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Home My WebLink About20220810 - Sustainability Advisory Board - Water ConservationCity of Bozeman Water Conservation & Drought Management Jessica Ahlstrom City of Bozeman Water Conservation Program Manager August 10, 2022 Bozeman’s Water Supply 18 acre-feet/day (6 MGD) Hyalite Creek 40% Bozeman Creek 40% Lyman Creek 20% Integrated Water Resources Planning & Conservation Water Conservation to fill 50% of gap between supply and demand over next 40 years •Limited supplies •Semi-arid climate •Surface water -snowpack dependent •Projected climate change impacts •Less annual precipitation (more rain vs snow) •Earlier peak runoff and drier, hotter summers •Drought prone •Limited storage •Closed basin •Cost effective •Immediate return •High population growth “Water conservation and water-use efficiency should be the bedrock of the city’s water resource management” -IWRP Water Supply Planning Drought Management Planning Demand Management Rising Outdoor Water Use 50% of annual residential water use goes into lawns and landscapes TRENDS: •Single family homes builtsince2009: •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 Education & Incentives Educational Resources •Website resources •Sprinkler system assessments •Commercial water use assessments •Free water-savings products •Drought tolerant demonstration gardens •Customer water use portal •Leak alerts & end use disaggregation Indoor Rebates •HE toilets •HE showerheads •HE clothes washers •HE urinals •Free HE faucet aerators •Free HE showerheads Outdoor Rebates •Weather based irrigation controllers •Rain sensors •HE nozzles •Drip irrigation •Drought tolerant plants •Turf removal Sprinkler System Assessments (2018-2021) •320 residential assessments •Estimated reduction of 1,800 gal/week/home through custom watering schedule –peak season Water Rates •Different rates for different customer classes, based on cost of service •Conservation-based rate structure (SF) •Inclining block rate (4 tiers) •Tier sizes based on Bozeman SF water users •Cost per unit of water increase as tiers go up •‘The more you use the more you pay’ •Equitable and ensure customers pay for the true cost of their usage •The treatment plant and other infrastructure must be built to accommodate the few peak water use days in August when use is at it’s highest Drought Rates •2022 Drought Management Plan •4 stages of drought with pursuant response measures •Drought declaration based on data driven drought ‘tool’ •Drought Reserve •$0.08/HCF charge •Builds up financial reserve slowly to lessen financial impacts from drought event (stage 3 or 4) •Drought Surcharge •Applies only during a declared drought stage •Mitigates financial impacts to the utility when revenues decrease due to watering restrictions •Stage 1 and 2 = revenue neutral •Sends price signal to conserve when lawn watering ban is in place Permanent Watering Restrictions Effective June 16, 2022 Water Conservation Projects in the Works •Water Conservation Plan •Qualitative screening & benefit cost analysis of program measures •Implementation Plan •Program measure evaluation tool •Water offsets for new development •Expanding options for developers to offset water demand through conservation measures •City asset performance audits •Water distribution system •City facility irrigation systems From this… …to this! •Development code amendments •Landscape standards (vegetation type, soil depth & quality) •Irrigation performance and design standards Existing Development –Landscaping Trends Percent turfgrass of total irrigable area:•Single family: 85% turfgrass•Multi-family: 45% turfgrass•Commercial: 35% turfgrass The City’s current code has no limitations on turfgrass. In Bozeman, 1 𝐟𝐟𝐟𝐟𝟐𝟐of turf requires 15 gallons of supplemental water each season Typical SF home in Bozeman 3,445 ft2 of turfgrass Existing Development – Irrigation Performance & Design The City’s current code does not include irrigation performance and design standards. Without these standards, many irrigation systems: •Are not designed to achieve even coverage (head placement, hydrozoning) •Do not operate within optimal specified pressure ranges •Utilize inefficient irrigation technology (nozzles, controllers, weather sensing All of these issues lead to water waste and overwatering. Changes to the UDC •A benefit cost analysis of three ‘tiers’ of code changes was performed as part of the Water Conservation Plan program measure evaluation. •Work Session with City Commission in Feb 2022 •Proposed 3 tiers of code changes •City Commission gave staff directive to pursue tier 3 (the most ‘aggressive’ tier) •Concerns: housing affordability, plan review time •Internal kick-off meeting scheduled for later this month. •Hiring consultant for project support. New Development –Landscaping Requirements Turfgrass limits •Percent of total irrigable area •Easy, quick path to project approval •Single Family: 35% •Multi-family: 20% •Commercial: 20% •Water budget calculation •More flexibility in landscape design, more requirements to receive project approval •Water allowance worksheet (9 gal/ft2) •Plant list with plant factors •Irrigation efficiency consideration •Allowances for food gardens Soil Requirements •Adequate topsoil quality and depth •Mulch requirements for bare soil New Development –Irrigation Requirements Irrigation Design & Performance •Overhead spray prohibited in areas less than ~10 ft. wide. •Full design detail required for large projects •Head to head coverage •Hydrozoning •Low flow/drip irrigation requirements for trees, perennials, shrubs, etc. •Weather based controllers •High efficiency nozzles •Adequate operating pressure •Performance testing (distribution uniformity of 70%) second phase of code changes •Irrigation operation and maintenance plan Benefits of New Requirements 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 1 465 AF/YR 1,860 homes 3.68 Tier 2 751 AF/YR 3,004 homes 5.17 Tier 3 1,291 AF/YR 5,164 homes 5.45 Next Steps •Hire consultant •Identify timeline (goal of 6 months) •Inform the Bozeman community of new standards •Consult key groups on impacts and implementation of new standards (2-4 meetings) •Refine and revise new requirements as needed •Identify submittal requirements for large and small projects •Large projects >5 units •Full landscape and irrigation designs, water budget worksheet (if applicable), demonstration of soil quality, irrigation O&M manual •Small projects <5 units •Self-certification checklist agreeing to requirements such as turf limitations, irrigation performance, etc. Full landscape & irrigation designs will not be required. 50% less turfgrass35% outdoor water use reduction50% reduction in water bill (outdoor use) 35% higher installation cost, but lower maintenance costs Proposed Home (35%turfgrass) Thank you! Jessica Ahlstrom Water Conservation Program Manager 406-582-2265 jahlstrom@bozeman.net