San Luis Creek

Evolution of the network

Gage flow trend & changepoints

Of the 20 gages with enough record, 2 are trending down and 0 up, and 3 carry a detected shift. The clearest is KERBER CREEK NEAR VILLA GROVE, -4.8 points of its long-term median per decade over 84 years (p=0.0009). The other 16 show no clear signal either way.

16 other gage(s) show no significant trend or changepoint (not shown).

How the measurement network itself changed

This basin was not always measured the way it is today — the API-era record is dense and recent, the early record sparse. 14 gage(s) and 99 structure(s) report in 2026, but structure reporting only reached half its modern level around ~1969. Every historical claim below is checked against this: long-term shifts that co-move with the growth of the network carry an explicit measurement-evolution caution, and abandonment screens whose idleness begins before the modern reporting era are flagged †.

Mass-balance (network closure) trend

Structure divrec-history backfill coverage as of the last check: 12% of 273 schematic-relevant structures. 0 year(s) clear the 30% coverage gate so far -- the trend activates automatically once qualifying years span a full decade. No action needed; the nightly backfill keeps extending the record.

Reach gain/loss shifts (1951–2026)

Mass-balance kinks computed for every summer month back to 1951 (479 reach-snapshots) — which reaches gain or lose water, and how that has shifted across decades. Each shift is cross-checked against the observation record above: as more diversions became metered, "unaccounted" water shrinks mechanically, which can masquerade as a hydrologic shift.

No reach shows a statistically significant long-term gain/loss shift.

Groundwater now has its own tab: 206 monitored well(s), water-table trends, stream corridors, and the advisory depletion screen.

Cross-gage pattern fingerprint

Over the 28-year window with full coverage (1999–2026), the dominant shared pattern across 11 gage(s) explains 50% of year-to-year variance (almost certainly a basin-wide climate/snowpack driver).

CHECRECO, COCRESCO, GARVILCO, MAJVILCO, SPACRECO don't move with that shared pattern -- a real, localized signal (a new diversion, land-use change, or a gage-specific data problem) worth a closer look, not necessarily noise.

19,132 water-level measurements across 206 monitored well(s) — 70 alluvial, 62 bedrock — plus 1 administered well(s) reporting metered pumping.

Well map

3D aquifer x-ray

Every aquifer unit as its own head surface, animated through time.

Water-table trends

Of 71 well(s) with enough record for a trend test: 41 declining, 6 rising.

Wells labeled by administrative world before anything else is said about them: tributary alluvium participates in the priority system; designated-basin and Denver Basin bedrock aquifers are governed differently and are excluded from stream-connection reasoning. Read bedrock declines differently too: deep bedrock aquifers recharge negligibly on human timescales, so a falling bedrock level is storage mining — effectively permanent — not a drought response that a wet year undoes. All screens advisory.

If a call were placed at a given seniority, which structures in this basin would be out of priority, and how much of their decreed rate would be curtailed? Computed from this basin's cached decrees.

Pick a calling right

Real decrees from this basin, ordered by administration number — that is, by actual seniority. The years will look out of order, and that is correct: an administration number encodes the adjudication date as well as the appropriation date, so a right appropriated in 1970 can be administered ahead of one from 1950. A senior call curtails almost everything; a junior one curtails almost nothing.