The monitoring network within this area

Hydrionis holds 239 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
239
Values held
1924–2026
Record spans
Gauges within the West Fork San Jacinto huc8 subbasin
2 monitoring points, positioned as the publisher records them.
Gauges within the West Fork San Jacinto huc8 subbasinW Fk San Jacinto Rv nr Conroe, TX, W Fk San Jacinto Rv nr Humble, TXW Fk San Jacinto Rv nr Conroe, TXW Fk San Jacinto Rv nr Humble, TX

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 W Fk San Jacinto Rv nr Conroe, TX
The highest instantaneous discharge the publisher recorded in each year — a flood peak as measured, not a daily average of one. 1924–2025.
Shading marks when something was recorded, not what caused the line.
Largest measured flow of each year at W Fk San Jacinto Rv nr Conroe, TXLargest measured flow of each year at W Fk San Jacinto Rv nr Conroe, TX: W Fk San Jacinto Rv nr Conroe, TX in m³/s, from 1924 to 2025.Hurricane Katrina water and sanitation collapse01,0002,0003,0004,000m³/s19241948196019721983199520092021

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.

EventTypePeriodStandingAuthority
Hurricane Katrina water and sanitation collapseFlood2005-08-29 – 2005-09-30Documented 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
PeriodW Fk San Jacinto Rv nr Conroe, TX (m³/s)
19241,076
192512.5
19262,265
1927926
1940371
1942442
1943127
1944294
19451,164
1946711
194894.0
1949311
19501,048
195154.4
1952259
1953340
1955331
195673.1
1957396
1959487
1960731
196292.9
1964103
1965413
1966320
196746.7
1968688
1969371
197061.2
197143.6
1972147
1973547
1974357
1976213
1977334
1978185
19791,090
1980177
1981394
1982274
1983920
1984203
1985447
1987150
1989186
1990167
1991261
1992278
1993270
1994119
1995133
1997199
1998481
200028.0
2001682
20021,093
2004515
200551.8
2007575
2008214
2009236
201017.5
2012214
201347.0
2014127
2015654
20161,671
20173,455
2018496
202069.1
2021413
2022167
2023470
20242,217
2025150

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 existMeasured
Period held1924–2025
Completeness73.5% of the periods in that span are held. Gaps are drawn as breaks and never interpolated.
Known gaps
  • 16 separate periods inside 1924–2025 hold no value. The longest runs from 1928 to 1939 — 12 years with no reading. They are drawn as breaks in the line and are never interpolated across.
ContinuityThe record begins in 1924 and is not continuous from it: 102 years separate the first value from the last, and 74% of the years between them are held. The span is not the record.
Last read from the publisher2026-10-01
RedistributionPermitted by the upstream licences
Commercial reusePermitted by the upstream licences. No Hydrionis access tier can widen this.
MethodologyHow 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 W Fk San Jacinto Rv nr Conroe, TX, as a depth
The year's flow spread over the land draining to this gauge, in millimetres — the same unit rainfall is measured in. 1973–2025.
Shading marks when something was recorded, not what caused the line.
Water leaving the catchment above W Fk San Jacinto Rv nr Conroe, TX, as a depthWater leaving the catchment above W Fk San Jacinto Rv nr Conroe, TX, as a depth: W Fk San Jacinto Rv nr Conroe, TX in mm, from 1973 to 2025.Hurricane Katrina water and sanitation collapse0200400600800mm19731980198719942001200820152022W Fk San Jacinto Rv nr Conroe, TX 1973: 324 mmW Fk San Jacinto Rv nr Conroe, TX 1974: 300 mmW Fk San Jacinto Rv nr Conroe, TX 1975: 255 mmW Fk San Jacinto Rv nr Conroe, TX 1976: 213 mmW Fk San Jacinto Rv nr Conroe, TX 1977: 175 mmW Fk San Jacinto Rv nr Conroe, TX 1978: 112 mmW Fk San Jacinto Rv nr Conroe, TX 1979: 550 mmW Fk San Jacinto Rv nr Conroe, TX 1980: 123 mmW Fk San Jacinto Rv nr Conroe, TX 1981: 145 mmW Fk San Jacinto Rv nr Conroe, TX 1982: 192 mmW Fk San Jacinto Rv nr Conroe, TX 1983: 328 mmW Fk San Jacinto Rv nr Conroe, TX 1984: 185 mmW Fk San Jacinto Rv nr Conroe, TX 1985: 238 mmW Fk San Jacinto Rv nr Conroe, TX 1986: 175 mmW Fk San Jacinto Rv nr Conroe, TX 1987: 180 mmW Fk San Jacinto Rv nr Conroe, TX 1988: 74.0 mmW Fk San Jacinto Rv nr Conroe, TX 1989: 116 mmW Fk San Jacinto Rv nr Conroe, TX 1990: 121 mmW Fk San Jacinto Rv nr Conroe, TX 1991: 322 mmW Fk San Jacinto Rv nr Conroe, TX 1992: 398 mmW Fk San Jacinto Rv nr Conroe, TX 1993: 298 mmW Fk San Jacinto Rv nr Conroe, TX 1994: 447 mmW Fk San Jacinto Rv nr Conroe, TX 1995: 275 mmW Fk San Jacinto Rv nr Conroe, TX 1996: 28.0 mmW Fk San Jacinto Rv nr Conroe, TX 1997: 248 mmW Fk San Jacinto Rv nr Conroe, TX 1998: 506 mmW Fk San Jacinto Rv nr Conroe, TX 1999: 73.0 mmW Fk San Jacinto Rv nr Conroe, TX 2000: 64.0 mmW Fk San Jacinto Rv nr Conroe, TX 2001: 388 mmW Fk San Jacinto Rv nr Conroe, TX 2002: 321 mmW Fk San Jacinto Rv nr Conroe, TX 2003: 131 mmW Fk San Jacinto Rv nr Conroe, TX 2004: 357 mmW Fk San Jacinto Rv nr Conroe, TX 2005: 130 mmW Fk San Jacinto Rv nr Conroe, TX 2006: 84.0 mmW Fk San Jacinto Rv nr Conroe, TX 2007: 257 mmW Fk San Jacinto Rv nr Conroe, TX 2008: 144 mmW Fk San Jacinto Rv nr Conroe, TX 2009: 166 mmW Fk San Jacinto Rv nr Conroe, TX 2010: 86.0 mmW Fk San Jacinto Rv nr Conroe, TX 2011: 39.0 mmW Fk San Jacinto Rv nr Conroe, TX 2012: 82.0 mmW Fk San Jacinto Rv nr Conroe, TX 2013: 36.0 mmW Fk San Jacinto Rv nr Conroe, TX 2014: 83.0 mmW Fk San Jacinto Rv nr Conroe, TX 2015: 487 mmW Fk San Jacinto Rv nr Conroe, TX 2016: 504 mmW Fk San Jacinto Rv nr Conroe, TX 2017: 408 mmW Fk San Jacinto Rv nr Conroe, TX 2018: 354 mmW Fk San Jacinto Rv nr Conroe, TX 2019: 219 mmW Fk San Jacinto Rv nr Conroe, TX 2020: 63.0 mmW Fk San Jacinto Rv nr Conroe, TX 2021: 281 mmW Fk San Jacinto Rv nr Conroe, TX 2022: 99.0 mmW Fk San Jacinto Rv nr Conroe, TX 2023: 212 mmW Fk San Jacinto Rv nr Conroe, TX 2024: 713 mmW Fk San Jacinto Rv nr Conroe, TX 2025: 126 mm

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.

EventTypePeriodStandingAuthority
Hurricane Katrina water and sanitation collapseFlood2005-08-29 – 2005-09-30Documented 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
PeriodW Fk San Jacinto Rv nr Conroe, TX (mm)
1973324
1974300
1975255
1976213
1977175
1978112
1979550
1980123
1981145
1982192
1983328
1984185
1985238
1986175
1987180
198874.0
1989116
1990121
1991322
1992398
1993298
1994447
1995275
199628.0
1997248
1998506
199973.0
200064.0
2001388
2002321
2003131
2004357
2005130
200684.0
2007257
2008144
2009166
201086.0
201139.0
201282.0
201336.0
201483.0
2015487
2016504
2017408
2018354
2019219
202063.0
2021281
202299.0
2023212
2024713
2025126

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 existDerived Computed by Hydrionis
Period held1973–2025
Completeness100.0% of the periods in that span are held.
ContinuityContinuous: every year from 1973 to 2025 is held.
Inputs last read2026-10-01 · when the records this was computed from were last read from their publishers
Calculation date2026-08-24 · when the calculation method was last versioned, not a reading of any publisher
RedistributionPermitted by the upstream licences
Commercial reusePermitted by the upstream licences. No Hydrionis access tier can widen this.
MethodologyHow this was produced

Every gauge Hydrionis holds within this area

Gauges within the West Fork San Jacinto and what each holds
GaugeMeasuresValuesRecord
W Fk San Jacinto Rv nr Conroe, TXcatchment area, annual maximum river flow, mean river flow, mean river flow, water year1971924–2026
W Fk San Jacinto Rv nr Humble, TXcatchment area, annual maximum river flow421929–2026

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 — 12040101. 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
GaugeEvidenceEstablished
W Fk San Jacinto Rv nr Conroe, TXStated 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/42026-10-02
W Fk San Jacinto Rv nr Humble, TXStated 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/42026-10-02

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 2 of them, which makes it a profile, not indexed.

Information-gain signals held for this water body
SignalHeldCounts
Gauges holding a real record1no
Years spanned103yes, 20 or more
Values held239no
Distinct measurements4yes, 2 or more
Publishers measuring it1no
Official identifiers1recorded, not counted

Use this data

Use this data

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), West Fork San Jacinto gauge records, accessed 2026-10-05, hydrionis.com/waters/united-states-west-fork-san-jacinto/

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 West Fork San Jacinto 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 confidence2025-05-04

Source: USGS — National Water Information System, USGS site 08068000, 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.