Douglas County water commissioners press consultants on demand assumptions, ‘paper’ water and supply risk

Commissioners at the Douglas County Water Commission workshop on Feb. 23 pushed Forsgren Associates and staff for more detail and scenarios in the county’s draft water plan, focusing on projected water demands, the treatment of domestic well users and whether supply figures overstate physically usable water.

Will Koger of Forsgren said the firm used the State Demography Office’s projections to calculate county demand rates and compared those figures to water-provider projections gathered via surveys. He told commissioners the 0.19 unit-per-capita figure in table 5‑3 was applied to the SDO population projection, while provider surveys likely incorporate conservation assumptions.

Commissioner questions centered on three data points: the county-average per-capita demand (discussed as 1.67 gallons per capita per day in the presentation), an assumed 0.75 acre-feet per home for rural domestic wells, and the need for indoor/outdoor splits and scenario runs. "If we send it out to the public and it's inaccurate... we're wasting a lot of time of the publics to comment on a document that's not accurate," said Sean Tonner, summarizing why commissioners wanted the commission’s edits incorporated before public outreach.

Several commissioners cautioned that the supply charts in chapter 8 appear to rest on water-right or “paper” volumes rather than physically producible or economically producible water. "If the physical water proves to be less than the paper water, less water will be available and safety factors will be reduced," Harold Smethill said; commissioners asked the consultant to break out renewable, nonrenewable and reuse sources and to show safety-factor implications.

Consultant Jason Broom said chapter 8 will add provider-level pie charts and attempt to show renewable versus nonrenewable sources but acknowledged that some providers did not supply future splits between renewable and groundwater in the surveys. Commissioners recommended the consultant add scenario modeling (low/medium/high) to demonstrate impacts of stronger conservation measures and to recheck provider-supplied numbers and well assumptions.

Next steps: Staff and the consultant said they will recheck provider numbers, add requested detail (indoor/outdoor splits, renewable vs nonrenewable breakdowns where possible), discuss scenario outputs with the demographer, and prepare a revised draft for further commission review and focus‑group input before posting for public comment.