The monitoring network within this area

Hydrionis holds 2,143 values from 7 gauges within it. Discharge is a property of a gauge and its reach, not of this drainage area, so this page reports the network and its records rather than a single figure.

7

Gauges

2,143

Values held

1909–2026

Record spans

Gauges within the Upper Snake-Rock huc8 subbasin

7 monitoring points, positioned as the publisher records them.

Flood peaks, as measured

This gauge's flood record, as measured. Unlike a daily mean it is the discharge at the moment the river was highest, which is the figure flood frequency analysis is built on.

Largest measured flow of each year at SNAKE RIVER NR KIMBERLY ID

The highest instantaneous discharge the publisher recorded in each year — a flood peak as measured, not a daily average of one. 1923–2009.

Show relevant events (1 event)Shading marks when something was recorded, not what caused the line.

Published by the gauge's own operator from its sub-daily record; Hydrionis stores the figure rather than recomputing it. A year the gauge did not cover produces no value rather than a low one, and the gaps are stated below the chart. A peak is a property of this gauge and its reach: a larger flood upstream or downstream of it is not in this series.

What the shaded periods are (1 event)

A shaded period marks when something was recorded, not what caused the shape of the line. Where the two coincide, they coincided.

Documented record — A documented event, compiled from cited sources after it happened. The dates are as good as the record, which for older events can mean the month rather than the day.

Event	Type	Period	Standing	Authority
Hurricane Katrina water and sanitation collapse	Flood	2005-08-29 – 2005-09-30	Documented record	Compiled record

Not shown on this chart

The 1976 drought — This event’s area does not contain this chart’s subject. Sharing a country is not sharing an event, so it is not drawn.
The 2022 drought — This event’s area does not contain this chart’s subject. Sharing a country is not sharing an event, so it is not drawn.
Yorkshire drought — This event’s area does not contain this chart’s subject. Sharing a country is not sharing an event, so it is not drawn.
Cantareira water crisis, São Paulo — This event’s area does not contain this chart’s subject. Sharing a country is not sharing an event, so it is not drawn.
Cape Town Day Zero — This event’s area does not contain this chart’s subject. Sharing a country is not sharing an event, so it is not drawn.
European drought — This event’s area does not contain this chart’s subject. Sharing a country is not sharing an event, so it is not drawn.

View the data behind this chart

Underlying data
Period	SNAKE RIVER NR KIMBERLY ID (m³/s)
1923	201
1925	561
1927	770
1928	626
1929	416
1930	197
1932	131
1933	51.3
1935	26.9
1936	600
1937	201
1938	612
1939	334
1940	139
1941	66.0
1942	396
1943	646
1944	544
1945	453
1946	541
1947	609
1948	473
1949	303
1950	535
1951	416
1952	419
1953	459
1954	274
1955	190
1956	561
1957	544
1958	220
1960	142
1961	60.3
1962	334
1963	487
1964	617
1965	447
1967	340
1968	337
1969	411
1970	436
1971	603
1972	564
1973	377
1974	541
1975	498
1976	544
1978	280
1979	317
1980	575
1981	391
1982	504
1983	674
1984	725
1986	603
1987	89.2
1989	53.5
1991	62.6
1993	419
1995	558
1996	657
1997	968
1998	473
1999	481
2006	123
2008	124
2009	527

About this series

Everything below is a property of the data rather than a rating of it. There is deliberately no single confidence score: how much a gap matters depends on what you are about to do with the series, and only you know that.

Source	United States Geological Survey — National Water Information System · US Government work — public domain
How the values came to exist	Measured
Period held	1923–2009
Completeness	78.2% of the periods in that span are held. Gaps are drawn as breaks and never interpolated.
Known gaps	14 separate periods inside 1923–2009 hold no value. The longest runs from 2000 to 2005 — 6 years with no reading. They are drawn as breaks in the line and are never interpolated across.
Continuity	The record begins in 1923 and is not continuous from it: 87 years separate the first value from the last, and 78% of the years between them are held. The span is not the record.
Last read from the publisher	2026-10-01
Redistribution	Permitted by the upstream licences
Commercial reuse	Permitted by the upstream licences. No Hydrionis access tier can widen this.
Methodology	How this was produced

How much of the rain came back out

A discharge in cubic metres per second cannot be compared with anything: the larger number may only mean the larger catchment. Divided by the area draining to the gauge it becomes a depth of water over that land, which answers a question a reader already has — of the rain that fell here, how much came back out as river?

Water leaving the catchment above SNAKE RIVER NR KIMBERLY ID, as a depth

The year's flow spread over the land draining to this gauge, in millimetres — the same unit rainfall is measured in. 1924–2024.

Show relevant events (1 event)Shading marks when something was recorded, not what caused the line.

Computed by Hydrionis from the published annual mean flow and the catchment area the station's own publisher states. It is not a water balance: the difference between rainfall and runoff is not evaporation alone but also change in groundwater storage, water abstracted and taken elsewhere, and water imported by transfer schemes — which is why a catchment can yield more runoff than the rain that fell on it without anything being measured wrongly. A different area figure rescales every value here by the ratio between them.

What the shaded periods are (1 event)

A shaded period marks when something was recorded, not what caused the shape of the line. Where the two coincide, they coincided.

Documented record — A documented event, compiled from cited sources after it happened. The dates are as good as the record, which for older events can mean the month rather than the day.

Event	Type	Period	Standing	Authority
Hurricane Katrina water and sanitation collapse	Flood	2005-08-29 – 2005-09-30	Documented record	Compiled record

Not shown on this chart

The 1976 drought — This event’s area does not contain this chart’s subject. Sharing a country is not sharing an event, so it is not drawn.
The 2022 drought — This event’s area does not contain this chart’s subject. Sharing a country is not sharing an event, so it is not drawn.
Yorkshire drought — This event’s area does not contain this chart’s subject. Sharing a country is not sharing an event, so it is not drawn.
Cantareira water crisis, São Paulo — This event’s area does not contain this chart’s subject. Sharing a country is not sharing an event, so it is not drawn.
Cape Town Day Zero — This event’s area does not contain this chart’s subject. Sharing a country is not sharing an event, so it is not drawn.
European drought — This event’s area does not contain this chart’s subject. Sharing a country is not sharing an event, so it is not drawn.

View the data behind this chart

Underlying data
Period	SNAKE RIVER NR KIMBERLY ID (mm)
1924	34.0
1925	86.0
1926	31.0
1927	63.0
1928	86.0
1929	52.0
1930	29.0
1931	14.0
1932	14.0
1933	14.0
1934	9.00
1935	8.00
1936	23.0
1937	17.0
1938	38.0
1939	29.0
1940	12.0
1941	11.0
1942	24.0
1943	71.0
1944	33.0
1945	43.0
1946	58.0
1947	44.0
1948	50.0
1949	44.0
1950	69.0
1951	80.0
1952	73.0
1953	34.0
1954	30.0
1955	23.0
1956	64.0
1957	45.0
1958	26.0
1959	14.0
1960	12.0
1961	9.00
1962	29.0
1963	31.0
1964	47.0
1965	75.0
1966	34.0
1967	24.0
1968	31.0
1969	53.0
1970	54.0
1971	130
1972	113
1973	52.0
1974	92.0
1975	96.0
1976	108
1977	19.0
1978	40.0
1979	44.0
1980	38.0
1981	33.0
1982	98.0
1983	134
1984	158
1985	78.0
1986	138
1987	29.0
1988	12.0
1989	15.0
1990	10.0
1991	12.0
1992	10.0
1993	25.0
1994	24.0
1995	39.0
1996	91.0
1997	165
1998	95.0
1999	95.0
2000	37.0
2001	10.0
2002	10.0
2003	9.00
2004	9.00
2005	12.0
2006	40.0
2007	18.0
2008	15.0
2009	47.0
2010	22.0
2011	110
2012	34.0
2013	12.0
2014	13.0
2015	16.0
2016	10.0
2017	80.0
2018	72.0
2019	38.0
2020	25.0
2021	10.0
2023	9.00
2024	24.0

About this series

Everything below is a property of the data rather than a rating of it. There is deliberately no single confidence score: how much a gap matters depends on what you are about to do with the series, and only you know that.

Source	United States Geological Survey — National Water Information System · US Government work — public domain
How the values came to exist	Derived Computed by Hydrionis
Period held	1924–2024
Completeness	99.0% of the periods in that span are held. Gaps are drawn as breaks and never interpolated.
Known gaps	One period inside 1924–2024 holds no value: 2022. It is drawn as a break in the line and is never interpolated across.
Continuity	The record begins in 1924 and is not continuous from it: 101 years separate the first value from the last, and 99% of the years between them are held. The span is not the record.
Inputs last read	2026-10-01 · when the records this was computed from were last read from their publishers
Calculation date	2026-08-24 · when the calculation method was last versioned, not a reading of any publisher
Redistribution	Permitted by the upstream licences
Commercial reuse	Permitted by the upstream licences. No Hydrionis access tier can widen this.
Methodology	How this was produced

The snow standing above this water

2 automated snow stations sit inside this drainage area, weighing the snowpack rather than measuring how deep it is.

857

Fullest snowpack recorded at Magic Mountain, in 1984 (mm of water)

165

Thinnest, in 2026 (mm of water)

March

Month the pack is usually at its fullest

June

Month the pack has gone by, in half of years

Peak snowpack at Magic Mountain

Water years 1981–2026. Each point is the fullest month of that snow season.

A water year runs October to September and is named for the year it ends, so the snow of one winter stays in one point. The value is the fullest month, not the fullest day: a pack that peaked sharply mid-month reads lower here than a single measurement taken at the right moment would.

View the data behind this chart

Underlying data
Period	Magic Mountain (mm)
1981	279
1982	690
1983	628
1984	857
1985	487
1986	566
1987	260
1988	357
1989	555
1990	318
1991	334
1992	234
1993	500
1994	326
1995	380
1996	500
1997	697
1998	471
1999	518
2000	458
2001	311
2002	502
2003	272
2004	573
2005	392
2006	687
2007	368
2008	512
2009	513
2010	389
2011	561
2012	460
2013	380
2014	419
2015	406
2016	515
2017	498
2018	300
2019	501
2020	510
2021	395
2022	396
2023	759
2024	610
2025	586
2026	165

Why the snow is not read against the river here

MILNER LOW LIFT CANAL NR MILNER ID measures a canal, not a natural channel. What passes through it is an operating decision — how much was diverted, and when — so comparing it with what the sky or the mountain delivered would describe the operator rather than the hydrology.

Every gauge Hydrionis holds within this area

Gauges within the Upper Snake-Rock and what each holds
Gauge	Measures	Values	Record
SNAKE RIVER NR KIMBERLY ID	burned area within 50 km, catchment area, annual maximum river flow, mean river flow, mean river flow, water year	316	1923–2026
SNAKE RIVER AT MILNER ID TOTAL FLOW	burned area within 50 km, catchment area, annual maximum river flow, mean river flow, mean river flow, water year	303	1918–2026
NORTH SIDE TWIN FALLS CANAL AT MILNER ID	burned area within 50 km, mean river flow, mean river flow, water year	170	1909–2019
MILNER LOW LIFT CANAL NR MILNER ID	burned area within 50 km, mean river flow, mean river flow, water year	150	1920–2019
SNAKE RIVER NR TWIN FALLS ID	catchment area, annual maximum river flow	43	1913–2026
ROCK CREEK NR ROCK CREEK ID	catchment area, annual maximum river flow	32	1944–2026
ROCK CREEK BELOW POLELINE ROAD NR TWIN FALLS ID	catchment area, annual maximum river flow	30	1922–2026

How these gauges were attached to this water

Assigned by the publisher to a numbered basin Every gauge here is assigned to this drainage area by its own publisher, which issues the area an official code — 17040212. A drainage area is not a river: it contains the tributaries as well as the main channel, and a gauge in it may be on any of them.

What each gauge’s link to this water rests on
Gauge	Evidence	Established
SNAKE RIVER NR KIMBERLY ID	Stated by the publisher — USGS site service, huc_cd field — https://waterservices.usgs.gov/nwis/site/ ; named from the USGS Watershed Boundary Dataset 8-digit HU (Subbasin) layer — https://hydro.nationalmap.gov/arcgis/rest/services/wbd/MapServer/4	2026-10-02
SNAKE RIVER AT MILNER ID TOTAL FLOW	Stated by the publisher — USGS site service, huc_cd field — https://waterservices.usgs.gov/nwis/site/ ; named from the USGS Watershed Boundary Dataset 8-digit HU (Subbasin) layer — https://hydro.nationalmap.gov/arcgis/rest/services/wbd/MapServer/4	2026-10-02
NORTH SIDE TWIN FALLS CANAL AT MILNER ID	Stated by the publisher — USGS site service, huc_cd field — https://waterservices.usgs.gov/nwis/site/ ; named from the USGS Watershed Boundary Dataset 8-digit HU (Subbasin) layer — https://hydro.nationalmap.gov/arcgis/rest/services/wbd/MapServer/4	2026-10-02
MILNER LOW LIFT CANAL NR MILNER ID	Stated by the publisher — USGS site service, huc_cd field — https://waterservices.usgs.gov/nwis/site/ ; named from the USGS Watershed Boundary Dataset 8-digit HU (Subbasin) layer — https://hydro.nationalmap.gov/arcgis/rest/services/wbd/MapServer/4	2026-10-02
SNAKE RIVER NR TWIN FALLS ID	Stated by the publisher — USGS site service, huc_cd field — https://waterservices.usgs.gov/nwis/site/ ; named from the USGS Watershed Boundary Dataset 8-digit HU (Subbasin) layer — https://hydro.nationalmap.gov/arcgis/rest/services/wbd/MapServer/4	2026-10-02
ROCK CREEK NR ROCK CREEK ID	Stated by the publisher — USGS site service, huc_cd field — https://waterservices.usgs.gov/nwis/site/ ; named from the USGS Watershed Boundary Dataset 8-digit HU (Subbasin) layer — https://hydro.nationalmap.gov/arcgis/rest/services/wbd/MapServer/4	2026-10-02
ROCK CREEK BELOW POLELINE ROAD NR TWIN FALLS ID	Stated by the publisher — USGS site service, huc_cd field — https://waterservices.usgs.gov/nwis/site/ ; named from the USGS Watershed Boundary Dataset 8-digit HU (Subbasin) layer — https://hydro.nationalmap.gov/arcgis/rest/services/wbd/MapServer/4	2026-10-02

What this record holds

Hydrionis decides which waters get a page, and which of those are offered to search, from what is actually held rather than from how the page reads. Five signals are counted; this record has 5 of them, which makes it a full profile.

Information-gain signals held for this water body
Signal	Held	Counts
Gauges holding a real record	4	yes, 3 or more
Years spanned	118	yes, 20 or more
Values held	2,143	yes, 1000 or more
Distinct measurements	6	yes, 2 or more
Publishers measuring it	2	yes, 2 or more
Official identifiers	1	recorded, not counted

Use this data

Machine-readable JSON /api/v1/observations/by-subject/gauge-usgs-13090000.json
How to cite this, and who you must credit
How these figures were produced
Request this at a different scale, format or geography

No bulk download is offered here, which is a licence position rather than a product one: at least one contributing publisher does not permit redistribution. The values can be read on the page, cited, and pointed to at source.

Attribution and citation

Suggested citation for Hydrionis

Hydrionis (2026), Upper Snake-Rock gauge records, accessed 2026-10-05, hydrionis.com/waters/united-states-upper-snake-rock/

Cite Hydrionis where you rely on values Hydrionis computed, on the method that produced them, or on the compilation itself. The underlying measurements remain the publishers’ and their attribution requirements apply to you directly.

Recommended, not required. Hydrionis does not claim rights over unmodified public data it relayed, and doing arithmetic on somebody else’s measurements does not make them Hydrionis’s. Cite the version and the access date: the Upper Snake-Rock gauge records changes as publishers release and as methods are revised, and a citation without both cannot be checked later. Full guidance is on cite and reuse.

None of the contributing licences requires attribution. Crediting the publishers is still good practice and they are listed above.

Where these figures come from

MeasuredHigh confidence2009-04-17

Source: USGS — National Water Information System, USGS site 13090000, annual peak streamflow. Licence: Open.

Method: The instantaneous maximum discharge of each water year as published by USGS, dated to the day it occurred. One value per October-to-September water year; where the publisher lists both a systematic and a historic peak for a year, the larger is the annual maximum. Values the publisher marks as maximum daily averages are not held here, because they are not instantaneous peaks. Values marked as bounded rather than measured are held as censored observations carrying the bound. Cubic feet per second are converted to cubic metres per second and the publisher unit is recorded alongside.

Rating curves are extrapolated at extreme discharges, so the largest values in a peak series carry the largest measurement uncertainty. Data from the U.S. Geological Survey National Water Information System, a work of the United States government and therefore in the public domain.

Retrieved 1 October 2026.