The Environment Agency have a number of telemetry stations on the Great Ouse system, which collect information on river levels and flows. This data is now made available via a number of websites. One favourite is gaugemap (other brands are available), and this page includes links to the relevant gauges and some tips on how to use them.
The table below shows the sites on the Great Ouse system that are visible via gaugemap:
Click on “station details”, “river level”, “flow” as appropriate.
Click on “graph options” to see data for the last day, week, month or year
All show the current river level – with the exception of the flow gauge at Offord which measures cubic metres a second.
Note that each gauge has its own “datum” – ie the level which produces a zero reading on the gauge. In some cases this information is provided eg Ely has a datum of 1.0m above that used in Ordnance Survey maps (“1m AOD”).
It’s usually pretty obvious if the gauge is stuck or broken, and giving a silly reading.
Many of these stations also issue alerts twice a day on Twitter. If you want to see those then you need to:
Create an account on twitter, if you do not already have one, either on a computer or using the twitter app on a smartphone (Android or Apple)
Search for the relevant site using the number in the “Twitter ref” column below (eg riverlevel_1498 for Earith). Note that, just for fun, this number is different to the numbers in the main link.
Click the “follow” button.
Note: 1) There is no requirement for you to start tweeting yourself. But you do need an account to enable you to follow the sites that you are interested in.. 2) You may wish to use Ctrl+click to open the links in a new tab.
Normal summer flows often under 5 cumecs. If you get a number rising towards 40, expect a strong stream alert soon. I believe this gauge “maxes out” at about 130.
To find the headroom at Hermitage Lock, in metres, subtract this number from 4.1. So if the gauge reads 1.8m (a typical summer level) the headroom will be 2.3m. Note that you can sometimes see the tidal effect here, with a peak every 12 hours or so.
If the sluices at Denver are working hard, you can see the effect when the sluice closes around high tide. The level peaks in Ely about five hours after HW in Kings Lynn. The EA aim to keep the level here pretty constant, at about 0.5-0.6m