HomeMy WebLinkAbout09-25-17 City Commission Packet Materials - A2. Resolution 4838, Adoption of the 2017 Water Facility Plan Update
Commission Memorandum
REPORT TO: Honorable Mayor and City Commission FROM: Brian Heaston, Project Engineer
Craig Woolard, Director of Public Works
SUBJECT: Resolution 4838, Adopting the 2017 Water Facility Plan Update MEETING DATE: September 25, 2017
AGENDA ITEM TYPE: Action RECOMMENDED MOTION: Having considered the staff presentation and materials provided, I hereby move to adopt Resolution 4838, adopting the 2017 Water Facility Plan Update.
BACKGROUND: The 2017 Water Facility Plan Update (WFPU) is a comprehensive master plan of the City’s water distribution, storage, and supply systems. The plan encompasses a broad scope of items ranging from evaluating existing system performance, existing and future pressure zone configurations, future system transmission and distribution needs, future system finished water
storage requirements, and preparation of non-potable irrigation system design standards and
construction specifications. A substantial effort was undertaken to develop and calibrate a comprehensive water system hydraulic model to identify existing system deficiencies and to size and locate major future transmission, storage, and distribution facilities. The water model will be continuously updated as the water system expands into the future and serve as a crucial planning
and evaluation tool.
The basis of planning employed in development of water system capital improvement needs over the short-term (0 – 5 years), near-term (5-15 years), and long-term (15+ years), is the ultimate build out of the city’s adopted growth policy boundary with a small addition at the northwestern-
most extremity to capture an area included with the recently adopted transportation master plan.
The City’s current water system spans a service area boundary of nearly 13,000 acres, whereas the ultimate build out area planned for the city’s future water system covers an area of nearly 45,000 acres. Significant investments in future system transmission, storage and supply are required to meet the service needs of the ultimate build out of the water system as the City continues to grow
within the planning area.
The capital improvements strategy laid out in the WFPU is to focus short-term (0 – 5 years) efforts on correcting existing system deficiencies, make continued progress on developing future water supplies pursuant to the adopted Integrated Water Resources Plan, and optimizing existing system
operations. Near-term (5- 15 years) capital improvements address future system expansion to meet
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development demands within the northwest and southwest portions of the planning area as these
quadrants are anticipated to experience the heaviest growth pressures over the coming 15 years. Long-term (15+ years) capital improvements identify improvements necessitated to meet the ultimate build out of the 45,000 acre planning area. All told, the capital outlay required to meet ultimate build out of the system is upwards of $300 million if the City and its water system
eventually expands to occupy the entirety of its planning boundary. This cost figure represents the
upper end of what could be expected; however, realized capital costs for system expansion will generally follow actual development patterns. Furthermore, the ultimate build out capital cost does not include costs for distribution mains 12” or less in diameter as construction of mains of these sizes, for purposes of high level capital planning, are assumed to be borne by development.
The City’s unified development code, codified as Chapter 38 of Bozeman Municipal Code, incorporates the adopted water facility plan by reference and requires that any water system expansions necessary to support proposed development be completed in conformance with the water facility plan. Conformance with the plan in the context of proposed development typically
requires large diameter distribution mains (typically 12” or larger in diameter) within or adjacent
to the development be installed by the development and also meet pressure standards within the pressure zone in which the development is situated. The WFPU also contains policy recommendations for the below-listed items. Formal development
and adoption of these policy recommendations is a follow-on pursuit requiring individual action
by the City Commission upon presentation and debate of staff recommendations. - Adopt new maximum pressure standards for future growth areas, specifically new pressure zones. - Adopt a long-term pressure reduction strategy that addresses high pressures found in the
existing distribution system.
- Develop new policies and codes for fire suppression design that consider the long-term pressure reduction strategy as well as future growth areas. - Develop new policies that establish requirements for regulating the placement of pressure reducing facilities serving developments and growth areas.
- Adopt design standards and specifications to ensure uniformity for all future non-potable
water supply development. FISCAL EFFECTS: Cost estimates of all recommended projects are described in the facility plan. Total capital outlay for recommended projects is upwards of $300 million to develop the
water distribution, storage, and treatment system necessary to serve the ultimate build out of the
planning area. This cost figure represents the upper end of what could be expected; however, realized capital costs for system expansion will generally follow actual development patterns. ALTERNATIVES: As suggested by the Commission
ATTACHMENTS: Resolution 4838 Graphical Executive Summary Narrative Executive Summary 2017 Water Facility Plan Update (Please note that due to file size and
document length only a link is being provided to the full facility plan)
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COMMISSION RESOLUTION NO. 4838
A RESOLUTION OF THE CITY COMMISSION OF THE CITY OF BOZEMAN,
MONTANA, ADOPTING THE 2017 WATER FACILITY PLAN UPDATE
WHEREAS, the City of Bozeman is committed to addressing the community’s expressed
needs and desires for essential services including water facilities; and
WHEREAS, the City of Bozeman is committed to meeting those desires and demands for
water facility services in a fiscally responsible manner; and
WHEREAS, the City of Bozeman is committed to meeting those desires and demands for
water facility services in a prudent manner to safeguard public health and safety and provide for
uninterrupted commerce; and
WHEREAS, The City of Bozeman is authorized pursuant to the laws of the State of
Montana including Section 7-13-4301 MCA to establish, build, construct, reconstruct, or extend a
water supply or distribution system and to operate and maintain said system for public use; and
WHEREAS, The City of Bozeman has developed a water facility plan update which
examines current and future water system needs that provides a lawful, logical, balanced,
operationally sound, and cost effective basis upon which to develop and maintain the City’s water
facilities.
NOW, THEREFORE, BE IT RESOLVED by the City Commission of the City of
Bozeman, Montana, that the Water Facility Plan Update, dated July 2017, as attached hereto and
by this reference made a part hereof, is hereby adopted.
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PASSED, ADOPTED, AND APPROVED by the City Commission of the City of
Bozeman, Montana, at a regular session thereof held on the 25th day of September, 2017.
___________________________________
CARSON TAYLOR Mayor
ATTEST:
________________________________________ ROBIN CROUGH City Clerk
APPROVED AS TO FORM:
___________________________________
KAREN STAMBAUGH Assistant City Attorney
229
BOZEMAN
MOST LIVABLE PLACE
PROPOSAL FOR BOZEMAN WATER FACILITY PLAN UPDATE
WATER
FACILITY
PLAN UPDATE
JULY 2017
230
City of Bozeman WFPU | Page 2
INTRODUCTION
VISION FOR THE FUTURE
The previous update to the City of Bozeman (City) Water Facility Plan was completed in 2005. Water Facility Plans
are an integral part of a dynamic and ongoing infrastructure planning process. The Water Facility Plan is intended to be
reviewed and revised periodically to influence the City’s Capital Improvement Program (CIP) development.
Recent acceleration in population growth, combined with aging infrastructure, stresses the need for a Water Facility
Plan Update. Growth induced projects must be balanced with existing system needs. The City is proactively planning to
improve existing utility infrastructure and expand water supply, storage, and distribution capacity in order to maintain a
high level of customer service in the face of ongoing pressure exerted on the utility by growth.
The Water Facility Plan Update (Plan) addresses existing system deficiencies and identifies new water infrastructure
needs necessary for the City to continue to provide Best-in-Class water service to its ratepayers.The study area was developed by reviewing the 2009
Community Plan, the 2016 Transportation Master Plan
(TMP), the Wastewater Collection Facility Plan Update,
known geographical boundaries, and discussions with City
staff. Ultimately, the UBO reflects the planning area based on
the Bozeman Community Plan Future Land Use Map with
the addition of a small Northwestern development included in
the TMP Study Area Boundary.
SERVICE AREA BOUNDARY
12,803 Acres (within City Boundary)
(44,881 Acres of Ultimate Build-Out (UBO)
A total of three planning periods were established for this study. The planning
milestones include a short-term (0-5 years), near-term (5-15 years), and long-term
(15+ years) period. While the scope of the Plan was to identify future system needs
over the entire Ultimate Build Out (UBO) area, improvements were sequenced in order.
SHORT-TERM: The City will address existing
deficiencies, investigate additional supply opportunities,
and optimize the system to increase efficiency.
NEAR-TERM: Future system priorities will stem
from short-term data collected (i.e. groundwater supply,
increased transmission capacity to the west, water rights,
etc.) to address growth and development within the
northwest and southwest portions of the planning area.
LONG-TERM: Improvements will focus on serving
the entire UBO as dictated by future land development.
VISION FOR THE FUTURE
The Plan provides a roadmap to the future by addressing short-term, near-term, and
long-term capital planning needs.
WATER: HOW MUCH DO WE USE?
Understanding water use characterization is critical to assess the performance of the
existing and future distribution systems.
HYDRAULIC MODELING: A TOOL FOR ASSESSING NEEDS
The future is anything but certain. The development of an accurately calibrated model
provides the City the ability to analyze countless scenarios and answer the looming “What
If” questions as the City grows and expands.
EXISTING SYSTEM ANALYSIS SUMMARY
Overall, the City’s water system is in good shape. Excessively high water pressure can put
the City’s infrastructure at risk. Plans to reduce water pressure will help prolong the life of
the water system and reduce water loss.
NON-POTABLE WATER SOURCES
Potable water is a finite and expensive resource. Does it make sense to install a separate
pipe system to distribute non-potable water for outdoor water use?
RECOMMENDED IMPROVEMENTS
Recommend improvements address the City’s short-term, near-term, and long-term needs.
Each project was prioritized based on several factors including risk, criticality, and benefit.
POLICY RECOMMENDATIONS
Effective system management begins at the policy level. This Plan recommends policies to
be considered for long-term system sustainability.
STUDY AREA
NW
N
SW
231
AVERAGE DAILY WATER USAGE (METERED)
0
2
4
6
8
10
12
Millions of Gallons per Day (MGD)Average Daily Water Usage (Metered)
2006 2007 2008 2009 2010 2011 2012 2013 2014 2015
WATER: HOW MUCH DO WE USE?
Characterizing water use reveals demand patterns that can:
•Affect the performance of the existing system
•Impact the timing and design of the future distribution system
•Inform water conservation strategies
Over the past ten years, the City’s population has continued to grow while the overall Gallons per Capita per Day
(GPCD) has decreased. The decreasing water usage trend is most likely due to a combination of improved water
distribution efficiency (leakage reduction), reduced water use stemming from the City’s robust water conservation
education and incentive efforts, high efficiency plumbing fixtures in newer developments and renovations, and an
increase in multi-family development, which reduces per-capita outdoor irrigation demand.
The existing demands were determined by analyzing both customer meter data as well as water production data
generated by the City. From the existing demand analysis, Water Duty Factors (WDFs) were created to categorize
typical water demands (in gallons per day per acre) for specific land use classifications within the City (e.g. residential,
commercial, industrial, etc.). The WDFs were then applied to both existing infill and future growth areas located
outside of the City’s current limits within the UBO boundary to project future demand.
System infrastructure is sized to meet the Maximum Day Demand
CURRENT DEMAND (MGD)
PROJECTED FUTURE UBO DEMAND (MGD)
TOTAL WATER TREATMENT PLANT PRODUCTION
DECREASING GALLONS PER CAPITA PER DAY
WATER DEMANDS
HIGH SUMMER DEMANDS =
NEED FOR CONSERVATION
MAX - 11.7 MAX - 53.6 MAX - 49.8
Summer - 8.6
WITHOUT
CONSERVATION
WITH
CONSERVATION
AVG - 5.2
Winter - 3.6 AVG - 21.5AVG - 23.8
City of Bozeman WFPU | Page 4
30,000
35,000
40,000
45,000
50,000
0
20
40
60
80
100
120
140
160
2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 PopulationAverage Day Demand (GPCD)Year
Total Population
30,000
35,000
40,000
45,000
50,000
0.0
2.0
4.0
6.0
8.0
10.0
12.0
14.0
2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 PopulationMillions of Gallons per Day(MGD)Historical Production
Average Day (ADD)Maximum Month (MMD)Maxium Day (MDD)Population
30,000
35,000
40,000
45,000
50,000
0
20
40
60
80
100
120
140
160
2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 PopulationAverage Day Demand (GPCD)
Year
Total Population
30,000
35,000
40,000
45,000
50,000
0.0
2.0
4.0
6.0
8.0
10.0
12.0
14.0
2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 PopulationMillions of Gallons per Day (MGD)Historical Production
Average Day (ADD)Maximum Month (MMD)Maxium Day (MDD)Population
232
City of Bozeman WTFP | Page 4
PLANNING FOR GROWTH
Keeping up with rapid growth is a challenge for the City. A semi-
automated process was developed to help the City keep its water
model and asset management database current. The process will
provide the City with an intuitive tool for planning and increase the
effectiveness of the hydraulic model moving forward.
INTEGRATION WITH GIS & ASSET MANAGEMENT
The City recognizes that keeping track of the intricacies of a water
system is not an easy task. To assist in this challenge, the City has
previously invested in tools such as GIS and Asset Management.
The new hydraulic model, developed for the facility plan update,
integrates with the City’s GIS and Asset Management software,
further enhancing the power of these tools.
75
HYDRANT FLOW TESTS
12
EXTENDED PERIOD TESTS
• System Pressure
• Storage Requirements
• Storage Operation
• Transmission Capacity
• Fire Flow
• Water Source Management
• Criticality Assessment
• Emergency Water Management
Valuable Tool to Quickly Diagnose
System Challenges and Plan for Growth
HYDRAULIC MODELING: A TOOL FOR ASSESSING NEEDS EXISTING SYSTEM ANALYSIS SUMMARY
NON-POTABLE WATER SOURCES
Overall, the existing water distribution system is in good shape, which is a
reflection of the City’s commitment to operations and maintenance (O&M)
efforts. A few key findings are summarized below.
Many municipalities across the U.S. have installed non-potable water systems (in
addition to the standard potable system) to provide water for outdoor (irrigation) use.
Non-potable water use reduces demand, specifically summer peak demands on the
potable water supply, which can defer future potable water treatment and conveyance
projects. There are numerous factors considered in this cost/benefit analysis. What is
advantageous for one municipality may not be feasible for another.
Existing Operational Storage: Meets day to day demands
Existing Emergency Storage: Enough water in the event of a major transmission
or treatment plant failure
Existing Fire Storage: Enough water to fight fires
Water Turnover:
COST BENEFIT
RESULTS
Water Rights & Treatment With current water
rights and low water treatment and distribution
costs, construction of a dual pipe system would
provide marginal benefit to the City. As these
factors change over time, the City should reevaluate
the cost/benefit ratio.
Economies of Scale Smaller dual pipe systems
for entire developments do not match a cost
comparison against potable only systems. The cost
to install and maintain the additional infrastructure
will likely outweigh the benefit of reduced water
treatment and water rights acquisition costs.
Parks and Open Space If available, non-potable
sources should be utilized for large public spaces.
City of Bozeman WFPU | Page 6
MODEL DEVELOPMENT AND CALIBRATION
Creating a model that accurately simulates a water distribution
system is essential to ensure the usefulness of the model. Actual
water usage was spatially allocated in the model to accurately
simulate the demand on the system. Numerous flow tests were
conducted throughout the City to ensure the model was calibrated
correctly and accurately simulates existing conditions.
SINGLE VS. DUAL
PIPED SYSTEM
PRESSURE
STORAGE
TRANSMISSION
FIRE FLOWS
PRESSURE ZONE AND REDUCTION EVALUATION
System pressures are generally between 50 Pounds Per Square
Inch (psi) and 150 psi, with a few select areas exceeding 150 psi.
Operating at high pressures (>110 psi) can result in increased
water loss, create higher O&M costs due to more frequent failures,
and increase the risk of catastrophic pipe breaks. To address
these higher pressures, a pressure zone and pressure reduction
evaluation was conducted to identify potential means to reduce
high pressures currently experienced in portions of the City.
RECOMMENDATION: Operational changes along with mixing system
retrofits or inlet/outlet piping reconfigurations are recommended to
reduce stratification and water age in existing storage tanks.
Increased Redundancy Redundancy reduces risk and improves system capacity. Priority should be
placed on installing an additional transmission main from the Sourdough Water Treatment Plant to
provide redundancy and reduce the impacts of maintaining the existing Sourdough transmission main.
Additional Transmission Main As the City continues to expand to the west, an additional transmission
main is needed in the near-term to keep pace with projected water demands. Additional transmission will
reduce headloss within the system and provide additional redundancy and operational flexibility.
Excellent fire flow throughout a
majority of the existing system.
Hydrants that did not meet fire flow goals have been identified and
flagged for additional field testing to confirm model results and
determine the best path forward.
$+
PRESSURE ZONE AND REDUCTION EVALUATION
Most of the building fire suppression (sprinkler)
systems in the City have been designed around
actual system pressures. System pressure can
only be lowered if the fire suppression systems
are modified to handle lower pressure, which
can be costly.
LONG-TERM PRESSURE REDUCTION STRATEGY =
NEW POLICIES AND CODE RECOMMENDATIONS
New Fire Suppression Systems
Meet new and reduced pressure standards.
Existing Fire Suppression Systems
Conform to new City codes and policies
triggered by building upgrades, renovations, or
suppression system modifications.
Note: The transition to lower system pressure
in the historic core areas would not occur until
enough re-development of existing structures
with fire suppression systems has taken place
to make retrofit of the remaining suppression
systems economical.
Average Pressure During Maximum Day Demand
(Percent of System)
35-110 psi (52%)110-150 psi (46%)
>150 psi (2%)
233
City of Bozeman WTFP | Page 10
Projects within the Capital Improvement Plan (CIP) were divided into eight categories briefly summarized below. The
development of the categories provided the conceptual framework of how the system would ideally work at UBO, facilitated
CIP prioritization and timeframe progressions, and correlated the projects to the City’s present fiscal resources (i.e. what type
of project makes the best use of the available capital improvement budget).
RECOMMENDED IMPROVEMENTS
CONDITION ASSESSMENT
Used to identify high-risk degradation of
a pipeline before failure, or to verify that
there is viable life remaining in a segment of
pipeline so that money is spent strategically
on its replacement or rehabilitation.
REHABILITATION & REPAIR
Rehabilitation and repair projects
are generally associated with pipe
segments that experience high
break rates, water quality issues,
are undersized (cannot attain fire
flow goal), or require maintenance.
SUPPLY
Increase the overall water supply available
to the distribution system, which ensures
the City maintains its current level of
service and can adequately provide water
to existing and future customers.
GROWTH & DEVELOPMENT
Provide the necessary infrastructure
to serve both existing and future
customers. These projects primarily
consist of “backbone” water mains and
PRV facilities to establish proposed
pressure zones.
STORAGE
Increase the overall water storage
capacity of the system, ensure
adequate fire flow, and supplement
water supply during periods of
planned maintenance or emergencies.
TRANSMISSION
Consists of large diameter transmission
main (16-inch to 48-inch) that originate
from sources of supply and convey large
volumes of water throughout the entire
distribution system.
OPTIMIZATION
Improve system water quality, promote
network efficiency, help with pressure
management, or eliminate facilities to
reduce operating costs and improve
overall network performance.
STUDIES
Studies provide more detailed
information so that the City
can make informed decisions
regarding the cost and timing of
future projects.
City of Bozeman WFPU | Page 8
A challenging aspect in prioritizing CIP projects was
that the cost to implement the several large-scale water
supply related projects prohibits short-term implementation.
Identifying the most cost-effective projects will depend on
the completion of near-term studies. A planning roadmap was
created to help the City make these decisions. The roadmap
provides the City flexibility to select the most advantageous
path forward in order to meet future water system needs based
on the completion of near-term study efforts.
The figure below illustrates the decision making process
and provides a basic overview of the different planning options
that would be evaluated.
CIP PRIORITIZATION AND IMPLEMENTATION SHORT-TERM PLANNING5 YEAR CIPNEAR-TERM PLANNING5-15 YEARLONG-TERM PLANNING15+ YEARSHyalite Dam and
Reservoir Optimization
Improvements
Sourdough Canyon
Natural Storage -
Planning and Design
Groundwater
Development -
Phase 1
West Transmission
Main Planning
Study
1st Priority:
Groundwater
Development
1st Priority:
West Transmission/Sourdough
and Hyalite Water
1st Priority:
Lyman Creek Water System
Improvements
2nd and 3rd Priorities:
West Transmission/Sourdough
Water and Lyman Creek Water
System Improvements
2nd and 3rd Priorities:
Groundwater Development
and Lyman Creek Water System
Improvements
2nd and 3rd Priorities:
Groundwater Well Field
Development and West
Transmission/Sourdough Water
FUTURE WATER FACILITY PLAN UPDATE
Which path for near- and long-term projects?
The decision making process
allows the City to select the most
viable project as better short-term
information becomes available.
234
FY 2018 FY 2019 FY 2020 FY 2021 FY 2022
SCADA Master Plan Hilltop Tank Inspection and
Mixing System
Sourdough Canyon Natural Storage -
Planning and Design
Hyalite Dam and
Reservoir Optimization
Improvements
SCADA Upgrades &
Improvements
Pear St. Booster Station
Upgrade
Sourdough Tank Inspection
and Improvements Redundant North 5038 Zone Feed
Lyman Tank and
Transmission Main
Construction
Water System Condition
Assessment
Watershed & Reservoir
Optimization Study
Lyman Tank and
Transmission Main Design Water System Condition Assessment Pipe Replacement
PRV Phase 2 - Automation
and Instrumentation
Upgrades
Lyman Transmission Main
Condition Assessment
PRV Phase 1 - Mechanical
and Structural Upgrades
Groundwater Well Field and
Transmission Construction Pipe Replacement
Water System Condition
Assessment
Groundwater Well Field and
Transmission Main Design
Davis Street 12" Water Main & Valley
Center 16" Water Main Extension
Groundwater Test Well South 11th 12" Water Main
Extension
Sourdough Transmission Main –
Phase 2
Sourdough Transmission Main
– Phase 1
Lead Service Line
Replacement Pipe Replacement
Lead Service Line Replacement Pipe Replacement
Pipe Replacement
The hydraulic model was used to develop the
infrastructure necessary to serve the UBO water
distribution system. Objectives included:
PROPOSED DISTRIBUTION,
PRESSURE, & STORAGE SYSTEM
SYSTEM IMPROVEMENTS
•Develop & provide conceptual design of future
pressure zones
•Establish future storage capacity needed &
general tank locations
•Identify any pumping requirements
•Plan for distribution mains based on water de-
mand allocation & hydraulics
•Evaluate potential impacts of water conservation
•Optimize overall system functionality
A prioritization methodology was developed to ensure
consistent and transparent assessment of each project
considered for inclusion in the CIP. The methodology
consisted of developing a matrix, representing a flexible ranking
system that assesses each project on several factors including
risk, criticality, and benefit.
During the City’s internal CIP development process,
projects were screened by City staff and the CIP was adjusted
depending on whether modifications to the initial scope, cost,
and timeframe were necessary.
The prioritization planning process has the flexibility of
allowing City staff to quickly re-prioritize projects based
on growth and development. A brief overview of the fiscal
year (FY) 2018 - 2022 CIP projects is shown in the table below
and summarized in the figure to the right.
Facility Type Existing Additional Facility
Improvements
Major Distribution
Pipeline (miles)
(size 12-14 inches)
38 106 miles of 12-inch major
distribution main
Transmission Main (miles)
(size 16-30 inches)
14 94 miles of transmission main
ranging from 16-48 inches in
diameter
Pressure Zones 6 8 new main pressure zones (2
existing zones are combined to a
single new zone)
Pressure
Reducing Stations
22 25 new Pressure Reducing Stations
to serve new zones and to allow
emergency flow between zones
Storage Reservoirs
(Volume)
4 (16.6 Million
Gallons (MG))
12 new reservoirs (72 MG total
system storage)
OVERVIEW OF
PROPOSED SYSTEM IMPROVEMENTS
FLEXIBLE PROJECT RANKING SYSTEM
HGL “Hydraulic Grade Line”
235
Prepared By:
ADVANCED ENGINEERING AND ENVIRONMENTAL SERVICES, INC.
1050 East Main Street, Ste 2 Bozeman, MT 59715 | (406) 219-2633
POLICY RECOMMENDATIONS
As the City continues to grow and evolve, occasional policy creation or adjustment is necessary for the
City to continue to best serve its citizens. Below are several policy recommendations stemming from the
Plan (listed in no particular order) for consideration to enhance the City’s existing policies:
Adopt new maximum pressure standards for future growth areas, specifically new
pressure zones.
Adopt a long-term pressure reduction strategy that addresses high pressures found in the
existing distribution system.
Develop new policies and codes for fire suppression design that consider the City’s long-
term pressure reduction strategy as well as future growth areas.
Develop new policies that establish City requirements for regulating the placement of
pressure reducing facilities serving developments and growth areas.
Implementation of a non-potable system will require the City to develop and adopt
standard specifications to ensure uniformity for all future non-potable development.
236
Wa ter Facility Plan
Update
PREPARED FOR:
AE2S Project No. P05097-2013-001
July 2017
EXECUTIVE SUMMARY
Advanced Engineering and Environmental Services, Inc.
1050 East Main Street, Ste. 2
Bozeman, MT 59715
Ph: 406-219-2633
Web: www.AE2S.com
237
Water Facility Plan Update Report
Executive Summary
July 2017
P05097-2013-001 Page ES-1
EXECUTIVE SUMMARY
Introduction
The previous update to the City of Bozeman (City) Water Facility Plan was completed in 2005.
Water Facility Plans are an integral part of a dynamic and ongoing infrastructure planning
process. The Water Facility Plan is intended to be reviewed and revised periodically to
influence the City’s capital improvement program (CIP) development.
Recent acceleration in population growth, combined with aging infrastructure stresses the need
for a Water Facility Plan Update. Growth induced projects must be balanced with existing
system needs. The City is proactively planning to improve existing utility infrastructure and to
expand water supply, storage and distribution capacity in order to maintain a high level of
customer service in the face of ongoing pressure exerted on the utility by growth.
This Water Facility Plan Update addresses existing system deficiencies and identifies new water
infrastructure needs necessary for the City to continue to provide Best-in-Class water service
to its ratepayers. Specifically, the plan includes the following key elements:
1) Identifies short-term (0 to 5 year), near-term (5 to 15 year), and long-term (15+ years)
capital project needs.
2) Quantifies current and future water demand while providing a thorough characterization
of water use across the City.
3) Provides a state of the art hydraulic model that the City can continuously use to identify
developing system needs. Over time City staff can enhance the model to capture the
City’s long-term vision of asset management and risk-based capital improvement
planning.
4) Evaluates the potential to reduce high system pressure in portions of the City, documents
the effects, and develops a long-term plan for pressure reduction.
5) Evaluates the feasibility of a non-potable (dual pipe) water distribution system for
irrigation.
6) Prioritizes capital improvement projects utilizing a risk-based approach.
7) Identifies potential policies to be considered that address long-term pressure
management and increase system sustainability.
238
Water Facility Plan Update Report
Executive Summary
July 2017
P05097-2013-001 Page ES-2
Project Contact Information
The primary contact person for the AE2S project team is:
Scott Buecker, PE
Advanced Engineering and Environmental Services, Inc. (AE2S)
1050 East Main Street, Ste 2
Bozeman, MT 59715
Email: scott.buecker@ae2s.com
Ph: (406) 219-2633
Report Organization
The Water Facility Plan Update is organized into 10 chapters described in Table ES. 1.
Supporting documents and detailed technical information are included in the appendices.
Chapter Description
Chapter 1 - Existing System Provides an overview of the existing system and facilities.
Chapter 2 - Basis of Planning Describes the planning and service area for both existing and future
conditions.
Chapter 3 - Water Use
Characterization
Characterizes current water use patterns by usage class and land
use and projects future water demand.
Chapter 4 - Water Distribution
System Model Update
Describes the hydraulic model, model demand allocation process,
field testing & data collection, model calibration, and modeling
scenarios used in the evaluation.
Chapter 5 - Design Parameters and
Evaluation Criteria
Recommends design standards and performance guidelines for
distribution system infrastructure, and provides criterion against
which system performance is evaluated.
Chapter 6 - Existing System Evaluation Evaluates the City’s existing water distribution system and its ability
to meet recommended design standards under various water
demand conditions.
Chapter 7 - Pressure Zone and
Pressure Reduction Evaluation
Analyzes existing system pressure. Assesses the feasibility of
reducing pressure in portions of the distribution system. Outlines a
long-term plan to achieve pressure reduction.
Chapter 8 - Non-Potable Irrigation
Evaluation
Provides conceptual design and a cost-benefit evaluation for a dual
pipe distribution system to assess the potential cost-benefit of non-
potable projects. Provides standard details, specifications and cost
estimation tools for non-potable infrastructure.
Chapter 9 - Future System Evaluation Develops the City’s future water distribution system, using the
hydraulic model, planning area map and design standards and
performance guidelines, to identify future infrastructure that will
be necessary to accommodate ultimate build-out.
Chapter 10 - Recommended
Improvements
Presents the recommended and prioritized capital improvements
and costs for identified existing system deficiencies and future
system expansion.
Table ES. 1: Water Facility Plan Update Organization
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Service Area & Basis of Planning
Study Area Boundary
The study area boundary for the Water Facility Plan Update is presented in Figure ES-1. The
study area map was developed in collaboration with City staff, and utilized elements of the
2009 Community Plan, 2016 Transportation Master Plan (TMP) and 2015 Wastewater
Collection Facility Plan Update. The Ultimate Build-Out (UBO) map is based on the 2009
Community Plan Future Land Use Map, with a small Northwestern development included in
the 2016 TMP Study Area Boundary.
The result is a final, UBO, service area boundary that encompasses approximately 44,881 acres,
of which 12,803 are located within the current municipal boundaries of Bozeman. The City’s
water supply and distribution systems will expand in response to growth and development
patterns.
Planning Periods
Three planning periods are utilized in the Facility Plan, which matches the City’s existing CIP
planning methodology: short-term (0-5 years), near-term (5-15 years), and long-term (15+
years). Projects were preliminarily scheduled based on the following priorities:
In the short-term, the City will address existing system deficiencies, investigate
additional supply opportunities, and improve the efficiency of the existing distribution
system.
In the near-term, capital improvement priorities will be driven by water supply
improvements, optimization of transmission, and distribution infrastructure necessary
to address growth and development in areas of highest growth. Studies completed in
the short-term will inform which near-term projects are the most cost-effective for long-
term reliable water supply and distribution.
In the long-term, capital improvements are the major infrastructure projects that will
be necessary to serve ultimate build-out of the City.
240
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Water Use Characterization
Characterizing water use reveals demand patterns that can 1) affect the performance of the
existing system, 2) impact the timing and design of the future distribution system, and 3) inform
water conservation strategies.
Historical Water Use
Historical water production records from 2006 through 2015 were evaluated to determine
system demand and develop water usage parameters. Figure ES-2 presents an annual
breakdown of total water treatment plant production over the period of analysis.
Figure ES-2: Historical Annual Water Production 2006 – 2015
Remarkably, as can be seen in Figure ES-2, water usage has not increased over the last 10
years despite significant population growth.
30,000
35,000
40,000
45,000
50,000
0.0
2.0
4.0
6.0
8.0
10.0
12.0
14.0
2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 PopulationMillions of Gallons per DayHistorical Production
Average Day (ADD)Maximum Month (MMD)Maxium Day (MDD)Population
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Figure ES-3: Average Metered Daily Water Usage 2006 – 2015
Figure ES-3 shows a significant increase in potable water usage during the summer months.
From October through April the average daily water usage is less than 4 MGD. Demand peaks
in June, July or August with the highest observed monthly average over 10 MGD in July of
2011. The magnitude of the summer demand increase is important for the City of Bozeman, as
the peak demand is what drives water supply needs, and depending on growth rates and water
conservation, the City’s water demand is projected to exceed its current supply within the next
20 years (2013 Bozeman Integrated Water Resources Plan).
Figure ES-4: Per Capita Water Use
0
2
4
6
8
10
12
(MGD)Average Daily Water Usage (Metered)
2006 2007 2008 2009 2010 2011 2012 2013 2014 2015
30,000
35,000
40,000
45,000
50,000
0
20
40
60
80
100
120
140
160
2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 PopulationAverage Day Demand (GPCD)Year
Per Capita Water Use
Total Population
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Figure ES-4 shows the per capita water use for the City between 2006 and 2015. The 10-year
annual daily per capita water use in the City ranges from 142 (2006) to 111 (2014) GPCD, with
a 10-year average at 123 GPCD. As the City’s population has grown, the overall GPCD has
decreased. This trend is most likely due to a combination of 1) improved water distribution
efficiency (leakage reduction), 2) reduced water use stemming from the City’s robust water
conservation education and incentive efforts, 3) high efficiency plumbing fixtures in newer
developments and renovations, and 4) an increase in multi-family development, which reduces
per-capita outdoor irrigation demand.
Existing Water Demands & Future Demand Projections
The existing demands were determined by analyzing consumer meter data and water production
data. From the existing demand analysis, water duty factors (WDFs) were calculated to identify
water demand (in gallons per day per acre) for specific land use classifications found within the
City (e.g. residential, commercial, industrial, etc.).
To allocate future demands, the WDFs were applied to future infill and future growth and
development outside of the City’s current limits but within the UBO boundary. These demands
were spatially allocated in the hydraulic model. Totaling these demands provides an estimate
for total system demand for the existing and projected UBO conditions. Table ES. 2 shows the
existing and future demand projections resulting from this analysis.
An additional analysis was completed to reflect potential future increases in water conservation
and efficiency that could reduce both the maximum and average day demand.
Current Demand Condition Demand (MGD)
Average Day 5.2
Summer Day 8.6
Maximum Day 11.7
Winter Day 3.6
UBO Demand Condition Demand (MGD)
Average Day 23.8
Average Day with Conservation 21.5
Maximum Day 53.6
Maximum Day with Conservation 49.8
Table ES. 2: Existing and Future System Demands
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Water Distribution System Model Update
City of Bozeman staff recognize the value and fiscal importance of tracking and monitoring the
condition of its existing infrastructure. Consequently, the City has made significant investments
into GIS and asset management. InfoWater® hydraulic modeling software was selected for
development and calibration of a new hydraulic model for the City. InfoWater® is a fully GIS
integrated water distribution modeling and management software which runs the widely
accepted EPANET hydraulic engine. The model that has been created within the scope of this
Facility Plan can be seamlessly integrated with the City’s GIS system and asset management
software.
Using the model, system demands were spatially allocated across the City based on water meter
addresses. A diurnal demand curve was created by completing a mass balance on water
treatment plant flow rates and changes in storage levels to estimate typical water usage over a
24-hour period. The hydraulic model was calibrated using field data from 75 hydrant flow tests
and 12 extended period pressure monitoring tests, conducted in the Fall of 2015.
The new hydraulic model is an “all pipes” model, meaning that it maintains a one-to-one
relationship between individual elements in the City’s GIS database and pipes in the model. It
replaces the City’s previous “skeletonized” model. An all pipes model results in a more
accurate simulation, and enables continuous model updates and maintenance with changes in
the City’s GIS database (that reflect changes in its infrastructure). This is critical for a City
growing as fast as Bozeman, to avoid the model becoming outdated. The City now has a
valuable tool that can be utilized with a higher degree of confidence.
Design Parameters and Evaluation Criteria
The water system design parameters and evaluation criteria for evaluating the capacity and
performance of the City’s potable water distribution are summarized in Table ES. 3. This
includes recommendations for the minimum and maximum system pressures, storage capacity,
maximum pipeline velocity and headloss, and fire flow/duration requirements.
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Table ES. 3: Summary of Design/Evaluation Criteria
Component Criteria
Distribution System Pressures Pressure (psi)
Maximum Pressure a 110
Mountain Zone b Maximum Pressure 150
Minimum Pressure during Peak Hour demand 50
Minimum Pressure during a Fire Flow 20
Building Fire Suppression System Design Determined using model with Reduced Pressure Scenarioc
a- 110 psi maximum for all new pressure zones. Existing system pressure zones will remain unaltered to satisfy present fire suppression
system design requirements.
b- Mountain Zones involve regions within the study area with extreme topographic change.
c- The hydraulic model can estimate pressure at the fire suppression system connection under a Reduced Pressure Scenario.
All pressure zones should have redundant transmission feeds.
Water Demand for Distribution Sizing
Gallons Per Capita Per Day (gpcd) for Average Day Demand (ADD) 135
Maximum Day Demand (MDD) Peaking Factor (MDD/ADD) 2.25
Peak Hour Demand (PHD) Peaking Factor (PHD/ADD) 1.75
Storage Capacity d
Operational Storage 40 percent of the maximum day demand
Fire Storage Fire storage to be provided is based on two fires occurring
within a 24-hr period
Emergency Storage Emergency storage equal to 2 days average day demand
Total Water Storage Capacity
Storage should be the greater of:
1.The sum of operational storage plus fire flow; or
2.The sum of emergency storage plus operational storage
(which is equal to approximately 3 days average day demand)
d- Storage parameters should be met in each pressure zone. If a lower pressure zone is unable to meet these requirements, higher
zones with excess storage capacity can supplement the deficiency.
Water Transmission and Distribution Pipelines e Velocity (ft/s) Headloss (ft/1000 ft)
Transmission pipelines (12-inch and larger) Less than 3 Less than 2
Distribution pipelines (10-inch and smaller) Less than 5 Less than 5
Fire Flow Requirements f Flow Rate (gpm) Duration (hrs) Resident High and Medium Density (R-4,R-3) 3,000 3
Single-family Medium Density (R-2) 1,500 2
Residential, Single-family Low Density (R-1) 1,500 2
Public Lands and Institutions (PLI) 3,000 3 Com.Neighborhood/Community Business (B-1, B-2) 3,000 3
Central Business (B-3) 4,000 4 Ind Light Manufacturing (M-1) 4,000 4
Manufacturing and Industrial (M-2) 5,000 4
e - PHD under ADD and MDD conditions
f- The City Fire Department follows the International Fire Code to determine Needed Fire Flow. These are general requirements for
master planning purposes and may not be indicative of the requirements for specific developments or buildings. Each development
should be evaluated on a case-by-case basis.
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Existing System Evaluation
The existing system was evaluated against the recommended criteria in Table ES. 3. The
results of this evaluation are summarized briefly below.
Pressure Summary
System pressures are generally between 50 psi and 150 psi. The design criteria for the
distribution system is 50 to 110 psi.
High Pressure Areas
Approximately 46 percent of the City currently has pressures that exceed 110 psi. This area is
in the South Pressure Zone, and generally encompasses the downtown core and extends north
and west to Oak St. corridor. Pressures are highest along Oak St., between N 25th Ave and N
Rouse Ave, with pressures above 150 psi. Reducing the pressures in this portion of the system
would reduce the risk and consequence of failures, prolong the lifespan of the distribution
piping and improve the safety of the working conditions.
However, there are hundreds of fire suppression sprinkler systems in this area that were
designed based on the available water pressure. If the City were to reduce the pressure in these
locations, the fire suppression systems would no longer comply with performance standards.
Low Pressure Areas
The following locations operate under relatively low water pressures:
The vicinity of Hilltop reservoir with higher elevations experiences pressures less than
35 psi during ADD and MDD conditions.
The addition of individual home booster pumps or connecting into the
Knolls Pressure Zone would increase system pressures in this particular
area.
Two areas located on the southwest edge of the City experience pressures less than 50
psi during ADD conditions and pressures less than 35 psi during MDD conditions.
o The area along Blackwood Rd between 19th Ave and 31st Ave.
o The area along 3rd Ave between Cambridge Dr and Goldenstein Ln.
Low pressure in these areas can be raised by 5 to 10 psi with additional
looping and construction of the West Transmission Main included in the
CIP.
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Water Storage Summary
Operational storage was determined to be adequate for current demand conditions.
Fire storage was determined to be adequate for the existing distribution system.
Emergency storage was determined to be adequate for the existing population.
Operational changes along with mixing system retrofits or inlet/outlet piping
reconfigurations are recommended to reduce water age and improve water quality.
Transmission Main Capacity Summary
There is currently a single, 40-plus year old pipeline connecting the City to the majority
of its water supply (Sourdough WTP). If this pipeline were to fail, the City would be at
immediate risk of a water shortage. Redundant transmission of water from the
Sourdough WTP would significantly reduce the consequence of a failure in the existing
pipe, while also improving system capacity and enabling the existing transmission main
to be removed from service for inspection and repair. This redundant Sourdough
Transmission Main is the highest priority project recommended in the CIP.
Several water mains conveying water from the Sourdough Tank north and west into the
City exhibit headloss greater than 5 ft/1000 ft during PHD of MDD (the established
goals for the system). As the City continues to expand to the west, an additional
transmission main will be needed to convey water from the Sourdough WTP to the
western portions of the City. The headloss would be reduced by constructing the West
Transmission Main included in the CIP.
Fire Flow Summary
Utilizing the hydraulic model, fire flow demands (consistent with the needed fire flow
per land use) were simulated on each of the hydrants throughout the system. Hydrants
unable to provide the needed fire flow (NFF) while maintaining a minimum residual
pressure of 20-psi were noted as deficiencies in the system. Additional field-testing
should be conducted by the City to confirm the findings of the fire flow evaluation and
determine the most effective path forward (e.g. looping, upsizing lines, utilize multiple
hydrants in the area, etc.).
In many cases, the NFF may be achieved by utilizing more than one hydrant, where a
nearby hydrant is available.
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Pressure Zone and Pressure Reduction Evaluation
The pressure zone and reduction evaluation was conducted to identify feasible alternatives to
reduce excessively high pressure (> 110 psi) currently experienced in a significant portion of
the City. The goal of pressure reduction would be to meet the pressure criteria listed in Table
ES. 3. Throughout the current and future system pressure reduction would provide the
following benefits:
Reduced operating stress on aging pipes, valves and fittings.
Reduced probability and magnitude of pressure spikes (transients), subsequent damage
to pipes, and potential catastrophic failures.
Reduced water loss rates from system leaks.
Reduced safety risks for operators when conducting system maintenance.
The impact of implementing pressure reduction on overall system performance and end users
was assessed. Most of the building fire suppression (sprinkler) systems in Bozeman have been
designed around actual system pressure at the connection location, with no safety factor. City
GIS records indicate there are approximately 200 documented fire suppression systems in
Bozeman; however communications with fire suppression system designers revealed that
nearly 800 fire suppression systems currently exist in the City’s distribution network.
Even a minor pressure reduction (e.g. 10 psi) in the distribution system would result in many
fire systems failing to perform as designed. The pressure reduction needed is much greater than
10 psi, and would result in most fire suppression systems unable to comply with design
standards. Replacing hundreds of fire suppression systems (or installing fire pumps, in some
cases) is not economically feasible – preliminary estimates indicate it would likely exceed $50
million. Instead, a longer-term approach to pressure reduction is recommended. This approach
includes the following elements.
Existing pressure zones would remain unaltered for the short-term and near-term.
As the City continues to expand into the UBO, all new pressure zones developed in the
future will be designed to conform to the hydraulic criteria recommended in Table ES.
3, using pressure reducing stations where necessary.
In the short-term, the City should adopt new polices and codes requiring new fire
suppression systems to be designed based on the future reduced pressure.
Fire suppression systems that have been designed to operate off existing high pressure
should be required to conform to new City codes and policies only when significant
building upgrades or renovations occur.
Overall system pressure reduction would not be implemented until a sufficient number
of fire suppression systems have been upgraded to make retrofit of the remaining
systems economical.
This is a long-term approach that could potentially take decades, but enables the City to
implement system wide pressure reduction at a reasonable cost and risk.
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Non-Potable Irrigation Evaluation
In an effort to better understand the potential cost-benefit of non-potable water systems in
Bozeman, a proxy study area was identified for a hypothetical dual pipe project. The area
selected is located in the Northwest portion of the service area (see Figure 8-1 of the Facility
Plan Update), bounded on the north by Baxter Road, on the south by Durston Road, on the
east by Ferguson Street, and on the west by Gooch Hill Road.
A cost-benefit analysis for a 30-year life cycle was developed, comparing a traditional single
pipe distribution system (potable water only) to a dual pipe system (consisting of both a potable
distribution system and non-potable distribution system for irrigation use). For each of the
options, estimated capital costs, life cycle operating costs, life cycle income and other benefits
were quantified. The results are summarized in Table ES.4.
The life cycle cost of a dual pipe system was estimated to be about $400,000 dollars less than
a single pipe system. This estimated savings is less than 1 percent of the total cost for the proxy
water system analyzed, an order of magnitude less than the accuracy of the cost estimate,
indicating that the life cycle costs for the systems are approximately equivalent. However,
there are some key lessons learned from the analysis that the City can consider when
contemplating future dual pipe systems:
1) The value of water rights strongly influences the cost-benefit of a dual pipe system.
Significant changes in the value of water rights will change the economic viability of
dual pipe systems.
2) Currently, the City’s cost to treat and distribute water is relatively low. Increases in
this cost over time would improve the cost-benefit of a dual pipe system.
Dual Piped System and Potable Only System NPV Comparison
Option Capital Costs Annual O&M
Costs
O&M Costs Over
Project Life1 Benefits2 Net Costs3
Dual Piped
System $34,200,000 $531,323 $9,930,000 ($2,420,000) $41,710,000
Potable Only
System $29,650,000 $669,186 $12,500,000 $0 $42,150,000
Notes:
1. 30 year project life, 3.375% discount rate.
2. Deferred water treatment plant expansion.
3. Total Costs – Benefits.
Table ES. 4: Non-Potable Irrigation Overall Cost-Benefit Summary
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Summary of Future System
The infrastructure needed for UBO of the City was sized to satisfy the performance criteria in
Table ES. 3.
The objectives for the UBO hydraulic modeling effort included the following:
Develop and provide conceptual design of future pressure zones;
Determine future storage capacity needs and general tank locations;
Identify booster pumping requirements;
Size and locate distribution mains based on water demand allocation and hydraulics;
Evaluate potential impacts of water conservation; and
Optimize overall system functionality.
UBO Distribution, Pressure and Storage System Overview
The UBO water distribution system is summarized in Table ES. 5 and shown in Figure ES-5.
Facility Type Existing Additional Facility Improvements
Major Distribution Pipeline (miles)
(size 12-14 inches) 38 106 miles of 12-inch major distribution main
Transmission Main (miles)
(size 16-30 inches) 14 94 miles of transmission main ranging from 16-48 inches in
diameter
Pressure Zones 6 8 new main pressure zones
(2 existing zones are combined to a single new zone)
Pressure Reducing Stations 22
25 new Pressure Reducing Stations to serve new zones and to
allow emergency flow between zones
(sub-zone PRVs in mountain zones are not included)
Storage Reservoirs
(Volume)
4
(16.6 MG)
12 new reservoirs
(72 MG total system storage)
Table ES. 5: Summary of Proposed System Improvements
UBO Water Main Overview
A total of 200 miles of distribution and transmission main, ranging from 12-inches to 48-inches
in diameter will be needed to provide projected UBO water demand. The proposed distribution
system was developed using the following concepts:
A framework of 12-inch and 16-inch water main were used to establish the backbone of
the future distribution network.
o 12-inch water mains were routed along half-section lines
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o 16-inch water mains were routed along section lines and large transportation
corridors identified in the TMP
Water mains less than 12-inch are generally considered local distribution mains and are
planned on a development level basis and are beyond the scope of the UBO analysis.
Where necessary, water mains are larger than 16-inch in order to convey higher flow
with acceptable headloss.
UBO Transmission Mains
The conceptual UBO distribution system is comprised of approximately 94 miles of new
transmission main ranging in size from 16-inches to 48-inches in diameter. Nine key
transmission mains are necessary to convey the UBO demand while meeting the hydraulic
criteria in Table ES.3. Three of these transmission mains are projected near-term projects:
Sourdough Transmission Main (3.9 Miles of 30”-36” pipe) – provides critical,
redundant transmission of water from the Sourdough WTP to the distribution system.
Lyman Transmission Main (1.6 Miles of 18” pipe) – replaces existing asbestos cement
water main, improving reliability and providing additional needed conveyance capacity
for anticipated growth areas.
West Transmission Main (20.8 Miles of 16”-48” pipe) – serves anticipated growth areas
on the west side of the planning boundary.
The remaining six identified transmission mains necessary for the UBO scenario are long-term
projects:
East Transmission Main (3.8 Miles of 24” pipe)
Southeast Mountain Zone Transmission Main (5.6 Miles of 16”-24” pipe)
Southwest Transmission Main (1.4 Miles of 24”-30” pipe)
North Mountain Zone Transmission Main (2.5 Miles of 16”-24” pipe)
East Mountain Zone Transmission Main (1.6 Miles of 18”-24” pipe)
Groundwater Well Field Transmission Main (5.7 Miles of 36” pipe)
UBO Pressure Zones
The pressure zones required for the UBO condition are listed in Table ES. 6, along with the
operating hydraulic grade line.
Four existing zones are unchanged or expanded: South, Knolls, Northeast, and Gallatin
Park.
A new Northwest 1 Zone (HGL 4975 ft) is comprised of the existing West Zone (HGL
4980 ft) and Northwest Zone (HGL 4940 ft) as well as surrounding growth areas.
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Eight new pressure zones are created to cover the UBO and include: Northwest 1,
Northwest 2, Northwest 3, Southwest Mountain, Water Treatment Plant, Southeast
Mountain, East Mountain, and North Mountain.
Transmission and distribution mains were configured to allow zone feed redundancy with two
or more PRVs feeding each zone. Pressure zones along the West Transmission Main are
primarily fed from the main transmission pipeline, with connections to adjacent pressure zones
serving as emergency or redundant connections.
Pressure Zone Operating HGL (ft)
Northwest 3 4725
Northwest 2 4850
Gallatin Park 4885
Northwest 1 4975
Northeast (Lyman) 5038
South (Sourdough) 5125
Knolls 5185
Water Treatment Plant 5221
Southwest 5350
North Mountain
Zone (2 subzones) 5360
Southeast Mountain Zone (2 subzones) 5560
East Mountain Zone (3 subzones) 5630
Table ES. 6: Future Pressure Zones at UBO
UBO Storage Reservoirs
A total of 12 new storage reservoirs, with a total storage capacity of approximately 57 MG will
be necessary to serve UBO water demand while satisfying the established hydraulic criteria in
Table ES.3. Including existing storage, the total system storage for UBO will be 72.3 MG.
Table ES. 7 summarizes UBO storage recommendations.
UBO Pumping Facilities
The proposed mountain pressures zones in the UBO boundary will require new pump stations
to meet the hydraulic criteria of Table ES.3. Reservoirs are recommended for each of these
zones and pump stations are generally sized to meet MDD at UBO. The following pump stations
will be needed to serve the mountain zones:
Southwest Mountain Zone Pump Station: 1,800 gpm at 135 ft TDH
Southeast Mountain Zone Pump Station: 2,100 gpm at 345 ft TDH
East Mountain Zone Pump Station: 3,100 gpm at 530 ft TDH
North Mountain Zone Pump Station: 1,450 gpm at 340ft TDH
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Zone with Storage Reservoir ID Overflow Status
Reservoir
Size
(MG)
Total Storage
Within Zone
(MG)
South Zone
Sourdough 5125.7 Existing 4.0
20.0
Sourdough 2 5125 Proposed 4.0
Hilltop 5125.2 Existing 2.0
West Sourdough Reservoir 1 5125 Proposed 5.0
West Sourdough Reservoir 2 5125 Proposed 5.0
Southwest Zone Southwest Reservoir 5350 Proposed 4.0 4.0
Water Treatment Plant
WTP Reservoir 1 5221.4 Existing 5.3
15.3 WTP Reservoir 2 5221 Proposed 5.0
WTP Reservoir 3 5221 Proposed 5.0
Southeast Mountain
Zone Southeast Reservoir 5560 Proposed 4.0 4.0
East Mountain Zone East Mountain Reservoir 5630 Proposed 6.0 6.0
Northeast Zone Lyman Reservoir 5038 Existing/
Proposed 10.0 10.0
North Mountain Zone North Mountain Reservoir 5360 Proposed 3.0 3.0
Northwest Zone Southwest Reservoir 1 4975 Proposed 5.0 10.0 Southwest Reservoir 2 4975 Proposed 5.0
Total System Storage (Existing and Proposed) 72.3
Table ES. 7: Storage Reservoirs at UBO
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Recommended Improvements
Capital improvement projects (CIPs) are necessary to resolve existing system deficiencies, and
keep pace with growth and development, including associated increases in water demand. To
facilitate organization and prioritization of the identified CIPs, projects were categorized as
follows.
Condition Assessment (CA)
CA projects are pipeline condition evaluations undertaken to identify high-risk degradation of
a pipeline to identify impending failure, or to document that there is significant viable life
remaining in a pipeline so that money is not spent unnecessarily on replacement or
rehabilitation.
Growth and Development
Growth and development driven projects are those that become necessary to continue to provide
service to existing customers while also providing water to new growth areas. These projects
primarily consist of “backbone” water transmission mains and PRV facilities to establish
appropriate pressure zones.
Optimization
Projects that improve water quality, improve transmission and/or distribution efficiency or
system pressure, replace facilities that are obsolete, or decommission infrastructure that is no
longer needed.
Rehabilitation and Repair (R&R)
R&R projects target pipe segments that are under-sized or known to be in poor condition.
Identification of these segments may stem from a history of failure, acoustic leak detection
results, or previous observations. A risk assessment process was used to identify segments with
highest risk, using consequence and likelihood of failure, and then developing projects to
mitigate the highest risk segments.
Storage
Storage projects are necessary to increase the water storage capacity, ensure adequate fire flow,
and supplement water supply during periods of planned maintenance or emergencies.
Studies
Studies develop more detailed information so that the City can make informed decisions
regarding future CIP projects.
Supply
Supply projects are necessary to increase the overall water supply, secure water rights, or
capture and convey water more efficiently.
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Transmission
Consists of large diameter transmission main (16-inch to 48-inch) that originate from sources
of supply and convey large volumes of water throughout the entire distribution system
CIP Prioritization and Implementation
Decision Making Process
At recent growth rates and water use, water demand will likely exceed the water supply that is
currently available through the Sourdough WTP and Lyman Spring within the next 20 years.
In addition, the majority of the City’s supply originates in two adjacent, heavily forested
watersheds. Supply from these watersheds is vulnerable to drought and wildfire. Therefore, the
City will continue to identify and develop water supply improvements (e.g. groundwater
development, natural storage in Sourdough Canyon, controls improvements and storage
improvements on the Lyman source).
The size and cost of most of these projects prohibits short-term implementation, and
simultaneous near-term implementation. One challenge in prioritizing the CIP was to prioritize
these larger, near-term projects that need more evaluation to determine feasibility and cost-
benefit. Therefore, the City will study these projects in the short-term and use the results to
inform and adjust prioritization of subsequent near-term projects to best utilize available funds.
A planning “roadmap” was created to show key milestones and decisions that will be necessary
to identify the most cost-effective pathway (series of near and long-term CIP projects). Figure
ES-6 illustrates the decision making process and provides a basic overview of the different
planning options that would be evaluated.
CIP Prioritization
CIP prioritization methodology was developed to provide a consistent and transparent process
for ranking each project considered for inclusion in the CIP. Each project was evaluated on
nine prioritization factors:
Capacity Expanding Risk Assessment
Criticality Efficiency
Reliability/Redundancy Impact
Safety Necessary Prerequisite for a Future Project
Regulatory Compliance
Each criterion was assigned an importance factor. Projects were scored and then ranked. The
initial ranking was provided to the City in late August 2016 for use in staff’s internal CIP
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development process. During the City’s internal CIP development process, the project
prioritization was reviewed and some adjustments were made based on staff knowledge and
available budgets. The final FY2018-2022 CIP was adopted by the City of Bozeman in
December of 2016 and is included in the Water Facility Plan Update.
City staff will revisit the CIP prioritization process created within the Water Facility Plan during
subsequent CIP planning periods to adjust prioritization based on new information, growth and
development pressures, and available budget.
Figure ES-6: Future City Planning Options
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Water Facility Plan Update Report
Executive Summary
July 2017
P05097-2013-001 Page ES-22
Policy Recommendations
As the City continues to grow and evolve, occasional policy creation or modifications will be
necessary for the City to continue to best serve its citizens. Below are several policy related
issues that have been identified during the water facility planning update process:
Adopt new maximum pressure standards for future growth areas, specifically new
pressure zones.
Adopt a long-term pressure reduction strategy to address high pressure in a portion of
the existing distribution system.
Develop new policies and codes for fire suppression design that factor in the City’s
long-term pressure reduction strategy and goals.
Develop new policies that establish City requirements for placement of pressure
reducing facilities serving developments and growth areas.
Potential implementation of non-potable irrigation will require the City to develop and
adopt standards and specifications to ensure uniformity for all future non-potable
development. These standards and specifications are included in the Water Facility Plan
Update.
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