HomeMy WebLinkAbout2022 Drought Management Plan
Table of Contents
1 INTRODUCTION................................................................................................................ 6
1.1 Drought Management Plan Objectives .................................................................................7
1.2 Drought Management Plan Components ............................................................................. 7
1.3 Defining Drought................................................................................................................... 7
1.4 Water Supplies ...................................................................................................................... 8
1.5 Strategic Water Reserve........................................................................................................ 9
1.6 Long Term Drought Mitigation Efforts..................................................................................9
1.7 Drought Communications ................................................................................................... 10
2 DROUGHT SEVERITY INDICATORS ................................................................................... 11
2.1 Vulnerability Assessment .................................................................................................... 11
2.1.1 Drought History......................................................................................................... 11
2.1.2 Potential Climate Change Impacts ............................................................................ 13
2.1.3 Wildfire Risks and Impacts ........................................................................................ 16
2.1.4 Population Growth.................................................................................................... 18
2.1.5 Increased Summer Water Usage .............................................................................. 18
2.1.6 Requirements of Neighboring Water Users.............................................................. 19
2.2 Drought Monitoring ............................................................................................................ 19
2.2.1 Local Indicators ......................................................................................................... 20
2.3 Drought Monitoring and Response..................................................................................... 26
2.4 Uncertainty Associated with Forecasts...............................................................................28
3 DROUGHT RESPONSE ACTIONS.......................................................................................28
3.1 Increasing Water Supply ..................................................................................................... 29
3.2 Reducing Water Use............................................................................................................ 29
3.3 Monitoring, Evaluation and Declaration............................................................................. 29
3.4 Water Use Restrictions ....................................................................................................... 31
3.5 Water Use Education .......................................................................................................... 31
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3.5.1 Communications Campaign ........................................................................................ 32
3.6 Drought Management for Master Meter Customers ......................................................... 32
3.7 Drought Surcharge Rates...................................................................................................... 33
3.7.1 Drought ReserveRate.................................................................................................34
3.8 Drought Stages.................................................................................................................... 34
3.8.1 Stage 1 -Drought Watch: Customer Outreach ......................................................... 35
3.8.2 Stage 2 -Drought Advisory: Mandatory Watering Restrictions ............................... 36
3.8.3 Stage 3 -Drought Warning: Ban on Targeted Water Uses ....................................... 37
3.8.4 Stage 4 -Drought Emergency: Rationing .................................................................. 39
4 DROUGHT RESPONSE PROGRAM MEASURES .................................................................. 40
5 DROUGHT RESPONSE PROGRAM ENFORCEMENT............................................................ 45
5.1 Drought Management Plan Updates .................................................................................. 46
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List of Figures
Figure 1-1: Regional Map of the City of Bozeman's Water Supply Sources....................................... 8
Figure 2-2: Historical Streamflow and Snow Water Equivalent Trends from the Tree Ring Data for
Figure 2-3: Monthly Palmer Drought Severity Index (PDSI) for Bozeman Region (Jan 2000-Feb
Figure 2-5: Historical and Projected April Snow for Missouri River Headwaters Region (Mean
Figure 2-10: Hyalite/Middle Creek Reservoir Historic Minimum and Maximum Storage Volumes
Figure 2-1: Palmer Drought Severity Index for the United States (1895-1995).............................. 12
the Upper Missouri Basin ................................................................................................................. 13
2022)................................................................................................................................................. 14
Figure 2-4: Future Climate Trend Consisting of Natural Variability and Climate Change ............... 14
Mode) ............................................................................................................................................... 15
Figure 2-6: Northern Gallatin Snowpack Snow Water Equivalent .................................................. 16
Figure 2-7: Relative Increased Risk of Very Large Wildfires in Contiguous United States .............. 17
Figure 2-8: City of Bozeman Population Growth from 1950 to 2020.............................................. 18
Figure 2-9: City of Bozeman Average Monthly Water Demand by Customer Class (2016-2020)... 19
(1951 – 2015).................................................................................................................................... 21
Figure 2-11: Gallatin River Watershed ............................................................................................ 22
Figure 2-12: Location of Bozeman Area SNOTELs ........................................................................... 23
List of Tables
Table 2-1: Recommended Additional/Future Local Monitoring Locations ..................................... 24
Table 2-2: Drought Severity Categories and Inputs for the U.S. Drought Monitor......................... 25
Table 2-3: October-June Indicators for Monitoring in Relation to Response Stages ...................... 27
Table 2-4: July-September Drought Indicators for Monitoring in Relation to Response Stages ... 27
Table 3-1: Drought Surcharge Rates by Customer Class ................................................................. 34
Table 3-2: Distribution System Wide Water Reduction Targets During Declared Drought Stages. 35
Table 3-3: Drought Tool Indicators, Seasonal Weighting Factors, and Percent Exceedance for a
Stage 1 Drought ................................................................................................................................ 35
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Table 3-4: Drought Tool Indicators, Seasonal Weighting Factors, and Percent Exceedance for a
Stage 2 Drought ................................................................................................................................ 36
Table 3-5: Drought Tool Indicators, Seasonal Weighting Factors, and Percent Exceedance for a
Table 3-6: Drought Tool Indicators, Seasonal Weighting Factors, and Percent Exceedance for a
Table 4-1: Outdoor Watering and New Vegetation Installation Recommended Response
Stage 3 Drought ................................................................................................................................ 38
Stage 4 Drought ................................................................................................................................ 39
Measures .......................................................................................................................................... 41
Table 4-2: Water Feature Recommended Response Measures...................................................... 42
Table 4-3: Washing Events Recommended Response Measures.................................................... 42
Table 4-4: Commercial-Institutional Recommended Response Measures ..................................... 43
Appendices
Appendix A: Drought Management Team … ................................................................................ 47
Appendix B: Drought Monitoring Tool and Dashboard Snapshot ................................................. 49
Appendix C: Drought Monitoring Tool Calibration Snapshots...................................................... 50
Appendix D: Bozeman Municipal Code Outdoor Water Use Restrictions and Drought Contingency
Response .......................................................................................................................................52
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1 INTRODUCTION
The Drought Management Plan is designed to maximize available water supplies and reduce water use
during times of shortage and provide guidelines the City of Bozeman will use to manage water supply and
water use during drought. The guidelines are designed to maintain the health, safety and economic vitality
of the community; to avoid adverse impacts to public activity and quality of life for the community; and
to consider individual customer needs as much as possible to the greatest extent possible in the face of
water shortages.
Because each drought is different, it is not practical to develop a set of hard-and-fast rules to apply to all
droughts. Rather, these guidelines are intended to provide a framework for timely drought response while
maintaining flexibility to respond to unique drought conditions. These guidelines are intended to assist
the City Manager in making decisions throughout the course of a drought. The City Manager may adjust
or refine the response based on actual droughtconditions.
Drought is a natural occurring phenomenon that may affect any climate zone in any part of the world at
a given time. Depending on drought severity and characteristics of the area, the repercussions of drought
can be significant -impacting local economies, disrupting quality of life, and disturbing the health and
welfare of a population and its environment.1
Chronic drought is a part of the Gallatin Valley’s history and is of particular concern to the City of Bozeman
as the City has experienced rapid growth in recent decades. The impact of drought on Bozeman is further
compounded by its location in the headwaters of the Gallatin River watershed, the susceptibility of the
City’s source waters to drought conditions and limited water storage.
This Plan was designed with input from the 2017 City of Bozeman Drought Management Team and
community stakeholders. The Drought Management Team was revised in 2022 to include additional
members of City staff and other organizations in the Gallatin Valley in order to increase the effectiveness
of drought communications. Drought Team members comprise a diverse group of water supply and
communications experts to aid in data driven decision making and ensure adequate and consistent
drought messaging and communications throughout organizations across the Gallatin Valley. Team
members are identified in Appendix A. Select City staff included in the City of Bozeman Drought
Management Team represent key decision makers who, together, will make recommendations to the City
Manager regarding drought declaration and pursuant response measures.
The Plan is based on an analysis of Bozeman’s climate and available water supplies, a review of other
drought plans from across the United States and lessons learned from past drought events in communities
throughout the Western United States. This Drought Management Plan should be updated regularly to
ensure that it addresses current conditions and will be administered by the City of Bozeman’s Utility
Department staff.
1 https://www.ncdc.noaa.gov/news/drought-monitoring-economic-environmental-and-social-impacts
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1.1 Drought Management Plan Objectives
Preserve essential public services during any level of drought severity.
Reduce adverse impacts on public health, safety, economic activity, environmental resources, and
quality of life during a drought event.
Ensure that drought management programming and outreach are accessible and targeted to reach
renters, low-income residents, residents of multi-unit buildings, and other vulnerable or
marginalized groups, while also ensuring that rate structures (including drought surcharges) do not
disproportionately impact these groups.
Provide a complete but flexible roadmap to guide implementation and enforcement of the Drought
Management Plan.
Develop an effective public communications strategy to raise the level of drought awareness
throughout the community and to provide sufficient information about the importance of drought
preparedness and response and the public’s role in the effective implementation of the response
measures set forth in the Plan.
Coordinate drought management with the City of Bozeman’s water supply planning and demand
management efforts and regional policies and planning initiatives. This includes City, County, and
State laws and regulations, the City of Bozeman’s water conservation program and Gallatin County’s
Hazard Mitigation and Emergency Response Plans.
1.2 Drought Management Plan Components
Drought Severity Indicators (Vulnerability Assessment and Drought Monitoring) – Factors that should be
considered in choosing appropriate drought response.
Drought Mitigation and Response Actions – Guidelines for generating additional water supplies and
reducing water use during times of drought.
Drought Response Program – Strategies for reducing water use during each stage of drought and
enforcement actions for violations. The authority to enforce response measures and water reduction
targets provided in the Plan is provided for in the Bozeman Municipal Code and can result in fines or, in
some cases, the potential for water shut offs.
1.3 Defining Drought
While drought is a widely-used term, there is no single universally-accepted definition of drought. From a
meteorological perspective, drought is defined as an extended period of below average precipitation for a
given region. Hydrologic drought refers to reduced stream flows, reservoirs, lakes and groundwater to
below-normal levels and tends to lag behind the onset of low precipitation due to the buffering effects of
soil moisture, groundwater and snowpack. Droughts are most often discussed from this perspective when
water shortages begin to impact people in terms of water supply, loss of hydropower production, loss of
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fisheries, agricultural production losses and food shortages. Thus, drought is most commonly thought of as
an interplay between climate and water-dependent processes. Often, drought is defined by its effects rather
than its causes.
For the City of Bozeman, a drought is a condition of insufficient water supplies caused by deficits in
precipitation and hydrologic conditions. When the amount of water flowing in streams and into reservoirs
is less than average, the City of Bozeman should more closely monitor its water supply outlook. If continued
low stream flows stress water supplies, City staff will seek City Manager approval to implement the Drought
Management Plan. The extent and duration of implementation will depend on actual drought conditions.
Unfortunately, no one can predict how long drought conditions will last once they begin.
1.4 Water Supplies
Drought indicators are based on quantification of available water supplies which are set forth in the City
of Bozeman’s Integrated Water Resources Plan (IWRP) and the estimated amount of water available from
its collection system to meet customer demand.2 Figure 1-1 depicts Bozeman’s existing water supply
sources.
Figure 1-1: Regional Map of the City of Bozeman's Water Supply Sources
2 City of Bozeman Integrated Water Resources Plan, EX-2 (2013).
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The water supply data set forth in the IWRP is incorporated into monitoring near and long-term water
availability, with the goal of providing a framework for predicting future drought probability, or confirming
the intensity of an existing drought. A robust monitoring plan is critical to recognize and respond as soon
as possible to the onset of a drought event. This is of particular importance in light of the fact that
currently, year over year storage is not part of reservoir management practice, which can rapidly change
the severity of impacts from drought events.
As a part of this Drought Management Plan, it is recommended that upon approval by the Commission,
the City develop a strategic water reserve from Bozeman’s water supplies to provide protection against
circumstances such as climate change or drought conditions of greater severity than have been projected
to occur within the thirty year planning horizon.3 Implementation and operation of the strategic water
reserve will be determined by the Commission, subsequent to the adoption of this Plan.
1.5 Strategic Water Reserve
Strategic water reserves are volumes of water set aside by a utility or water purveyor for use in a drought
or other water shortage emergency. In recent years, several utilities have established water reserves to
provide water resiliency in the event of a prolonged or severe drought event.4 The development of a
strategic water reserve necessitates that water is set aside and removed from the accounting used to
determine the water supply available for additional population growth.
Consideration of a strategic water reserve is recommended for the City of Bozeman to reduce future
drought vulnerability. This reserve could comprise existing water rights stored from Hyalite Reservoir or
from aquifer storage, from water saved as a result of water conservation measures or established via
private agreement with interested parties. If a drought was especially severe and persistent, having a
drought reserve that could ensure enough water to provide minimum water usage to the next wet
weather period would be prudent. The volume of a reserve will be determined by the City Commission
after review of additional information specific to the City of Bozeman’s water supplies in order to
facilitate the development of a strategic water reserve.
The City is currently underway with the development of a water supply optimization study that includes
the examination of developing a strategic water reserve. The implementation of a strategic water
reserve will be determined by the City Commission after review of recommendations that result from
the water supply optimization study.
1.6 Long Term Drought Mitigation Efforts
The drought response actions set forth in this Plan should not be confused with long term drought
mitigation. The City of Bozeman engages in long term drought mitigation through on-going water
3 Id. At Appendix A: Climate Change Adjustments to Firm Yield and Demand for Bozeman, MT, Technical
Memorandum.
4 Examples include Albuquerque, Bernalillo County Water Utility Authority, Santa Fe, Denver Water, Truckee
Meadows Water Authority.
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conservation efforts and supply projects outlined in Bozeman’s Integrated Water Resources Plan.
The City of Bozeman’s semi-arid climate requires water efficiency become a way of life. The City of
Bozeman’s Water Conservation Division has been effective in reducing water consumption and is
committed to water efficiency and customer outreach. While the City of Bozeman has a separate Water
Conservation Division and water conservation savings goal, water conservation program development is
directly linked to drought mitigation. For more information about how water conservation is an integral
component of long-term drought management, and what the City is doing to increase water resiliency,
please visit www.bozemanwater.com.
Despite these long term water planning efforts, because of drought, there will be times when further
water use reductions are needed in addition to standard water conservation efforts. Drought restrictions
that are part of a response plan indicate urgency and are not intended for long-term application.
Because it is unknown how customers will respond during declared drought events, the reduction targets
presented in this Plan have been established based on documented achievable reductions in other
drought-prone communities in the Western United States, best practice and what is achievable and
necessary to mitigate economic impacts from drought and to preserve public health and safety.
1.7 Drought Communications
Drought communications are an integral component of this Plan and will be closely coordinated with the
Water Conservation Division to provide information regarding water resiliency and conservation.
Messaging should promote the importance of conserving water and achieving water savings in both
normal and drought years.
During non-drought years, drought communications should consist of resources and information
regarding customer-driven long-term drought mitigation efforts, general drought information and
drought preparedness tools to the community.
During a drought, the messages should increase in frequency and include information on the stages of
drought declared by the City Manager and the various response actions requested or required from
Bozeman residents in order to reduce impacts from drought.
Drought messaging should provide clear and effective drought information to water customers and the
media, adjust the scope of public education and outreach efforts pursuant to the drought stage, and
coordinate public communication efforts with county planning and hazard mitigation personnel, nearby
municipal entities, state agencies, and other conservation-focused organizations to convey, where
appropriate, a consistent drought message.
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2 DROUGHT SEVERITY INDICATORS
Drought severity indicators identify risks to critical resources during drought and the factors that
contribute to those risks. This Plan divides these indicators into two categories: (1) vulnerability
assessment and (2) drought monitoring. During a drought, the City Manager should consider drought
severity indicators in choosing the appropriate drought response actions. The Drought Response Actions
section below demonstrates how the drought severity indicators align with the suggested drought
response framework.
2.1 Vulnerability Assessment
Risks to critical water resources in the Bozeman area combine the frequency of occurrence, magnitude
and severity, and consequences of drought. The vulnerability assessment drives the development of
potential drought mitigation and response actions. Assessing the level of risk requires a review of past
drought impacts, and an analysis of historical water supply and water use trends which demonstrate how
trends may change over time.
The City of Bozeman is extremely vulnerable to drought due to a long history of drought in the region,
increased potential for impacts from climate change, increased risks for wildfire, rapid population growth,
dramatic increases in water use during the summer months, and the needs of other water users in the
watershed.
2.1.1 Drought History
Southwestern Montana has experienced severe drought in its recorded history and is located in a region
that is relatively prone to drought conditions according to historical Palmer Drought Severity Index data.
Figure 2-1 represents the historical Palmer Drought Severity Index. Based on the figure, southwestern
Montana has been in severe or extreme drought 15% to 19.9% of the time between 1895 and 1995, which
is significant given only two other areas of the continental U.S. in southwest Wyoming and south central
Colorado appear to be more susceptible to drought conditions.
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Figure 2-1: Palmer Drought Severity Index for the United States (1895-1995)
In addition, recent improvements in paleoclimate data examination using tree-ring analysis indicate that
more severe and prolonged droughts have occurred in the region than are reflected by recorded history.5
Figure 2-2 shows the historical snow water equivalent from tree ring data in the Upper Missouri Basin for
the last six hundred years. The historical data indicate that prolonged and severe drought in the area is
chronic, and the importance of adequately preparing for such periods via the adoption of this Drought
Management Plan is a necessary step to increasing water security for the City ofBozeman.
5 Ault, T. R., Cole, J. E., Overpeck, J. T., Pederson, G. T., & Meko, D. M. (2014). Assessing the risk of persistent
drought using climate model simulations and paleoclimate data. Journal of Climate, 27(20), 7529-7549; See also,
City of Bozeman Integrated Water Resources Plan (2013).
12
Figure 2-2: Historical Streamflow and Snow Water Equivalent Trends from the Tree Ring Data for the Upper
Missouri Basin
In the more recent past, the Bozeman area experienced moderate to extreme drought in several months
between 2000 and 2022. Figure 2-3 illustrates rainfall and temperature in the Bozeman region from 2000-
2022, and while it does not evaluate snowpack, it is still a very relevant illustration of water impacts in
Bozeman as late spring and early summer precipitation and evapotranspiration rates are strongly
correlated to the City’s water demand. 6
2.1.2 Potential Climate Change Impacts
Climate change models predict warming in the region and longer dry spells which could reduce snowfall
and result in earlier melting of the snowpack and increased evapotranspiration in the area.7 Even without
any changes in precipitation intensity, this could lead to a shift in peak stream runoff to early spring or
even late winter, away from the mid to late summer when water demand is greatest. Warming
temperatures could also cause more precipitation to occur in the form of rain instead of snow.
All of the City’s water supply sources are heavily reliant on snowpack, which has generally decreased in the
region since approximately 1980.8 Climate change models predict snowpack will decrease substantially in
6 National Drought Mitigation Center Drought Risk Atlas: http://droughtatlas.unl.edu/
7 Barnett, T. P., Adam, J. C., & Lettenmaier, D. P. (2005). Potential impacts of a warming climate on
water availability in snow-dominated regions. Nature, 438(7066), 303-309.
8 Pederson, G. T., S. T. Gray, C. A. Woodhouse, J. L. Betancourt, D. B. Fagre, J. S. Littell, E. Watson, B. H.
Luckman, and L. J. Graumlich (2011), The unusual nature of recent snowpack declines in the North American
Cordillera, Science, 333(6040), 332–335, doi:10.1126/science.
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coming years due to early spring warming.9 Additionally, climate models demonstrate increased climate
variability rather than a linear trend due to a combination of climate change and natural variability as
shown in Figure 2-4.10
Figure 2-3: Monthly Palmer Drought Severity Index (PDSI) for Bozeman Region (Jan 2000-Feb 2022)
Figure 2-4: Future Climate Trend Consisting of Natural Variability and Climate Change
Climate variability must be taken into account with future consideration of drought management and
9 UW Climate Impacts Group – http://cses.washington.edu/cig/
10 Gray, S. T., Betancourt, J. L., Jackson, S. T., & Eddy, R. G. (2006). Role of multi-decadal climate variability in a range
extension of pinyon pine. Ecology, 87(5), 1124-1130.
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response due to the increased probability of long-term drought, and an increase in the magnitude and
related impacts of short-term drought. Due to current limitations on accounting for storage of water from
a previous water year and the reliance on snowpack, a severe short-term drought could have significant
impacts.
Figure 2-5 shows the historical April snowpack for the Missouri River Headwaters Region, as well as the
United States Geological Survey’s projection of future snowpack based on two levels of solar radiation.
Regardless of solar radiation levels, the overall estimates predict substantial reductions in April snowpack.
Figure 2-5: Historical and Projected April Snow for Missouri River Headwaters Region (Mean Mode)
Figure 2-6 is a compilation of Hyalite snowpack snow water equivalent data (Shower Falls and Lick Creek
SNOTEL sites) and Bridger Mountain snowpack snow water equivalent data (Sacajawea and Brackett Creek
SNOTEL sites), with non-exceedance projections based on historical values depicted on the graph. The
term non-exceedance is used to describe a method of cumulative frequency analysis and refers to how
likely various changes in the current snowpack are to occur based on historical data. The graph in Figure
2-6 displays non-exceedance projections which correspond to the amount of time that the snowpack has
historically held more water on the same date as the current measurement.
The graph projects that over time the snowpack snow water equivalence will decrease as less snow water
is present in the snowpack, and what is present will melt earlier in the spring.
Regionally, early snowpack melt has been occurring with what appears to be increasing frequency.11 The
early occurrence of winter and spring snowmelt is anticipated to place increased strain on the adequacy
of the City of Bozeman’s water supplies in the late summer and fall months. The arrow in Figure 2-6
illustrates the predicted trend for future snowpack and timing of snowmelt.
11 Gregory T. Pederson, et al, (2011). Climatic Controls on the Snowmelt Hydrology of the Northern Rocky Mountains.
J. Climate, 24, 1666–1687.
15
General future trend
predicted by climate
change models
Figure 2-6: Northern Gallatin Snowpack Snow Water Equivalent
2.1.3 Wildfire Risks and Impacts
Climate change models also predict increased wildfire frequency and duration, as well as longer wildfire
seasons.12 Wildfire risk has a tendency to follow drought conditions. All of the City’s watersheds
(Sourdough, Hyalite and Lyman) are forested and therefore susceptible to wildfire, which would likely
reduce the amount and quality of water available from the municipal watersheds for an extended period
of time. Nationally, wildfire already occurs with more frequency. A warming climate leads to increased
rates of evapotranspiration resulting in drier forests in the late summer and fall months. Figure 2-7 depicts
increased risks of very large wildfires in the contiguous UnitedStates.13
12 https://www.epa.gov/climate-indicators/climate-change-indicators-wildfires An, H., Gan, J., & Cho, S. J. (2015).
Assessing climate change impacts on wildfire risk in the United States. Forests, 6(9), 3197-3211.
13 Barbero, R.; Abatzoglou, J.T.; Larkin, N.K.; Kolden, C.A.; Stocks, B. (2015). Climate change presents increased
potential for very large fires in the contiguous United States. International Journal of Wildland Fire.
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Figure 2-7: Relative Increased Risk of Very Large Wildfires in Contiguous United States
Wildfires negatively impact water sources by increasing ash and sediment mobilization, thus reducing
water quality as a result of ash and sediment-laden reservoirs and streams. A fire in the Hyalite watershed
could result in substantial increases in sediment deposition, reducing the capacity of Hyalite Reservoir.
Water utilities impacted by wildfire have reported that intense rains subsequent to a wildfire event caused
massive sediment accumulations that damaged infrastructure and resulted in power outages, long-term
reduction in source water quality, short-term contamination of drinking water sources, loss of source
water, and water demand in excess of water production.14 Due to the fact that Bozeman Creek and Hyalite
Creek watersheds are at risk of high severity fire, the City of Bozeman’s new water treatment plant was
specifically designed to function even with some sediment loading from a wildfire event. However, it is
not equipped to handle the aftermath of large and prolonged fires. As a result, fuel reduction measures
in these source watersheds are necessary to reduce wildfire impact severity.15
The City is currently underway with the Bozeman Municipal Watershed Fuels Reduction Project, a joint
effort between the City of Bozeman and Custer Gallatin National Forest, which aims to reduce forest fuel
14 Sham, C.H., Tuccillo, M.E., and Rooke, J. (2013). Effects of Wildfire on Drinking Water Utilities and Best Practices for
Wildlife Risk Reduction and Mitigation. Water Research Foundation, Web Report #4482.
15 City of Bozeman Source Water Protection Plan, Western Groundwater Services, Bozeman, 2004; USFS, Bozeman
Municipal Watershed Risk Assessment. Bozeman, MT, 2003.
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loads. The project will help protect Bozeman’s drinking water supply and will increase public and
firefighter safety.
2.1.4 Population Growth
A rapidly growing population (3% to 6% growth rate in recent years) increases vulnerability to drought.
The City of Bozeman’s Integrated Water Resources Plan (IWRP) determined that without substantial
conservation Bozeman will likely experience a water supply and demand gap within the next 25 years.16
However, current growth trends and water use trends indicate that Bozeman may experience a water
supply and demand gap within the next 15 years. Figure 2-8 shows the population growth of Bozeman
from 1950 to 2021. Rapid population growth in an area without a large, stable raw water source (large
river, groundwater aquifer, or very large raw water reservoir) increases vulnerability to drought, unless
new sources are developed to accommodate growth.
-
10,000
20,000
30,000
40,000
50,000
60,000 Population 195019611964196719701975197819811984198719901993199619992002200520082011201420172020 Year
Figure 2-8: City of Bozeman Population Growth from 1950 to 2021
2.1.5 Increased Summer Water Usage
Water usage significantly increases during the months of June, July, and August as a result of outdoor
watering. The peak summer demands for lawn watering are roughly 250% of the average winter demand.
During drought, lawns become drier, prompting homeowners to irrigate more, rather than less.
Figure 2-9 shows the average monthly water demand by water customer class from 2016 – 2020. When
evaluating water usage across all customer classes, summer demands are approximately 2.5 times higher
than winter demands. If the data represented in Figure 2-9 are disaggregated by year, a correlation
16 City of Bozeman Integrated Water Resources Plan (IWRP), Advanced Engineering and Environmental Services, 2013
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between monthly water demand and evapotranspiration becomes very apparent. Single family residents
use a high proportion of water for irrigation compared to othercustomerclasses, and residents who irrigate
their lawn use more water during dry years than normal years. This practice will be reduced or curtailed as
a component of drought response set forth in this Plan.
Figure 2-9: City of Bozeman Average Monthly Water Demand by Customer Class (2016-2020).
2.1.6 Requirements of Neighboring Water Users
Bozeman’s vulnerability to drought is further subject to the water needs of neighboring communities and
user groups. Agricultural interests, adjacent cities, towns and residential communities, and recreational
and environmental interests have rightful claims to water supplies in the Gallatin Valley and are
significantly impacted during drought.
Additional complications arise when drought is incorporated into the legal framework allocating water in
Montana. This structure is based on the doctrine of prior appropriation in which the date the water is
appropriated and placed to beneficial use determines the priority of the water right. The oldest or most
senior dates of appropriation are administered first. As a result, during times of shortage, priority
determines who is entitled to divert and use water. As increasing demands are placed on the finite amount
of water available, the risks for conflicts between water users increase. An effective Drought Management
Plan can reduce the likelihood for such conflicts.
2.2 Drought Monitoring
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A Drought Management Plan must include a means of monitoring current drought conditions and applying
the conditions to the development of an overall drought stage framework. The primary goal of drought
monitoring is to recognize a drought in its early stages and accurately assess its severity over time so that
appropriate responses are successfully implemented.
A transparent, quantifiable, and scientific basis for drought declaration is critical for timely decision-
making, effective communication, and managing expectations of the public. Drought monitoring allows for
the use of local and national data in decision-making, implementation of appropriate restrictions at the
appropriate times, and allowances for different types of uses and the needs of different water users.
For purposes of this Plan, a drought monitoring protocol was developed that incorporates local data such
as reservoir storage, area streamflow, snowpack, precipitation, temperature, evapotranspiration and
weather forecasts, as well as national drought indices. City staff will monitor these data, including the use
of a customized monitoring tool comprising local and national indicators described in this Section. These
data should be monitored all year, and during summer months data should be monitored alongside water
demand order to understand how water supply availability and weather patterns are impacting demand
trends. Select outputs from the drought monitoring tool are set forth in Appendix B. Calibration of the
City’s drought monitoring tool ensures the accuracy and reliability of the data generated by the drought
monitoring tool. A snapshot of the calibration of the tool is provided in Appendix C.
2.2.1 Local Indicators
Droughts are highly variable, complex, and specific to a region’s local climatic conditions. Due to the fact
that 80% to 85% of Bozeman’s water supply is surface water, monitoring will primarily rely on levels in
Hyalite Reservoir, area streamflow and snow water equivalence.
2.2.1.1 Reservoir Storage
Because much of the water supply during summer drought events comes from storage reservoirs,
reservoir contents are an accurate indicator of a drought’s impact on available supplies when conditions
are hot and dry and water use increases due to irrigation. Reservoir contents are the bottom line result of
the factors affecting supply, including weather, snowpack, soil moisture, runoff, water rights, collection
system limitations and water use.
Although the City of Bozeman currently has limited storage capacity, seasonal water elevation in Hyalite
Reservoir, and the corresponding volume in storage, is an immediate and direct assessment of the area’s
water supply status, particularly during summer months. Reservoir levels are regularly monitored by the
Department of Natural Resources and Conservation (DNRC), and the data are easily accessible. The volume
of water in Hyalite Reservoir alone is not indicative of what is available to the City at any given time, but
due to the City’s reliance on Hyalite Reservoir as a source of water to support irrigation demands during
summer months, the reservoir level serves as a key general indicator of drought conditions in a given year.
As a result, Hyalite Reservoir volume is given a relatively significant weighting factor in the City’s drought
monitoring tool during summer months.
20
The historical storage volume in Hyalite Reservoir from 1951-2015 is shown in Figure 2-10 and cycles
through the year, typically reaching maximum volume in late May or June. The reservoir is drawn
down to its winter pool level in mid to late fall. In order to accurately assess a drought condition at
any given time, the storage volume in Hyalite Reservoir must be normalized to the time of year. This
is accomplished using a cumulative frequency analysis method referred to as “frequency of
exceedance,” or the amount of time expressed as a percentage that the reservoir has historically held
more water on the same date as the current measurement. This is the method that will be used to
evaluate how likely low reservoir levels will be in the future based on how often low reservoir levels
occurred in the past. For example, an exceedance value of 90% for Hyalite storage volume indicates
that 90% of historical storage volumes on that same date have been greater than the current
measurement and the current measurement has been exceeded by 10% of the historical data.
Aggregate reservoir contents in Hyalite usually peak in June following spring snowmelt. Since the dam
was raised in 1991-92, this metric was divided into pre-and post-1992 periods to reflect the increased
storage subsequent to the dam raise.
Figure 2-10: Hyalite/Middle Creek Reservoir Historic Minimum and Maximum Storage Volumes (1951 – 2015)
2.2.1.2 Area Streamflow
Bozeman is located near multiple streams and creeks including Lyman Creek, Sourdough Creek, Hyalite
Creek, the East Gallatin River and Gallatin River, situated at the headwaters of the Gallatin River
Watershed shown in Figure 2-11. These streams are also indicators of local drought conditions. However,
21
due to the lack of data on key streams, overall streamflow is not weighted as heavily as reservoir storage
data in the City’s drought monitoring tool during summer months. As the period of record increases, these
parameters should be incorporated into the Plan.
More specifically, Sourdough (Bozeman) Creek flow would likely offer the most direct assessment of the
status of water availability for the City. Unfortunately, streamflow on Sourdough has not historically been
monitored. A new gage has been installed on Sourdough, but without a robust historical record, it is not
possible to evaluate and compare current water status accurately with historical flows. As future data are
collected, the information will become increasingly valuable.
The same is true of the East Gallatin River, which drains the portion of the Gallatin watershed that includes
Lyman Creek. The Gallatin River streamflow monitored at a USGS gaging station at Logan is used as it
offers a robust historical data set which provides valuable information on drought conditions throughout
the watershed and is well suited to long-term drought monitoring. However, the usefulness of the Logan
gage data is somewhat minimized as the City of Bozeman’s source watersheds comprise only approximately
one quarter of the total Gallatin watershed flows that are measured at the Logan gage and there are
numerous agricultural diversions upstream of Logan, impacting flows measured at the Logan gage.
Figure 2-11: Gallatin River Watershed
Hyalite Creek itself is also a water source for the City. Flow in the creek is monitored at a USGS gaging
station with a reliable historical data set downstream of the dam. However, due to the influence of dam
22
releases to the flows in Hyalite Creek downstream of the dam, Hyalite Creek flow is not included in the
monitoring plan. The East and West Forks of Hyalite Creek, which flow directly into Hyalite Reservoir, are
monitored by the USGS and also have a reliable historical data set. These data have a direct impact on the
volume of water in Hyalite Reservoir throughout the year and are therefore important indices included in
the drought monitoring tool.
2.2.1.3 Snow Water Equivalents (SNOTEL)
The City’s water supply is directly influenced by snowpack; therefore, the inclusion of snowpack data is also
critical to include in the drought monitoring tool. Snow-water equivalence (SWE) provides the most
accurate indication of water availability in snowpack. A map showing the general locations of the SNOTEL
sites is provided in Figure 2-12. One SNOTEL site in the Bridger Range and one site from the Gallatin Range
in the Hyalite watershed were selected for inclusion in the monitoring tool.
Figure 2-12: Location of Bozeman Area SNOTELs
23
Snow Water Equivalence data from the Sacajawea SNOTEL shows a very strong correlation with flows from
Lyman Spring and as a result is included in the monitoring tool.17
Snow Water Equivalence data in the Hyalite watershed is monitored using the Shower Falls SNOTEL site,
as this SNOTEL lies above the Hyalite Reservoir and is more indicative of the water that contributes to
reservoir storage.
2.2.1.3 Recommended Future Local Indicators
Due to the limited number of local indicators for monitoring purposes, valuable drought information that
is not currently available could be acquired from additional monitoring devices, including stream gages in
Sourdough Creek and snow-water equivalence sites in the Sourdough Creek and Lyman Watershed. Table
2-1 summarizes recommended additional monitoring parameters that should be considered.
Location / Source Monitoring Situation
Sourdough Watershed SNOTEL site in the Sourdough Watershed
Additional real time stream gages at multiple locations
Lyman Spring SNOTEL site in Lyman Canyon
Table 2-1: Recommended Additional/Future Local Monitoring Locations
2.2.2 U.S. Drought Monitor
The U.S. Drought Monitor (USDM) is a composite index based on measurements of hydrologic, climatic,
and soil conditions and accounts for the importance of snow in the hydrologic cycle of the Bozeman area
via the use of snow water content information, river basin precipitation levels, and the Surface Water
Supply Index.18 The USDM identifies areas of drought and labels them by intensity. D1 is the least intense
level and D4 the most intense. D0 areas are not in drought, but are experiencing abnormally dry conditions
that could turn into drought or are recovering from drought but are not yet back to normal.
The USDM indicates whether primary physical effects are for short-or long-term drought:
S = Short-term, typically less than 6 months (agriculture, grasslands)
L = Long-term, typically more than 6 months (hydrology, ecology)
SL = Area contains both short-and long-term impacts
Due to the combination of various national drought indicators and streamflow data included in the USDM,
the USDM is the only national drought index included in the City’s drought monitoring tool. A summary
of the U.S. Drought Monitor and drought severity categories is included in Table 2-2.
17 SNOTEL site correlation data 2009-2015 on file with City of Bozeman (2016).
18 Additional information about the U.S. Drought Monitor is available at: https://droughtmonitor.unl.edu/ Last visited
April 12, 2022.
24
--
Category
D0
D1
D2
Description
Abnormally
Dry
Moderate
Drought
Severe
Drought
Possible Impacts
Going into drought:
short-term
dryness slowing
planting, growth
of crops or
pastures
Coming out of drought:
Palmer
Drought
Severity
Index
(PDSI)
-1.0 to -
1.9
-2.0 to -
2.9
-3.0 to -
3.9
CPC Soil
Moisture
Model
(Percentile)
21 to 30
11 to 20
6 to 10
USGS
Weekly
Streamflow
(Percentile)
21 to 30
11 to 20
6 to 10
Standardized
Precipitation
Index (SPI)
-0.5 to -0.7
-0.8 to -1.2
-1.3 to -1.5
Objective
Drought
Indicator
Blends
(Percentile)
21 to 30
11 to 20
6 to 10
some lingering water
deficits
pastures or crops not
fully recovered
Some damage to crops,
pastures
Streams, reservoirs, or
wells low, some water
shortages developing or
imminent
Voluntary water-use
restrictions requested
Crop or pasture losses
likely
Water shortages
common
Water restrictions
imposed
D3 Extreme
Drought
Major crop/pasture
losses
Widespread water
shortages or
restrictions
-4.0 to -
4.9 3 to 5 3 to 5 -1.6 to -1.9 3 to 5
D4
Exceptional
Drought
Exceptional and
widespread
crop/pasture losses
Shortages of water in
reservoirs, streams, and
wells creating water
emergencies
5.0 or
less 0 to 2 0 to 2 2.0 or less 0 to 2
Table 2-2: Drought Severity Categories and Inputs for the U.S. Drought Monitor
25
As drought events and impacts of climate change continue to threaten water supply availability across the
West, additional drought indices have become available to better monitor national and regional drought
events and their local impacts. The City is currently underway with making improvements to its drought
monitoring protocol through incorporation of additional data into the drought monitoring tool. This
includes:
Local Hydrologic Indicators
o Lick Creek SNOTEL to capture mid-elevation snow water equivalence in the Hyalite
watershed,
o USGS Stream Gage 06043500 (Gallatin River near Gallatin Gateway) to capture Gallatin
River flows upstream of agricultural diversions in the Gallatin Valley,
o AgriMet station “BOZM” modified Penman ET data to capture evapotranspiration trends
which directly correlate to water demands in Bozeman during summer months,
National and Regional Drought Indices
o Evaporative Demand Drought Index (EDDI), which can offer early warning of hydrologic
drought and fire-weather risk by providing near-real-time information on the emergence or
persistence of anomalous evaporative demand in a region,
o Standardized Precipitation Evaporative Index (SPEI), an extension of the Standardized
Precipitation Index (SPI), which is designed to take into account both precipitation and
potential evapotranspiration in determining drought; and
o Standardized Snow Water Equivalent (SWE), for the Gallatin and Bridger Mountain areas.
2.3 Drought Monitoring and Response
Tables 2-3 and 2-4 illustrate the relationship between the local and national drought severity monitoring
indicators currently represented in the drought monitoring tool and the corresponding drought response
stage. The response stages in the table are illustrative only as there are no hard-and-fast relationship
between the indicators and the appropriate drought response stages. These tables are guidelines only, as
the City Manager may evaluate many factors in addition to those represented in the drought monitoring
tool when making decisions regarding drought response decisions. This may include but is not limited to
area snowpack, soil moisture, streamflow, precipitation, evapotranspiration, water rights, reservoir levels,
weather forecasts, and water demand compared to normal use and weather-adjusted expected use.
Actual summer and winter weighting factors and percent exceedance values for data included in the
drought monitoring tool are shown in Tables 2-3 and 2-4 and are subject to change.
26
-
-
Indicators
October -June
Weighting
Factor
Response Stages
Percent Exceedance
Stage 1
Drought
Watch
Stage 2
Drought
Advisory
Stage 3
Drought
Warning
Stage 4
Drought
Emergency
Hyalite Reservoir Storage 10% 70% 85% 90% 95%
Stream Flow 25%
Hyalite Creek
East Fork 25% 80% 92% 95% 98%
Hyalite Creek
West Fork 25% 80% 92% 95% 98%
Gallatin River
At Logan 50% 88% 92% 95% 97%
Snow Water Equivalence 50%
Shower Falls
SNOTEL 80% 70% 80% 90% 95%
Sacajawea
SNOTEL 20% 70% 80% 90% 95%
U.S. Drought Monitor 15% D1 D2 D3 D4
Table 2-3: October-June Indicators for Monitoring in Relation to Response Stages
Indicators
July –
September
Weighting
Factor
Response Stages
Percent Exceedance
Stage 1
Drought
Watch
Stage 2
Drought
Advisory
Stage 3
Drought
Warning
Stage 4
Drought
Emergency
Hyalite Reservoir Storage 40% 70% 85% 90% 95%
Stream Flow 35%
Hyalite Creek
East Fork 25% 80% 92% 95% 98%
Hyalite Creek
West Fork 25% 80% 92% 95% 98%
Gallatin River
At Logan 50% 88% 92% 95% 97%
Snow Water Equivalence 0%
Shower Falls
SNOTEL 0% 0% 0% 0% 0%
Sacajawea
SNOTEL 0% 0% 0% 0% 0%
U.S. Drought Monitor 25% D1 D2 D3 D4
Table 2-4: July-September Drought Indicators for Monitoring in Relation to Response Stages
27
2.4 Uncertainty Associated with Forecasts
Just like other weather phenomena, forecasting a drought and knowing with certainty if one exists can be
difficult. When a dry year occurs, for example, it is unknown whether it is the first year of a three-, five-
or 10-year drought, or if it is merely a dry year somewhere in a series of average-to-wet years. Even though
droughts cannot always be predicted, the City of Bozeman should continue to advise customers of the
latest water supply information so they can consider it in their own planning.
3 DROUGHT RESPONSE ACTIONS
As reservoir levels, stream flows and snowpack decrease, efforts to add water supplies and reduce water
demand should increase. The City of Bozeman’s response actions should consist of the following
components:
Utilization of the drought monitoring tool to help facilitate data driven decision making
regarding drought stage declaration;
Drought declaration, including the implementation of pursuant:
o Response measures that residents will be required to adhere to,
o Drought surcharges; and
Implementation of a robust communications campaign which should increase in scope and
frequency pursuant to drought stage.
This Plan delineates four stages of drought severity. Each stage is based on local and national indicators
included in the drought monitoring tool described in Section 2 , as well as area snowpack, soil moisture,
streamflow, precipitation, evapotranspiration, water rights, reservoir levels, weather forecasts, and water
demand compared to normal use and weather-adjusted expected use.
Progressively more stringent response measures are recommended when moving from one drought stage
to the next. Some drought response measures, particularly those designated for mild episodes of drought,
require minimal customer effort. However, as drought intensifies, measures can become increasingly
restrictive, are associated with increasing costs due to the implementation of drought surcharges, and are
sometimes intrusive.
The recommended response measures associated with each stage of drought are meant to ensure
adequate water supplies for essential uses and are summarized as follows:
Stage 1 ─ Drought Watch asks for increased communication on dry conditions;
Stage 2 – Drought Advisory implements mandatory watering restrictions;
Stage 3 – Drought Warning prohibits lawn watering; and
Stage 4 – Drought Emergency rations water supplies for essential uses.
At the onset of drought, an interdivisional team of select City staff from the Drought Management Team
will increase drought monitoring procedures in order to advise the City Manager on drought declaration
28
and response. To activate the response component of this Plan, the City Manager declares a drought stage
and corresponding response measures, including the implementation of pursuant drought surcharge rates.
Select staff from the Drought Management Team should monitor drought conditions and evaluate the
effectiveness of the drought response measures implemented during each stage. Because every drought
is different, the City Manager may refine drought response actions based on actual conditions.
Stage 2, Stage 3 and Stage 4 droughts involve mandatory water use restrictions which are authorized by
the Bozeman Municipal Code (BMC), described further in Section 5 below. The declaration process is
outlined in detail in Section 3.3.
The declaration of a drought should be followed by a robust communications campaign which may
increase in scope and frequency pursuant to drought stage.
3.1 Increasing Water Supply
In addition to managing water use during a drought, the City may try to increase its supplies by gaining
access to other temporary water sources.19 Each supply alternative presents unique intergovernmental,
legal and technical issues, and each will depend on the current conditions.20
3.2 Reducing Water Use
The City’s primary response to drought is to reduce customer water demand so that existing supplies will
be available for the most essential uses for the duration of the drought. A variety of actions, rather than
one single approach, is generally more effective at creating an overall atmosphere that promotes water
use reductions.
The actions discussed in the sections that follow are based on drought severity indicators and include
monitoring and evaluation, restrictions, water use education and enforcement, and drought rates.
Generally speaking, restricting the number of days and times allowed for watering landscapes or providing
a maximum water allowance can be effective methods for reducing water use. Other methods, such as
implementing drought rates and public information efforts, complement those watering restrictions.
Other restrictions may not substantially reduce water use but may eliminate discretionary uses of water
or heighten public awareness of drought severity.
3.3 Monitoring, Evaluation and Declaration
When drought conditions emerge, monitoring and evaluation activities should be intensified. The
19 Detailed information about current and future plans to increase water supplies is set forth in the Integrated Water
Resources Plan available at:
https://weblink.bozeman.net/WebLink/DocView.aspx?id=95444&dbid=0&repo=BOZEMAN&searchid=f0a91343-923b-
4846-b47d-dbf547c5a123 , last visited: March 21, 2022; See
alsohttps://www.bozeman.net/departments/utilities/water-conservation, last visited: April 12, 2022.
20 Id.
29
monitoring and evaluation program will track information described in Section 2, which includes but is not
limited to snowpack, soil moisture, streamflow, precipitation, water rights, reservoir levels, weather
forecasts, and water demand compared to normal use and weather-adjusted expected use. Together, this
information will facilitate data-driven decision making. The water reduction goals associated with each
drought stage are based upon what is needed in order to preserve economic vitality of the community
while also preserving public health and safety. If water reduction goals are not being met, the City may
increase public outreach and/or implement additional drought response measures.
The four stages of drought outlined in this Section will be utilized for the purposes of assessing,
communicating, and responding to drought conditions. The drought stages will increase with worsening
drought conditions and reduce progressively as conditions improve.
Drought events are eminent, unpredictable, and can be severe in nature. Declaring a drought immediately
upon recognition of drought conditions is necessary in order to ensure adequate water supplies for
essential uses and responsible management of the water utility as a whole. The procedure for utilization
of the drought monitoring tool and drought declaration process is included below, and is intended to
facilitate immediate action during times of shortage.
1. The drought monitoring tool should be updated no less than monthly during non-drought or
Drought Watch stages, and no less than weekly during Drought Advisory, Warning, and
Emergency stages. City staff will update the City Manager as to current drought conditions as
needed.
2. The City Manager will decide whether or not to enact a drought declaration based on staff
recommendations, the drought monitoring tool, and other information tracked as part of the
monitoring and evaluation program. This declaration will include the drought stage and
corresponding response measures, which will generally be pursuant to response measures
outlined in this Plan.
3. Upon enacting a drought declaration, the City Manager will notify the City Commission of the
declared drought stage and corresponding response measures.
4. City staff will present an update on drought conditions to the City Commission during a public
meeting as soon as possible after the declaration.
5. The City Manager will also enact changes in drought stages (increasing or rescinding stage
declarations), as well as declaring an end to the drought, based on staff recommendations, the
drought monitoring tool, and other information tracked as part of the monitoring and evaluation
program.
6. The City Manager will notify the City Commission upon increasing, decreasing, or rescinding a
drought stage declaration.
7. The City Commission may request a presentation on changing drought conditions from City staff,
which should be held at a public meeting as soon as possible after the new drought stage
declaration has been enacted, or at the end of the drought.
8. A drought communications campaign may follow any drought declaration, stage increase, the
30
rescinding of a declared drought stage, or the end of the declared drought. The communication
campaign should increase in scope and frequency pursuant to drought stage severity.
3.4 Water Use Restrictions
Once a drought stage and corresponding response measures have been declared, residents may be
required to reduce water use. The goal of these drought response measures is to maintain the health,
safety and economic vitality of the community to the greatest extent possible in the face of water shortage.
The following principles guide the implementation of water use restrictions during a drought:
Implement extensive public information and media relations programs.
Inform customers about conditions and actions they can take to reduce water use.
Have open, clear and consistent messaging and communication.
Maintain the trust of customers and stakeholders.
Minimize adverse financial effects.
Be respectful of water-based businesses that will be financially affected by restrictions.
Engage in ongoing dialogue with the landscaping industry to obtain input and to allow these
businesses to plan for future months.
Avoid irretrievable loss of natural resources.
Allow for watering of trees if possible.
Avoid damaging perennial landscaping if possible.
Tailor watering restrictions to known landscape needs as much as possible.
Restrict less essential uses before essential uses.
Curtail outdoor water use (except for trees and shrubs and potentially urban gardens) before
restricting domestic indoor use.
Eliminate water waste.
Affect individuals or small groups before affecting large groups or the community as a whole,
allowing as much public activity as possible to be unaffected.
Consider a maximum allowable water allowance program for playing fields or other
high-traffic landscapes in order to prevent permanent damage to these areas, when
appropriate.
Preserve community pools before residential pools.
3.5 Water Use Education
The City should develop a water use education and enforcement program based on the elements of the
Plan to educate customers about efficient water use, to enforce water waste rules and drought
31
restrictions, and to save water. During a drought, the Water Conservation Division may coordinate with
the Water and Sewer Operations Division and the Bozeman Police Department to monitor Bozeman’s
water service area for customers who are not complying with drought response measures.
The goal of the program is to educate and inform customers, not to merely penalize violators. City staff
should distribute educational materials, and initiate targeted outreach to help customers reduce their
water use and answer questions about the drought. Customers will be able to report water waste through
the Water Conservation Division’s phone number and website.
3.5.1 Communications Campaign
An on-going communications campaign should be a significant component of the City of Bozeman’s
Drought Management Plan and closely coordinated with the Water Conservation Division’s education and
outreach initiatives. When appropriate, these programs may be integrated into a single program by the
Water Conservation Division. These initiatives promote the value of water, the need to conserve and ways
in which to achieve water savings under normal climatic conditions and during drought events.
During non-drought years, the communication campaign should provide general information on drought
and drought preparedness. During a drought event, the campaign should increase the scope and specificity
of messaging to the public and include information pertaining to drought stages and associated responses.
The objectives of the communication campaign are to:
Provide clear and consistent drought information to City of Bozeman watercustomers;
Adjust the scope and frequency of messaging in accordance with drought stage and restrictions;
and
Coordinate implementation of the campaign with Gallatin County, nearby municipalities and
other affected communities to provide consistent drought messaging.
The Water Conservation Division will be responsible for developing communications campaigns identifying
specific drought messaging delivered to targeted audiences before, during and after a drought event.
Specific communications plans may depend upon the current and forecasted water supply and weather
conditions present at the time. Outreach will primarily consist of website communications, social media,
newspapers, bill inserts, and mailers. During a drought, communications may be expanded to television,
radio, newspapers, emails, public meetings, presentations at community events and school programs.
3.6 Drought Management for Master Meter Customers
The City of Bozeman’s master meter customers (e.g. MSU) are governed by the City’s drought management
guidelines. Master meter customers can make and enforce their own plans as long as they are consistent
with drought management guidelines set forth in this Plan. Master meter customers should also assist the
City in enforcing the Drought Management Plan.
It is recommended that master meter customers have a water use education and enforcement program
32
during drought response to ensure customers comply with operating rules. Master meter customers can
choose to opt in to the City of Bozeman’s water use education and enforcement program or create their
own program. If opting in to the City’s program, City staff should work closely with the customer to
facilitate proper communication with customers.
If a master meter customer chooses to create its own water use education and enforcement program, the
following program elements are recommended to be considered for inclusion:
Creating a mechanism to educate customers about drought restrictions, such as online or printed
materials and direct customer interaction.
Creating a reporting tool, such as a phone number or email, that allows customers to report
violations of water waste rules.
Monitoring for violations of water waste rules.
Tracking customer violations.
3.7 Drought Surcharge Rates
Drought surcharge rates were adopted by City Commission and went into effect in September of 2019 and
were updated September 2021. Drought surcharges are implemented during a declared drought event
and vary based on water customer class. Drought surcharges are designed to encourage conservation and
supplement lost revenue from watering restrictions through increased rates in the event of a drought.
Drought rates are different from regular water-use rate structures in that they are temporary in nature
(effective only during a declared drought) and are required across all customer classes during a declared
drought.
Drought surcharge rate percentages are tied directly to the severity of the declared drought stage. The
following guiding principles were key considerations in the development and implementation of drought
surcharge rates:
Drought surcharges are aligned with water availability – when water supplies are scarce, the true
cost of water for non-essential usage, such as outdoor watering, increases.
Customer class-based volumetric drought surcharges are tied to the varying water reduction
abilities of each user class.
Drought surcharge rates were developed to ensure that the City has enough water to meet the
needs of essential uses.
Drought surcharges in a stage 1 and 2 declared drought are intended to provide revenue neutrality
for the utility service as well as water customers.
Drought surcharges are higher during drought stages 3 and 4 to discourage outdoor watering when
lawn watering bans are in place, as well as provide adequate revenue for the water utility.
Effective drought surcharge rates as of April 2022 are included in Table 3-1.
33
Drought Rate Customer Class Category Stage 1 Stage 2 Stage 3 Stage 4
Single Family and Low Income
Residential
Drought surcharges are subject to change based on ongoing evaluations of water
use patterns in Bozeman. Changes may be adopted by Commission Resolution.
Tier 1 (0-6 HCF*) 0.0% 10.0% 20.0% 25.0%
Tier 2 (6-25 HCF*) 21.9% 39.6% 100% 200%
Tier 3 (25-55 HCF*) 21.9% 39.4% 100% 200%
Tier 4 (55+ HCF*) 21.8% 39.4% 100% 200%
Multi-Family Residential 15.6% 23.8% 23.8% 25.0%
Government 15.6% 25.0% 25.0% 25.0%
MSU 15.6% 20.9% 20.9% 25.0%
Commercial 15.6% 25.0% 25.0% 25.0%
Industrial 11.1% 11.1% 11.1% 11.1%
*1 HCF = 748 gallons
Table 3-1: Drought Surcharge Rates by Customer Class
3.7.1 Drought Reserve Rate
After adoption by the City Commission, drought reserve rates went into effect in September 2019. The
drought reserve is separate from, but used in conjunction with, drought surcharge rates to continue to
provide quality service when revenues decrease during a drought. A monthly charge of $0.08/HCF21 is
applied to every customer’s water bill regardless of customer class or drought declaration status. The
drought reserve was established with the following intentions:
• Minimize financial impacts of drought surcharge severity during a drought event;
• Work alongside the drought surcharge rates to continue to provide quality service when revenues
decrease during a declared drought event; and
• Create a revenue reserve to help the City avoid extreme rate increases during drought events.
3.8 Drought Stages
Drought stages are determined, in part, by the outputs from the drought monitoring tool. The most
important indicator during summer months is storage levels in Hyalite Reservoir, and during winter months
is snow water equivalence. Stages are determined using the exceedance method. The exceedance value
corresponds to the amount of time (expressed as a percentage) that the identified water supply source
(reservoir, stream, snowpack) held more water on the same date as the current measurement.
21 Effective drought reserve rate as of April 2022.
34
--
If the reduction targets for each stage are met, drought declarations of increasing severity may be delayed
or avoided.
The water reduction targets model industry best practices and reflect reductions achieved in similarly
situated municipalities during drought events. If water-reduction goals are not being met, the City Manager
may increase public outreach and/or the level of drought response.
Drought Stage
Stage 1:
Drought
Watch
Stage 2:
Drought
Advisory
Stage 3:
Drought
Warning
Stage 4:
Drought
Emergency
System-wide
Water Reduction
Targets
10% 20% 30% 40%
Table 3-2: Distribution System-wide Water Reduction Targets During Declared Drought Stages
3.8.1 Stage 1 -Drought Watch: Customer Outreach
Description:
A Drought Watch declaration should increase communication to customers to alert them that water
supplies are below average and Stage 1 drought surcharges are in effect. Messaging about current drought
conditions should increase to inform customers that continued dry weather could lead to mandatory
watering restrictions. A Drought Watch will require a formal declaration from the City Manager. Table 3-3
outlines Stage 1 drought indicator weighting factors and exceedance percentages. The exceedance
method looks at the amount of time (expressed as a percentage) that the identified source held more
water, had higher flows or snow water equivalent on the same date as the current measurement.
Indicator Indicator Detail
Weighting
Factor:
Winter
(Oct June)
Weighting
Factor:
Summer
(July Sept)
Percent
Exceedance
for a Stage 1
Drought
Hyalite Reservoir Volume N/A 10% 40% 70%
East and West Fork Hyalite Creek 80%
Streamflow
Gallatin River at Logan
25% 35%
88%
Shower Falls SNOTEL
50% 0% 70% Snow Water Equivalence
Sacajawea SNOTEL
U.S. Drought Monitor N/A 15% 25% N/A
Table 3-3: Drought Tool Indicators, Seasonal Weighting Factors, and Percent Exceedance for a Stage 1 Drought
35
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Use Reduction Target: 10 % reduction of current use. This is a system-wide target, and individual or
customer group-specific response measures should be implemented.
Response Measures:
Increase communication and outreach to customers and stakeholders to explain the City is beginning to
see indicators of drought.
Encourage customers to use water efficiently and provide suggestions for reducing water use
in order to reduce the risk of progression to mandatory restrictions.
Notify customers and prepare for the possibility of mandatory watering restrictions.
Enhance the water use education program.
Notify customers of the implementation of Stage 1 drought surcharges.
3.8.2 Stage 2 -Drought Advisory: Mandatory WateringRestrictions
Description:
A Stage 2 drought declaration imposes mandatory watering restrictions, Stage 2 drought surcharge rates,
and requires effort on the part of customers. Circumstances warrant possible adverse impacts on water-
dependent businesses involved in outdoor water use. Table 3-4 outlines Stage 2 drought indicator
weighting factors and exceedance percentages. The exceedance method looks at the amount of time
(expressed as a percentage) that the identified source held more water, had higher flows or snow water
equivalent on the same date as the current measurement.
Indicator Indicator Detail
Weighting
Factor:
Winter
(Oct June)
Weighting
Factor:
Summer
(July Sept)
Percent
Exceedance
for a Stage 2
Drought
Hyalite Reservoir Volume N/A 10% 40% 85%
East and West Fork Hyalite Creek
25% 35% 92% Streamflow
Gallatin River at Logan
Shower Falls SNOTEL
50% 0% 80% Snow Water Equivalence
Sacajawea SNOTEL
U.S. Drought Monitor N/A 15% 25% N/A
Table 3-4: Drought Tool Indicators, Seasonal Weighting Factors, and Percent Exceedance for a Stage 2 Drought
Use Reduction Target: 20% reduction of current use. This is a system-wide target, and individual or
customer group-specific response measures should be implemented.
36
Response Measures: Spray Irrigation Watering Restrictions recommend for Stage 2 response
A. Outdoor watering should be limited to two days per week in accordance with the following
schedule:
Single residential properties with odd-numbered addresses: Saturday, Wednesday
Single residential properties with even-numbered addresses: Sunday, Thursday
All others (multi-unit, HOAs, commercial, industrial, government): Tuesday, Friday.
B. The City Manager may by formal action establish a limit on the number of minutes of irrigation that
each area of turf may receive or a maximum total amount of time during which irrigation at a
premises may occur.
C. This subsection may not apply to athletic or playing fields, and tees and greens at golf courses,
heavily used by the community so long as irrigation of such landscapes is accomplished without
waste of water.
D. Watering prohibited between the hours of 10:00 a.m. and 8:00 p.m., except when limited watering
is essential to preserve turf subject to heavy public use.
E. Watering prohibited on Mondays, except for irrigators operating under special exemptions as
approved by the City Manager.
F. Restaurants permitted to serve water only upon request.
G. Hotels/motels and other lodging establishments must comply with the City of Bozeman’s signage
program, providing guests with the option to forgo having towels and linens laundered daily.
H. Permissible watering should be conducted without any water waste, pursuant to B.M.C. Section
40.02.1310.
Strategic Water Reserve:
Pursuant to the future adoption of a strategic water reserve by the Commission, the Commission may
make water from the strategic water reserve available for use during a Stage 2 drought. Such action could
reduce the severity of Stage 2 restrictions, or be used to delay or eliminate a Stage 3 drought response.
3.8.3 Stage 3 -Drought Warning: Ban on Targeted Water Uses
Description:
A Stage 3 drought imposes mandatory watering restrictions and Stage 3 drought surcharge rates on City
of Bozeman water customers. Stage 3 drought restrictions are severe and will likely result in damage to or
loss of landscapes. Circumstances warrant possible adverse impacts on water-dependent businesses
involved in outdoor water use. Table 3-5 outlines Stage 3 drought indicator weighting factors and
exceedance percentages. The exceedance method looks at the amount of time (expressed as a percentage)
that the identified source held more water, had higher flows or snow water equivalent on the same date
as the current measurement.
37
--
Indicator Indicator Detail
Weighting
Factor:
Winter
(Oct June)
Weighting
Factor:
Summer
(July Sept)
Percent
Exceedance
for a Stage 3
Drought
Hyalite Reservoir Volume N/A 10% 40% 90%
East and West Fork Hyalite Creek
25% 35% 95% Streamflow
Gallatin River at Logan
Shower Falls SNOTEL
50% 0% 90% Snow Water Equivalence
Sacajawea SNOTEL
U.S. Drought Monitor N/A 15% 25% N/A
Table 3-5: Drought Tool Indicators, Seasonal Weighting Factors, and Percent Exceedance for a Stage 3 Drought
Use Reduction Target:
30% reduction of current use. This is a system-wide target, and individual or customer group-specific
response measures should be implemented.
Response Measures:
A. Recommended watering restrictions for a Stage 3 drought response:
Ban on all lawn watering.
Existing trees and shrubs and flower and vegetable gardens may be watered with hand held
hose or low-volume, non-spray devices.
Community gardens may be watered on assigned watering days.
Athletic and playing fields may irrigate pursuant to a water schedule.
Golf courses may irrigate tees and greens only.
Ban on water fountains and filling private swimming pools.
B. The City Manager may by formal action establish a limit on the number of minutes of irrigation that
each area of turf may receive or a maximum total amount of time during which irrigation at a
premises may occur.
C. This subsection may not apply to athletic or playing fields, and tees and greens at golf courses,
heavily used by the community, however these landscapes may be subject to a mandatory
schedule or water budget to be developed in coordination with the Water Conservation Division
and based on current conditions at the time of the declaration.
D. Watering prohibited between the hours of 10:00 a.m. and 8:00 p.m., except when limited watering
is essential to preserve turf subject to heavy public use.
E. Watering prohibited on Mondays, except for irrigators operating under special exemptions as
approved by the City Manager.
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F. Restaurants permitted to serve water only upon request.
G. Hotels/motels and other lodging establishments must comply with the City of Bozeman’s signage
program, providing guests with the option to forgo having towels and linens laundered daily.
H. Permissible watering shall be conducted without any water waste, pursuant to B.M.C. Section
40.02.1310.
Strategic Water Reserve:
Pursuant to the future adoption of a strategic water reserve by the Commission, the Commission may
make water from the strategic water reserve available for use during a Stage 3 drought. Such action could
reduce the severity of Stage 3 restrictions, or it could be used to delay or eliminate a Stage 4 drought
response.
3.8.4 Stage 4 -Drought Emergency: Rationing
Description:
A Stage 4 drought may activate a rationing program for City of Bozeman water customers. Conditions that
would lead to a Stage 4 drought are highly unlikely. However, if conditions warrant, the City may
implement a rationing program for an indefinite period of time to ensure, to the extent possible, that there
is adequate water for essential uses. Stage 4 drought surcharge rates will be in effect. No outdoor watering
will be allowed. Stage 4 drought restrictions will damage the quality of life in the City of Bozeman’s service
area, including the long-term loss of landscapes. Table 3-6 outlines Stage 4 drought indicator weighting
factors and exceedance percentages. The exceedance method looks at the amount of time (expressed as
a percentage) that the identified source held more water, had higher flows or snow water equivalent on
the same date as the current measurement.
Indicator Indicator Detail
Weighting
Factor:
Winter
(Oct June)
Weighting
Factor:
Summer
(July Sept)
Percent
Exceedance
for a Stage 4
Drought
Hyalite Reservoir Volume N/A 10% 40% 95%
East and West Fork Hyalite Creek 98%
Streamflow
Gallatin River at Logan
25% 35%
97%
Shower Falls SNOTEL
50% 0% 95% Snow Water Equivalence
Sacajawea SNOTEL
U.S. Drought Monitor N/A 15% 25% N/A
Table 3-6: Drought Tool Indicators, Seasonal Weighting Factors, and Percent Exceedance for a Stage 4 Drought
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4
Use Reduction Target: 40% reduction of current use. This is a system-wide target, and individual or customer
group-specific response measures should be implemented.
Response Measures:
Stage 4 response measures will aim to ensure water is available for essential uses and may include a water
rationing program for City water customers.
Strategic Water Reserve:
Pursuant to the future adoption of a strategic water reserve by the Commission, due to the severity of the
situation, the Commission will likely make any water remaining in the strategic water reserve available for
essential uses during a Stage 4 drought.
DROUGHT RESPONSE PROGRAM MEASURES
The drought response program measure Tables 4-1 – 4-4 below are meant to serve as a guide to water
uses under various levels of drought severity. Actual water use limitations associated with a drought
declaration will be adopted by administrative order of the City Manager. The City reserves the right to
modify these program measures as needed to meet changing water supply conditions.
40
Outdoor Watering and New Vegetation Installation Recommended Response Measures
Water Use
Element
Turf grass
watering
New
installation of
seed and/or
sod
Watering trees, shrubs,
perennials
New installations
of trees, shrubs,
perennials
Watering vegetables
and community
gardens
Watering
athletic and
playing fields
Watering
golf
courses Drought Stage Declared Stage 1
Customer
Outreach
No restrictions. Permitted. Water efficiently with
no water waste. Permitted. No restrictions.
Water
efficiently
with no water
waste.
Water
efficiently
with no
water
waste.
Stage 2
Mandatory
Restrictions
2 days/week
mandatory
watering schedule
based on
customer class
and/or address.
Permitted with
exemption.
May be watered by
hand-held hose or low-
volume non-spray
irrigation on any day not
between 10a.m. -8p.m.
Not
permitted/limited
installations from
June-August.
May be watered by
hand-held hose or
low-volume non-
spray irrigation on
any day not between
10a.m. -8p.m.
Irrigated per
mandatory
scheduling or
water budget
restrictions.
Irrigated
per
mandatory
scheduling
or water
budget
restrictions.
Stage 3
Ban on Lawn
Watering No watering
permitted. Not permitted.
May be watered by
hand-held hose or low-
volume non-spray
irrigation no more than
once/week on
scheduled day and not
between 10a.m. -8p.m.
Not permitted.
May be watered by
hand-held hose or
low-volume non-
spray irrigation on
assigned watering
day and not between
10a.m. -8p.m.
Trees and
greens
only.
Stage 4
Rationing
No watering
permitted/may be
limited to 1 assigned
day/month.
No watering
permitted.
No watering
permitted.
No
watering
permitted.
Table 4-1: Outdoor Watering and New Vegetation Installation Recommended Response Measures
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Water Feature Recommended Response Measures
Water Use Element Swimming pools Other water features (fountains, splash pads, ponds and waterfalls) Drought Stage Declared Stage 1
Customer Outreach
No restrictions.
No restrictions.
Stage 2
Mandatory Restrictions
All ornamental fountains on City-owned property and in City owned
buildings and splash parks are turned off.
Stage 3
Ban on Lawn Watering
Single-family residential pools and spas shall not be filled
or refilled. Operation of other pools and spas will be
permitted.
All ornamental fountains and splash parks are turned off.
Stage 4
Rationing No filling of any pools or spas. All ornamental fountains, outdoor drinking fountains, and splash
parks are to be turned off.
Table 4-2: Water Feature Recommended Response Measures
Washing Events Recommended Response Measures
Water Use
Element Car-washing at home Commercial
car washes Fleet vehicle washing Street cleaning Driveway and sidewalk washing Drought Stage Declared Stage 1
Customer
Outreach Permitted with bucket
or hand-held hose with
shutoff nozzle.
No
restrictions.
No restrictions.
No restrictions.
Use dry clean-up methods prior to
washing.
Stage 2
Mandatory
Restrictions
Washing is limited to once
every 2 weeks.
Use dry clean-up methods prior to
washing. High efficiency equipment
required.
Stage 3
Ban on Lawn
Watering Not permitted. Must
use commercial car
wash.
Limited to 1 time per month
only for health and safety. Washing and spraying on impervious
surfaces (driveways and sidewalks) is
prohibited. Stage 4
Rationing
Not permitted unless for
public health and safety
reasons.
Permitted for extreme
health and safety issues
only.
Table 4-3: Washing Events Recommended Response Measures
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Commercial-Institutional Processes Recommended Response Measures
Water Use Element Restaurants Lodging Construction water Hydrants Drought Stage Declared Stage 1
Customer Outreach
No
restrictions. No restrictions. No restrictions. No restrictions.
Stage 2
Mandatory Restrictions
Water served
only on
request.
Laundry restrictions.
Must comply with City’s
signage program.
Conserve and prevent wasting
of construction water.
Hydrant flushing is prohibited unless
necessary for public safety reasons.
Stage 3
Ban on Lawn Watering Hydrant flushing is prohibited unless
necessary for public safety reasons. Use of all
water for fire training and use of water from
hydrants is not permitted unless necessary
for public safety.
Stage 4
Rationing
Use of all construction water is
prohibited unless necessary for
air quality, public health and
safety reasons.
Table 4-4: Commercial-Institutional Recommended Response Measures
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5 DROUGHT RESPONSE PROGRAM ENFORCEMENT
The authority to enforce the water reduction targets provided in the Plan and City of Bozeman customers’
violations of the response measures is provided for in the Bozeman Municipal Code (BMC). Relevant code
provisions are set forth in their entirety in Appendix D and summarized below.
BMC Section 40.02.1280 states that all provisions addressing outdoor water use restrictions are
applicable to all persons both in and out of the City and regardless of whether any person using
water has a contract for water service with the City.
BMC Section 40.02.1300 establishes that the City Manager is authorized to enact a drought
declaration including the implementation of pursuant response measures and drought
surcharges. This includes the authority to restrict or wholly prohibit the outdoor use of the water
supply.
BMC Section 40.02.1300.H states that whenever drought restrictions are in effect, certain indoor
uses are also not permitted. This includes requiring business establishments which serve
beverages for human consumption to only serve water upon request and that hotels, motels, and
other commercial lodging establishments provide guests with the option to forgo having used
towels and linens laundered daily.
BMC Section 40.02.1310 prohibits the waste of water including but not be limited to permitting
water to escape or run to waste, excessive use, and escape of water through breaks, leaks, or
malfunctions in the plumbing or irrigation system.
Additional drought contingency provisions pertaining to the timing of outdoor watering,
installation of new landscape vegetation, other outdoor water uses, as well as the implementation
of drought surcharge rates are set forth in BMC Section 40.02.1300.
Enforcement provisions for violations of drought response measures are set forth in BMC Sections
40.02.1340 and 40.02.1350. Enforcement provisions include fines and discontinuation of water service.
Violation of the watering restrictions and mandatory drought response measures constitutes a
misdemeanor pursuant to BMC Section 40.02.1350. Upon conviction thereof, the violator shall be fined
an amount not less than $100 and not more than$500.
Violators will be located based on citizen complaints received at 406.582.3220 from 8am to 5pm or via
the City of Bozeman’s (www.bozemanwater.com) Drought Management Webpage. The City should issue
a warning to the customer notifying the water user that there has been a complaint. Individuals with
numerous complaints may receive special attention by the City of Bozeman’s enforcement team.
45
5.1 Drought Management Plan Updates
The Drought Management Plan should be updated regularly for the following reasons:
1. The local and national drought monitoring parameters should be refined over time as new and
improved data become available.
2. The City has recently added monitoring on Sourdough Creek and the East Gallatin River. As these
data sources become more robust, they can be utilized by the City for drought monitoring
purposes.
3. Demand volumes and patterns may change over time.
4. The City’s infrastructure, specifically its raw water supply portfolio and distribution system, may
grow and change over time.
5. Drought surcharge and reserve rates may change over time.
6. Response actions identified in this Plan may be improved upon, or new response actions may be
identified.
It is recommended that the City update the Drought Management Plan at a minimum of every 5 years.
However, if a moderate to severe drought is encountered, and in the process of monitoring and
responding to that drought the City encounters weaknesses or gaps in the Drought Management Plan,
then the Plan should be updated at that time.
Updates to the Plan may necessitate the re-establishment of the Drought Management Team and other
vested stakeholders to provide subject matter expertise.
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APPENDIX A – Drought Management Team
Organization Title/Role Drought Team Function Responsibilities
City of Bozeman Water Conservation Program
Manager Drought Plan coordinator Manage the Drought Team and Drought Plan
City of Bozeman Utilities Director Utilities coordination Direct oversight of Utilities
City of Bozeman Water/Sewer Superintendent Water distribution impacts and
response, lead of City water crews
Coordinate water distribution activities and utilize
crews for monitoring water use during drought
City of Bozeman Senior Water Resources Engineer Water/wastewater infrastructure
and water supply contact Support coordination of Drought Plan
City of Bozeman Parks and Cemetery Superintendent Parks and cemetery irrigation
coordination
Manage parks and recreation water usage and
responses to drought stages
City of Bozeman Chief of Police Law enforcement Enforcement of violations to enacted response
measures
City of Bozeman Fire Chief Fire hazard authority Enactment of burn ban during severe drought
City of Bozeman Water Treatment Plant
Superintendent
Water treatment plant operations
and water supply contact
Monitor and report water supply and demand
information
City of Bozeman Finance Director Drought surcharge coordinator Ensure timely implementation of drought surcharges
as needed
City of Bozeman Associate Planner Planning coordinator Coordinate solutions for restrictions that impact the
development review and approval process
City of Bozeman Communications and Engagement
Manager Communications coordinator Coordinate City communications, ensure consistent
messaging
City of Bozeman Sustainability Program Manager Climate Plan coordination Coordinate with Climate Plan efforts
47
Gallatin County Disaster and Emergency Coordinator Disaster and Emergency Services
Contact and Coordination
Disaster and emergency coordination and drought
communications coordination.
Gallatin County Communications Coordinator Gallatin County drought education
coordination Drought communication and education coordination.
Gallatin County Planning Director Gallatin County Drought Plan
communications coordinator
Coordinate/assist with county-wide drought planning
and response
Gallatin County Local
Water Quality District District Manager Gallatin County water supply
monitoring
Provide county water supply monitoring data and
support
Montana State
University Director of Facility Services MSU drought coordinator Coordinate MSU water use and assist with drought
communication to MSU community
Montana State
University Grounds Manager MSU irrigation coordinator Coordinate MSU irrigation use
Bozeman Public
Schools Director of Facilities BPS drought coordinator Coordinate BPS water use and assist with drought
communication to BPS community
US Forest Service Fire Management Officer Fire management coordinator Fire condition monitoring, planning fire
communications
Dept. of Natural
Resources and
Conservation
Bozeman Regional Manager DNRC coordinator Assist with drought communications and response
and regional water supply coordination
AE2S Project Manager Drought Management Plan point of
contact
Provide short-term, as-needed support and
modifications to the drought monitoring tool
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APPENDIX B -Drought Monitoring Tool and Dashboard Snapshot
49
APPENDIX C -Drought Monitoring Tool Calibration Snapshots
50
51
APPENDIX D – Bozeman Municipal Code Outdoor Water Use Restrictions
and Drought Contingency Response
DIVISION 4. -OUTDOOR WATER USE RESTRICTIONS AND DROUGHT CONTINGENCY RESPONSE
Sec. 40.02.1250. -Findings.
A. A reliable minimum supply of water is essential to the public health, safety and welfare of the people
and the economy of the City of Bozeman.
B. Bozeman is a semi-arid, headwaters community dependent on limited water supplies that are driven by
snowpack and subject to impacts from drought. Drought events, population growth, and impacts of
climate change on water supply yields, make Bozeman highly-susceptible to water supply reliability
challenges.
C. Responsible water management requires active conservation measures not only in times of drought but
at all times.
D. A reliable minimum supply of water is essential to meet current and future water supply needs.
Sec. 40.02.1260. – Purpose and intent
To minimize or avoid the effect and hardship of potential water supply shortages to the greatest extent
possible, this division establishes the means and authority to:
1. Implement the City of Bozeman’s Drought Management Plan;
2. Reduce water consumption long-term through permanent, outdoor water use restrictions, and short-
term through additional water demand mitigation actions;
3. Enable effective water supply reliability planning;
4. Assure reasonable and beneficial use of water;
5. Ensure adequate supplies of water are available for essential uses during times of water shortage; and
6. Prevent waste of water and ensure water use efficiency.
Sec. 40.02.1270. – Definitions.
A. For the purposes of this division only, the following terms, phrases, words, and their derivations shall
have the meaning given herein.
1. “Drought restriction” means a required curtailment of specific water uses enacted due to a drought
declaration.
2. “Essential use” means the use of water necessary for firefighting, health, welfare and safety; water
needed to sustain basic human, aquatic and animal life; and water necessary to satisfy federal, State,
and local laws for the protection of public health, sanitation and safety.
3. “Excessive water use” means use that is not considered reasonable, prudent, or a wise use of water
52
for an authorized purpose.
4. “Landscape” means an area with vegetative groundcover or other natural living plant materials
including but not limited to: grass, turf, trees, ornamental perennials, shrubs, perennial flowers, annual
flowers, food gardens, and surrounding landscape design elements such as rock mulch and wood mulch.
5. “Low volume drip irrigation” means the application of irrigation water at low pressure through a
system of tubing or lateral lines and low volume emitters such as drip, drip lines, and bubblers.
6. “Non-essential use” means the use of water not for essential use, which may be curtailed during
times of shortage without compromising public health, sanitation, welfare and safety.
7. “Outdoor water use” means the use of water, excluding water which has been used indoors and is
being recycled for outdoor use, for:
a. Sprinkling or irrigating gardens, lawns or other outdoor vegetation;
b. Washing motorized and non-motorized vehicles, including but not limited to automobiles, trucks,
vans, buses, motorcycles, boats, bikes and trailers;
c. Washing sidewalks, walkways, driveways, parking areas, outside building walls, patios, alleys or
other outdoor surfaces;
d. Washing any business or industrial equipment machinery;
e. Operating any ornamental fountain or other similar structure not employing a recirculating
system; and
f. Filling swimming pools, wading pools, hot tubs and spas not employing a filter and recirculating
system.
8. “Spray irrigation” means the act of applying water to landscape by sprinklers or spray nozzles that
deliver water to the landscape through the air.
9. “Turf” means grass and the surface layer of earth held together by its roots, including but not limited
to cool season lawn grasses.
10. “Water” means water from the city's water service utility.
11. “Water waste” means the intentional or unintentional excessive use of water; allowing water to be
applied in any manner, rate or quantity such that the runoff from the landscaped area being watered is
allowed to pool or flow across the ground, into any drainage way, or onto any impervious surface; water
that has escaped or run to waste; and the escape of water through defective plumbing, breaks, leaks,
or malfunctions in the plumbing or irrigation system.
12. “Watering window” means the period, timeframe, or continuous hours of the day(s) in which
outdoor watering is permitted.
Sec. 40.02.1280. – Application of division.
A. The provisions of this division or any restriction or prohibition in force shall apply as follows:
1. To all persons using water both in and outside the city, and regardless of whether any person using
water shall have a contract for water service with the city; or
2. To persons contracting for water service at a location who shall be responsible and strictly liable for
all water use at that location.
53
B. This division is intended to ensure an adequate and reliable water supply for essential uses, ensure the
public’s health safety during times of water shortage, and to further the beneficial use and conservation of
water.
Sec. 40.02.1290. – Outdoor water use restrictions.
A. Authority to restrict outdoor use of water. The city manager is authorized and empowered, whenever
the situation demands, to restrict or wholly prohibit outdoor water use of the city’s water service utility.
This includes the power to approve exemptions and relaxations to outdoor water use restrictions. Except
for the restrictions in 40.02.1290.B, any restriction imposed by order of the city manager shall become
effective at midnight immediately following notice posted and available on the city’s website.
B. Outdoor water use restrictions. Notwithstanding the city manager’s authority in 40.02.1290.A, the
following restrictions apply to all property using water from the city’s water utility:
1. Permanent time of day and day of week watering restrictions. Outdoor watering of landscapes
with the use of spray irrigation shall be limited to an assigned three (3) days per week watering
schedule as follows:
a. Properties with even numbered physical addresses: Tuesday, Thursday, and Saturday;
b. Properties with odd numbered physical addresses: Wednesday, Friday, and Sunday; and
c. Public parks, private open spaces, street right-of-ways: Monday, Wednesday, and
Friday.
2. Time of day watering prohibition. The outdoor watering of landscapes with the use of spray
irrigation is prohibited seven (7) days a week between the hours of 10:00am and 8:00pm.
3. Watering window. For the purposes of identifying the allowable watering windows associated
with the allowable watering day and times of day, the watering window begins at 12am and ends
at 10am, and the second watering window begins at 8pm and ends at 11:59pm on the allowable
watering day. The allowable watering day refers to a calendar day (12:00am – 11:59pm).
4. Water waste prohibited. Outdoor water use that results in water escaping or running to waste,
excessive use, and the escape of water through breaks, leaks, or malfunctions in the plumbing or
irrigation system is prohibited.
C. Exemptions to outdoor water use restrictions. The following activities are exempt from the
requirements of 40.02.1290.B:
1. Outdoor watering of trees, drought tolerant ornamental perennials, shrubs, flowers and food
gardens only when watered with the use of a hose equipped with positive shut-off nozzle or
device, hand-held bucket or similar container, slow release watering bag, or landscape irrigation
system that exclusively uses low-volume drip irrigation.
2. Turf establishment. Watering, for the sole purpose of turf establishment, is permitted for up to
45 days upon the installation of new turf from sod or seed.
3. Irrigation system maintenance. Water use associated with irrigation system operation for the
purposes of installation, repair, adjustments, performance assessments, and other related
54
maintenance issues provided that the system is attended to throughout the period of operation.
D. Special circumstances. The city manager may establish standards for the exemption or relaxation of the
restrictions in this division. When reasonable cause exists, the city manager may grant an exemption or
relaxation for special circumstances not described in this division, including but not limited to the use of
new irrigation technology, and preservation of turf subject to heavy public use. The city manager must
maintain a list of approved exemptions and relaxations to requirements in this section.
Sec. 40.02.1300. – Drought contingency response.
A. Authority to enact a drought declaration. The city manager is, upon notification to the city commission,
authorized to order a drought declaration and corresponding water use restrictions. This includes the
power to approve exemptions and relaxations to enacted water use restrictions.
B. Drought restriction and response measure implementation.
1. Response measures must substantially protect the City’s water supply as drought severity
increases or water supply availability decreases, in order to preserve the City’s available water
supply for purposes essential to public health, sanitation, safety, welfare and essential services
including but not limited to police and fire services.
2. A drought declaration may necessitate that the city manager implement additional water use
restrictions not listed in 40.02.1290. These drought restrictions may vary based upon drought
severity and other pertinent circumstances. Any additional water use restriction must consider the
response measures outlined in the city’s Drought Management Plan.
C. Drought surcharge rates.
1. Effective Date. Upon a drought declaration, drought surcharge rates provided for in the
effective water utility rate structure adopted by the city commission shall go into effect pursuant
to the drought stage, customer class, and water rate tier, as applicable.
2. Billing Cycle. Drought surcharge rates shall not go into effect prior to the effective date of the
declared drought, and shall be reflected in utility customer billing statements representing water
usage during the declared drought.
D. Water Superintendent Emergency Authority. Nothing in this division diminishes the authority given to
the water superintendent in 40.02.840 to prohibit or restrict water use during an emergency.
E. Irrigation systems; timing. When drought restrictions are in effect, the city manager may set alternative
watering time and/or duration restrictions for the use of automatic irrigation systems or those which are
equipped with a timing device.
F. Landscaping; seeding; sodding; planting. When drought restrictions are in effect, the city manager may
restrict or wholly prohibit the seeding, sodding or planting of live vegetation. Landscaping not installed for
new development projects due to the implementation of this section may be allowed an extended time to
complete landscaping improvements of an additional 12 months to the timing provisions outlined in
38.270.060 for the purpose of receiving issuance of a certificate of occupancy.
G. Restriction of certain outdoor uses when drought restrictions are in effect.
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1. Hosing or washing down hard or paved surfaces.
a. When drought restrictions are in effect, hosing or washing down hard or paved surfaces
including, but not limited to, sidewalks, walkways, driveways, parking areas, outside
building walls, patios or alleys is prohibited.
b. When it is necessary to hose or wash down hard or paved surfaces for purposes
essential to protect public health, sanitation, safety, and welfare, the following devices
may be used: hand-held bucket or similar container; hand-held hose equipped with a
positive shut-off nozzle or device; and low volume, high-pressure cleaning machine.
2. Hosing or washing down vehicles.
a. When drought restrictions are in effect, hosing or washing down motorized and non-
motorized vehicles, including but not limited to automobiles, trucks, vans, buses,
motorcycles, boats, bikes and trailers is prohibited.
b. The following devices are exempt from this restriction: use of hand-held bucket or
similar container; use of hand-held hose equipped with a positive shut-off nozzle or
device; and commercial car washing facility.
3. A drought declaration may warrant the implementation of drought restrictions that require
additional curtailments of outdoor water uses beyond those identified in this division. All
additional curtailments must consider the city’s Drought Management Plan.
H. Restriction of particular indoor uses when drought restrictions are in effect.
1. Water served only upon request. When drought restrictions are in effect, business
establishments are prohibited from serving complimentary water for human consumption unless
requested by a customer.
2. Option not to have towels/linens laundered. Whenever drought restrictions are in effect, hotels,
motels, and other commercial lodging establishments must provide guests the option to decline
having used towels and linens laundered daily. Such establishments must prominently display
notice of this option in each room using clear and easily understood language.
Sec. 40.02.1310. – Wasting water prohibited.
No person shall waste water which shall include but not be limited to permitting water to escape or run to
waste, excessive use, and escape of water through breaks, leaks, or malfunctions in the plumbing or
irrigation system.
Sec. 40.02.1330. -Exception to maintain sanitation.
The director of public works shall have the authority to permit a reasonable use of water in any case
necessary to maintain adequate health and sanitation standards.
Sec. 40.02.1340. -Enforcement.
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A. Police officers to enforce. Every police officer of the city shall, in connection with the duties
imposed by law, diligently enforce the provisions of this division.
B. Discontinuance of service. The City Manager shall have the authority to enforce the provisions of
this division by the discontinuance of water service in the event of violation hereof.
Sec. 40.02.1350. -Penalties.
Any person who violates this division or the restrictions issued hereunder shall be deemed guilty of a
misdemeanor and upon conviction thereof shall be fined in an amount not less than $100.00 or more than
$500.00.
Sec. 40.02.1360. -Legislative intent.
It is the intent of the City Commission that the criminal offense listed in this division shall be an offense
involving absolute liability. Unless specifically provided otherwise, this offense shall not require proof of
any one of the mental states described in MCA 45-2-101(33), (37), and (58).
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