Official Data

The data for the following river and rain gauges is 'official' and is gathered from the Environment Agency's official data feed:

• Frilsham
• Bucklebury
• Tidmarsh
• Pangbourne
• Sulham
• West Ilsley rain
• Yattendon rain

While the level data is gathered every 15 minutes, it is not always published by the EA every 15 minutes and can take up to 24 hours to be transmitted.

The level of the Tidmarsh gauge shown here has been adjusted by subtracting 100cm.

Unofficial Data - Automatic

The data for the following gauges is 'unofficial':

• Sulham A329
• Bucklebury Village
• Stanford Dingley

This unofficial data is recorded automatically using an ultrasonic gauge installed by the PVFF. It is subject to an error of about +/- 1cm. A reading is taken every hour and transmitted every 4 hours.

Unofficial Data - Manual

The data for the following gauges is 'unofficial'. This data is recorded by selected Pang Valley residents:

• Stanford Dingley
• ORC - Old Rectory Cottage (between Tidmarsh and Pangbourne)

This unofficial data is recorded from a gauge board at the side of the river. It is subject to an error of about +/- 1cm. It is not recorded continually and thus for now, is shown as points rather than lines.

The official and unofficial data is shown together for ease of use by Pang Valley residents.

Groundwater

This is the most recent 'Groundwater %' value. The 'Groundwater %' figure averages a figure calculated figure for each of the following groundwater gauges: Ridgeway Down, Gibbet Cottages, Hodcott 2, Saltbox. The calculated figure for each is the % value that the current level AOD (m) is between the Typical Low and the Highest Observed for each gauge. This single figure has been provided to simplify 4 readings into 1.

The calculation is:

Ridgeway Down B latest level AOD (m) = RDB
Gibbet Cottages latest level AOD (m) = GC
Hodcott 2 latest level AOD (m) = H2
Saltbox B latest level AOD (m) = SB

Bucklebury, Tidmarsh, Pangbourne, Sulham

These are the most recent river level values for the level above base value (in cm) published by the Environment Agency for each river gauge. These tend to represent the river depth at the gauge, but actually represent the level above a defined point. In the case of the Tidmarsh gauge, the actual river depth is the level shown minus 100cm.

Click here to learn how the Environment Agency measure river, sea and groundwater levels.

Sul A329

This is most recent recorded depth (in cm) of the Sulham Brook on the upstream side of where is passes underneath the A329 measured from a base level that is the river bed (= 84cm below the bottom of the steel girder). This level is not published by the Environment Agency, but by the Pang Valley Flood Forum.

Gauge / Alert	Latest	1	2	3	4
Frilsham	23.5	44	48	59	62
Bucklebury	13.6	55	65	72	83
Tidmarsh	116.7	145	156	170	190
Pangbourne	14.2	75	78	110	140
Sulham	4.4	30	40	75	106

Values are in cm

Alert	Definition	Action
1	River levels are rising	Monitoring and Forecasting Duty Officer starts monitoring
2	River levels are at bankfull	Flood Alerts issued (for whole length of the river) if forecast is for this level to be exceeded.
3	River levels are getting near to flood warning	Consider issuing a Flood Warning (for just the Warning Area associated with the relevant gauge)
4	River level is at property level (first to Flood in Warning Area)	Flood Warning issued (for just the Warning Area associated with the relevant gauge) if forecast is for this level to be exceeded.

Message issued 10/10/2023 6:00pm

The Flood Warning (for Frilsham, Stanford Dingley and Bradfield) and the Flood Alert (for the whole of the Pang and the Sulham Brook) issued this evening by the Environment Agency has been issued in error.

Some members of the Environment Agency river monitoring team are on strike and the issuing of Flood Warnings and Flood Alerts has been automated. A spurious reading from the Frilsham River gauge triggered the alert and warning.

The Environment Agency will remove the Flood Warning and Flood Alert in the next few hours, assuming the same fault doesn't trigger it again.