Constructed during the 1790s to channel drinking water from three rivers in Dartmoor to the busy port of Devonport, near Plymouth, the Devonport Leat has since been shortened so that it supplies the Burrator Reservoir, which was built in 1898 to help supply the surrounding area's growing population. However, the upper section of the leat still remains completely intact, snaking around the hillsides of Dartmoor to carry the water of the West Dart, Cowsic and Blackbrook Rivers over 12 miles while dropping just 200 metres.

Except for a tunnel and a waterfall, the leat remains more or less level throughout and is easy to follow, thus making it a good place for a walk. The leat has a path alongside it but meets several paths and roads along its route, and so there are many ways in which it can be incorporated into walks. Although the weather can often be quite inclement, the moors surrounding the leat provide a picturesque background, which is added to by the presence of various wildlife, including the sheep and Dartmoor ponies which come to drink from the leat.

History

Devonport was known as Plymouth Dock until 1824 despite being a separate town. Plymouth had its own water supply from a leat created by Sir Francis Drake in 1590, and Plymouth's inhabitants were fiercely protective of their water supply, claiming there was only just enough for their own use. It's said that some Plymouth Dock citizens made a decent living by collecting rainwater in buttresses and selling it, and there were occasional night raids on Drake's Leat by the water sellers. Eventually, a controversial proposal was made to build a Devonport Leat - the businessmen of Plymouth argued against it, claiming they had enough water for the people of the Dock after all. Regardless, a Bill was lodged with Parliament proposing the new leat, and even Dr Samuel Johnson had a say during a visit to Plymouth:

The Dockers shall have none of Plymouth's water; not a drop!

The leat was thus constructed during the 1790s, and originally ended at a reservoir in Devonport itself. The navy were allowed to take as much as they needed whenever they wanted it, but residents had just an hour a day to get theirs. Small reservoirs were built around Devonport as the town expanded, until finally in 1878 a large one was built at Crownhill to handle all of Devonport's water, with the supply from the reservoir being piped into the town. This set-up was again replaced with a reservoir further from the sea at Dousland, with the leat having been shortened all the while after leaving the moors, each section being replaced by pipework over the years. The completion of the pipework from Dousland in 1908 meant that the only sections of leat in use were the Dartmoor sections. In 1951, Dousland itself was decommissioned, and the leat was shortened by another mile to deposit the water directly into Burrator reservoir.

Construction

The leat mostly consists of trenches formed roughly out of Dartmoor granite, effectively creating a miniature grass-covered canal which steadily drops in height. The skill of the leat's engineers is apparent from the way in which the water in the leat is forever flowing rapidly despite the leat closely following the contours of the surrounding tors. While it is crossed by a raft of footbridges and sheep leaps¹, the leat itself runs across a series of small aqueducts which allow it to cross over a series of small streams which can be found trickling down the hillsides at right angles to the leat.

However, the leat is forced to run underground in a tunnel for 500m at Nun's Cross. While this may seem a drastic measure, the only alternative to the tunnel would have been a cutting at least ten metres deep, and a test leat dug at the time must surely have dissuaded the engineers from that course of action. The tunnel is the only part of the leat's course not navigable on foot, as the radioactive radon gas which slowly seeps out of the ground has led to the tunnel being closed off for safety reasons.

Further downstream is another small feat of 18th Century engineering where the leat gives up 40 metres of height in order to gush down the side of Raddick Hill in the form of a waterfall before crossing the River Meavy via an aqueduct which bears great resemblance to a half-pipe. As if this were not enough, the leat then seems to head uphill again, with the speed of the water running down the hillside, boosted by a small contribution from the Meavy, keeping the leat flowing.

A final consideration in the construction of the leat was the inclusion of a series of sluice gates and overflows which control the volume of water in the leat, lest it be damaged by heavy rainfall. The sluices are all still in good condition and are well-greased, indicating the extent to which the leat is still used even today.

Route

The leat begins next to a weir² on the West Dart river a short way upstream of Wistman's Wood and runs southwards along the side of the Beardown Tors while the West Dart drops away down the valley towards Two Bridges. The leat then runs westwards through Beardown Woods to reach the valley of the Cowsic River, the presence of which forces the leat into a large detour northwards up the Cowsic valley. However, the leat is free to tap off some of the river's water before running south again, heading towards Two Bridges and passing under the B3357 before curving westwards to head towards Princetown. The leat taps off some water from the Blackbrook River and crosses it via an aqueduct before running around the edge of Princetown just a short distance from the Dartmoor Prison.

Having visited Princetown without stopping at any of the three pubs, the leat passes under the A3212 and then turns southwards, sticking to the side of South Hessary Tor before taking a slightly tortuous route to reach Nun's Cross Farm³. Here, the leat enters a tunnel under the hill (see above) which takes it into the next valley to the west, home to both the oddly-named Newleycombe Lake (a river) and a series of disused tin workings. Although this valley leads to Burrator Reservoir, it is a mark of the leat's original destination that it sticks to the hillside, opting instead to run down the waterfall at Raddick Hill to cross the aqueduct over the River Meavy⁴. Having done this, the leat turns south and passes through the Raddick Plantation and, while it tries to stick to the side of the Sharpitor massif, is eventually diverted down into the Burrator Reservoir.

The course of the leat towards Plymouth still remains but is dry and is filled with stones in a number of places. The disused part can be followed in some parts, but mostly runs through private land. Even if you do try to follow it for some reason, don't expect views anywhere near as good as those available while walking the upper sections of the leat.

Burrator Reservoir

If you're planning on walking to the lower end of the leat, a visit to Burrator Reservoir would be a better idea - it's a very popular place for Plymouth folk in the summer. It's especially popular with cyclists and fishermen (permit only), and as the area is quite sheltered it positively heaves with people, especially at weekends. There are good but steep walks up to Leather Tor and Sheeps Tor, both of which have tremendous views; Sheeps Tor is also a good spot for climbers. You can take bus number 82 (runs twice a day on Sundays) from Plymouth to Princetown and follow the leat down to Burrator; number 82 buses back towards Plymouth run from Dousland.