The monitoring network within this area

Hydrionis holds 915 values from 6 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.

Gauges

915

Values held

1911–2026

Record spans

Gauges within the Santa Clara huc8 subbasin

6 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 SANTA PAULA C NR SANTA PAULA

The highest instantaneous discharge the publisher recorded in each year — a flood peak as measured, not a daily average of one. 1933–2025.

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	SANTA PAULA C NR SANTA PAULA (m³/s)
1933	75.0
1935	43.3
1936	82.1
1937	38.2
1938	382
1939	10.5
1940	10.3
1941	89.2
1943	283
1944	53.8
1945	70.8
1946	38.2
1948	2.41
1949	4.16
1950	18.7
1951	0.224
1952	207
1954	27.7
1955	2.21
1956	23.6
1957	23.4
1958	259
1959	27.0
1960	4.42
1962	89.2
1963	19.4
1964	16.2
1965	15.5
1966	127
1967	9.77
1969	595
1970	26.6
1971	26.5
1973	379
1974	17.4
1976	13.0
1977	3.79
1978	453
1979	104
1980	334
1981	14.9
1982	54.1
1983	135
1984	2.55
1986	101
1987	4.81
1988	55.2
1989	3.09
1990	14.1
1991	28.6
1992	283
1993	202
1994	19.8
1995	230
1996	34.8
1999	2.75
2000	39.9
2001	98.5
2003	22.1
2004	68.2
2005	779
2006	86.1
2007	2.04
2008	130
2009	8.13
2010	86.1
2011	354
2012	22.7
2013	0.510
2014	34.8
2016	17.7
2017	111
2018	25.5
2019	98.5
2020	28.9
2021	0.323
2023	385
2024	110
2025	21.8

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	1933–2025
Completeness	84.9% of the periods in that span are held. Gaps are drawn as breaks and never interpolated.
Known gaps	13 separate periods inside 1933–2025 hold no value. The longest runs from 1997 to 1998 — 2 years with no reading. They are drawn as breaks in the line and are never interpolated across.
Continuity	The record begins in 1933 and is not continuous from it: 93 years separate the first value from the last, and 85% 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 SANTA PAULA C NR SANTA PAULA, as a depth

The year's flow spread over the land draining to this gauge, in millimetres — the same unit rainfall is measured in. 1928–2024.

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	SANTA PAULA C NR SANTA PAULA (mm)
1928	19.0
1929	18.0
1930	20.0
1931	65.0
1932	226
1933	119
1934	134
1935	142
1936	187
1937	388
1938	560
1939	83.0
1940	73.0
1941	730
1942	62.0
1943	508
1944	280
1945	165
1946	153
1947	44.0
1948	20.0
1949	27.0
1950	41.0
1951	17.0
1952	395
1953	38.0
1954	74.0
1955	36.0
1956	64.0
1957	75.0
1958	559
1959	63.0
1960	31.0
1961	14.0
1962	326
1963	43.0
1964	40.0
1965	272
1966	237
1967	390
1968	70.0
1969	1,407
1970	160
1971	110
1972	36.0
1973	445
1974	145
1975	130
1976	48.0
1977	39.0
1978	1,086
1979	244
1980	424
1981	69.0
1982	158
1983	881
1984	56.0
1985	42.0
1986	251
1987	35.0
1988	92.0
1989	32.0
1990	30.0
1991	194
1992	429
1993	888
1994	96.0
1995	788
1996	157
1999	53.0
2000	107
2001	310
2002	29.0
2003	104
2004	149
2005	1,254
2006	278
2007	35.0
2008	348
2009	81.0
2010	220
2011	371
2012	44.0
2013	11.0
2014	25.0
2015	9.00
2016	19.0
2017	190
2018	56.0
2019	294
2020	108
2021	31.0
2022	55.0
2023	1,004
2024	465

About this series

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	1928–2024
Completeness	97.9% of the periods in that span are held. Gaps are drawn as breaks and never interpolated.
Known gaps	One period inside 1928–2024 holds no value: 1997 to 1998, 2 years with no reading. It is drawn as a break in the line and is never interpolated across.
Continuity	The record begins in 1928 and is not continuous from it: 97 years separate the first value from the last, and 98% 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

Every gauge Hydrionis holds within this area

Gauges within the Santa Clara and what each holds
Gauge	Measures	Values	Record
SANTA PAULA C NR SANTA PAULA	burned area within 50 km, catchment area, annual maximum river flow, mean river flow, mean river flow, water year	321	1927–2026
SESPE C NR FILLMORE	burned area within 50 km, catchment area, annual maximum river flow, mean river flow, mean river flow, water year	308	1911–2026
SANTA CLARA RIVER AT MONTALVO CA	burned area within 50 km, catchment area, annual maximum river flow, mean river flow, mean river flow, water year	197	1927–2026
PIRU C NR PIRU CA	catchment area, annual maximum river flow	31	1933–2026
SANTA CLARA R NR SAUGUS CA	catchment area, annual maximum river flow	30	1930–2026
SANTA CLARA R NR PIRU CA	catchment area, annual maximum river flow	28	1999–2026

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 — 18070102. 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
SANTA PAULA C NR SANTA PAULA	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
SESPE C NR FILLMORE	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
SANTA CLARA RIVER AT MONTALVO CA	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
PIRU C NR PIRU CA	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
SANTA CLARA R NR SAUGUS CA	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
SANTA CLARA R NR PIRU CA	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	3	yes, 3 or more
Years spanned	116	yes, 20 or more
Values held	915	no
Distinct measurements	5	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-11113500.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), Santa Clara gauge records, accessed 2026-10-05, hydrionis.com/waters/united-states-santa-clara/

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 Santa Clara 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 confidence2025-02-13

Source: USGS — National Water Information System, USGS site 11113500, 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.