HomeMy WebLinkAboutCity Commission Work Session_Landscape and Irrigation Standards for New DevelopmentMemorandum
REPORT TO:City Commission
FROM:Jessica Ahlstrom, Water Conservation Program Manager
John Alston, Director of Utilities
SUBJECT:Direction to City Staff on the Development of Water Conservation Standards
for New Development and City-Wide Outdoor Watering Restrictions
MEETING DATE:February 15, 2022
AGENDA ITEM TYPE:Policy Discussion
RECOMMENDATION:City Staff seek direction from the City Commission to develop landscape and
irrigation performance and design standards for new development as well as
city-wide time-of-day and day-of-week outdoor watering restrictions.
STRATEGIC PLAN:6.1 Clean Water Supplies: Ensure adequate supplies of clean water for today
and tomorrow.
BACKGROUND:In 2013, the City Commission adopted an Integrated Water Resources Plan
(Plan) in order to guide future water use and supply policies and practices.
The Plan calls for water conservation to fill fifty percent of the gap between
water supply and demand over the next 40 years. Upon adoption of the
Plan, the City Commission specifically supported an education and incentive-
based approach to conservation while recognizing that the Plan
acknowledges a future need to take a regulatory approach to water
conservation.
Outdoor watering of lawns and landscapes represents fifty percent of annual
residential water use in Bozeman. A recent analysis of single family water
use based on year-built indicates that homes built over the last decade are
applying over twice the amount of water to landscapes as compared to older
homes, despite being located on smaller lots with less landscaping. This is
likely due in large part to the installation of inefficient irrigation systems and
high water use turfgrass in new construction.
Bozeman is a fast-growing drought-prone community facing numerous water
supply constraints posed by its headwaters location in the Upper Missouri
River Watershed, impacts of climate change on water supply yields, and
challenging legal framework regarding new water right appropriations. In
order to ensure that Bozeman has a reliable water supply available for the
future, City Staff ask the City Commission to consider landscape and
irrigation performance and design standards for new development to ensure
that outdoor watering associated with future growth is more efficient; as
well as to consider establishing time-of-day and day-of-week watering
restrictions for all water customers, regardless of drought condition.
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UNRESOLVED ISSUES:None.
ALTERNATIVES:As suggested by the City Commission.
FISCAL EFFECTS:None at this time.
Attachments:
Proposed Revisions to Landscape and Irrigation Performance
and Design Standards_Presentation Slides_Feb 15.pdf
Report compiled on: December 27, 2021
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Work Session
Proposed Landscape and Irrigation Performance
and Design Standards
Jessica Ahlstrom
Water Conservation Program Manager
February 15, 2022
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Integrated Water Resources Planning
•IWRP & Implementation Plan adopted in 2013
•Water conservation to fill 50% of gap between supply and demand
•Upon adoption, City Commission supported an initial focus on
water conservation outreach and education
Water Supply Constraints:
•Limited supplies
•Limited storage
•Drought prone
•Snowpack reliant
•Climate change
•Closed basin status re:
new water right appropriations
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Rising Outdoor Water Use 50% of annual residential
water use goes into lawns
and landscapes
TRENDS:
•Single family homes built
since 2009:
•lots are 20% smaller,
•outdoor water use is 2x
higher,
•outdoor water use exceeds
plant water demands
•More large developments
are expected to connect to
city water for irrigation in
the future
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Questions for Consideration
•Does the City Commission agree with proposed water
conservation standards for new development (Tier 2:
Recommended Standards)?
•Does the City Commission support implementing time of day
& day of week watering restrictions for all water customers
city-wide?
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Code Change Approaches
•Four Elements
•Landscape design standards
•Irrigation design standards
•Irrigation performance standards
•Large landscape standards
•Three Tiers:
1) Minimum standards
2) Recommended standards
3) Maximum standards
•Two Administrative Processes:
•Residential & Commercial >5 units
•Formal plan review process
•Residential 4 unit or less
•Building permit process
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Minimum Standards Included in ALL Tiers
Landscape
design
standards
-Limit installation of high water use turfgrass, focusing on ‘functional turf’ areas
-Varies based on project/land use type
-Topsoil depth & quality requirements
-Mulch requirements
Irrigation
performance
standards
-Weather based controllers
-High efficiency nozzles
-Adequate operating pressure
Irrigation
design
standards
-Require irrigation design plans for projects >5 units
-Head to head coverage
-Hydrozoning
-Low flow or drip irrigation requirements (trees, perennials, etc.)
-Prohibit overhead spray from being installed in narrow vegetated areas
Overarching Goals:
-Limit high water use turfgrass
-Require drought tolerant landscaping
-Require high efficiency irrigation
-Limit overhead spray irrigation
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Tier I:
Minimum
Standards
Tier II:
Recommended
Standards
Tier III:
Maximum Standards
Additional
Landscape
Design
Standards
Turfgrass limits based
on total vegetated
area:
-SF: 75%turf
-MF & COM: 50%
turf
Turfgrass limits based on
total vegetated area:
-SF: 50%turf
-MF & COM: 40% turf
-Option not to exceed
water budget of <11
gal/sq. ft. of landscaped
area
Turfgrass limits based on total vegetated area:
-SF: 35%turf
-MF & COM: 20%turf
-Option not to exceed water budget of <9 gal/sq.
ft. of landscaped area
-Require submittal of lab test to demonstrate
topsoil quality
-All landscape retrofit projects require landscape
permit to ensure project complies with new
standards
Additional
Irrigation
Design &
Performance
Standards
-Prohibit overhead
spray from being
installed in areas less
than 6 ft. wide
-Prohibit overhead spray
from being installed in areas
less than 10 ft. wide
-Irrigation design plans and
O&M plans required for all
projects subject to plan
review
-Prohibit overhead spray from being installed in
areas less than 12 ft. wide
-Prohibit turf from being installed in all boulevard
areas
-Irrigation permit and performance requirement of
70% distribution uniformity (verified by third party
certified contractor) required
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Tier I:
Minimum Standards
Tier II:
Recommended
Standards
Tier III:
Maximum Standards
Large
Landscape
Requirements
-None -Flow sensor installation
required
-Irrigation sub-meter required
-Irrigation rate structure for sub-metered
accounts
Compliance
Review &
Inspections
-Plan review & compliance
inspections for >5 units
-‘Self-certification’
compliance checklist for
residential 4 units or less
-Plan review & compliance
inspections for >5 units
-‘Self-certification’ compliance
checklist for residential 4 units
or less
-Inspect 5% of SF homes
annually
-Plan review & compliance inspections
for projects of all sizes
-‘Self-certification’ compliance checklist
for residential 4 units or less with
inspections for all SF homes.
Time of Day &
Day of Week
Watering
Restrictions
-Watering limited to the
hours of 6pm to 10am
-Watering limited to three
assigned days per week
-Watering limited to the hours
of 8pm to 8am
-These requirements will
apply to every water customer
-Watering limited to three assigned days
per week
-Watering limited to the hours of 10pm
to 8am
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Typical Bozeman Single Family Home
Proposed landscape:
35% less turfgrass
25% outdoor water use reduction
40% reduction in water bill (outdoor use)
35% higher installation cost, but lower maintenance costs
Existing Home (85% turfgrass)Proposed Home (50% turfgrass)
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Benefits of Recommended Standards
Qualitative Benefits to Proposed
Standards
-Increased plant
diversity
-Improved
watershed health
-Climate adaptive
landscapes
during drought
-Lower
maintenance
-Increased
wildlife habitat
-Reduced
stormwater
runoff
-Increased shade
-Reduced
pesticides and
fertilizers
Ability for residents to landscape
yards to align with values
Best in class
utility
Leader in
conservation
Water Saved in
2040
Single Family Home
Equivalents
Benefit / Cost
Ratio to City
Tier 1: Minimum
Standards
465 AF/YR 1,860 homes 3.68
Tier 2: Recommended
Standards
751 AF/YR 3,004 homes 5.17
Tier 3: Maximum
Standards
1,291 AF/YR 5,164 homes 5.45
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Next Steps
•If the City Commission directs staff to move forward, staff will
begin community engagement
•Consult key groups on impacts and implementation of new standards
•Inform the Bozeman community
of new standards
•A communication and education
campaign will follow any formal
adoption of new standards
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Thank you.
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Questions for Consideration
•Does the City Commission agree with proposed water
conservation standards for new development (Tier 2:
Recommended Standards)?
•Does the City Commission support implementing time of day
& day of week watering restrictions for all water customers
city-wide?
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