The monitoring network within this area

Hydrionis holds 363 values from 3 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

363

Values held

1913–2026

Record spans

Gauges within the San Luis Rey-Escondido huc8 subbasin

3 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 SAN LUIS REY R A OCEANSIDE CA

The highest instantaneous discharge the publisher recorded in each year — a flood peak as measured, not a daily average of one. 1913–2025.

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	SAN LUIS REY R A OCEANSIDE CA (m³/s)
1913	9.63
1914	178
1915	198
1930	9.34
1932	114
1933	4.13
1935	9.20
1936	2.75
1937	467
1938	467
1940	21.1
1942	8.50
1952	13.3
1958	49.8
1965	17.7
1966	133
1968	4.16
1969	326
1970	15.0
1971	1.19
1973	4.39
1974	14.3
1975	4.36
1976	4.36
1977	7.45
1978	277
1979	144
1980	708
1981	27.5
1982	162
1983	265
1984	12.1
1986	68.2
1987	5.52
1988	9.09
1990	1.44
1991	131
1992	12.8
1993	728
1994	8.61
1995	552
1996	4.76
1997	25.4
1999	5.61
2000	4.42
2001	7.87
2002	0.793
2003	17.2
2004	7.42
2005	617
2006	6.65
2007	2.07
2008	96.3
2010	59.2
2012	2.38
2013	4.47
2017	77.9
2018	3.43
2019	233
2020	156
2021	2.70
2023	86.4
2024	30.6
2025	3.85

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	1913–2025
Completeness	56.6% of the periods in that span are held. Gaps are drawn as breaks and never interpolated.
Known gaps	17 separate periods inside 1913–2025 hold no value. The longest runs from 1916 to 1929 — 14 years with no reading. They are drawn as breaks in the line and are never interpolated across.
Continuity	The record begins in 1913 and is not continuous from it: 113 years separate the first value from the last, and 57% 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 SAN LUIS REY R A OCEANSIDE CA, as a depth

The year's flow spread over the land draining to this gauge, in millimetres — the same unit rainfall is measured in. 1930–2025.

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	SAN LUIS REY R A OCEANSIDE CA (mm)
1930	2.00
1931	0
1932	35.0
1933	4.00
1934	0
1935	4.00
1936	3.00
1937	87.0
1938	67.0
1939	14.0
1940	14.0
1941	71.0
1947	0
1948	0
1949	0
1950	0
1951	0
1952	1.00
1953	0
1954	0
1955	0
1956	0
1957	0
1958	2.00
1959	0
1960	0
1961	0
1962	0
1963	0
1964	0
1965	1.00
1966	4.00
1967	1.00
1968	2.00
1969	22.0
1970	4.00
1971	3.00
1972	3.00
1973	8.00
1974	7.00
1975	7.00
1976	5.00
1977	8.00
1978	104
1979	105
1980	262
1981	24.0
1982	48.0
1983	132
1984	19.0
1985	19.0
1986	35.0
1987	16.0
1988	15.0
1989	8.00
1990	6.00
1991	27.0
1994	16.0
1995	116
1996	11.0
1999	8.00
2000	5.00
2001	14.0
2002	4.00
2003	21.0
2004	19.0
2005	134
2006	15.0
2007	8.00
2008	32.0
2009	8.00
2010	37.0
2011	25.0
2012	7.00
2013	1.00
2014	0
2015	0
2016	0
2017	20.0
2018	1.00
2019	25.0
2020	26.0
2021	4.00
2022	1.00
2023	38.0
2024	22.0
2025	4.00

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	1930–2025
Completeness	90.6% of the periods in that span are held. Gaps are drawn as breaks and never interpolated.
Known gaps	3 separate periods inside 1930–2025 hold no value. The longest runs from 1942 to 1946 — 5 years with no reading. They are drawn as breaks in the line and are never interpolated across.
Continuity	The record begins in 1930 and is not continuous from it: 96 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

Every gauge Hydrionis holds within this area

Gauges within the San Luis Rey-Escondido and what each holds
Gauge	Measures	Values	Record
SAN LUIS REY R A OCEANSIDE CA	burned area within 50 km, catchment area, annual maximum river flow, mean river flow, mean river flow, water year	286	1913–2026
SAN LUIS REY R NR BONSALL CA	catchment area, annual maximum river flow	46	1930–2026
WF SAN LUIS REY R NR WARNER SPRINGS CA	catchment area, annual maximum river flow	31	1914–2026

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 — 18070303. 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
SAN LUIS REY R A OCEANSIDE 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
SAN LUIS REY R NR BONSALL 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
WF SAN LUIS REY R NR WARNER SPRINGS 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 3 of them, which makes it a full profile.

Information-gain signals held for this water body
Signal	Held	Counts
Gauges holding a real record	1	no
Years spanned	114	yes, 20 or more
Values held	363	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-11042000.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), San Luis Rey-Escondido gauge records, accessed 2026-10-05, hydrionis.com/waters/united-states-san-luis-rey-escondido/

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 San Luis Rey-Escondido 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 confidence2025-03-14

Source: USGS — National Water Information System, USGS site 11042000, 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.