Mardock water level
River gauge, River Ash, Hertfordshire, United Kingdom
Right now
Normal for mid-October
Water level
History
20252026
What this means
The River Ash at Mardock is at 0.10 m, in the normal range for mid-October.
The median for mid-October is 0.11 m, based on 21 years of readings, so the river level is 0.01 m below typical. A year ago it stood at 0.11 m as well.
It has barely moved over the past 24 hours. In the last month it has stayed between 0.10 m and 0.11 m.
Autumn rain usually starts to lift rivers again after the summer low.
Compared with 21 years of daily readings for this time of year. How to read levels
Key numbers
- Median for this date
- 0.11 m0.01 m below the median for this date
- Normal for this date
- 0.09 m – 0.17 m8 years in 10 fall in this range (21 years of records)
- Normal range
- 0.10 m – 0.80 m
- Same day last year
- 0.11 m0.00 m
- Lowest and highest in 30 days
- 0.10 m – 0.11 m
- Lowest and highest in 12 months
- 0.10 m – 0.39 m
- Highest on record
- 1.61 mOctober 21, 2001
- Lowest on record
- 0.06 mSeptember 25, 1997
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 Ash
The River Ash is a small, shallow river in Surrey, England. Its course of 10 kilometres (6.2 mi) is just outside Greater London. Work has been carried out to re-align, clear and build up a small, Littleton head of water and create two backwaters. One backwater dates to the medieval period; the other to the 1990s. It flows as one of the six distributaries of the River Colne from the south of Staines Moor immediately south of the Staines Bypass eastwards through the rest of the borough of Spelthorne before meeting the River Thames.
Text and image from Wikipedia and Wikimedia Commons, licensed under CC BY-SA.
Weather at the gauge
Rain in the last 3 days: 1.5 mm. Rain that falls upstream can take hours or days to show up at a river gauge.
Forecast: Open-Meteo
Map
Other gauges on the River Ash
| Gauge | Level | Compared with normal | 24 hours | Distance |
|---|---|---|---|---|
| Little HadhamRiver gauge, River Ash | 0.02 m | Normal | ±0 | 9.1 km |
| Furneux PelhamRiver gauge, River Ash | 0.14 m | Very low | +0.08 m | 14 km |
| Staines AshRiver gauge, River Ash | 0.10 m | Very high | ±0 | 56 km |
| Knowle GreenRiver gauge, River Ash | 0.51 m | Normal | ±0 | 56 km |
Nearby gauges
| Gauge | Level | Compared with normal | 24 hours | Distance |
|---|---|---|---|---|
| Tumbling Bay WeirRiver gauge, Amwell Loop | 30.41 m | Normal | +0.01 m | 3.0 km |
| WadesmillRiver gauge, River Rib | 0.19 m | Normal | ±0 | 4.3 km |
| Hoddesdon, Rye BridgeRiver gauge, River Lee | 2.84 m | Normal | ±0 | 5.1 km |
| Roydon, Glen FabaRiver gauge, River Stort | 1.43 m | Normal | ±0 | 5.6 km |
| Harlow, Elizabeth WayRiver gauge, Canons Brook | 0.07 m | Normal | +0.02 m | 5.8 km |
| Hertford, Hartham ParkRiver gauge, River Beane | 0.21 m | High | +0.04 m | 7.0 km |
| Harlow MillRiver gauge, River Stort | 0.91 m | Normal | −0.01 m | 8.1 km |
| Pishiobury BrookRiver gauge | 0.93 m | Low | ±0 | 8.1 km |
Questions and answers
Is the River Ash at Mardock higher than last year?
It is about the same as on this day last year, when the reading was 0.11 m.
What is a normal level for the River Ash at Mardock in mid-October?
The median for mid-October is 0.11 m. In 8 years out of 10 the reading falls between 0.09 m and 0.17 m, based on 21 years of records.
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 0.10 m on the gauge does not mean the water is that deep.
What is the water level of Mardock today?
On 19 Oct 2026, 05:00 BST, the water level was 0.10 m. Steady over the last 24 hours.
Is Mardock rising or falling?
Steady over the last 24 hours. Steady over the last 7 days.
Is the level of Mardock normal?
Normal for mid-October. Compared with 21 years of daily readings for this time of year.
What is the highest water level ever recorded at Mardock?
The highest level on record is 1.61 m on October 21, 2001. The lowest is 0.06 m on September 25, 1997.
For specialists
Station codes, datum, parameters, data quality and downloads
- Operator
- Environment Agency
- Station code
ea:5080TH(Agency page)- Coordinates
51.81482, 0.02030(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 | 0.10 m | 2026-10-19 04:00 | Provisional |
Download
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How to cite
Environment Agency: Mardock (ea:5080TH). Accessed October 19, 2026 via Nivelmap, https://nivelmap.com/en/united-kingdom/hertfordshire/mardock
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