The monitoring network within this area

Hydrionis holds 563 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.

Gauges

563

Values held

1899–2026

Record spans

Gauges within the Middle James-Willis 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 JAMES RIVER AT CARTERSVILLE, VA

The highest instantaneous discharge the publisher recorded in each year — a flood peak as measured, not a daily average of one. 1899–2025.

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	JAMES RIVER AT CARTERSVILLE, VA (m³/s)
1899	3,143
1900	1,393
1901	3,794
1903	2,345
1904	1,138
1905	1,535
1906	1,549
1908	1,957
1909	1,365
1910	2,039
1911	1,436
1912	2,447
1913	2,650
1915	1,962
1917	1,877
1918	1,495
1919	2,347
1920	1,906
1922	1,320
1923	1,705
1924	3,002
1926	1,283
1928	2,752
1929	1,603
1931	804
1932	1,552
1934	1,388
1935	3,794
1936	4,701
1937	3,766
1939	1,855
1940	4,106
1941	1,124
1942	2,124
1944	5,097
1945	1,909
1946	1,237
1947	1,102
1948	2,364
1950	1,943
1951	1,708
1953	2,141
1954	1,801
1955	2,945
1956	674
1957	1,909
1958	1,464
1959	1,198
1960	2,005
1961	1,274
1963	2,209
1964	1,017
1965	1,957
1966	1,506
1967	1,928
1969	7,079
1970	1,838
1971	2,248
1972	10,251
1973	2,138
1975	3,398
1976	1,540
1978	3,087
1979	3,483
1980	1,812
1981	841
1982	2,152
1983	2,036
1984	2,458
1985	1,710
1987	4,021
1989	2,656
1990	1,481
1992	3,200
1993	2,860
1994	2,410
1995	2,336
1996	4,474
1998	2,328
1999	2,296
2000	937
2001	1,070
2002	736
2003	2,945
2004	2,081
2005	1,651
2006	2,195
2008	1,019
2009	915
2010	2,789
2011	1,951
2013	1,945
2014	2,081
2015	1,385
2016	1,501
2017	1,758
2018	2,095
2019	2,183
2020	1,951
2022	1,036
2023	1,566
2024	2,214
2025	2,447

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	1899–2025
Completeness	81.1% of the periods in that span are held. Gaps are drawn as breaks and never interpolated.
Known gaps	24 separate periods inside 1899–2025 hold no value. They are drawn as breaks in the line and are never interpolated across.
Continuity	The record begins in 1899 and is not continuous from it: 127 years separate the first value from the last, and 81% 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 JAMES RIVER AT CARTERSVILLE, VA, as a depth

The year's flow spread over the land draining to this gauge, in millimetres — the same unit rainfall is measured in. 1899–2025.

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	JAMES RIVER AT CARTERSVILLE, VA (mm)
1899	467
1900	394
1901	634
1902	478
1903	545
1904	258
1905	372
1906	512
1907	497
1908	491
1909	414
1910	326
1911	324
1912	449
1913	437
1914	358
1915	433
1916	320
1917	330
1918	429
1919	435
1920	437
1921	300
1922	400
1923	306
1924	502
1925	250
1926	334
1927	398
1928	428
1929	476
1930	177
1931	202
1932	376
1933	376
1934	340
1935	509
1936	522
1937	587
1938	332
1939	324
1940	439
1941	213
1942	399
1943	343
1944	340
1945	309
1946	323
1947	296
1948	577
1949	547
1950	403
1951	397
1952	463
1953	341
1954	284
1955	355
1956	211
1957	364
1958	402
1959	317
1960	380
1961	435
1962	417
1963	257
1964	269
1965	270
1966	237
1967	331
1968	250
1969	318
1970	288
1971	447
1972	719
1973	566
1974	383
1975	529
1976	402
1977	265
1978	448
1979	663
1980	382
1981	178
1982	397
1983	460
1984	522
1985	415
1986	231
1987	487
1988	208
1989	515
1990	462
1991	384
1992	397
1993	487
1994	456
1995	389
1996	616
1997	338
1998	571
1999	252
2000	265
2001	194
2002	189
2003	754
2004	448
2005	344
2006	350
2007	286
2008	209
2009	366
2010	369
2011	378
2012	270
2013	446
2014	404
2015	389
2016	410
2017	274
2018	636
2019	463
2020	601
2021	371
2022	318
2023	269
2024	346
2025	327

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	1899–2025
Completeness	100.0% of the periods in that span are held.
Continuity	Continuous: every year from 1899 to 2025 is held.
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 Middle James-Willis and what each holds
Gauge	Measures	Values	Record
JAMES RIVER AT CARTERSVILLE, VA	catchment area, annual maximum river flow, mean river flow, mean river flow, water year	381	1899–2026
WILLIS RIVER AT LAKESIDE VILLAGE, VA	catchment area, annual maximum river flow, mean river flow, mean river flow, water year	182	1926–2026

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 — 02080205. 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
JAMES RIVER AT CARTERSVILLE, VA	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
WILLIS RIVER AT LAKESIDE VILLAGE, VA	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 2 of them, which makes it a profile, not indexed.

Information-gain signals held for this water body
Signal	Held	Counts
Gauges holding a real record	2	no
Years spanned	128	yes, 20 or more
Values held	563	no
Distinct measurements	4	yes, 2 or more
Publishers measuring it	1	no
Official identifiers	1	recorded, not counted

Use this data

Machine-readable JSON /api/v1/observations/by-subject/gauge-usgs-02035000.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), Middle James-Willis gauge records, accessed 2026-10-05, hydrionis.com/waters/united-states-middle-james-willis/

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 Middle James-Willis 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 confidence2025-02-17

Source: USGS — National Water Information System, USGS site 02035000, 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.