Evaluating the Water Savings from Irrigation Efficiency Upgrades

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Evaluating the Water Savings from Irrigation
Efficiency Upgrades

• Jenna Smith
• Seattle Public Utilities and the Saving Water
  Partnership

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How much water can be saved?

• Very difficult to evaluate landscape or
  irrigation measures to determine how much water
  can be saved per measure, but

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What we do know

• Typical customers landscape management practices
  shows great potential for water savings
• Irrigation typically wastes between 30 and 50
• Total water use for a customer segment can be
  tracked

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Where does waste occur (everywhere!)

• Poor design
• Poor installation
• Poor management (base schedules and adjusting for
  ET)
• Poor maintenance
• Inherently inefficient

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Approach toDeveloping, tracking and reporting
on irrigation water conservation initiatives
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Holistic and Comprehensive

• Target all inefficiencies
• Hardware and behavior measures
• Start with biggest opportunities
• Target all stakeholders
• Customers start with biggest opportunities
• Contractors
• Distributors
• Professional organizations
• Target all landscape utility resources
• Water, solid waste, water quality

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Use Best-Guess Estimated Method combined with and
Benchmarking and Tracking Determine how much
irrigation and landscape water conservation
measures save using the
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Best-Guess

• Gather information from irrigation labs and
  customers
• Estimate water savings for per measure savings
  theoretically (only way to hold all other
  variable constant) but based on as much real
  world data as possible
• Example Rain Sensors

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Best-Guess

• Develop water savings goals based on
  participation potential and long-term goals
• Use water savings estimates as an accounting tool
  and only report the aggregate

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Benchmark Track

• customer and contractor behaviors
• irrigation market indicators
• aggregate water use

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Benchmark Track

• Collect information about customer behaviors and
  issue
• Measure the change in behaviors and attitudes
  through surveys
• Focus program initiatives on the barriers or
  issues identified in surveys or in depth
  interviews with customers related to irrigation
  inefficiencies
• Track peak and adjust for weather

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SWP Water Efficient Irrigation Programs (WEIP)

• Program Costs
• 350,000
• 130,000 for rebates
• 17,000 for marketing
• 34,000 for consultants
• 12,000 for IWMS website
• 21,000 for conservation tool
• The rest for staff and training logistics

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WEIP

• 1 full time employee (two part-timers)Savings
  Target 125,000 gpd (annual)
• Rebates for multiple measures typically about
  50 of cost of hardware and installation.

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WEIP

• Custom and standard rebates available
• Cost-analysis model used to determine
  cost-effectiveness of measures
• Maximum allowable cost per CCF saved

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Major Findings

• Survey findings and utility data
• Over 60 of auto irrigators are in the high
  peak use group
• 35 use an irrigation specialist to check their
  system once per year

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• 73 set their own schedules
• Customer with automatic irrigation systems water
  more often
• 4 water their lawn every day or every other day,
  compared with 5 of non-auto irrigators
• 41 water their garden every day or every other
  day, compared to 19 of those without an auto
  irrigation system

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• More water savings per customer opportunities
  from commercial and multifamily than
  single-family residential
• However, total residential water use is higher
  than commercial and multifamily combined

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Qualitative and Program Research

• Design program initiatives with input from
  industry
• Contractors are the best marketing tool for
  rebates and conservation tool.
• Audits not cost-effective too much time
  required for too few savings, customers may not
  implement measures

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• Poor scheduling
• inexpensive for customers but not necessarily for
  the utility
• Everything watered for the same amount of time
• Not taking advantage of features on controllers
  (multiple start-times)
• Not adjusting schedules to changing plant water
  need (ET)
• Contractors and customers do not understand how
  to program smart controllers

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• Easier to administer standard rebates than custom
  ones but accounting for savings more difficult

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Opportunities to count savings

• Hardware upgrade or add irrigation technology
  that saves water
• Tune-up fix leaks and fine-tune system
• Scheduling input water efficient schedules

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Use whats out there

• Borrow as much as you can from other utilities
• SWAT irrigation.org
• Irrigation Water Management Society iwms.org
• Center for Irrigation Technology