The monitoring network within this area

Hydrionis holds 2,046 values from 2 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.

2

Gauges

2,046

Values held

1904–2026

Record spans

Gauges within the Big Lost huc8 subbasin

2 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 BIG LOST RIVER AT HOWELL RANCH NR CHILLY ID

The highest instantaneous discharge the publisher recorded in each year — a flood peak as measured, not a daily average of one. 1910–2024.

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	BIG LOST RIVER AT HOWELL RANCH NR CHILLY ID (m³/s)
1910	25.9
1912	57.5
1913	79.9
1914	71.9
1920	45.9
1921	99.1
1922	95.1
1923	66.8
1924	26.4
1925	63.4
1926	23.5
1927	70.5
1928	57.2
1929	44.2
1930	54.1
1931	23.6
1932	68.0
1933	54.1
1934	18.1
1935	64.0
1936	34.8
1937	25.8
1938	89.8
1939	28.3
1940	38.2
1941	43.3
1942	58.6
1943	67.1
1944	65.4
1945	53.5
1946	47.0
1947	53.5
1948	67.7
1949	43.9
1950	43.3
1951	62.6
1952	83.8
1953	68.0
1954	112
1955	49.3
1956	96.6
1957	101
1958	92.9
1959	47.3
1960	43.9
1961	41.3
1962	59.7
1963	73.1
1964	58.0
1965	97.7
1966	32.6
1967	125
1968	59.7
1969	88.9
1970	91.7
1971	79.6
1972	91.5
1973	56.4
1974	99.4
1975	93.7
1976	52.7
1977	48.1
1978	65.4
1980	58.9
1981	83.8
1982	83.0
1983	105
1984	92.6
1985	34.0
1986	109
1987	50.7
1988	38.5
1989	40.8
1990	62.9
1991	71.6
1992	20.1
1993	69.1
1994	34.3
1995	104
1996	83.3
1997	89.5
1998	69.7
1999	91.2
2000	41.6
2001	26.2
2002	49.0
2005	95.7
2006	142
2007	30.6
2008	49.6
2009	66.8
2010	85.0
2011	75.0
2012	75.9
2013	39.9
2014	32.3
2015	43.6
2016	62.3
2017	119
2018	71.4
2019	77.6
2020	47.6
2021	31.7
2022	116
2023	88.3
2024	49.6

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	1910–2024
Completeness	92.2% of the periods in that span are held. Gaps are drawn as breaks and never interpolated.
Known gaps	4 separate periods inside 1910–2024 hold no value. The longest runs from 1915 to 1919 — 5 years with no reading. They are drawn as breaks in the line and are never interpolated across.
Continuity	The record begins in 1910 and is not continuous from it: 115 years separate the first value from the last, and 92% 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 BIG LOST RIVER BL MACKAY RES NR MACKAY 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. 1904–2025.

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	BIG LOST RIVER BL MACKAY RES NR MACKAY ID (mm)
1904	171
1905	109
1913	168
1914	160
1919	90.0
1920	91.0
1921	163
1922	154
1923	148
1924	77.0
1925	134
1926	80.0
1927	122
1928	114
1929	79.0
1930	99.0
1931	68.0
1932	112
1933	89.0
1934	53.0
1935	102
1936	83.0
1937	69.0
1938	162
1939	97.0
1940	94.0
1941	107
1942	141
1943	185
1944	166
1945	122
1946	128
1947	133
1948	131
1949	112
1950	106
1951	147
1952	177
1953	138
1954	122
1955	99.0
1956	164
1957	145
1958	178
1959	94.0
1960	89.0
1961	75.0
1962	108
1963	138
1964	140
1965	243
1966	104
1967	213
1968	128
1969	214
1970	159
1971	193
1972	150
1973	120
1974	195
1975	190
1976	160
1977	83.0
1978	140
1979	117
1980	151
1981	155
1982	201
1983	255
1984	265
1985	142
1986	189
1987	105
1988	81.0
1989	82.0
1990	89.0
1991	97.0
1992	73.0
1993	133
1994	81.0
1995	191
1996	155
1997	184
1998	158
1999	162
2000	99.0
2001	74.0
2002	76.0
2003	81.0
2004	71.0
2005	115
2006	168
2007	87.0
2008	94.0
2009	127
2010	117
2011	135
2012	122
2013	92.0
2014	70.0
2015	88.0
2016	105
2017	234
2018	166
2019	139
2020	91.0
2021	60.0
2022	88.0
2023	168
2024	102
2025	88.0

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	1904–2025
Completeness	91.0% of the periods in that span are held. Gaps are drawn as breaks and never interpolated.
Known gaps	2 separate periods inside 1904–2025 hold no value. The longest runs from 1906 to 1912 — 7 years with no reading. They are drawn as breaks in the line and are never interpolated across.
Continuity	The record begins in 1904 and is not continuous from it: 122 years separate the first value from the last, and 91% 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

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

696

Fullest snowpack recorded at Bear Canyon, in 1983 (mm of water)

199

Thinnest, in 1987 (mm of water)

April

Month the pack is usually at its fullest

June

Month the pack has gone by, in half of years

Peak snowpack at Bear Canyon

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	Bear Canyon (mm)
1981	355
1982	689
1983	696
1984	437
1985	334
1986	569
1987	199
1988	268
1989	393
1990	247
1991	282
1992	263
1993	440
1994	202
1995	604
1996	443
1997	605
1998	401
1999	507
2000	325
2001	227
2002	320
2003	394
2004	328
2005	326
2006	582
2007	222
2008	385
2009	385
2010	236
2011	451
2012	308
2013	294
2014	260
2015	222
2016	321
2017	621
2018	303
2019	483
2020	261
2021	217
2022	285
2023	489
2024	333
2025	351
2026	362

Read against the river

Bear Canyon and BIG LOST RIVER AT HOWELL RANCH NR CHILLY ID both sit in this drainage area, and their records overlap by 44 years. That is the span the two have in common, not a count of years both actually hold — either record may have gaps inside it. The two are shown separately rather than on one axis: millimetres of stored water and cubic metres per second are not commensurable, and a difference between them would mean nothing.

Being in the same drainage area does not put the snowpack upstream of the gauge. A subbasin is an area, and snow on one tributary can join the river below a gauge on another — so a weak relationship here may say more about which tributary was measured than about the snow.

Every gauge Hydrionis holds within this area

Gauges within the Big Lost and what each holds
Gauge	Measures	Values	Record
BIG LOST RIVER BL MACKAY RES NR MACKAY ID	burned area within 50 km, catchment area, annual maximum river flow, mean river flow, mean river flow, water year	344	1904–2026
BIG LOST RIVER AT HOWELL RANCH NR CHILLY ID	burned area within 50 km, catchment area, annual maximum river flow, mean river flow, mean river flow, water year	297	1904–2026

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 — 17040218. 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
BIG LOST RIVER BL MACKAY RES NR MACKAY 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
BIG LOST RIVER AT HOWELL RANCH NR CHILLY 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 4 of them, which makes it a full profile.

Information-gain signals held for this water body
Signal	Held	Counts
Gauges holding a real record	2	no
Years spanned	123	yes, 20 or more
Values held	2,046	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-13127000.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), Big Lost gauge records, accessed 2026-10-05, hydrionis.com/waters/united-states-big-lost/

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 Big Lost 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 confidence2024-06-13

Source: USGS — National Water Information System, USGS site 13127000, 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.