Roaring Fork River Basin

Evolution of the network

Gage flow trend & changepoints

What counts as a trend here

Computed 2026-08-20 09:10 from 72 gage(s) with cached period-of-record data. Mann-Kendall (trend) and Pettitt (changepoint) both require at least 8 years spanning at least 10 years of record. A gage below that reports no signal — which is not the same as “no change.”

Of the 72 gages with enough record, 13 are trending down and 0 up, and 13 carry a detected shift. The clearest is ROARING FORK RIVER AB DIFFICULT C NR ASPEN, CO., -18.0 points of its long-term median per decade over 47 years (p<0.0001). The other 56 show no clear signal either way.

Gage	Trend	Change / decade points of median	Significance	Years	Changepoint
▸ IVANHOE CREEK NEAR NORRIE, CO.☆ IVANORCO	↓ decreasing	-62.8	p=0.044	13	—
▸ NF FRYINGPAN R AB CUNNINGHAM C, NR NORRIE, CO.☆ NOFRYACO	↓ decreasing	-58.8	p=0.003	17	~1973
▸ CUNNINGHAM CREEK NEAR NORRIE, CO.☆ CUNNORCO	↓ decreasing	-50.5	p=0.006	17	~1973
▸ SNOWMASS CREEK☆ SNOCRECO	↓ decreasing	-30.6	p=0.008	27	~2017
▸ ROARING FORK RIVER AB DIFFICULT C NR ASPEN, CO.☆ ROADIFCO	↓ decreasing	-18.0	p=0.000	47	~2000
▸ CRYSTAL RIVER NEAR REDSTONE, CO.☆ CRYREDCO	↓ decreasing	-10.0	p=0.012	28	—
▸ FRYINGPAN RIVER NEAR IVANHOE LAKE, CO.☆ FRYIVLCO	↓ decreasing	-10.0	p=0.016	62	~1971
▸ FRYINGPAN RIVER AT NORRIE, CO.☆ FRYANOCO	↓ decreasing	-9.5	p=0.000	42	~1972
▸ FRYINGPAN RIVER NEAR RUEDI, CO.☆ FRYRUDCO	↓ decreasing	-7.9	p=0.001	62	~1999
▸ ROCKY FORK CREEK NEAR MEREDITH, CO.☆ RFCMERCO	↓ decreasing	-7.8	p=0.000	58	~1999
▸ MAROON CREEK ABOVE ASPEN, CO.☆ MARASPCO	no clear trend	+7.7	p=0.234	25	~1981
▸ ROARING FORK RIVER NEAR ASPEN, CO.☆ ROAASPCO	↓ decreasing	-4.9	p=0.020	62	~2000
▸ MAROON CREEK NEAR ASPEN, CO.☆ MARNASCO	↓ decreasing	-4.4	p=0.016	14	—
▸ SOUTH FORK FRYINGPAN RIVER AT UPPER STATION NEAR NORRIE☆ FRYSFUCO	no clear trend	+2.8	p=0.275	63	~1971
▸ ROARING FORK RIVER AT GLENWOOD SPRINGS, CO.☆ ROAGLECO	↓ decreasing	-2.1	p=0.002	120	~1930
▸ CHAPMAN GULCH NEAR NAST, CO.☆ CHAGULCO	no clear trend	+0.6	p=0.896	53	~1980

56 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. 22 gage(s) and 263 structure(s) report in 2026, but structure reporting only reached half its modern level around ~1975. 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 †.

Decade	Gages with data (median yr)	Structures reporting (median yr)
1900s	1	0
1910s	8	0
1920s	1	0
1930s	2	0
1940s	4	0
1950s	9	42
1960s	22	68
1970s	26	230
1980s	20	326
1990s	19	307
2000s	21	204
2010s	23	254
2020s	22	262

Mass-balance (network closure) trend

Structure divrec-history backfill coverage as of the last check: 4% of 1922 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 (1950–2026)

Mass-balance kinks computed for every summer month back to 1950 (2628 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.

• CRYSTAL RIVER AT PLACITA, CO.: reach shifted from +123 cfs to +180 cfs summer mean (more gaining, p=0.011, 12 yr) [alluvial valley: real alluvial aquifer -- a decades-long shift toward losing is the classic signature of alluvial pumping and urbanization]
• ROARING FORK RIVER AT GLENWOOD SPRINGS, CO.: reach shifted from +2386 cfs to +1075 cfs summer mean (more losing, p=0.000, 77 yr) [alluvial valley: real alluvial aquifer -- a decades-long shift toward losing is the classic signature of alluvial pumping and urbanization]
• CRYSTAL RIVER ABV AVALANCHE CRK, NEAR REDSTONE, CO: reach shifted from +295 cfs to -136 cfs summer mean (more losing, p=0.000, 63 yr) [sedimentary uplands: moderate groundwater connectivity -- gain/loss shifts can be real aquifer response; corroborate with nearby well records]
• HUNTER CREEK AT ASPEN, CO: reach shifted from -54 cfs to -104 cfs summer mean (more losing, p=0.004, 17 yr) [sedimentary uplands: moderate groundwater connectivity -- gain/loss shifts can be real aquifer response; corroborate with nearby well records]
• MAROON CREEK ABOVE ASPEN, CO.: reach shifted from +17 cfs to +59 cfs summer mean (more gaining, p=0.011, 26 yr) [sedimentary uplands: moderate groundwater connectivity -- gain/loss shifts can be real aquifer response; corroborate with nearby well records]
• HUNTER CREEK NEAR ASPEN, CO: reach shifted from -27 cfs to -111 cfs summer mean (more losing, p=0.046, 48 yr) [alluvial valley: real alluvial aquifer -- a decades-long shift toward losing is the classic signature of alluvial pumping and urbanization]

Groundwater now has its own tab: 46 monitored well(s), water-table trends, stream corridors, and the advisory depletion screen.

Reservoirs now has its own tab: 165 reservoir(s), end-of-year storage back to 1953, click-to-chart histories.

Cross-gage pattern fingerprint

Over the 63-year window with full coverage (1964–2026), the dominant shared pattern across 3 gage(s) explains 65% of year-to-year variance (almost certainly a basin-wide climate/snowpack driver).

FRYSFUCO doesn'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.

Structures most implicated by reconciliation (as of 2026-07-06)

Which structures' data absorbed the most correction when the current mass-balance snapshot was reconciled -- see the Historical tab for the full picture on any date.

• WHITMER D & PD PR STO RT (return): -83.7 cfs (100% of that reach's correction)

149 water-level measurements across 46 monitored well(s) — 19 alluvial, 0 bedrock — plus 28 administered well(s) reporting metered pumping.

What is being counted

Observation wells and pumping wells are different populations and are never conflated: water levels come from monitored observation wells, and metered pumping comes from administered wells reporting through diversion records. Click any well to chart its own record.

Well map

3D aquifer x-ray

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

Load 3D x-ray

How the surfaces are built, and what they are not

Alluvial water table on top, Denver Basin members (Dawson, Denver, Arapahoe, Laramie–Fox Hills) stacked beneath where measured, interpolated from measured water levels. Units are never mixed; a surface exists only inside its own unit's well coverage, with no extrapolation; thin epochs are suppressed and say why. Vertical scale is exaggerated for readability and z is head elevation in feet. These are measured heads, not a calibrated groundwater model.

Water-table trends

Of 0 well(s) with enough record for a trend test: 0 declining, 0 rising.

Stream corridors — the surface connection

Where a reach's gain or loss has shifted, the wells within two miles of its anchoring gage and what their water table did over the same era.

How the corridor is assembled

For each reach whose gain/loss has shifted (Trends tab): the wells within 2 miles of its anchoring gage, their pooled water-table history over the same era, and an advisory Glover screen of lagged stream depletion from nearby metered pumping. v1 proximity = distance to the reach's anchoring gage; segment-based reach join is a flagged upgrade.

CRYSTAL RIVER AT PLACITA, CO.: 0 alluvial well(s) nearby

CRYSTAL RIVER ABV AVALANCHE CRK, NEAR REDSTONE, CO: 1 alluvial well(s) nearby. Glover screen: 0.1 cfs of nearby metered alluvial pumping → est. lagged depletion 0.0–0.1 cfs (uncalibrated T/S ranges; flagged for SPDSS calibration, AWAS cross-check, and expert review — DWR's AWAS is the authority).

HUNTER CREEK AT ASPEN, CO: 0 alluvial well(s) nearby. Glover screen: 0.0 cfs of nearby metered alluvial pumping → est. lagged depletion 0.0–0.0 cfs (uncalibrated T/S ranges; flagged for SPDSS calibration, AWAS cross-check, and expert review — DWR's AWAS is the authority).

HUNTER CREEK NEAR ASPEN, CO: 0 alluvial well(s) nearby. Glover screen: 0.0 cfs of nearby metered alluvial pumping → est. lagged depletion 0.0–0.0 cfs (uncalibrated T/S ranges; flagged for SPDSS calibration, AWAS cross-check, and expert review — DWR's AWAS is the authority).

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.

165 reservoir(s) with 7,787 storage measurement(s), 1953–2025. Basin storage as of 2024-10-31 (the record's own end — reservoir records publish ~annually): 79,357 AF across 3 reservoir(s).

Why storage matters to the flow network

Storage change is real water the mass balance must credit — a losing reach beside a filling reservoir isn't losing water, it's banking it.

Reservoir map — how full is each vessel?

What “full” is measured against

Bubble size is proportional to a reservoir's record-high storage. Fill is its last recorded storage as a share of its surveyed capacity (USACE National Inventory of Dams) where a confident NID match exists — the tooltip names the matched dam — and as a share of its own record high otherwise. A wrong capacity would be worse than an honest record high, so only confident joins upgrade.

A dashed teal ring marks reservoirs reporting live DWR telemetry: their fill reflects yesterday's storage, is drawn as a dotted tail on charts, and is treated as provisional until the next verified HydroBase snapshot supersedes it.

Basin storage, end of each water year

End-of-water-year totals; per-year reservoir counts shown because reporting coverage varies -- a total is only comparable to years with similar counts.

Largest reservoirs on record

Click a reservoir to chart its full storage history.

Reservoir	Last recorded storage (AF)	As of
▸ RUEDI RESERVOIR (3803713) ☆	78,521	2024-10-31
▸ WILDCAT RESERVOIR (3803759) ☆	1,140	2005-10-31
▸ MESA RESERVOIR (3803738) ☆	848	1985-10-31
▸ IVANHOE RESERVOIR (3803732) ☆	836	2024-10-31
▸ ALICIA LAKE RESERVOIR (3803711) ☆	673	2010-05-25
▸ SPRING PARK RESERVOIR (3803744) ☆	332	2022-08-14
▸ WOODS LAKE RESERVOIR (3803760) ☆	300	2005-10-31
▸ JACOBSON LAKES & PONDS (3803832) ☆	225	2002-10-31

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.

Or enter an administration number directly

Administration number
Simulate

DWR administration numbers encode appropriation and adjudication dates; lower is more senior.