Salt Lake City utilities director: long-range water supplies will meet demand only if conservation and new sources proceed

Salt Lake City Public Utilities Director Laura Briefer on Wednesday told the Planning Commission that the city’s long-range water supply-and-demand planning to 2060 shows supplies will meet projected demand in a historic dry-year scenario only if sustained conservation measures are implemented and additional water sources are developed.

Briefer said the city currently serves roughly 400,000 people and manages water “from the tops of the Wasatch Mountain watersheds, to Great Salt Lake, to Utah Lake, to the Jordan River.” She told commissioners that planning incorporates changing climate information, land-use forecasts and evolving public values about Great Salt Lake and reuse.

The water master-plan nut graf: Briefer presented the city’s supply-and-demand projections and recommended planning scenario, and warned that without further conservation the city would need on the order of 26,000 to 46,000 additional acre-feet per year beyond currently anticipated new sources to meet growth and dry-year demand.

Most important findings and context

Briefer described the city’s mix of water rights and sources — City Creek, Parleys Creek, Mill Creek, Big Cottonwood and Little Cottonwood canyons, and groundwater — plus allocations tied to the Provo River project (water stored in Deer Creek Reservoir) and the Central Utah Project. She said the city stacks long-term average production and dry-year production to plan for supply interruptions ranging from minor outages to catastrophic loss (for example, loss of Big Cottonwood Creek, which provides roughly 20% of the city’s supply).

On demand, the department uses zoning maps, census data and regional transportation analysis zones to project residential, nonresidential and irrigation demand under scenario-based conservation assumptions. Briefer said the planning team selected a ‘‘scenario 2’’ demand projection for budgeting and capital planning — more conservation than recent historic trends but less aggressive than the highest-conservation scenario — and described example measures (high-efficiency fixtures, leak reduction, irrigation efficiency and turf conversion).

Without additional conservation, Briefer said, ‘‘we would need somewhere in the range of 26,000 to 46,000 additional acre-feet a year on top of the sources that we use and have anticipated developing.’’ She added the figure in context: city annual production today is on the order of 180,000 acre-feet, so even the lower end of that range is a substantial share of current supply.

Questions and follow-up

Commissioners and residents asked about transmission losses, potential Olympic-related infrastructure investment, and groundwater risks. Briefer said the city recently completed a water-loss audit that raised questions about accounting, meters and development-related flushing; she said transmission and leakage remain part of the aging-infrastructure work plan. On possible accelerated capital work connected to the Olympics, Briefer said the utilities’ revenue comes from water rates, not property tax, and the city prioritizes work the community can afford; she noted that replacement of mid-20th-century treatment plants alone represents costs in the hundreds of millions of dollars.

On groundwater, Briefer said groundwater is used to supplement surface water during peak season and droughts and that the city coordinates with state agencies and neighboring suppliers to stay within sustainable yield limits.

Great Salt Lake and planning

Briefer said earlier long-range plans did not treat Great Salt Lake as a ‘‘customer’’ but that future plans should. She said the city is exploring wastewater reuse and legislative avenues to explicitly include the lake in long-range water planning; she noted that the state requires 40-year water-supply plans under state statute and that updated climate information will be folded into upcoming planning efforts.

What officials took away

No formal action or vote was required; the presentation was a work session. Briefer provided links and resources and said the utilities department will continue to refine climate inputs, conservation programs and source-development timelines as the city moves from planning to capital projects.

Ending

Briefer closed by directing commissioners to online resources and to the Intermountain West Climate Dashboard for regional climate data; commissioners thanked her for the overview and posed follow-up questions on infrastructure funding, metering and lot-split impacts on service.