized as follows:
• Topography and Geology
• Emergency Access
• Water Supply and Distribution System
• Geotechnical Conditions Assessment
o Geologic and Non-Geologic Hazards
• Areas of Concern for Rehabilitation of Water Distribution Facilities • Recommended Future Actions
• Limitations
HDR’s review of the subsurface conditions as described in the provided reports is briefly summarized in Attachment A. Although some portions of this evaluation may include discussions on climate change, a separate report is being prepared by HDR addressing climate change implications.

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9 4 Background
The City is located along the coast of Mendocino County. The City is approximately 2.92 square miles in size and includes five island areas (non-contiguous land) totaling 0.15 square miles in size and comprised of city-owned property that was annexed on April 7, 1997.

While Fort Bragg is a small community, it is the largest city on the coast between San Francisco and Eureka and is a popular tourist and recreational destination. Commercial land uses in the City are located along the California State Route 1 (Highway 1) and Franklin Street corridors. The Central Business District, located between Oak Street and Pine Street, is the historic, civic, and cultural core of the community. Industrial lands are located on the Georgia-Pacific Mill property located west of Highway 1 on North Franklin Street, immediately north of the Central Business District, and on Highway 1 north of Pudding Creek. Residential neighborhoods are located east of the commercial core and in the west Fort Bragg area.

For planning purposes, the City is divided into the Coastal Zone as described in Coastal Act Section 30150 (July 2008 Land Use Element Fort Bragg Coast General Plan) and the Inland Zone for areas within the City influence but outside of the Coastal Zone (bounded by the City limits on the north and east, and the coastal zone to the south [Walnut Street] and west [Highway 1]). These zones are shown on Map LU-1, Land Use Designations and LU-2 City Boundary and Sphere of Influence, both contained in the updated 2012 Inland General Plan. The Coastal zone includes a specific plan area in the Timber Resources Industrial Land Use Designation (former Georgia-Pacific Properties) between Walnut Street to the South and Elm Street to the North and Highway 1 on the east.

Figure 1 presents a graphic showing the existing City water distribution system that consists of a network of pipes within the central portion of the City, primarily in the Inland Zone with supply provided to the south of the Noyo River in the Pomo Bluffs area north of Hare Creek, and to the north across Pudding Creek to the Fort Bragg Airport area. The coastal area west of Highway 1 and the main part of the City was previously occupied by the now closed Georgia-Pacific Mill with limited connection to the water distribution system.

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10 Figure 1 – City of Fort Bragg Water Distribution System Schematic (no scale) City of Fort Bragg | Geotechnical Evaluation of City of Fort Bragg Seismic Safety Elements related to Water Distribution Facilities
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11 5 Topography and Geology
The City is located on an uplifted terrace along the California Pacific North Coast. The uplifted terrace has created a coastal bluff that is approximately 50 feet tall at Soldier Point near the existing City’s wastewater treatment plant and 85 feet tall at Pomo Bluffs State Park. Site grades slope gently upwards towards the east to approximately El. 400 feet where the terrace meets the western edge of the Coastal Range Mountains. A topographic terrain map of the region is provided below.

Figure 2 – Area Topography
Source: www.topozone.com
The elevations used in this study are relative to the 1929 National Geodetic Vertical Datum (NGVD 1929) which is sufficient for the general purposes of this discussion. Coastal Area elevations range on the east boundary from El. 78 feet (Main Street at Pine Street) to El 82 feet (Simpson Lane at Highway 1). Inland areas rise in elevation to about El. 200 feet (Marsben Lane at Sherwood Road).

The terrace is incised by the Noyo River, Pudding Creek, and Hare Creek. Pudding Creek and the Noyo River have incised at least 160 feet into the terrace where the California Western Railroad once crossed these creeks and enters a now collapsed tunnel beneath Sherwood Road. United States Geologic Survey Benchmark at Noyo Harbor is listed as El. 11.73 feet. The mouth of Pudding Creek and Hare Creek are at or slightly above sea level where beaches have formed (El. 0 feet).

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12 Noyo Harbor has been dredged to provide access to the Noyo Basin Marina. The most recent nautical charts should be reviewed to determine the depth of the dredged channel.

There is limited published geologic mapping of the City vicinity. The most detailed mapping was prepared as part of the Noyo River Watershed program in 2025 that includes preliminary mapping performed by Durham for the Department of Forestry in 1979. A portion of the Durham 1979 map and maps from the Noyo Watershed mapping are presented in Figure 3, Figure 4, and Figure 5.

These figures are provided for illustrative purposes and are not presented to scale. The actual maps should be referenced for more specific information.

The primary units mapped by Durham are quaternary aged Terrace Deposits (Qtm) and tertiary aged Franciscan bedrock. These units are further differentiated and described by Manson as Pleistocene aged Marine Terrace Deposits Undifferentiated (Qmts) and tertiary - cretaceous aged Coastal Belt Franciscan (TKfs). Manson also maps an additional unit Older Dunes (Qods), briefly described as follows and shown in Figure 4.

5.1 Mapped Units
• Older Dunes (Qods) – Well-sorted, semi-consolidated, fine- to medium grained overlying various marine terrace deposits (Qtmts)
• Marine Terrace Deposits Undifferentiated (Qmts) Deposits generally consist of well sorted sand with minor gravel and have courser textures near major drainages, may include some dune sand.
• Coastal Belt Franciscan (TKfs) – Broken formation consisting of light colors, well-cemented to deeply weathered and sheared, clastic sedimentary rock (sandstone, conglomerate, shale).

Durham mapped a number of active landslides along the incised slopes of Pudding Creek, Hare Creek, and the Noyo River identified with the letter “A” and an arrow showing the direction of movement. Mapping by Mason et. al for the Noyo River (Figure 5) also includes shading depicting the relative risk of landslide in areas that were also mapped by Durham and show a correlation between the risk of landslide and slope inclination. Review of current Map SF-1 Geologic Hazards contained in both the Coastal and Inland General Plans include identification of landslide hazards in the City’s sphere of influence and references mapping by the State of California dated 1983.

These figures are in general agreement with the Manson landslide mapping. As the data for the General Plan maps is approximately 40 years old, a site reconnaissance by a registered engineering geologist should be considered to update the general plan Map SF-1. The State of California has prepared a map of deep landslide susceptibility originally published in 2011 as California Geologic Service Map Sheet 58 (CGS 2011). This map ranks landslide susceptibility to underlying bedrock strength and slope inclination. This map does not present the location of mapped/identified landslide and is discussed in more detail in the Geologic Hazard Section.

Mapped instability identified in Figure 5 are areas of surficial instability in the immediate City limits as points and the actual mapping of large deep-seated sliding are shown a distance approximately 2.5 miles east of the Noyo River Bridge along the Noyo river south Bank. Deep-seated landslides are more abundant within the State of California Jackson Demonstration Forest located to the east and southeast of the City with the closest slides located about 3.5 miles east of the Noyo River Bridge.

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13 Additional insight into the surficial geology is provided from the review of mapped conditions within the City north of the Noyo River as depicted by the NCRS Soil Survey and review of the geotechnical report performed for the Aquatic Center near the intersection of Maple Street and South Lincoln Street. The 2003 geotechnical study (see Table 1) did not include a location plan for their borings; however, NCRS Soil Survey reports the material to the east of this site as fluvial marine derived deposits.

The 2003 SHN report identified the presence of soft soils and a layer of peat at a depth of 15.5 to 22 feet in Boring B-3. Boring B-2 found a gravel strata at a deeper depth. The study found the site contained fill to a depth of 4.5 feet along the north side of the site, underlain by dense sandy deposits to a depth of 18.5 feet. Boring B-3 depicts slightly different conditions suggesting that the terrace deposits mantled the bedrock and state that “the data indicates potentially variable or erratic soil conditions.”
However, an alternate interpretation may be that the boring data suggests that the Noyo River or Pudding Creek may once have crossed the site and later shifted as the underlying bedrock was tectonically uplifted. The former drainage may have connected to the Soldier Bay cove at the coast, located to the west of Fort Bragg – Sherwood Road (Sherwood Road) shown in Figure 6. Studies performed for the restoration of the former mill pond document that Alder and Maple Creeks do cross the City and discharge into Soldier Bay that was dammed to form the mill pond (Arcadis 2011).

The creeks were later placed in culverts and buried. The drainage could indicate more variable subsurface conditions and effect groundwater conditions beneath the main portion of the City (see https://www.fortbragghistory.org/?page_id=1071 for the 1873 map). The location of the postulated drainage roughly corresponds to the west end of the Noyo Anticline (geologic ridge formed by tectonic movement) shown on the geologic map in Figure 3. The anticline is an extension of the anticline mapped on the adjacent geologic map, the Geologic Map of the Comptche Quadrangle prepared by the State of California Department of Forestry also by Durham, 1979. If present, the drainage feature may follow a less resistant bedrock zone along the north side of the mapped anticline.

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14 Figure 3 – Excerpt Geologic Mapping by Durham, 1979
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15 Figure 4 and Figure 5 – Excerpt from Noyo Watershed Mapping Relative Landslide Potential with Geology and Geomorphic Features (Manson et Al. 2001)
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16 Figure 6 – Postulates Path of Historical Drained Beneath the City (No Scale) City of Fort Bragg | Geotechnical Evaluation of City of Fort Bragg Seismic Safety Elements related to Water Distribution Facilities
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17 6 Emergency Access
Subsurface conditions can impact City features such as vehicle access. The main vehicle access (and emergency evacuation/access routes) into and out of the City is Highway 1, which includes bridges that cross Hare Creek, Noyo River and Pudding Creek (from north to south). If these bridges were damaged during a seismic event or a large storm event, such as an intense storm washing out the bridge approaches or a tsunami damaging the bridge foundations, access would be limited.

The conditions of the logging roads that would be traveled to reach these points have not been evaluated as part of this study and do cross areas with high landslide susceptibility. Pedestrian access to the north from central Fort Bragg could be provided over the train trestle that crosses Pudding Creek west of the Highway 1 Bridge. The bridges are under the jurisdiction of the California Department of Transportation (Caltrans). The Noyo River Bridge replacement was completed in 2005. The previous bridge was replaced due to the seismic vulnerability. Pudding Creek Bridge was seismically retrofitted in 1998 and is currently being widened by Caltrans (2023). The Hare Creek Bridge is to be widened and retrofitted by Caltrans in the future.

It should be noted that Caltrans has its own design standards for bridges that is different than other codes such as the California Amendments to the International building Code (IBC) that govern design of occupied structures and American Water Works Association (AWWA) that govern design of water treatment, storage, and distribution systems.
7 Water Supply and Distribution
The following description of the water supply and distribution system is taken from Section 3 Public Facility Element included in the Inland General Plan.

The City's current water supply system consists of the Newman Reservoir, the Simpson (Waterfall Gulch) diversion, and a direct diversion in the Noyo River (which includes a wet well in the Noyo River, a pump station at the Noyo River, and various conveyances to the water treatment plant.

The City currently obtains about 50 percent of its water from the Noyo River. Under its existing temporary license, the City is entitled to draw up to 1,500 acre feet of water per year from the Noyo River so long as withdrawals do not exceed 3.0 cubic feet per second and specified amounts are maintained in the river to meet the needs of the fish population. The City's Water Permit limits how much water can be pumped from the Noyo River during drought conditions. These limits were established by the State Department of Health Services because it concluded that the City must ensure sufficient flows within the river necessary to support the fish population. To comply with these Permit conditions, the City requires that new development implement measures that limit new water demand. Additionally, the City is developing new water storage facilities to ensure adequate water during severe drought years and to meet the needs of future development in both the Inland Area and the Coastal Zone.

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18 Since the Inland General Plan was last updated, the City constructed a new 45-acre-foot lined water storage reservoir and then purchased 580 acres of land south and east of the city limits on Summer Lane for future reservoirs. The City is also in the process of designing and replacing raw water pipelines connecting to the water treatment facility on Cedar Street that includes two older abovegrade welded steel storage reservoirs (tanks) and one above-grade welded steel reservoir. The city also has a tall above grade welded steel reservoir at the corner of Highway 20 and Babcock Lane.

As the treated water steel reservoirs will be subject to strong ground shaking during an earthquake the design and maintenance of the reservoirs are governed by AWWA D-100 for welded steel tanks and D103 for bolted steel tanks, including requirements for having retrained foundations. Steel structures require inspection and maintenance and may require seismic upgrades as design codes evolve. Geotechnical reports related to these tanks have not been provided for review and comments regarding the design of the reservoirs is beyond the scope of this report.

Pipeline connections to these reservoirs present a seismic vulnerability as the structure and the pipe connection movement can cause localized stresses and cause failures. Flexible/articulating connections are usually provided to connect the reservoir to pumping to accommodate differential movement.

Distribution piping itself can be at risk due to many geotechnical causes, such as:
• Corrosive soils that weaken the pipe itself
• Differential settlement or pipe lengthening due to land sliding, bluff retreat, soil densification, or liquefaction resulting in large magnitude settlements or lateral spreading, static settlement due to change of overburden or imposed loads, or hydro-compression due to changes in saturation
• Differential movement during earthquake such as at service or distribution connections such as large manhole or bridge crossings
The fire hydrant network is also critical infrastructure for the City. The hydrant system needs to remain operational for small and large events such as wildfire and after a large seismic event.

The following sections discuss the different geotechnical conditions that are present within the City of Fort Bragg and its areas of influence.
8 Geotechnical Conditions Assessments
The City of Fort Bragg provided eight geotechnical reports from their files to provide a background of near surface soils conditions listed in Table 1 below and the location of the investigations are shown on Figure 7. Geotechnical information provided in these reports and in other information reviewed include the following topics, to some degree:
• Review of existing data
• Geologic setting
• Site conditions
• Site geology
• Subsurface conditions
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19 • Groundwater
• Soil corrosivity
• Geologic hazard including:
o Seismicity and strong ground motion
o Soil liquefaction
o Expansive soils
o Bluff retreat
General geotechnical subsurface conditions within the coastal and inland areas of Fort Bragg are discussed in the following sections referencing the eight reports provided for review. Each report is identified in the specific area it is located. All the reports include a very limited review of existing data and typically limited review of available published geology and other historical investigations that were performed at the site being investigated.

Figure 7 – Location Map – Reference Geotechnical Investigations Other sources of data that were reviewed for this evaluation and may be of interest are cited below to provide additional insight in the geotechnical conditions and geologic hazards within the City’s area of influence.
• California Department of Conservation, Mendocino County Tsunami Hazard Areas https://www.conservation.ca.gov/cgs/tsunami/maps/mendocino • California Department of Conservation - Alquist-Priolo Earthquake Fault Zones (ca.gov) • California Geological Survey (CGS) 2011, Sheet 58, Deep Seated Landslide Susceptibility • California Office of Emergency Services online MyHazard Maps myhazards.caloes.gov City of Fort Bragg | Geotechnical Evaluation of City of Fort Bragg Seismic Safety Elements related to Water Distribution Facilities
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20 • Geotracker - Environmental Clean-up Areas within and in the Vicinity of Fort Bragg https://geotracker.waterboards.ca.gov/map/?CMD=runreport&myaddress=Fort+Bragg+Ca • Coastal Conservancy – Projects and Land Acquisitions the Coastal Conservancy is s supporting along the coastline in Fort Bragg -
http://websites.greeninfo.org/mapcollaborator/sccpv/prod/# • Mendocino County Hazard Management Plan (2020)
https://mitigatehazards.com/mendocino-county/final-mjhmp/ • Office of the State Fire Marshal – Fire Hazard Severity Zones Pacific Institute – California Flood Risk: Sea Level Rise, For Bragg Quadrangle
https://pacinst.org/reports/sea_level_rise/hazmaps/Fort_Bragg.pdf (Link not active in 2025) • TRC, 2004, Phase II Environmental Site Report, Georgia-Pacific California Wood Product Manufacturing Division, 90 Fort Bragg Avenue, Fort Bragg, California, May (EnviroStor. ca.gov))
• United Stated Department of Agriculture Web Soil Survey https://websoilsurvey.nrcs.usda.gov/app/WebSoilSurvey.aspx • United States Geological Survey Quaternary fault map - USGS.maps.arcgis.com/apps

8.1 Geologic Hazards

8.1.1 Seismicity
The City of Fort Bragg is located in an area that is known for seismic activity; however, the City is not within a currently established State of California Earthquake Fault Zone for surface fault rupture hazards and there are no known active fault traces in the immediate project vicinity. The nearest Alquist-Priolo Earthquake Fault Zone to the project site is associated with the North San Andreas Fault system and located approximately 6.5 miles west of the site, which is the most likely source of earth shaking. The Maacama Fault zone is approximately 21 miles to the east of the City; the Mendocino Fracture Zone is approximately 60 miles to the northwest (Figure 8). The recently identified, potentially active, Pacific Star Fault is located to the northeast between the towns of Fort Bragg and Westport. All the faults could potentially cause earth shaking activity. Potential hazards associated with earthquakes includes rupture of the ground surface by displacement along faults, shaking of the ground caused by the passage of seismic waves through the earth, ground failure induced by shaking, such as landslides, liquefaction and subsidence of unstable ground, and tsunamis. The Pacific Star and Pudding Creek Faults were identified in 2006 and are reported as connecting to the San Andreas fault paralleling the Pacific Coast though they are not located within a special fault study zone.

The 1977 5.2 magnitude earthquake near Willits is the largest magnitude earthquake in the vicinity of the City, approximately 28 miles east of the City. Fort Bragg reported severe losses after the 1906 earthquake due to structure damage and fire. A 7.0 magnitude earthquake offshore Cape Mendocino occurred on December 12, 2024, approximately 90 miles northwest of Fort Bragg, with little damage report in the City as a result. Strong ground shaking is likely for a large earthquake event along the North California Coast region on the Maacama fault zone east of the city, the San Andreas Fault west of the City, and the Mendocino Fracture Zone/Cascadia Thrust Zone off the Pacific Coast near Eureka, California. USGS estimates that there is a 64.92% chance of an earthquake with a magnitude greater than 5 to occur in the next 50 years.

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21 Figure 8 – Quaternary Fault Map (Source USGS.maps.arcgis.com/apps)

8.1.2 Fault Offset, Strong Ground Shaking, Liquefaction and Tsunami Impacts The fault offset hazard in the City is very low. There are no Alquist Priolo Hazards Zones identified within or near the City (www.conservation.ca.gov). The City will be subject to strong ground shaking that could induce densification of loose to medium dense terrace deposits and slope movement within the steeply incised river and creek channels and along the coastal bluff. Loose, saturated cohesionless soils are susceptible to liquefaction, including sediments that have accumulated within and at the mouth of the coastal, river, and creek channels and potentially in eolian (windblown) derived terrace deposits that become saturated due to groundwater.

The State of California Office of Emergency Services online MyHazard maps (myhazards.caloes.gov) does not identify Fort Bragg as having a mapped liquefaction zone; however, the risk of liquefaction is judged to be moderate in the terraces and high in the river and creek channels and could occur in the event of strong ground shaking.

Fort Bragg
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22 Tsunamis would impact the coastal areas, the Noyo Harbor and upstream areas of Noyo River Pudding Creek and Hare Creek (Figure 9). The Pacific Institute presents the effect of 55 inches of sea level rise on their Sea Level Rise Map of the Fort Bragg Quadrangle referenced above. The map shows that sea level rise will exceed the 100-year flood level within the Noyo River and Pudding Creek. The occurrence of tsunami(s) combined with sea level rise would impact the areas shown effected by sea level rise within the limits of Pudding Creek, Hare Creek, and the Noyo River including impacting existing raw water intakes along the Noyo River with salt water. The intakes have been impacted in the past with saltwater intrusion from high tides, and beginning in 2021 the City began using a desalination system to treat high salinity raw water from the Noyo River (Water Boards Media Release October 12, 2021).

Figure 9 – Tsunami Hazard Area - Shaded (source Cal OES MyHazard) City of Fort Bragg | Geotechnical Evaluation of City of Fort Bragg Seismic Safety Elements related to Water Distribution Facilities
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23 Table 1 – Geotechnical Reference Provided by City of Fort Bragg by Area Date Area Author Address Rock
Depth
Bluff
Erosion
Estimated
Dynamic
Densification Liquefaction Lateral Spreading
Tsunami
Risk
2022
Inland
Crawford
Segment
2 NE NA Low Low ND ND
Inland * Segment
3 NE NA low Low ND ND
Inland * Segment
4 NE NA Low Low ND ND
Inland * Segment
5 NE NA Low Low ND ND
2018 South
Coastal
Salem 1151
South
Main
Street
>20 ft
NA Yes Low Low Low
2016 Central
Coastal
HDR 101
Cypress
Street

11.5 to
18 No Yes No No NA
2016 Central
Coastal
Brunsing 101
Cypress
Street
ND
Yes
(14.75 ft/75
years)

NA NA NA NA
2015 North
Coastal
Brunsing 1201
North
Main
Street
10 to16
ft Yes (31.25
ft /75 yrs)
Yes Yes (0.4g
shallow
GW)
Yes Low
2011 South
Coastal
Caltrans Highway
1 (ADA
Project)
10 to
11 ft NA ND ND ND ND
2007 Inland
(outside
City
Limits)
Curry
Group
Summers
Lane NE NA Yes
Yes (0.65g
and GW at
ground
surface)
Yes NA
2003 Inland SHN Green
Memorial
Field/Star
r State
Park

11.5 to

38.5 ft NA Low Low ND ND
Note: * - Outside of City Limits
ND – Not Determined
NA – Not Analyzed
NE – Not Encountered
Low, No, Yes – Individual Report Author’s Opinion

8.1.3 Non-Seismic Hazard
Non-seismic geologic hazards include the presence of unstable soils on steep slopes and expansive soils which, in the presence of moisture, will swell and shrink when returning to a dry condition, and compressible soils. Map SF-1: Geologic Hazards identifies areas of potential landslides and is discussed in more detail in the Section of Topography and Geology earlier in this evaluation.

Bluff retreat (erosion) is estimated for two locations in the provided reports, and is discussed in more detail in the following sections. The Pacific Institute has provided graphical estimates of bluff retreat by the year 2100 on their Sea Level Rise Map of the Fort Bragg Quadrangle referenced above. It is City of Fort Bragg | Geotechnical Evaluation of City of Fort Bragg Seismic Safety Elements related to Water Distribution Facilities
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24 unlikely that bluff retreat will impact the City’s water distribution system unless there are existing distribution pipelines or connections within that zone.

The presence of loose and/or weak compressible soils has been noted in the reference geotechnical reports. The presence and mitigation, if required, would be determined on a project-specific investigation/basis. It would be beneficial to document the past performance of the water distribution system (Geographic Information System [GIS], mapping and tabular format) including areas of past pipe repairs/leak/breaks and areas of known surface (street pavement and hardscape) distress to identify areas that may be underlain by weaker soils.

8.1.4 Regional Geology
The bedrock of this part of the Mendocino coast is comprised of well-consolidated sedimentary rocks of the Cretaceous-Tertiary Period coastal belt Franciscan Complex, such as sandstone and shale.

The bluff-top property occupies a near-level marine terrace underlain by the Franciscan Complex bedrock. The terrace was formed during the Pleistocene Epoch, when periods of glaciation caused sea level fluctuations, which created a series of steps, or terraces, cut into the coastal bedrock by wave erosion. Shallow marine sediments (Pleistocene terrace deposits) were deposited on the wave-cut, bedrock platforms while they were submerged beneath the ocean during interglacial sealevel high stands. Some of these marine deposits have been locally eroded as the terraces began to emerge from the ocean due to uplift associated with the San Andreas Fault Zone during the middle and late Pleistocene. Present sea levels are believed to have been achieved about 5,000 to 7,000 years ago.

8.1.5 Near-Surface Geology and Surface Condition
The following descriptions of site near-surface geotechnical conditions are excerpted from the geotechnical reports provided by the City separated by zone, Coastal (North, Central and South) and Inland zones, and by report author to provide a basis to understand the variability of subsurface geotechnical and groundwater conditions of the terrace deposits that mantle the bedrock within the city. It should be noted that the geotechnical reports have been developed to different standards based on their age and their primary purpose. However, the reports provide insight into the variable subsurface conditions across the city, particularly the thickness of fill materials and terrace deposits.

The identification of Zones is based on the City of Fort Bragg Inland and Coast General Plans (City of Fort Bragg 2012 and 2008) The Inland Zone is identified as a generally a westward project extending from the intersection of Walnut Street and Highway 1, projecting east to the top of the Noyo River north bank and to the north from the intersection of Walnut Street and Highway 1, following Highway 1 north to beyond Virgin Creek, as shown on Map LU-1, Land Use Designation.

The Coastal Zone is all areas west and south of the Inland Zone, including the intersection of Highway 1 and Highway 20, for areas within the City boundary and sphere of influence as shown on Figure LU-1 Land Use Designations. The Noyo River has been included in the Coastal Zone. For this document, Pudding Creek and the Noyo River have been selected to divide the Coastal Zone into the North, Central and Southern zones. Therefore, historical investigations that extend or are located south of the Noyo River north top of bank are included in the southern Coastal Zone.

A summary of the conditions reported at each of the eight reports are provided in attachment A.

Included is a comparison to the data available from the NCRS Soil Survey data regarding the City of Fort Bragg | Geotechnical Evaluation of City of Fort Bragg Seismic Safety Elements related to Water Distribution Facilities
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25 composition of new surface soil composition. The NCRS Soil Survey Data is provided in an online map of soil conditions for depths on the order of 6 feet. A map of the units overlain on an aerial map for the City and surrounding area is provided as Attachment B as well as tabular list data of typical engineering and chemical properties contained in the NCRS database organized by soil unit number. The tabulated values are developed focused on agricultural uses but can provide insight into the soil texture and chemical nature of the soil. This data can be used for a preliminary highlevel assessment of near surface site conditions in areas within a specific zone but not explicitly investigated. More detailed investigations may be warranted depending on the project under consideration.

It is particularly important to note that groundwater conditions documented in the reference reports represent conditions observed at the time of investigation and are generally poorly understood.

Groundwater (at depth) and near surface perched groundwater are two different groundwater occurrences and both have been reported. Additional groundwater investigations would be required to better understand the current temporal variations in groundwater at a specific site with the City’s area of influence. The assumptions related to groundwater levels have a significant impact on the occurrence of liquefaction induced by strong ground shaking and the values reported in the different documents should not be relied on for future project.

Documents related to the environmental cleanup of the Georgia-Pacific site (Central Coastal Zone) are available through the California Department of Toxic Substances (DTSC) using the Envirostor system (https://www.envirostor.dtsc.ca.gov). Groundwater in the central portion of the Coastal Zone is depicted in a series of monitoring reports that show a groundwater depression in the vicinity of Soldier Bay. The 2004 Phase 1 study described this area as a natural low spot and groundwater at the eastern edge of the zone was measured at El. 65 feet.

Fill – All Reports
Variable thickness of fill is present throughout the City due to historical grading and development. Fill is likely locally derived and can be highly variable. Fill material may contain significant organics (such as topsoil) and can have little to no compaction efforts. Suitability for reuse of fill will need to be determined on a case-by-case basis.

Marine Terrace Deposit – Coastal (five report sources)
The Coastal Zone generally consists of sand with variable amounts of gravel, silt and in some instance s clay. It is listed as being eolian (windblown) origin by NCRS, is under consolidated and can be susceptible to liquefaction due to strong ground shaking depending on the level of groundwater. Where estimated, the liquefaction hazard is generally low and liquefaction induced settlement has been calculated based on conservative (elevated) groundwater levels. The liquefiable soils are also susceptible to lateral spreading.

The depth of bedrock is variable. Bedrock was not encountered in the southern coastal zone. In the Coastal Central Zone, depth to bedrock varies from to within 2 feet of the ground surface to a depth of 9.5 feet at the City WWTP and 20 to 30 feet at the Georgia-Pacific facility in the topographic low point at Soldier Point. In the Coastal Northern Zone the depth of bedrock varied from 7 to 15 feet.

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26 The depth to groundwater has been reported to occur at a depth of 7 to 8 feet in Georgia-Pacific monitoring wells. Groundwater encountered at the time of drilling in the north and south area was reported between 2 and 7 feet and are expected to vary seasonally.

Marine Terrace Deposits – Inland (two report sources)
The Inland Zone is likely comprised of both eolian and fluvial terrace deposits depending on the distance east from Highway 1. The terrace deposits transition to fluvial derived deposits that have higher clay and silt contents up to materials being classified as clay. These have been identified at the Aquatic Center and along the raw water pipeline alignment. The transition between the two types of terrace deposits are not defined but, for a first estimate, may be located along the El. 160-foot contour.

A potential buried drainage (bedrock depression) may be located beneath the Aquatic Center and may extend to the west towards the bay north of Soldier Point. The buried drainage would have thicker terrace deposits than the adjacent areas that could increase the risk of differential settlements due to seismic densification liquefaction. Bedrock was only encountered by the 2003 Aquatic Center investigation at depths of 5 to 10 feet but was below a depth of 22 feet at one location. A compressible peat layer was found at depths of 22 feet.

Shallow groundwater was encountered during the 2003 investigation.

Colluvium – Incised River and Creeks Slopes
Colluvium is mapped as being along slopes that have moderate to high risk for landslides. The thickness of the colluvium is not defined but is estimated in one report as being on the order of 5 feet.

Alluvium and Beach Deposits
Alluvium and beach deposits have accumulated along the river and creek channels. The Noyo River is maintained by the United Stated Corps of Engineers that periodically dredge the channel. Beach deposits are located at the mouth of Hare and Pudding creeks. Alluvium derived from erosion of adjacent areas has accumulated in the stream bottoms and likely varies from sand bars to siltation within the channel that are likely saturated and loose (granular deposits) and soft and weak (cohesive deposits). Targeted geotechnical studies would need to be performed to assess the conditions that existing for projects that are located across these deposits.

8.2 Other Geologic Related Concerns

8.2.1 Mineral Resources
According to a 2019 Initial Study and Mitigated Negative Declaration, the City does not have any identified locally important mineral resources recovery sites delineated in the general plan, specific plan, or other land use. The City has also not been utilized for Surface Mining and Reclamation Act (SMARA) activities, as noted in the City of Fort Bragg General Plan Amendment 1-19 (GPA 1-19), Inland General Plan Amendment – Housing Element Update (2019).

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27 8.2.2 Corrosivity (Chemical Analysis)
As stated in the previous sections, the near-surface soil blanketing the site is acidic and has a low cation exchange capacity being more acidic closer to the ocean. Corrosivity analyses were only available from two of the eight studies reviewed, reported as follows.

South Coastal Zone (Salem 2018)
Soluble Sulfate - 100 mg/kg
Soluble Chloride - 36 to 37 mg/kg
pH – 7.1
The water-soluble chloride concentration detected in saturation extract from the soil samples was 37 mg/kg.

The reports states that this level of chloride concentration is considered slightly corrosive.

Inland – (Crawford 2022)
Pipeline Segment 4 – two samples depths 2.0 to 3.0 feet.

Minimum Resistivity (Ohm-CM) - 4,290 and 10,990
Sulfate Content (ppm) - 3.1 and 15.1
pH - 3.99 and 4.26
The report states that in accordance with Caltrans Standards, the soil tests indicate corrosive to structural steel materials and non-corrosive to structural concrete materials. The Crawford results correlate with NCRS data for pH.

The terrace deposits soils should be considered corrosive to steel and slightly corrosive to concrete unless specific testing is performed or the performance of buried structures can be determined from visual inspection. A testing standard should be developed for all corrosion testing so that a “Zone” database can be developed by the city to aid in their management of the water system.

8.2.3 Erosion
For the steeper slopes, Crawford (2022) stated the following for the proposed pipelines:

The proposed pipeline alignment meanders through steep slopes with a few areas mapped as inner gorge which are prone to landslides, erosion, and creeping. Based on our review of the project plans, the slopes are shown to range from 1H:1V to 4H:1V along the pipeline alignment. Observations along the proposed alignment showed the existing slopes are performing adequately and consist of heavily established vegetation. Following the completion of construction, overly steepened areas (such as between Station 125+00 through 126+60 and Station 130+00 through 132+00) where vegetation is being removed will be susceptible to erosion and may require periodic maintenance while the vegetation is reestablished.

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28 Removal of vegetation and redirection of surface water could induce erosion on any area of the City.

Care must be taken to restore disturbance to reduce the risk of developing areas of concentrated surface water flow that could induce erosion. Care must be also taken to install trench dams along long lengths of pipeline in and in areas of elevation transitions so that the pipeline trench does not act as collection drawings redirecting and concentrated seepage to the trench outlet, which could lead to ground saturation and potential slope failure and erosion.

8.2.4 Non-Geotechnical Hazards

8.2.4.1 Flooding
Flooding Hazard is typically determined for a 100-year flood level for insurance purposes using maps developed by the Federal Emergency Management Agency (FEMA). As described in the Inland General Plan:
“FEMA … requires the City to establish development standards for construction in the 100-year floodplain. Typically the standards developed by a city or county can range from limits on the intensity of development to requirements to raise the "habitable floor" of the structure to at least one foot above the 100-year flood peak elevation. Most of the City, over 99% of the land area, is situated above both the 100-year and the 500-year floodplains. The only areas in the Inland Area located within the 100-year flood plain are along the Noyo River and Pudding Creek. The presence of riparian habitat and excessive slopes in this area prohibits development within the 100-year flood plain.”
And,
“Portions of the City have areas subject to potential flooding during severe storms.

Because of the generally flat terrain in the Fort Bragg area, a 100-year storm could exceed the ability of the City's infrastructure to move runoff water from the City to outfalls into natural drainages and the ocean. This drainage overload may result in standing water in low areas. High tides and severe storms may also cause flooding in low-lying areas near creeks and drainages.”
The Coastal Zone Map SF-2 references flood mapping dated 1992 while the Inland Zone map references mapping stated in 2011. The FEMA updated flood maps for Fort Bragg area are dated as being published in 2017 that show larger 100-year flood hazard than shown in the Coastal General Plan Map. The Inland Zone General Plan includes Map SF-3 Tsunami Inundation Map and Map SF4 100-year Sea Level Rise Inundation Area, which is the Pacific Institute map previously referred as an additional source document for this evaluation. The most recent FEMA flood mapping and the Pacific Institute mapping of sea level rise is recommended as references for assessing flooding impacts.

8.2.5 Fire Hazard
The City’s fire hydrant system is critical infrastructure for public safety. Significant fires have occurred in Northern California in the last few years and the ability to protect the City from structure fires and wildfire is important. The fire hydrant system is also critical after a large seismic event.

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29 In 2022, the California Department of Forestry and Fire Protection (CAL FIRE) published large-scale maps depicting Fire Hazard Severity Zones for Mendocino County as part of the Fire and Resource Assessment Program
(https://osfm.fire.ca.gov/media/loqhpr10/fhsz_county_sra_e_2022_mendocino_ada.pdf).

Zones north and south of the City are zoned as having a high severity and the east is zoned as moderate severity. The City is outside the jurisdiction of CAL FIRE and the City itself is zoned as a local responsibility area (LRA). The Fire Hazard Zone Severity Viewer is located at https://egis.fire.ca.gov/FHSZ/. The viewer shows the area south and east of the Noyo River zoned as very high and the area north and east of the City as moderate. High risk zones are located east of the City on the north back of the Noyo River and east of the north Coastal Area. The south Coastal area is located in a moderate risk zone west of Highway 1 and in the lower elevations east of Highway 1.

8.2.6 Extreme Weather Events
In February 2023, the United States Department of Agriculture (USDA) declared Mendocino County a Disaster Area due to severe winter storms and flooding. The occurrence of heavy storms and storm events, characterized as atmospheric rivers, are defined by National Oceanic and Atmospheric Administration (NOAA) as long narrow regions in the atmosphere that transport most of the water vapor out of the tropics that have an equivalent flow at the mouth of the Mississippi River and exceptionally strong events can have 15 times that amount. The Pineapple Express is a strong atmospheric river bringing moisture from the tropics near Hawaii to the west coast. The rain events can induce slope instability and rapid slope movement and debris flows. One such event happened to the community of Rio Nido along the Russian River in 1998 and have also been attributed to coastal landslides in 1962.

Figure 10 presents a ranking of the potential deep-seated landslide occurrence-based on rock strength and slope inclination from CGS Map Sheet 58. The darker the color red indicates the higher potential risk. Rock strength in Mendocino County is generally ranked as moderate; therefore; the instability is a function of slope inclination ranging from 3 degrees to over 40 degrees, with rocks inclined 15 to 20 degrees or greater having the highest susceptibility (approximately equivalent to a 27 percent grade or higher). Therefore, the susceptibility of landslides impacting the City water supply and distribution system or evacuation routes directly or from debris flows should be evaluated on a case-by-case basis. It should be noted that climate change may increase the risk of slope instability.

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30 Figure 10 - Relative Slope Instability in the Fort Bragg Area (After CGS Map 58, 2011)

8.2.7 Chemically Impacted Sites
A review of the DTSC GeoTracker website provides the locations of numerous identified chemically impacted sites that range from small underground storage tanks to large facility clean-up activity.

Many of the sites are identified as having closed files, meaning that the sites have been remediated to meet cleanup goals s set forward by regulatory agencies. It should be noted that there may be residual chemically impacted soils at these sites that did not require removal but, should they be excavated, may require special testing and handling to determine material reuse or disposal. The GeoTracker site and associated data should be checked as part of a future system upgrade or rehabilitation projects to be aware of potential impacted sites. 9 Areas of Concern for Rehabilitation of Water
Distribution Facilities
The following geotechnical factors should be considered when addressing water distribution design or rehabilitation.

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31 9.1 Densification and Liquefaction
The City will experience strong ground shaking that could induce seismically densification and/or liquefaction in saturated, loose granular soil. Liquefaction can also induce lateral spreading.

Differential movement both vertically and laterally can damage water distribution facilities such as when connected to structures founded on rock or connected to bridges. The magnitude of movement will dictate the appropriate measures to include in a repair or rehabilitation of the system including use of articulating joints for entering rigid structures and the use Earthquake Resistant Ductile Iron Pipe (ERDIP) if the anticipated movements are significant and would damage standard pipe systems, such as those being implemented by the Los Angeles Department of Water and Power (LADWP) to provide greater resilience to their distribution system. ERDIP allows for the pipeline to extend, accommodating seismic deformations limiting failures for pipelines failing at joint. The amount of movement that can be accommodated is a function of the length of ERDIP installed.

LADWP limits use of ERDIP to sites that are deemed critical to the function of the entire water system in the event of a major earthquake and are typically located in areas that are calculated to have widespread lateral spreading and large fault offset. For more information, see https://www.hdrinc.com/sites/default/files/2017-05/hdr-seismic-considerations-for-waterdistribution.pdf (link not active in 2025). and https://scag.ca.gov/sites/main/files/fileattachments/srpwebinar_orourkepresentation.pdf?1603219825 ) The American Lifeline Alliance is a public/private alliance between FEMA and the National Institute of Building Sciences. In 2005, they published Seismic Guidelines for Water Pipelines that provides extensive guidance for the design of water pipelines in the seismic environment. (https://www.americanlifelinesalliance.com/pdf/SeismicGuidelines_WaterPipelines_Comm.pdf.

There are also numerous articles published in AWWA and ASCE conference proceedings, including work by O’Rourke. In the 1970s, asbestos concrete pipe (ACP) was used for water distribution systems. As these pipes age the pipes can become brittle and fail catastrophically with no warning.

ACP also poses an environmental hazard. Therefore, the pipelines can be lined with a drinking water compatible resin cured-in-place pipe (CIPP) line technology that, when the resin hardens, forms a new ductile and deformation resistant pipe within the ACP. CIPP can also be applied to ductile iron pipes.

Seismic shaking itself can induce differential movement between structures and pipeline causing damage to connections, such as connections to vaults, steel reservoirs, or bridge crossings. Large, out-of-phase movement can cause damage to connections to structures. To improve resiliency flexible connections should be provided. The City will likely be subject to strong ground shaking due to earthquakes occurring on nearby faults. Existing and new connections should be evaluated by the appropriate design standards.

9.2 Corrosivity
Based on the limited amount of the data, the soils in and around Fort Bragg should be considered corrosive to iron and mildly corrosive to concrete. Site Specific testing should be performed and compiled to confirm the corrosivity of the soils. Testing should include:

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32 • As-received and saturated electrical resistivity per ASTM G-187 and pH per ASTM G-51; and • Chemical analysis for Major anions and cations per ASTM 6919, ASTM 4327 and AWWA 4110B

9.3 Groundwater
Groundwater levels are reported as varying seasonally, rising to near the ground surface in some instances. Long reaches of pipelines can interconnect areas of high groundwater and transmit water to other areas along the trench bedding or pipe zone material. This can be exacerbated by pipelines that run from higher elevations to lower elevations in the city. Trench dams should be included wherever expected or known groundwater is encountered during construction and spaced at the midpoint of each line segment, and where future construction access will be required. Trench dams consist of low permeability material (soil or Controlled Low Density Fill, manufactured materials that are slipped over the pipe at the time of installation).

9.4 Seismic Response
In addition to dynamic densification and liquefaction effects, pipe connections to structures, such as vaults, steel reservoirs or bridge crossing may experience differential movements based on the response of the ground compared to the response (shaking) of the structure. Out-of-phase movement can cause damage to connections to structures. To improve resiliency flexible connections should be provided. The City will likely be subject to strong ground shaking due to earthquakes occurring on nearby faults. Existing and new connection should be evaluated by the appropriate design standards.

9.5 Bluff Erosion
The bluffs along the coastline are actively eroding, which is referred to as bluff retreat or bluff erosion. Estimates of bluff erosion have been provided in two referenced geotechnical reports (Table 1) and from the Pacific Institute. Placement of distribution systems within the limits of future bluff retreat is not recommended.
10Recommended Future Actions
To better understand specific geologic risk to specific portions of the water distribution system, a more detailed understanding is needed at the location of critical components of the system.

Specifically, the following should be determined:
• The peak ground acceleration based on current code requirements, typically expressed as the design earthquake return period. Depending on the age of the facility the current design, the code may be different from what was used at the time the component was designed and constructed.
• The thickness of fill and/or terrace deposits at the site, the depth to bedrock and an understanding of the groundwater depth and seasonal fluctuation. Past geotechnical investigations associated with the original design of the component/facility or a report prepared for an adjacent property combined with review of the as-built grading plans would City of Fort Bragg | Geotechnical Evaluation of City of Fort Bragg Seismic Safety Elements related to Water Distribution Facilities
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33 typically provide data regarding the site soil stratigraphy and depth to bedrock.

Understanding groundwater conditions below the site would likely require additional study, as discussed below. This information is required as input into a seismic vulnerability assessment for understanding the potential for seismic densification or vertical or lateral deformation as a result of liquefaction, if potentially liquefiable soils are present at the specific site.
• Mapping of areas of slope instability along pipeline corridors and within 300 feet of a component or facility at a local scale will provide the input to assess the current hazard that slope instability poses to the facility as well as allow comparison for changes in the risk, specifically after major storms/flood events or a large seismic event. Each specific area of concern should be mapped at a scale of 1”=50 feet and fixed reference points set, such as rebar hubs setback (above) the area of instability in readily accessible areas that can be used to easily identify changes visually and hand measurement. Each location will need to be assessed on a case-by-case basis to establish the limits of mapping and location and number of reference points. Use of fixed features such as a fence, fire hydrant, or street curb may not be sufficient as they can be modified or damaged over time.

The depth to bedrock could be evaluated by performing limited geophysical surveys (Seismic Refraction) that is a non-invasive and lower cost method of field investigation. The geophysical surveys in combination with other geotechnical or environmental investigation reports available from the City could provide the level of detail required without the expense of drilling soil borings.

Understanding the depth of groundwater and fluctuation over time could require installation of strategically placed monitoring well(s) to understand the source and direction of groundwater flow and the effects of rainwater and irrigation infiltration. An initial widely spaced grid of wells could be established and monitored semi-annually to quarterly to develop an understanding of groundwater behavior. The wells could be supplemented if an area’s data seems erratic or if addition detail is desired.

Planning for such a study should be preceded by a desktop study reviewing available data contained in City files and interviewing local civil/geotechnical and geological consultants familiar with the Fort Bragg’s soil and geologic conditions that may offer specific knowledge from past experience within the City. All the groundwater, soil, and bedrock depth and slope instability data can then be collected through GIS and reviewed to determine where more detailed study would be warranted. The information would need to be reviewed and updated to provide a living document that can be used by all departments of the City for planning and risk assessment. HDR understands that they City is documenting the presence of shallow groundwater as part of ongoing maintenance work (unpublished).

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34 11Limitations
This report was developed by HDR for the client’s sole and exclusive use on this project for the purposes described in this report and within the scope of work, and in accordance with contract conditions. This report is not for the benefit of any third party and may not be distributed to, disclosed in any form to, used by, or relied upon by any third party without prior written consent of HDR.

Consent may be withheld by HDR at its sole discretion. Use of this work product by others is at their own risk and the user assumes all liability for its use. This report must be read as a whole; individual sections should not be considered or interpreted on a stand-alone basis. The content included in this report is correct to the best of HDR’s knowledge and has been developed in accordance with the standard of care that is customarily followed by a practitioner in this industry reviewing and reporting existing data. The scope of this project did not include collection and analysis of data and for calculations or modeling in support of this report.

The information provided in this report was developed or provided by others. Except as specifically identified in this report, HDR has not performed independent validation or verification of exploration data, modeling data, or other analysis data provided by others. HDR has used qualified and diligent staff to prepare this report and has assumed that third-party or client data are accurate, complete, reliable, and current. Depth to groundwater levels recorded on boring logs in these studies is subject to many variables and may not be indicative of long-term equilibrium conditions. These variables include water introduced during drilling operations, surface infiltration, puncture of perched horizons, build-up of mud against the walls of the boring (which can reduce infiltration), and inadequate time for equilibration of groundwater pressure.

HDR has not performed a site-specific seismic evaluation of ground shaking intensity or duration.

Recommendations in this report are based on published mapping prepared by others and standard practices for the area.
12 References
American Lifeline Alliance (2005) Seismic Guidelines for Water Pipelines(https://www.americanlifelinesalliance.com/pdf/SeismicGuidelines_WaterPipelines_Co mm.pdf.

Arcadis (2011) Draft Conceptual Design, Mill Pond Complex Restoration, Former Georgia Pacific Wood Products Facility (Text only) June (source savenoyoheadlands.org ) California Department of Conservation, Mendocino County Tsunami Hazard Areas https://www.conservation.ca.gov/cgs/tsunami/maps/mendocino California Department of Conservation - Alquist-Priolo Earthquake Fault Zones (ca.gov) California Geological Survey (CGS) 2011, Sheet 58, Deep Seated Landslide Susceptibility California Office of Emergency Services online MyHazard Maps myhazards.caloes.gov City of Fort Bragg | Geotechnical Evaluation of City of Fort Bragg Seismic Safety Elements related to Water Distribution Facilities
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35 Coastal Conservancy – Projects and Land Acquisitions the Coastal Conservancy is s supporting along the coastline in Fort Bragg - http://websites.greeninfo.org/mapcollaborator/sccpv/prod/# Durham, J.B., 1979, Title II Geologic Compilation Project, Ukiah and Santa Rosa Map Sheets:

California Department of Forestry, unpublished 15-minute quadrangle maps, scale 1:62,500 Fort Bragg (2008) Coastal General Plan, July
Fort Bragg (2012) Inland General Plan, November
Fort Bragg Mendocino Coast Historical Society – 1873 Coastal Survey Map, 18723/2023 Slider Maphttps://www.fortbragghistory.org/?page_id=1071
Geotracker - Environmental Clean-up Areas within and in the Vicinity of Fort Bragg https://geotracker.waterboards.ca.gov/map/?CMD=runreport&myaddress=Fort+Bragg+CaHDR 2017, Seismic Considerations for Water Distribution
https://www.hdrinc.com/sites/default/files/2017-05/hdr-seismic-considerations-for-waterdistribution.pdf. (link no longer active as of 3/2025)Manson, M.W., Sowma-Bawcom, J.A., and Parker, T.K. (2001) Geologic and geomorphic features related to landsliding, Noyo River watershed, Mendocino County, California, California Division of Mines and Geology. Publication DMG CD 2001-03
Office of the State Fire Marshal – Fire Hazard Severity Zones https://osfm.fire.ca.gov/divisions/community-wildfire-preparedness-and-mitigation/wildfirepreparedness/fire-hazard-severity-zones/fire-hazard-severity-zones-map/ O’Rourke, T.O. (Undated) Seismic Resilient Pipelines, Webinar Slides, Seismic Resilient Pipelines with Cornell Professor Thomas O’Rourke (ca.gov) Pacific Institute – California Flood Risk: Sea Level Rise, For Bragg Quadrangle https://pacinst.org/reports/sea_level_rise/hazmaps/Fort_Bragg.pdf TRC, 2004, Phase II Environmental Site Report, Georgia-Pacific California Wood Product Manufacturing Division, 90 Fort Bragg Avenue, Fort Bragg, California, May (EnviroStor.dtsc. ca.gov))
United Stated Department of Agriculture Web Soil Survey https://websoilsurvey.nrcs.usda.gov/app/WebSoilSurvey.aspx United States Geological Survey Quaternary fault map - USGS.maps.arcgis.com/apps USGS Publication Warehouse – Simon, R.B, Pampeyan, E.H. and Stover C.W. (1978) The Willits, California, magnitude-4.8 earthquake of November 22, 1977 https://pubs.usgs.gov/publication/ofr781075
USGS Earthquake Hazards Program M7.0- 2024 Offshore Cape Mendocino, California Earthquake - https://earthquake.usgs.gov/earthquakes/eventpage/nc75095651/executive City of Fort Bragg | Geotechnical Evaluation of City of Fort Bragg Seismic Safety Elements related to Water Distribution Facilities
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36 Attachment A – Summary of Geotechnical Conditions
Depicted by City-Provided Geotechnical Reports
The thickness of soil layers described below will likely vary across the project site. Borings indicate the depth across the site, but these elevations (or depths) may be somewhat higher/lower/greater between the borings.

The reports state that the materials encountered in exploratory borings were continuously logged in the field by an engineering geologist/geological engineer. The unconsolidated materials (soil) were visually classified using the Unified Soils Classification System (USCS), according to ASTM D-2487.

However, the quality of the observations, visual logging, and quantity supporting laboratory testing vary between the reports. HDR has not performed independent validation or verification of exploration data, modeling data, or other analysis data provided by others. HDR has used qualified and diligent staff to prepare this report and has assumed that third-party or client data are accurate, complete, reliable, and current.

The reports reviewed are:
• Brunsing and Associates (2015), Geotechnical Investigation, The Avalon Inn, 1201 North Main Street, Fort Bragg, December 4
• Brunsing and Associates (2016), Engineering Geologic and Geotechnical Reconnaissance, Blufftop Biological Treatment Facility, Fort Bragg Wastewater treatment Plan, 101 Cypress Street, Fort Bragg, California, September 12
• Caltrans (2011), Memorandum, Geotechnical Design Report, Fort Bragg ADA project October 31
• Crawford and Associates (2022), Final Geotechnical Report, City of Fort Bragg Raw Water Pipeline Replacement, Segment 2 – 5, Fort Bragg, California, March • Curry Group (CGI, INC) (2007), Geotechnical Study, 45-acre-foot Line Reservoir, Fort Bragg California, January 9
• HDR 2016 Fort Bragg Wastewater Treatment Plan Upgrade Project, Fort Bragg, California, February 19
• Salem Engineering Group, Inc. (2018), Geotechnical Engineering Investigation, Proposed AutoZone Retail Store, 1151 South Main Street, Fort Bragg, California, March 6 • SHN Consulting Engineers & Associates (2003) Revised Geotechnical Report, Proposed Recreation Building Green Memorial Field, Fort Bragg, California, August The identification of Zones is based on the City of Fort Bragg Inland and Coast General Plans (City of Fort Bragg 2012 and 2008) The Inland Zone is identified as a generally a westward project extending from the intersection of Walnut Street and Highway 1, projecting east to the top of the Noyo River north bank and to the north from the intersection of Walnut Street and Highway 1, following Highway 1 north to beyond Virgin Creek, as shown on Map LU-1, Land Use Designation.

The Coastal Zone is all areas west and south of the Inland Zone, including the intersection of Highway 1 and Highway 20, for areas within the City boundary and sphere of influence as shown on Figure LU-1 Land Use Designations. The Noyo River has been included in the Coastal Zone. For this document, Pudding Creek and the Noyo River have been selected to divide the Coastal Zone City of Fort Bragg | Geotechnical Evaluation of City of Fort Bragg Seismic Safety Elements related to Water Distribution Facilities
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37 into the North, Central and Southern zones. Therefore, historical investigations that extend or are located south of the Noyo River north top of bank are included in the southern Coastal Zone.

North Coastal Zone
Brunsing 2015
The report by Brunsing (2015) is located in the North Coastal Area along the west side of Highway 1 just south of the intersection of Airport Road. The report states:
• Surface soils depicted by the exploratory borings generally consist of about one to 2.5 feet of brown silty sand topsoil that is very loose to medium dense and porous. • Beneath the topsoil, the site is typically mantled by poorly-consolidated marine terrace deposits.
• The terrace deposits consist of beach or shallow marine sediments that are typically comprised of sands with some silt, gravel, and clay, along with incorporated rock fragments eroded from the underlying bedrock platform.
• The terrace materials were deposited in lenses that are generally flat, with local undulations caused by the variable-energy nature of the depositional environment and are mostly comprised of loose to medium dense, saturated sands. Clayey or silty sands were observed in some of the borings, generally just under the topsoil, but most of the terrace deposits encountered are relatively devoid of fines (silt- and clay-sized particles). • The terrace deposits generally extend to between 7.5 and 15 feet below the ground surface (bgs), and appear to generally thicken toward the east. • The terrace deposits we observed within the bluff face west of the property, up to about 10 feet thick, consisting of reddish brown silty sands interbedded with silty sandy gravels. • Bedrock was encountered at depths ranging from approximately 7.5 to 15 feet. The encountered bedrock generally consists of dark gray sandstone that is moderately to intensely fractured, moderately hard to very hard, and deeply- to little-weathered. • Practical drilling refusal was generally encountered after about one to three feet of penetration into the bedrock.

Unstabilized ground water levels were observed at the time the exploration was performed between about 2.5 and 7 feet below the ground surface. The report state states that shallow ground water can temporarily occur during, and immediately following wet weather periods.

The US Department of Agriculture provides maps of soil conditions depths on the order of 6 feet. A map of the units for the City and surrounding and typical engineering and chemical properties are provided in Attachment A. The units for this are (117, 161, and 214) are consistent with the Brunsing report’s description of near surface conditions.

The results of tests evaluating the corrosion protection of the soil on steel and concrete were not performed by the Author of the report. According to the available soil survey data the marine terrace deposits are acidic (pH range of 2 to 5.5) and have a low cation exchange capacity. Discussion of corrosivity testing results presented in other geotechnical report is discussed in the section entitled Other Geologic Related Concerns.

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38 Central Coastal Zone
HDR 2016
HDR performed a focused geotechnical investigation of the City’s Waste Water Treatment Plant (WWTP) Expansion in 2016. The plant is located on Noyo Point Road to the south west of the former Georgia-Pacific Lumber southern processing mill site, on the southside of the site. Other geotechnical investigation have been performed in the historical past related to the WWTP and are included within this report. This document reports near surface geotechnical conditions consisted of:
• Pleistocene age marine terrace deposits that overlie marine sedimentary bedrock consisting of sandstone, shale, and conglomerate.
• Past borings by others and borings for the current study indicate that fill generally overlies bedrock at the WWTP site except shallow bedrock was encountered for two structures. • Fill was reported as extending to depths of about 8 to 9½ feet, and the report states “generally consists of dark brown to black, loose to medium dense silty sand with varying amounts of gravel.
• Beneath the fill, brown-yellow loose to medium poorly-graded fine sand with silt was encountered.
• The sand deposits are consistent with descriptions of marine terrace deposits mapped by Kilbourne (1983). The sand deposits extend to depths of about 11½ feet (Elevation 38½ feet) in Boring K-2, 13 feet in Boring B-02 (Elevation 35 feet), and 18 feet in Boring B-01 (Elevation 30 feet), where bedrock was encountered suggesting that the depth to bedrock generally increases to the north and west.
• The bedrock encountered generally consists of slightly weathered to decomposed, weak to moderately strong sandstone and interbedded shale and sandstone and extended to the maximum depth explored of about 24 feet.

The units for the northern area just south of Pudding Creek are reported as the same as for the North Coast Area (117, 161, and 214). The unit for the majority of the Central Coast Zone and the Inland Zone of Fort Bragg is Unit 219 – Urban Land with little soil descriptions other that the material source is fluvial marine.

The results of tests evaluating the corrosion protection of the soil on steel and concrete were not performed by the Author of the report. According to the available soil survey data the marine terrace deposits are acidic (pH range of 2 to 5.5) and have a low cation exchange capacity. Discussion of corrosivity testing results presented in other geotechnical report is discussed in the section entitled Other Geologic Related Concerns.

Two boring (B-03 and B-04) were drilled in an area of shallow bedrock with near surface conditions reported as the upper approximately ½-foot to 1.5 foot silty sand fill and underlain by bedrock generally consisting of slightly weathered, moderately strong sandstone that extended to the depth explored of about 15 feet.

The report states that monitoring well data from studies performed in the surrounding area associated with the adjacent Georgia-Pacific operations were available online (Arcadis, 2010). “From a review of these data and what was encountered in the WWTP borings, … “true” groundwater may City of Fort Bragg | Geotechnical Evaluation of City of Fort Bragg Seismic Safety Elements related to Water Distribution Facilities
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39 exist in the bedrock at depths below the bottom elevation of the proposed structures (Elevation 28 feet).”
The report concluded that the reported groundwater in the past WWTP borings is perched water from near surface sources. Fluctuations in the groundwater level could occur due to changes in seasons, variations in rainfall, and other factors.

South Coastal Zone, Salem 2018 and Caltrans 2011
Salem (2018) - West of Highway 1
Salem performed a geotechnical investigation for a commercial development to be located at 1151 South Main Street northwest of the intersection of Highway 1 and Ocean View Street. The document reports:
• The soils encountered in the test borings drilled as part of this investigation generally consisted of silty and clayey sands with gravel underlain by interbedded layers of sandy silty clay, sand with silt, silty sands, and sandy silts to the maximum depth explored of 20.5 feet. • The upper 5 feet were noted to be loose to medium dense. Below 5 feet the soils were generally described as dense to very dense, however one boring encountered loose soils at 15 feet.
• The borings were checked for the presence of groundwater during and after the drilling operations. Free groundwater was not encountered within the borings excavated for this investigation. However, perched groundwater was encountered in two borings at depths of about 11 feet below ground surface.

Caltrans 2011 - East of Highway 1 on the North Side of Highway 20 Caltrans performed an investigation for a sidewalk/retaining structure at the intersection of Highway 20 and Boatyard Drive. Subsurface Material Consist of Terrace Deposits underlay by decomposed sandstone. Weathering progresses from decomposed to intensely weathered between depths of 10 to 12 feet.

Groundwater was encountered at about 9 feet below ground surface in one boring and not encountered in other borings.

The NCRS units for this area lying north of Hare Creek are Units 106 and 161 and south of Hare Creek 212. These units are windblown terrace deposits (Eolian) consistent with the conditions provided in the two reports. Within Hare creek and the incised drainage, it is Units 131 and 139 alluvial sediments derived from bedrock.

The results of tests evaluating the corrosion protection of the soil on steel and concrete were not performed by the Author of the report. According to the available soil survey data the marine terrace deposits are acidic (pH range of 2 to 5.5) and have a low cation exchange capacity. Discussion of corrosivity testing results presented in other geotechnical report is discussed in the section entitled Other Geologic Related Concerns. The Caltrans report states that corrosion testing of soils was ongoing and would be provided at a later date.

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40 Inland Zone – South (Outside City Limits)
CGI 2007 – Summer Lane Reservoir
The Summer Lane reservoir is located at the north end of Summer Lane north of Highway 20, located is outside of the City Limits and Inland of Southern Coastal Area. The report states the near surface conditions as:

The project site is located on an emergent marine terrace that is locally covered with older dune sands. According to Kilbourne (1983), the Fern Creek marine terrace deposits underlie the majority of the site and are exposed in Newman Gulch that projects north of the project. The Fern Creek marine terrace in the project area is composed predominantly of interbedded silty sand with intermittent sandy silt, clayey sand, and sandy clay. Minor fine to medium, subangular to subrounded gravels were observed in test pits and local cobbles might be encountered within these terrace deposits; however, cobbles were not observed during this study. The Fern Creek terrace is approximately 70 to 90 feet thick and is underlain by the Coastal Belt of the Franciscan Formation bedrock. Older dune sands were mapped by Kilbourne (1983) overlying the terrace deposits in the southwesterly corner of the site. The presence of these dune sands was not observed during this study.

Bedrock was not encountered within explorations made during this study. Regional geotechnical studies have encountered Franciscan Formation sandstone, siltstone, and shale at depths ranging from:
• 12 to 35 feet on the Boddy property located about 3,000 west of the project site (Wahler, 1994b);
• 25 to 32 feet at a site downstream of the existing Newman Reservoir (Wahler, 1994b); • 26 to 55 feet at GP-2 and GP-3, located about 5,000 feet east if the site (Wahler, 1994a and 1994b).

The report notes that groundwater was encountered at depths of 10 to 18 feet.

Crawford 2022
Crawford investigated near surface soil conditions for construction of a replacement pipeline that included 7 test pits excavated to a depth of 6 to 9 feet and 31 hand augers to depths of 3 to 5 feet.

The pipeline segments are located along the eastern edge of the City extending from the water treatment facility located at the intersection of Sherwood Road and Monsen Way, extending about 2,500 lineal feet south to Chestnut Street (Segment 2 discussed in the previous section), then about 5,000 lineal across the Noyo River and then to the southeast to the Summer Lane Reservoir (Segment 3). Two additional segments are located from Benson Lane water storage facility and progress to the south side of Hare Creek (Segment 4) to a hilltop above and to the south of Hare Creek Segment 5. Segments 4 and 5 have a straight-line distance of 4,500 feet. Bedrock was only encountered in one exploration at a depth of 3.5 feet and not encountered in the remainder of the explorations. Refusal was encountered in 16 of the 31 hand augers between 2 to 4.5 feet. No estimates of stiffness or consistency were provided on the log of borings. The report states for Segments 3,4 and 5:

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41 • Segment 3 and 4 – Encountered conditions: silty to clayey sand with interbedded silt and clay. Poorly graded sand was encountered along Dwyer Lane. Auger refusal ranged from 2 to 4 feet.
• Segment 5 – Encountered Conditions clayey sand, sandy silt and sandy lean clay. Auger refusal at a depth 4.0 to 5 feet along the alignment.

Groundwater was not encountered in the explorations. However, the report states that groundwater will likely fluctuate with the river and stream elevations in Hare Creek (Segment 5) and the Noyo River (Segment 3).

The units, as shown on Attachment B – NCRS Soil Survey Map, for Inland Zone are 122, 174 and 214 for the Segment 3 Noyo Creek crossing to the Summer Lane Reservoir. The soil unit for Segment 4 is primarily unit 122, and until 135 where it crosses hare Creek. Unit 5 is in Unit 157. Unit 122 is derived from salt affected marine terrace deposits with no reported depth to bedrock, Unit 214 are fluvial marine deposits with depth of bedrock in excess for 6 feet and Units 135 and 174 are colluvium derived material with bedrock at a depth of 5 feet or greater.

The units for the Inland Zone (south) is 196 and in the adjacent areas as 108, 122, 148, 149, 195, 199 and 214. These units are all described as marine terrace deposits derived from sandstone with the western units (122, 148, 149) comprised of Eolian Terrace Deposits that would be subsurface conditions similar to the Southern Coastal Area.

The results of tests evaluating the corrosion protection of the soil on steel and concrete were not performed by the Author of the report. According to the available soil survey data the marine terrace deposits are acidic (pH range of 4.5 to 5.5) and have a low cation exchange capacity. Discussion of corrosivity testing results presented in other geotechnical report is discussed in the section entitled Other Geologic Related Concerns.

Inland
SHN 2003
This report was prepared for the design and construction of the aquatic facility located at the intersection of South Lincoln Street and Maple Street. The report states that site soils include compressible upper deposits to depths of at least 6 feet, some minor layers of loose to moderately dense sandy soils below that depth and are variable (erratic), with low density Peat, or silty/clayey layers, extending as deep as 22 feet in some locations. The density of the sand layers below 155 feet was estimated as dense to very dense in one boring. Sand Heaving occurred in other borings resulting in lower density estimates and are not representative. Dense materials were encountered between 5 to 10 feet of the ground surface at the southern 2/3 building area (Location unknown). A compressible clay layer was encountered in three explorations between 11 and 15 feet. It is not clear if the dense sand below 15 feet is completely weathered sandstone.

Groundwater was monitored by what is described as installing a well screen at a depth of 20 feet then sealing the borehole. Groundwater reportedly rose to a depth of 3 feet below the ground surface. Other groundwater investigations are to be performed per the report. Log of borings report water at a depth of 6.5 to 7.5 ft at the time of drilling (October 28, 1998) City of Fort Bragg | Geotechnical Evaluation of City of Fort Bragg Seismic Safety Elements related to Water Distribution Facilities
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42 Crawford (2022)
As previously stated, Crawford investigated near surface soil conditions for construction of a replacement pipeline that included 7 test pits excavated to a depth of 6 to 9 feet and 31 hand augers to depths of 3 to 5 feet. Crawford performed a near surface geotechnical investigation for 4 segments of pipeline (Segments 2 through 5) that extends from the inland (segment 2) area to the south inlead area (Segments 3, 4 and 5). Segment 2 is located along the eastern edge of the City extending from the water treatment facility located at the intersection of Sherwood Road and Monsen Way, extending about 2,500 lineal feet south to Chestnut Street. Bedrock was only encountered in one exploration at a depth of 3.5 feet and not encountered in the remainder of the explorations. Refusal was encountered in 16 of the 31 hand augers between 2 to 4.5 feet. No estimates of stiffness or consistency were provided on the log of borings. The report states for Segment 2:
• Segment 2 – Encountered conditions: clayey sand to lean clay over slightly weathered sedimentary rock
Groundwater was not encountered in the explorations.

The units for the Inland Zone is 195 for the majority of the city (Urban Land) and 141, 199, 214 along the eastern edge of the city with and 136 and 174 along the north slope of the Noyo River incised channel. Units 199, and 214 are thick fluvial marine in origin derived from sedimentary rock and Unit 141 is comprised of Marine deposits. Units 136 and 174 are colluvial deposits.

The results of tests evaluating the corrosion protection of the soil on steel and concrete were not performed by the Author of the report. According to the available soil survey data the Unit 141 marine terrace deposits are acidic (pH range of 3.5 to 5.5) and have a low cation exchange capacity (5 to 50 meq/100g). Unit 199 upper soils are reported as having similar to Unit 141 while no data is provided for Unit 214. Colluvial units are report as being less acidic (Ph 5.6 to 6.5) and have a slightly higher cation exchange capacity. Discussion of corrosivity testing results presented in other geotechnical report is discussed in the section entitled Other Geologic Related Concerns.

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43 Attachment B – NCRS Soil Survey Map and Select
Data
Figure B-1 NCRS Map of Soil Units
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44 NCRS Engineering Properties by Unit (See Figure B-1 for Unit Numbers) City of Fort Bragg | Geotechnical Evaluation of City of Fort Bragg Seismic Safety Elements related to Water Distribution Facilities
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45 NCRS Chemical Properties by Unit (See Figure B-1 for Unit Numbers) Engineering Properties
This table gives the engineering classifications and the range of engineering properties for the layers of each soil in the survey area.

Hydrologic soil group is a group of soils having similar runoff potential under similar storm and cover conditions. The criteria for determining Hydrologic soil group is found in the National Engineering Handbook, Chapter 7 issued May 2007(http://directives.sc.egov.usda.gov/OpenNonWebContent.aspx? content=17757.wba). Listing HSGs by soil map unit component and not by soil series is a new concept for the engineers. Past engineering references contained lists of HSGs by soil series. Soil series are continually being defined and redefined, and the list of soil series names changes so frequently as to make the task of maintaining a single national list virtually impossible. Therefore, the criteria is now used to calculate the HSG using the component soil properties and no such national series lists will be maintained. All such references are obsolete and their use should be discontinued. Soil properties that influence runoff potential are those that influence the minimum rate of infiltration for a bare soil after prolonged wetting and when not frozen. These properties are depth to a seasonal high water table, saturated hydraulic conductivity after prolonged wetting, and depth to a layer with a very slow water transmission rate. Changes in soil properties caused by land management or climate changes also cause the hydrologic soil group to change. The influence of ground cover is treated independently. There are four hydrologic soil groups, A, B, C, and D, and three dual groups, A/D, B/D, and C/D. In the dual groups, the first letter is for drained areas and the second letter is for undrained areas.

The four hydrologic soil groups are described in the following paragraphs:

Group A. Soils having a high infiltration rate (low runoff potential) when thoroughly wet. These consist mainly of deep, well drained to excessively drained sands or gravelly sands. These soils have a high rate of water transmission.

Group B. Soils having a moderate infiltration rate when thoroughly wet. These consist chiefly of moderately deep or deep, moderately well drained or well drained soils that have moderately fine texture to moderately coarse texture.

These soils have a moderate rate of water transmission.

Group C. Soils having a slow infiltration rate when thoroughly wet. These consist chiefly of soils having a layer that impedes the downward movement of water or soils of moderately fine texture or fine texture. These soils have a slow rate of water transmission.

Group D. Soils having a very slow infiltration rate (high runoff potential) when thoroughly wet. These consist chiefly of clays that have a high shrink-swell potential, soils that have a high water table, soils that have a claypan or clay layer at or near the surface, and soils that are shallow over nearly impervious material. These soils have a very slow rate of water transmission.

Depth to the upper and lower boundaries of each layer is indicated.

Engineering Properties---Mendocino County, Western Part, California Natural Resources
Conservation Service
Web Soil Survey
National Cooperative Soil Survey
5/22/2023