Pumping now, depletion later

Lagged, and smeared

A well’s cone of depression intercepts water that was flowing toward the stream and, once wide enough, pulls streamwater toward the well. The effect travels through the aquifer slowly, so this year’s pumping becomes a depletion schedule spread over years — lagged (it starts late) and smeared (it lingers). Consequences follow: curtailing a well during a call may deliver the senior nothing this season, which is why the remedy is an augmentation plan replacing depletions on their schedule; and a retired well keeps depleting for years, so plans account for past pumping long after the switch is off. Timing, not volume, is the argument.

The standard first-cut model is the Glover analysis: aquifer transmissivity, storage coefficient and well-to-stream distance in, depletion schedule out. Our groundwater tab runs it as an advisory band from declared-but-uncalibrated parameter ranges, with the assumptions printed beside the number — a screen for where to look closer, never an accounting.

What this does not let you conclude

Real depletion accounting uses calibrated models and DWR-accepted tools with parameters argued over in court precisely because the schedule is where the money is — our uncalibrated band flags magnitudes, and the assumptions beside it are load-bearing. Advisory reading aid on public data — never an administrative or legal conclusion, and never a substitute for DWR administration or an engineer’s analysis. Our methodology has not yet had outside expert review: how this is built.