← Basin groundwater

DANG

Monitored well · 152897 · Division 1 · Water District 1

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 ↗

High Plains / Ogallala

Effectively non-recharging in eastern Colorado; declines are storage depletion, a separate ledger line.

Because this aquifer does not recharge on a human timescale, a decline here is storage being removed, not a stream being short. It is kept out of the stream-depletion math for that reason.

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 2019-05-08 (gamma, resistivity, spontaneous_potential). DWR's log page.

Formation picks (DWR)

AquiferTop ftBase ftNet sand ft
LOWER DAWSON336 518 53
DENVER604 119
UPPER DAWSON 274 96

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 DWR's own digital log (LAS): 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
LOWER DAWSON336–518 91 0.50 53 +39

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).

Curves digitized from the scan

Hydrohistorian traced the scanned log automatically. 1 curve passed the confidence gate; 6 did not and are listed with the reason. Screening data: the scan stays the record.

CurveInterval ftCoverageVerdict Curves like this one scored
Natural Gamma (CPS) 0–1039 98% pass r 0.99 median, error 3.3% of scale, 3% below r 0.8 (n 89) LAS
Spontaneous Potential (mV) 0–1039 90% 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)
mV (mV) 0–159 100% not used: ambiguous rows 37%; curve name not recognized: 'mV'
mV (mV) 180–379 100% not used: ambiguous rows 55%; curve name not recognized: 'mV'
mV (mV) 400–599 100% not used: ambiguous rows 42%; curve name not recognized: 'mV'
mV (mV) 620–819 100% not used: ambiguous rows 59%; curve name not recognized: 'mV'
mV (mV) 840–1040 95% not used: ambiguous rows 69%; curve name not recognized: 'mV'

"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

Designated basinKIOWA-BIJOU
Total depth1025.0 ft
Perforated interval605.0–1025.0 ft
Ground elevation6875.0 ft
Permit83163
Location39.23000, -104.48000
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.