|Short history: It
became clear that the leat described below as Clearbrook Leat i.e. that
which was formed by the water running from the breach in the Plymouth
(Drake's) Leat, that ran down the hill and then into a leat that ran
towards Clearbrook, and which is known to the Commoners as "Clearbrook
Leat", was actually the leat built by William Crymes, a tinner,
Around 1599, William Crymes, a tin mill owner, diverted Plymouth Leat
and entered into a dispute with Plymouth, incl. with Sir Thomas Drake
(elder brother of the then-late Sir Francis), that was resolved in the
Star Chamber court at Parliament in 1603, with him being granted rights
to take water to power two tin mills.
Clearbrook (Crymes') Leat never supplied drinking water and it does not run to Clearbrook. In recent times, when RAF Harrowbeer was built as a WW2 airfield at Yelverton, there was a problem with draining such a large flat area. A pipe was laid under the main road into Devonport Leat and another from Devonport Leat into Plymouth Leat. In times of heavy rain, the area could still flood, so a breach was made in Plymouth Leat, leading excess water downhill into a ditch that contours around a hill and is known as Clearbrook Leat when it is running. This leads further around the hill from where the water can drain down into the River Meavy. This flood relief work is maintained out of goodwill by SWW, because ownership of the leat is problematical.
Walk details below - Information about the route etc.
Link to Google Satellite view of the area - the breach in Plymouth Leat is seen at the top left corner, a track from the clapper bridge runs down from this corner to a quarter of the way along the bottom edge, the relief leat can be seen vaguely running at 45° towards a tree beside the road at the bottom right corner. A big, light-coloured track comes in from the bottom edge. Three clicks on the bottom of the magnification slider brings much of the Clearbrook leat into view.
NB - It should be noted that all the leats on Roborough Common (Devonport, Plymouth and Clearbrook) flow only after heavy rainfall.
This walk follows on from an investigation into the flowing Devonport and Plymouth leats on 21st December 2012.
Plymouth Leat at SX 52260 64914 ± 3 metres ..... Click on the photo to see a movie .....
Today, Plymouth Leat was flowing fast ..... this breach was made to deal with water collected during times of heavy rain. Possibly it goes back to WW2 when the drainage from the runways at RAF Harrowbeer was led into Devonport Leat and thence into Plymouth Leat (see HERE for further details). The water proceeds to run dow the hill towards the River Meavy. Click on the photo to see a movie.
Another view of the place where the leat is diverted to run down the hill. The diversion is accomplished by a dam in the leat, the other side of this bridge. The dam can be seen in the first movie linked from the first photograph.
The water running down the hill below the breach in Plymouth Leat ..... Click on the photo to see a movie. Once you see the movie, you will agree that the flow is as dramatic as that seen running down Raddick Hill as part of Devonport Leat!
This photograph shows the run-off water at SX 52414 64813 where it crosses under the road that runs from the Clearbrook road down to Goodameavy. Click on the photo to see a movie.
Having crossed under the road, the water is "leated" around the contour towards Clearbrook - hence it is known among the Commoners as the Clearbrook Leat (even though it doesn't reach Clearbrook). I found it difficult to see the leat in the distance while recording the movie, however it is edited to stop when the leat across the Common is in the centre of the picture. Click on the photo to see a movie
Clearbrook Leat at SX 52454 64849, where there is a breach. The movie starts with the water flowing from the Plymouth Leat, pans past the breach, looks further along the leat towards Clearbrook and then pans back to look at the breach again. Click on the photo to see a movie.
Clearbrook Leat running in from the right, with another breach at SX 52509 64912 seen at the left in the photograph, running away from the camera, and the leat continuing towards the left out of the photograph. It is difficult to show this clearly here because the bracken, gorse and bramble need trimming. The movie ends looking at where the leat continues o n towards Clearbrook, but unseen. Click on the image to see a movie.
Photograph taken a few yards from the end of the leat. The construction is such that the bank on the downhill side is quite considerable.
The end of any water in the leat, at SX 52548 65029. This location is an animal track crossing the (here) dry leat even though the leat construction continues further - although I went back to the car from this point.
A view down and left into the valley towards the River Meavy, where the water in Clearbrook Leat is destined to flow .....
A glimpse of the River Meavy in the valley bottom.
MAP: Blue = GPS track along Clearbrook Leat from the breach in the side of Plymouth Leat, Green = tracts of regenerating gorse along Plymouth Leat.
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Also, Copyright © 2005, Memory-Map Europe, with permission.