The monitoring network within this area

Hydrionis holds 1,120 values from 4 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

1,120

Values held

1889–2026

Record spans

Gauges within the North Branch Potomac huc8 subbasin

4 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 NORTH BRANCH POTOMAC RIVER NEAR CUMBERLAND, MD

The highest instantaneous discharge the publisher recorded in each year — a flood peak as measured, not a daily average of one. 1889–2025.

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	NORTH BRANCH POTOMAC RIVER NEAR CUMBERLAND, MD (m³/s)
1889	2,520
1924	2,322
1929	311
1931	382
1932	799
1933	663
1934	476
1935	362
1936	2,498
1937	1,464
1939	609
1940	476
1941	589
1942	476
1944	433
1945	515
1946	244
1947	268
1948	555
1950	337
1951	654
1952	586
1953	326
1954	538
1956	467
1957	530
1958	487
1959	216
1960	629
1961	716
1962	575
1963	665
1964	753
1965	270
1966	416
1967	719
1968	566
1969	206
1970	629
1971	385
1972	493
1974	394
1975	535
1976	320
1978	665
1979	578
1980	388
1981	394
1982	371
1983	428
1984	654
1985	249
1987	272
1988	425
1989	385
1990	272
1992	182
1993	733
1994	422
1995	402
1996	1,676
1998	419
1999	252
2000	343
2001	309
2002	219
2003	462
2004	555
2005	682
2007	257
2008	362
2009	665
2010	665
2011	617
2012	269
2014	430
2015	377
2016	236
2017	343
2018	711
2020	379
2021	702
2022	470
2023	156
2024	572
2025	1,113

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	1889–2025
Completeness	62.8% of the periods in that span are held. Gaps are drawn as breaks and never interpolated.
Known gaps	15 separate periods inside 1889–2025 hold no value. The longest runs from 1890 to 1923 — 34 years with no reading. They are drawn as breaks in the line and are never interpolated across.
Continuity	The record begins in 1889 and is not continuous from it: 137 years separate the first value from the last, and 63% 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 GEORGES CREEK AT FRANKLIN, MD, 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	GEORGES CREEK AT FRANKLIN, MD (mm)
1930	126
1931	250
1932	318
1933	415
1934	234
1935	393
1936	542
1937	609
1938	220
1939	303
1940	394
1941	280
1942	477
1943	283
1944	356
1945	440
1946	327
1947	240
1948	480
1949	390
1950	399
1951	453
1952	474
1953	375
1954	271
1955	420
1956	480
1957	376
1958	383
1959	294
1960	417
1961	498
1962	391
1963	334
1964	387
1965	343
1966	257
1967	381
1968	335
1969	155
1970	481
1971	495
1972	675
1973	507
1974	413
1975	589
1976	338
1977	346
1978	521
1979	623
1980	389
1981	337
1982	378
1983	442
1984	565
1985	455
1986	325
1987	305
1988	320
1989	514
1990	392
1991	293
1992	254
1993	506
1994	571
1995	327
1996	785
1997	353
1998	555
1999	237
2000	278
2001	335
2002	261
2003	835
2004	579
2005	369
2006	318
2007	352
2008	512
2009	422
2010	413
2011	708
2012	324
2013	396
2014	299
2015	332
2016	310
2017	460
2018	1,014
2019	520
2020	405
2021	300
2022	343
2023	236
2024	427
2025	482

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	100.0% of the periods in that span are held.
Continuity	Continuous: every year from 1930 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 North Branch Potomac and what each holds
Gauge	Measures	Values	Record
NORTH BRANCH POTOMAC RIVER NEAR CUMBERLAND, MD	catchment area, annual maximum river flow, mean river flow, mean river flow, water year	291	1889–2026
WILLS CREEK NEAR CUMBERLAND, MD	catchment area, annual maximum river flow, mean river flow, mean river flow, water year	290	1924–2026
GEORGES CREEK AT FRANKLIN, MD	catchment area, annual maximum river flow, mean river flow, mean river flow, water year	289	1924–2026
NORTH BRANCH POTOMAC RIVER AT LUKE, MD	catchment area, annual maximum river flow, mean river flow, mean river flow, water year	250	1899–2026

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 — 02070002. 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
NORTH BRANCH POTOMAC RIVER NEAR CUMBERLAND, MD	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
WILLS CREEK NEAR CUMBERLAND, MD	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
GEORGES CREEK AT FRANKLIN, MD	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
NORTH BRANCH POTOMAC RIVER AT LUKE, MD	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	4	yes, 3 or more
Years spanned	138	yes, 20 or more
Values held	1,120	yes, 1000 or more
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-01603000.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), North Branch Potomac gauge records, accessed 2026-10-05, hydrionis.com/waters/united-states-north-branch-potomac/

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 North Branch Potomac 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 confidence2025-05-14

Source: USGS — National Water Information System, USGS site 01603000, 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.