← Basin groundwater

SOKOLOV 77844-F

Monitored well · 150638 · Division 1 · Water District 7

Its well permit here · Well permit at DWR ↗

Source DWR administrative record · verify at DWR well record ↗ Source DWR administrative record · verify at DWR permit record ↗

Unclassified

No aquifer or designated-basin assignment — administrative world unknown, kept out of recharge math.

Water-level record

No water-level measurements are cached for this well. It is in the well inventory — permit, construction and aquifer below — but nobody has logged a level we hold.

Geophysical log

DWR holds a geophysical log for this well, run 2015-12-02 (gamma, resistivity, spontaneous_potential). DWR's log page.

Formation picks (DWR)

AquiferTop ftBase ftNet sand ft
ALLUVIAL0 18
LOWER ARAPAHOE244 20
UPPER ARAPAHOE 194 55

Net sand is DWR's own reading of the log (its gLogThickness), not the gross interval.

Net sand per aquifer, from the gamma curve

Computed here from gamma digitized from the scan (gate pass, coverage 94%): linear gamma index, clean/shale lines at p10/p90 of the gamma over the interval, sand where Vsh < 0.4, beds under 1.0 ft merged. DWR’s own pick is beside it, never averaged with it.

AquiferInterval ftNet sand ftNet / grossDWR net sand ftDifference ft
ALLUVIAL0–18 3 0.19

A gamma cutoff is a convention, not a measurement. Against DWR’s own picks on 50 wells this one correlates at r 0.86 with a median error near 30% and no bias (how it was scored). This well’s gamma was digitized from a scan: two conventions stacked, so read the beds, not the total.

Curves digitized from the scan

Hydrohistorian traced the scanned log automatically. 1 curve passed the confidence gate; 4 did not and are listed with the reason. Screening data: the scan stays the record.

CurveInterval ftCoverageVerdict Curves like this one scored
64" Normal Resistivity (Ohm-m) 10–350 77% not used: ambiguous rows 6%; scale OCR confidence 0.76
Natural Gamma (CPS) 10–350 94% pass r 0.99 median, error 3.3% of scale, 3% below r 0.8 (n 89) LAS
Spontaneous Potential (A) 10–350 80% not used: SP: the printed scale is a span with an unknown offset, and the benchmark could not verify the shape (median r 0.28 after offset removal)
Ohms (Ohms) 10–188 39% not used: coverage 40%; ambiguous rows 9%; curve name not recognized: 'Ohms'
Ohms (Ohms) 200–350 39% not used: coverage 39%; ambiguous rows 27%; curve name not recognized: 'Ohms'

"Curves like this one" is the benchmark row for this curve's class: curves of the same name traced the same way, scored against DWR's own digital log of the same run. r is correlation (the print's own smoothing allowed for); error is mean absolute error as a share of the track's printed range; "below r 0.8" is the share of passing curves in the class that still disagreed with DWR's log, which this curve's own numbers cannot rule out.

The LAS files and every verdict are in the statewide groundwater release (/data, table gw_digitized); the MCP server's gw_digitized_curves and gw_net_sand work from them. How well the tracer does was measured against DWR's own digital logs.

The well itself

Total depth395.0 ft
Perforated interval160.0–240.0 ft
Ground elevation5470.0 ft
Permit77844
Location39.83000, -105.14000
What this page is not

Monitoring records are irregular: measurements cluster where somebody chose to look, so a trend describes this well's record, not the aquifer as a whole. Levels are DWR's published measurements, unedited. A trend here is not a prediction, and it is not a determination about anyone's water right.