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0.05

High Ongar

Roding
Rodding catchment • High Ongar • Essex • ID: 5420TH • Level
(1h ago) • 4 readings/hr • 147 views

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Current Level
0.049 mASD
▬ Steady
24h Max
0.051 mASD
24h Min
0.043 mASD
Typical Range
0.05 - 1.45
mASD
Highest Recorded
2.18 mASD
EA official record
2.18 in our data (since Jan 1982)
Current level is 2% of this
🚽 Sewage overflows nearby

Recent Water Levels

🌍 floodradar.co.uk
1 day

Recent Readings

Steady over 6h
08 Oct 01:30 ▬ steady 0.049 mASD
08 Oct 01:15 ▬ steady 0.049 mASD
08 Oct 01:00 ▬ steady 0.049 mASD
08 Oct 00:45 ▬ steady 0.049 mASD
08 Oct 00:30 ▬ steady 0.049 mASD
08 Oct 00:15 ▬ steady 0.049 mASD
08 Oct 00:00 ▬ steady 0.049 mASD
07 Oct 23:45 ▬ steady 0.049 mASD
07 Oct 23:30 ▬ steady 0.049 mASD
07 Oct 22:30 ▬ steady 0.049 mASD
07 Oct 22:15 ▬ steady 0.049 mASD
07 Oct 22:00 ▬ steady 0.049 mASD
07 Oct 21:45 ▬ steady 0.049 mASD
07 Oct 21:30 ▬ steady 0.049 mASD
07 Oct 21:15 ▬ steady 0.049 mASD
07 Oct 21:00 ▬ steady 0.049 mASD
07 Oct 20:45 ▬ steady 0.049 mASD
07 Oct 20:30 ▬ steady 0.049 mASD
07 Oct 20:15 ▬ steady 0.049 mASD
07 Oct 20:00 0.049 mASD

Station Details

  • Monitoring Station: High Ongar
  • Watercourse: River Roding
  • Nearest Town: High Ongar
  • County: Essex
  • Nearest reservoir: Hanningfield (18.0 km) · 54.9% full (as of 28 Dec 2025)
  • Coordinates: 51°42'50"N 0°15'33"E (51.713888, 0.259177)
  • Open in: Google Maps · Apple Maps (opens your maps app)
  • Date Opened: 1 Jan 1963
  • Status: Active
  • Station Type: River level station
Technical details: references, datum, range, flow archive
  • Station Reference: 5420TH
  • RLOI id: 7376 (the EA's check-for-flooding station id)
  • EA Gauge ID: 5420TH-level-stage-i-15_min-mASD
  • Parameter: Level
  • Unit: mASD
  • Typical rise rate: 1 cm/hr (p95 sustained over 90 days)
  • Typical data delay: ~22 min (measured reading→publication lag)
  • Tidal: No
  • Lock / structure: No
  • Catchment Area: Rodding
  • Typical Range: 0.047 – 1.450 mASD
  • Drainage Area: 95 km² upstream of this gauge
  • Flow Data: Daily mean flow (m³/s) to 6 Oct (2 days behind — the EA publishes each day's mean a day or two after it ends; unchecked, provisional) via EA Hydrology
  • EA Cross-check: 0.05 mASD (EA at 8 Oct 01:45)
  • Flow Archive: National River Flow Archive ↗

Geographic coordinates may reflect the access point for the gauge, and not the precise location in the watercourse that it is taking readings from.

Nearby Stations

Gauges connected to this river, and others nearby. A distance “by river” follows the river on the map; any other is in a straight line.

Connected downstream

Same river system, separate branch

Distances by river: OS Open Rivers. Contains OS data © Crown copyright and database rights 2026.

💧 Storm overflows upstream of this gauge

Storm overflows whose water reaches this gauge on the mapped river network, nearest first by distance along the river. The status is each water company's monitor: it says whether an overflow is discharging, not how much or what it contains.

2 storm overflows are traced upstream of this gauge, the nearest 7.4 km away along the river. 0 report discharging now, 1 reports not discharging, and for 1 the monitor is offline or has not reported, so their status is not known.

💧
Thames Water · into Trib Of River Roding · 7.4 km upstream along the river
55 spills · 1,078 hours in 2025
Monitor offline: it cannot say whether it is discharging
💧
Thames Water · into Roding · 24.4 km upstream along the river
0 spills · 0 hours in 2025
Not discharging now · last

Nearby, connection not known

Within 6 km in a straight line, but the river map cannot say whether their water passes this gauge.

💧
Anglian Water · into Trib Of The River Wid · 4.9 km away in a straight line · not connected to this gauge on the river map
0 spills · 0 hours in 2025
Not discharging now · last

1 other overflow within 6 km is downstream of this gauge or on another branch of the river network, so it is not listed.

These are the water companies' monitor statuses; a spill does not by itself explain a change in the gauge level. River connections and distances are traced on OS Open Rivers (edition 2026-04), which leaves out many small channels. Explore the sewage map →

Contains OS data © Crown copyright and database rights 2026.

Rainfall & Weather

Loading rainfall and weather data...

How often this river runs high

This gauge rarely reaches its typical high of 1.45 m: 4 days since 2017. This year so far: 0 days.

2026 0 days so far
2025 0 days
2024 0 days
2023 1 day
2022 0 days
2021 1 day
2020 1 day
2019 1 day
2018 0 days
2017 0 days

Counted from each day's highest reading. Days with missing or implausible readings are left out.

Flood history near this gauge

Official Environment Agency warnings issued since 2011 for the 6 flood areas linked to this gauge (nearest 0.8 km away).

0flood warnings 72flood alerts

Most recent flood alert: 16 Feb 2026 — Upper Roding

Year by year
YearWarningsAlerts
2026 0 4
2025 0 2
2024 0 6
2023 0 7
2022 0 2
2021 0 4
2020 0 5
2019 0 4
2017 0 2
2016 0 6
2014 0 12
2013 0 5
2012 0 11
2011 0 2

Warnings apply to a whole flood area, not necessarily this exact spot. Years before 2006 aren't covered by the EA's historic record. See also the High Ongar flood history.

Flood areas linked to this gauge

Flood warnings and alerts are issued for whole areas. These are the 6 areas linked to this gauge, nearest first.

Catchment Character

🌊 Fairly flashy Responds fairly quickly to rain, with moderate baseflow between events.

Your catchment is all the land that drains rainfall into the river above this gauge. Its character — how steep, wet, wooded, urban or chalky that land is — decides how fast rain here turns into a rising river. A steep, bare or clay catchment is “flashy” (rises and falls quickly, floods easily); a flat, chalk or well-wooded one is slow and steady. The tiles below put numbers to that; the flow-duration curve reads left-to-right from the river’s typical high flows (Q5) down to its low flows (Q95) — a steep curve means a flashy river.

The physical character of the land that drains to this gauge, and how it shapes its flood response — from the National River Flow Archive (UKCEH).

Baseflow Index
0.40
mixed response
Avg Annual Rainfall
615 mm/yr
1991–2020 · +1% since 1941–70
Urban Extent
0.8%
largely rural
Median Annual Flood
11.10 m³/s
QMED — typical yearly peak flow
Highest Daily Mean Flow
14.30 m³/s
10 Feb 2009 · daily mean, not the instantaneous peak
Flow-Duration Curve
mean 0.5242.330.1420.0235% (high)% of days exceeded95% (low)
Daily flow (m³/s) exceeded each % of the time — a steep curve is flashy, a flat one is steady. Q5 high · Q50 median · Q95 low.
Land Cover (2023)
Woodland 3%Grassland 17%Arable 76%Urban 3%Other 1%
Arable 88% → 76% since 1990

Flow affected by: groundwater abstraction, industrial / agricultural abstraction.

Photos

Gauging-station photographs from the National River Flow Archive (UKCEH).

Photos © NRFA / UKCEH & the measuring authority — shown at web resolution. Full gallery on the NRFA ↗

About this gauge

Highest flow gauging station on the River Roding. Essex modified Flat V weir that was superceded by Ultrasonic time of flight due to repeated drowning.

More detail

The catchment

Generally low lying, largely impermeable (London Clay/glacial deposits), agricultural catchment with some industrial land use.

The station

Ultrasonic time of flight in an 11m section. Ultrasonic replaced Essex weir rating in November 2012. Essex weir used to maintain head for measuring cross section. Used for both water resource and flood warning/forecasting purposes.

How it measures flow

Originally Essex weir superseded by Ultrasonic time of flight with the weir used to retain depth. Bypassing can also occur on both banks and can occur surprisingly quickly. Structure subject to drowning during high flows due to backwater effects from two d/s bridges. Heavy in-channel vegetation and surcharging of bridge soffit also influence drowning. Evidence that the modular limit has reduced over time due to the reduction in channel clearance and maintenance. Evidence of weir settlement discovered in 1991. Flows were corrected from 1987-91 to take account of this.

Flow regime

Responsive flow regime. Minimal net import into the catchment but flows are influenced by groundwater abstraction/recharge. Abstraction for industrial/agricultural purposes, particularly spray irrigation, can substantially deplete low flows.

The flow record

Levels can exceed bankfull and gauge is bypassed. Naturalised flows available between 1964 and 1976. Full period of record peak flow data reviewed and released in August 2021 (WINFAP Files v10).

Descriptions from the National River Flow Archive (UKCEH). NRFA station record ↗

Gauge Details

How this gauging station is built and how long it has measured (NRFA / UKCEH).

Gauge type
Ultrasonic
Operating since
1963
Station datum
41.0 mAOD
Flow record
1963–2024 · 61 yrs · 100% complete
Peak-flow record
since 1963
Hydrometric area
37
Measured by
Environment Agency

Frequently asked questions

Is the River Roding at High Ongar flooding today?

The current level is 0.05m, which is within the typical range of 0.05 to 1.45m. Flooding is unlikely at this level.

Is the river level rising or falling at High Ongar?

Based on the most recent readings, the level is currently steady. The chart above shows the last 12 hours of measurements by default (up to 7 days), updated roughly every 15 minutes.

What is a normal level for the River Roding at High Ongar?

The typical range at this station is 0.05m to 1.45m, based on Environment Agency historical data. Levels above 1.45m are higher than usually seen and may indicate a flood risk.

How often is this river level data updated?

Readings are supplied by the Environment Agency gauge. FloodRadar checks for updates roughly every 15 minutes; the timestamp above shows how recent the latest available reading is.

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📮 Flood risk by postcode near this gauge

Postcodes within 5 km with properties in the Environment Agency’s rivers-and-sea flood-risk bands:

Check any UK postcode’s flood risk →

🏠 Buying or renting around here? Get the Property Flood-Risk Report for any English postcode — official risk band, recorded floods, warning history, river behaviour and nearby storm overflows. £19 one-off. Learn more →