Harlow Mill water level

Name: Harlow Mill water level (Environment Agency)
Creator: Environment Agency
License: https://www.nationalarchives.gov.uk/doc/open-government-licence/version/3/

River gauge, River Stort, Hertfordshire, United Kingdom

Directions

Within the normal range

Water level

0.92m Steady over the last 24 hours

Measured 20 Oct 2026, 03:15 BST (32 min ago)

History

7 days 30 days

Water level Top of normal rangeBottom of normal range

What this means

The River Stort at Harlow Mill is at 0.92 m, within its typical range.

The usual range here runs from −0.01 m to 2.02 m.

The level has held steady over the past 24 hours. In the last month it has stayed between 0.87 m and 0.96 m.

Autumn rain usually starts to lift rivers again after the summer low.

Compared with the normal range the agency publishes for this gauge. How to read levels

Key numbers

Normal range: −0.01 m – 2.02 m
Lowest and highest in 30 days: 0.87 m – 0.96 m
Lowest and highest in 12 months: 0.88 m – 0.95 m
Highest on record: 2.95 mFebruary 10, 2009
Lowest on record: 0.78 mMarch 5, 2008

Fishing and paddling

Paddlers and anglers can expect the river much as they know it, though a heavy shower upstream can change that within hours.

Flood alerts and warnings come from the Environment Agency.

About the River Stort

The River Stort is a chalk river in Essex and Hertfordshire, England. It is 24 miles (39 km) long and flows from near the village of Langley to the River Lea at Hoddesdon.

Weather at the gauge

Rain in the last 3 days: 1.3 mm. Rain that falls upstream can take hours or days to show up at a river gauge.

18 Sun 13° 7° 2.5 mm, 99% Wind 24 km/h

19 Mon 14° 9° 4.8 mm, 95% Wind 17 km/h

20 Tue 13° 11° 11 mm, 59% Wind 14 km/h

21 Wed 14° 7° 2.7 mm, 47% Wind 24 km/h

22 Thu 14° 5° 0.5 mm, 69% Wind 19 km/h

23 Fri 10° 7° 47 mm, 75% Wind 36 km/h

24 Sat 10° 4° – Wind 25 km/h

Forecast: Open-Meteo

Sunrise 07:33 AM Sunset 05:57 PM Daylight 10 hr, 25 min First quarter 64%

Map

Other gauges on the River Stort

Gauge	Level	Compared with normal	24 hours	Distance
SawbridgeworthRiver gauge, River Stort	1.11 m	Low	±0	2.5 km
Roydon, Glen FabaRiver gauge, River Stort	1.44 m	Normal	+0.01 m	8.9 km
Bishops Stortford, Grange PaddocksRiver gauge, River Stort	−0.26 m	Lowest on record	±0	9.4 km
ClaveringRiver gauge, River Stort	0.02 m	Very low	±0	19 km

Nearby gauges

Gauge	Level	Compared with normal	24 hours	Distance
Pishiobury BrookRiver gauge	0.95 m	Normal	+0.02 m	0.0 km
Sheering HallRiver gauge, Pincey Brook	0.09 m	Low	±0	2.3 km
Harlow, Elizabeth WayRiver gauge, Canons Brook	0.06 m	Normal	−0.02 m	4.8 km
MardockRiver gauge, River Ash	0.11 m	Normal	±0	8.1 km
MoretonRiver gauge, Cripsey Brook	0.11 m	Normal	±0	8.6 km
Hoddesdon, Rye BridgeRiver gauge, River Lee	2.85 m	Normal	+0.01 m	9.3 km
Little HadhamRiver gauge, River Ash	0.02 m	High	±0	10 km

Questions and answers

What is the typical range for the River Stort at Harlow Mill?

The Environment Agency gives a typical range of −0.01 m to 2.02 m for this gauge.

Is the river level the same as the depth of the water?

No. The reading is measured from a fixed zero mark at the gauge, so 0.92 m on the gauge does not mean the water is that deep.

What is the water level of Harlow Mill today?

On 20 Oct 2026, 03:15 BST, the water level was 0.92 m. Steady over the last 24 hours.

Is Harlow Mill rising or falling?

Steady over the last 24 hours. Up 0.02 m over the last 7 days.

Is the level of Harlow Mill normal?

Within the normal range. Compared with the normal range the agency publishes for this gauge.

What is the highest water level ever recorded at Harlow Mill?

The highest level on record is 2.95 m on February 10, 2009. The lowest is 0.78 m on March 5, 2008.

How often is this data updated?

The Environment Agency publishes a new reading every 15 minutes. This page refreshes within minutes of each update.

For specialists

Station codes, datum, parameters, data quality and downloads

Operator: Environment Agency
Station code: ea:5171TH (Agency page)
Coordinates: 51.79540, 0.13418 (WGS84)
Vertical datum: station datum
Update interval: every 15 minutes
Licence: Open Government Licence v3.0. Contains Environment Agency data licensed under the Open Government Licence v3.0

Published series

Parameter	Last value	Time (UTC)	Quality
Water level	0.92 m	2026-10-20 02:15	Provisional

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<iframe src="https://nivelmap.com/embed/1114?lang=en" width="360" height="230" style="border:0;max-width:100%" loading="lazy" title="Harlow Mill water level"></iframe>

How to cite

Environment Agency: Harlow Mill (ea:5171TH). Accessed October 20, 2026 via Nivelmap, https://nivelmap.com/en/united-kingdom/hertfordshire/harlow-mill

How we check values

Each reading is stored as published. We hold back values that jump faster than physically plausible and show the measurement time with every value.

Readings are provisional, can be delayed or wrong and are not a flood warning. Read the disclaimer