Eighteen DPA Members and friends met at the Venford Dam car park on Weds. 25th August, under blue sky and white clouds. The walk started with a look at the details of the dam and its features, followed by a walk towards the South Bench Tors that then cut down to the corner of the water works enclosure and finished with a circuit of the reservoir lake.
The reservoir was built between 1901 and 1907 to supply water initially to Paignton but now Brixham, Ashburton and Widecombe-in-the-Moor receive water from here. The land was bought from Richard Dawson, Lord of Holne Manor. The catchment area is 700 acres and is ringed by granite pillars marked “PUDC” on one side and “RD-H” on the reverse, signifying Paignton Urban District Council / Richard Dawson, Holne. There are 52 PUDC Boundary stones. The area of the lake is 33 acres. There were some renovations to the overspill arrangements in 2009. Water is supplied by the Venford Brook and other local streams but there is also an inlet for water piped from the Swincombe valley.
A good view of the dam is seen from the raised ground beside the car park, from where the draw-off “tower” and the four original overflow outlets.
Above is a view along the dam from the west end, near the car park. The stone pillar is one of the granite boundary stones around the catchment area of the reservoir marked “PUDC / RD-H”, signifying Paignton Urban District Council / Richard Dawson, Holne – lord of the manor when the stones were erected. There are 52 PUDC Boundary stones (on the Dartefacts web site), this one being Number 1, facing the camera is RD/H, PUDC can be found behind it.
Just around the corner of the near-end of the parapet seen in the previous photograph, on the road-side, (2nd row of stones up from the road surface, 3rd stone along the road from the end of the parapet), at SX 68604 71210, is a benchmark – a horizontal line with a “government arrow” below. The marks were made by the Ordnance Survey during surveying for the Principal Triangulation of Great Britain (1783-1851), when benchmarks were used. The Retriangulation of Great Britain (1935-1962), when permanent markers e.g. triangulation pillars came into use.
The reservoir overflow area features a labyrinth weir which is designed to convey large flows of water by increasing the effective length of the weir crest with respect to the channel breadth. It leads into a spillway that bypasses the dam in time of excess water leading to a buried culvert that bypasses the water treatment works and returns excess water to Venford Brook, below the dam.
The disturbance in the water towards the middle of the lake is where air is piped under the water to aerate it – this is the process of increasing or maintaining the oxygen saturation of water in both natural and artificial environments. Google Earth shows ten of these aeration points. Aeration techniques are commonly used in pond, lake, and reservoir management to address low oxygen levels or algal blooms.
First commemorative stone encountered …..
Top of the “draw-off tower” – photograph taken from the car park end of the dam of the draw-off valves ….. the left-hand yellow label says “Draw off valve No 4”. The valves control water flow into pipes taking untreated water from the reservoir to the treatment works before it is distributed as potable water – the pipes can draw water from different levels in the reservoir …..
The draw-off valves are covered with caps and padlocks are used for security.
A closer view f the valves, as seen from the road.
The second commemorative stone, to the “left” of the “valves”.
Looking up the lake. It is fed by Venford Brook and an inlet from the River Swincombe. This flooded area was known to William Crossing as “Wennaford Bottom” and the lake as Paignton Reservoir.
Looking over the parapet at the Water Works below the dam; the main buildings house the filtration beds and show the chimneys on the old watchman’s dwelling, Venford House, at the far end of the site. This is now a private house.
Photograph taken outside the walk area, across the road from the car park, showing four features on the water-side face of the dam that are, presumably, the original overflow outlets going under the road to cascade down the back of the dam.
The back of the dam where overflow water cascaded down to rejoin Venford Brook, before the new labyrinth weir system was built (2009).
View from above the east end of the dam looking north-east, up towards South Bench Tor, or South Benjy Tor, which is labelled Benchator on the 1839 Holne Tithe Map; near the top of the map, below the “I” in Parish of W”I”decombe. Note the “Pot water to Collings Stoke” label on the tithe map, and “West Stoke” on the 1888-1913 25-inch OS map.
Looking left of north at the pointed Sharp Tor (1.6 km/1 mile) distant, Corndon Tor to the right and Yar Tor towards the left (both at 1.8 miles). The house to the left is Rowbrook, the house in the centre is Rowbrook House.
Rowbrook, or Rowbrook Farm, is an ancient farmstead with a medieval longhouse still standing. This was the home of the farm Apprentice, Jan Coo, who was called away by the pixies on three occasions. Other people at the farm also heard the calling of the pixies. He did not return from the third calling of his name and was presumed taken by the pixies or lost in the River Dart below.
Granite stone at the corner of the water works enclosure. There are 52 PUDC Boundary stones (on the Dartefacts web site), this one being Number 50.
There are areas of tree roots across the footpath around the lake.
A little distance below the Workman’s Bridge (over Venford Brook) – this is possibly the site of the “Venford Tin Mill” or part of its leat. This is deduced from a possible leat that is drawn from Venford Brook and then leads back into the brook, as depicted on the 1885/1886 25-inch OS map ….. the mill would have been at approximately SX 68366 70714, halfway along the presumed leat ….. there is no sign of this feature on the subsequent 1904/1905 map ….. the mill is listed on the Legendary Dartmoor web site as “Venford Brook Mill” (pre-1750).
R Hansford Worth (1967), Worth’s Dartmoor, David & Charles, Newton Abbot, page 293, mentions this site as being at lat. 50°-31′-20″, lon. 3°-51′-26″. This converts to SX 68442 70808, a little further into the lake.
Possible site of Workman’s Ford, but this is doubtful. It is in the vicinitiy of Venford Brook.
“Venford Fall””, just above Workman’s Bridge.
Modern bridge at the site of Workman’s Bridge – this was probably a bridge for old-time tinners, associated with the “drowned” tin mill.
Just a view of the footpath around the lake.
As the caption says, Rhododendron.
The inlet of water from the River Swincombe, SX 68415 70991. The water level at the Swincombe dam is 1041 ft, here at Venford it is 935 ft, a drop of 106 ft. Out in the middle of the lake is an aeration upwelling. I started off being smart, thinking there was only one of these, so I was going to be clever and geolocate it on a map by taking compass bearings from two GPS’d locations, one each side of the lake. There were two upwellings! One is out in the middle of the lake and a second one is seen over the far side, at top left.
One of ten aeration upwellings seen on Google Earth.
A triple mortar stone from the nearby tinners’ mill that is under the reservoir, SX 68568 71180 …..
Wooden plaque above the mortar stone, somewhat defaced …..
THIS MORTARSTONE DATES TO ABOUT AD
1600 AND WAS USED AS A BASE ON WHICH
TIN ORE WAS CRUSHED CUP SHAPED
HOLLOWS WERE FORMED BY THE
MECHANICAL ACTION OF STAMPS POWERED
BY A WATERWHEEL EARLY THIS CENTURY
THE STONE WAS REMOVED FROM A SITE
ABOUT TO BE FLOODED BY THE RESERVOIR
IT WAS PLACED HERE IN 1984
Before reaching the west car park (with toilets) at Venford Reservoir, there are two PUDC marker stones, one each side of the road, about 90 yards up Waterworks Hill – more detail below …..
On the rear face of the left-hand one, away from the road – is a benchmark. This is an Ordnance Surveyor’s mark that consists of a short horizontal line, just below the “UD” in PUDC with a government broad arrow underneath it, pointing upwards. This stone is Number 4 in the Dartefacts web site sequence of the reseroir catchment area boundary stones: across the road is Number 3.