The river Plym is a fast rising and falling river when precipitation strikes South Dartmoor. There are several river-level guages along its length, most notably for Shaugh Prior is the Carnwood guage, which provides regular updates, at least once a day. This guage I have found to be a good indicator, albeit that it’s reading point is after the confluence of the Rivers Plym and Meavy.
This article gives a guide to the reality of the flow for both the Plym and Meavy when Carnwood is recording 30cm and 75cm. Hopefully it will allow you to make sensible decisions about whether to use the Rivers for activity or training. Please bare in mind that the Plym is a fast rising river during and after rain, so a measurement read whilst it is still raining may mean that the river level may continue rising.
Carnwood record 18th May 2017 – 0.30m
The following picture shows the river Plym when it is at its most docile (0.30m). It will drop further than 30cm, quite regularly through the summer months, when it will hold at 20cm but the visual cue will be similar. A safe, enticing and satisfying gurgling river with big rounded boulders, birds, insects, trout and other wildlife seen above and below its crystal clear waters.
The river remains like this for some extended time until rain strikes further upstream (Plym Steps, Dartmoor), this is when things start changing as the Plym redistributes it’s load very quickly through this gorge, just before it meets the Meavy at Shaugh Prior.
Plym and Meavy at Shaugh Prior: Carnwood 16/5/17 – 0.75m
So this is what the Plym and Meavy look like at their confluence whilst the River a level guage is reading 0.75m at Carnwood. That assumes that the river Meavy is affected by the same additional load. The Plym or Meavy could potentially fill up due to localised showers but often the case is that the Meavy lifts along with the Plym.
The side shot is of the Meavy at the same time as the above photo was taken. The depth and colouration of the water, along with the foam floating at the surface provide an indicator that the river is under excess load. It flow is definitely pushing but is quite tame due to it’s lesser gradient at Shaugh Prior.
Finally, the river Plym has taken on a new dimension from its regular predicable tumbling falls. The entire width of the river has a foamy green/brown flow, with only a few larger boulders breaking the surface. The river is only navigable by kayak and then only if you know what you are doing.
For those with a keen eye you will note that this shot is taken from the same location as Pic.2 above.