Wanstead Park

The Lake System of Wanstead Park - Part 1

The Lake System

Reprinted (with minor modifications) with acknowledgements to James Berry & Alan Cornish, from their work "The Lake System of Wanstead Park & The Mystery of The Heronry Pond" © James Berry & Alan Cornish, March 1978.

Before Man - The Physical Setting

The southern end of Epping Forest has a surface largely composed of gravels of lower level, belonging to the present systems of the valleys of the Thames and Lea. London Clay underlies all formations. The gravels were deposited in terraces when the rivers flowed at a somewhat higher level than they now do, and having more fall, brought down coarser material.

After the Glacial Period, the present river system came into being, and the Lea, Roding and Thames cut their way through preceding deposits of gravels, deepening and widening their valleys as they did so, and leaving behind them various beds of gravel, peaty matter and loam.

A deep boring made by the Metropolitan Water Board prior to 1921, in the grounds of the Redbridge Pumping Station, gives some idea of the nature and thickness of thin underlying strata:

Drift/Alluvium ........................14 feet ...............(Recent & Pleistocene)
London Clay.......................... 78 feet................(Eocene)
Woolwich/Reading ................. 78 feet................(Eocene)
Thanet Sand ..........................48 feet................(Eocene)
Chalk.................................... 60 feet............... (Cretaceous)
Water found at.......................200 feet

The immediate area of Wanstead Park is subject to two major river valleys. The Thames gives the park a gentle southward slope. The Roding is on the eastern boundary, and an eastward slope becomes very pronounced in the vicinity of the river.

To the north of the park lies a terrace of Boyn Hill Gravel, which extends beneath most of modern Wanstead centre, as well, as Leytonstone Flats, and the Hollow Ponds. The terrace rises to over 100 feet above Ordnance Survey Datum (OSD), and runs north-west at that level, merging into the main forest area to the north.

From the southern face of this northern terrace a number or natural springs emerge, from perched tables within the gravel, due to the impermeable nature of the underlying London Clay,

One such spring is shown on a map in John Nordon's 'Description of Essex" (1594), feeding a stream running due east into the valley of the Roding, across the enclosed estate of the 'Statelye howse at Wansted." This small stream in its shallow valley of exposed London Clay, between deposited gravel terraces to north and south, no doubt originally formed the drainage channel for the surrounding area, which we now know as Wanstead Park.

Finally, to the south of the park, another gravel terrace, this time of Taplow Gravel, rises to just over 50 feet above OSD, and underlies Wanstead Flats. However, this terrace also juts northwards slightly at its eastern end, near the Roding. (see bottom map, page 9).

The bed of the Roding itself now consists of quite extensive deposits of alluvium drift,

see maps - pages 7, 8, 9.

Historical Development of the Lakes System

The Park was first enclosed in 1545, and its history in the 16th and 17th centuries would require a complete separate book. However, apart from the stream indicated by Norden's map (1594), running west - east across the estate and down into the river Roding on the eastern boundary, no reference to other waterways can be found.

In 1667, the estate came into the ownership of Sir Josiah Child, who immediately began to spend large sums in improving the gardens, planting trees, laying out avenues, and forming a lake and canals. In the spring of 1683, the diarist Evelyn went to look at his improvements:

"16 March 1683 - I went to see Sir Josiah Child's prodigious cost in planting walnut trees about his estate, and making fish ponds, many miles in circuit, in Epping Forest."

The works appear to have consisted at that time of two separate endeavours. The major work consisted of extending the Roding into a series of ornamental waterways, known at that time as "The Serpentine River" later to become "The Great Lakes" and now known as "The Ornamental Waters." Initially the river actually flowed through the system, but in time a scheme was worked out so that dams across the Roding turned the waters or the river into the system when necessary, and by-passed it when not.

The other work was the creation of two semi-circular or kidney-shaped lakes, between the great house and its entrance drive to the west. In fact the entrance drive led through an avenue of trees from "The Green Man" Leytonstone, along what is now Bush Road, through the gates where massive gate posts now stand at the beginning of Overton Drive (photo), and then between those twin lakes, which each had its base, or flat side, actually alongside the approachway.

Thus from the great Wanstead House, one could look to the east, down into the valley of the river Roding, and see the Serpentine River, complete with artificial canal in the distance. Alternatively, if one looked westward from the front of the house, a driveway sped straight towards Leytonstone with twin semicircular lakes on either side in the foreground.

In fact precisely these views were shown in a series or three plates etched by Kip and dated about 1710, one of which (looking eastwards) is reproduced in the booklet on Wanstead Park published by the Conservators of Epping Forest (page 5).

Sir Josiah Child died in 1699, and the estate came into the ownership of the Hon. Josiah Child, his oldest son by his second wife. By about 1709 however, the estate was in the Control or Sir Richard Child, who was born of Sir Josiah Child's third marriage, and was the Hon. Josiah's stepbrother. Then began a most significant period of development, both for the great house, and for the lake system.

Sir Richard Child, created Lord Newton, Viscount Castlemaine and Earl Tylney, rebuilt the house in 1715, and about this time he also spent over £100,000 on the already magnificent gardens, lakes and grounds. Plans prepared by Colen Campbell in the Italian style, were considered by contemporaries as his best ever, and are detailed in his "Vitruvius Britannicus" Vol. I.

Again the works appear to have been approached in two distinct areas, the first of which concerned the approach to the front of the house. Here, the Earl's gardener, a man named Adam Holt, was required to turn his attention to the two semicircular lakes which lay on either side of the approachway.

Adam Holt appears to have been something of both a landscape artist, and no mean engineer. The two small semicircular lakes were joined together, by the simple method of cutting down the level of the road which ran between them. Thus joined into virtually a single almost circular pond, with the approachway to the house diverted round the northern side, formality was introduced. The circle was given eight corners, and a sluice gate was located on its southwest side to prevent overflow other than via an underground pipeline and open ditchway, running southwest and then south, into the valley.

The origin of what thus became The Basin can be seen from both its shape, and contents. It is not a perfect octagon, for instance, being longer on the two parallel sides running north-south. This is because the original two semicircular ponds had between them the approach road to the house, and thus did not form a perfect circle when joined, but more an oval. In addition, the original approachway to the house still runs across the lake, at a depth of about five feet in places. Investigations by the London Underwater Research Group in 1961 found several courses or brickwork still in situ, showing that the original lakes had been brick edged where they flanked the roadway.

It is probable that as well as re-modelling the Basin, Adam Holt also increased its depth somewhat, by an extremely ingenious method of increasing the inflow. Just how ingenious were his engineering works can only be judged by reference to an accurate Ordnance Survey map, and a careful tracing of the contours to the north of the Basin. Essentially he managed to tap a catchment area which faced entirely the wrong way for his purpose.

The catchment area was Leytonstone Flats, which are situated on higher ground to the northwest of the Basin. As previously noted, Leytonstone Flats are located on the top of a terrace of Boyn Hill Gravel, and this terrace slopes gently down to the Northeast, ending in Eagle Pond. However, a shoulder of higher ground juts out at the southeast edge, between the natural drainage slope, and the Basin.

The solution adopted by Adam Holt was to construct a ditch - known locally at the time as the "River Holt" after its designer - around the eastern edge of the offending spur of high ground - virtually following the contour round and into the Basin. On 1735 estate plans a small collecting reservoir is shown on the higher ground to the south of Eagle Pond, behind the former Royal Wanstead School, and abutting what is now Hollybush Hill. We cannot be certain that this collecting reservoir was ever so formally shaped as in the 1735 estate plans - see below - but its purpose was clear. From it the "River Holt" ran south east, close by where the "British Queen" public house now stands, and along what is now Spratt Hall Road. It then ran just east of due south, feeding into the Basin probably near its north east corner.

The south side of the same terrace of Boyn Hill Gravel probably drained naturally into the "Green Man" pond, and this too was probably tapped by Adam Holt, via ditches in the formal layout or the west gardens south-eastwards although any such ditches are not distinguishable (map - page 14).

In the second area or works conducted for Earl Tylney, attention was turned to the shallow valley to the south of Wanstead House and its now formalised west approachway. This was the valley which contained the stream running west east into the river Roding, as indicated on John Norden's map of 1594 (see page 7).

A series of embankments were thrown north-south across the valley, damming the stream to form a chain of ponds up the floor of the valley. From east to west, these were:

Perch Pond
Heronry Pond
The House Pond
The Reservoir
The Great Lake

Perch Pond and Heronry Pond were apparently known collectively at the time as "The Serpentine Ponde" - as distinct from "The Serpentine River" so called of Sir Josiah Child's first waterway diversions or the Roding. Earth embankments still exist at the eastern end of both ponds, holding them back within the valley.

The House Pond, or House Field Pond, later to become known as Shoulder of Mutton Pond from its odd shape, may not have required much development, since it appears to lay in a natural depression, and is reputed to be fed by its own independent underground spring, in addition to the stream flowing through it and down eastwards into the Roding. One may even speculate that it could have been a pond dug sometime much earlier, to serve as a source of domestic water for an adjacent large house, hence the name House Pond. When Richard Rich, 1st Lord Rich, built Wanstead house in 1549/50, he is known to have chosen higher ground as his site, rather than that of an older house, nearly derelict at that time, which he demolished. This was Naked Hall House, reputedly timber built. However, against such a theory it must be noted that no such pond was indicated at this site on Norden's map of 1594 - although that is not necessarily conclusive, taking into account the small scale, etc.

The Reservoir was intended to be roughly square in shape, and probably had retaining banks on all four sides. The north and south embankments have long since disappeared, but the eastern embankment still remains as a large and rather incongruous reminder, stranded on dry land now, and pierced by several footpaths and a ditch. (photo) The Reservoir was probably so-called with the aim of providing a steady source for the ponds down the valley, to the east of it.

Separating the west end of The Reservoir from the Great Lake was another massive earth embankment thrown north-south across the top end of the valley. This embankment also still remains - but is not recognised by the casual observer as anything but Blake Hall Road, between Wanstead Park and the Aldersbrook tennis courts. (Blake Hall Road was authorised to be constructed by an act of Parliament of 1816)

The Great Lake was the subject of greatest design-change between the time of its conception and ultimate creation, and the different designs, some of quite startling imagination, are of considerable interest.

Various designs and estate plans were drawn up by the French cartographer, Jean Rocque, for Earl Tylney in 1735. It was this same Jean Rocque who ten years later published the large-scale series "Environs of London" - and it is no pure coincidence that on this and other of his subsequent plans, he managed to just so "stretch" the boundaries of the Capital city to include the lake system of Wanstead Park - in the design of which he had a hand in 1735.

Rocque's plans of the Great Lake show at least two designs. One is an incredible cartwheel, with an island at the centre as a hub, and four great waterways radiating from it like spokes, ending in a circular waterway right around the rim. Had it been constructed, it would have been almost 1,000 feet in diameter at its widest points A second design took the form of a trapezium, on a similar massive scale. Complete plans of the entire estate show each of those designs as if they existed, and for the unwary can cause confusion between intent and reality. Rocque designs of 1735 also show Heronry Pond joined to a symmetrically-shaped House Pond - and the whole called "Leg of Mutton Pond." Imagination really ran amok with some of the islands on the lakes - for instance one plan shows the island in the Great Lake as a perfect miniature of Britain.

Even though some fairly amazing designs were dreamt up, there is no doubt that all of the lakes were constructed in some form, and reality can be established from the separately commissioned Rocque work of 1745 - "Environs of London" (page 14). Only ditches in the formal gardens, e.g. the "River Holt" and the connection with the "Green Man" pond, are indistinguishable from the formal walkways, and this "omission" signals the difference between their engineer-creator (Adam Holt), and the less practical, more artist-designer (Jean Rocque),

Nevertheless, it is considered that the map produced by Jean Rocque in 1745 shows the lakes system of Wanstead Park at probably the greatest point of its actual development.

Around seventy years (1670-l740), and several generations of immensely rich patrons and brilliant landscape artists and engineers had combined to produce a chain of artificial water-ways meticulously set into the parkland, taking advantage of every contour, and every possible source of precious water.

It will be shown that as the various sources of water were diminished or diverted - through ignorance, neglect, accident or malice - so the weak links in this Chain revealed themselves, right through to the present day.

The Lake System Today

The lake system of Wanstead Park as we now know it comprises five separate lakes, forming a chain running in a semi-circle from west, through south, to east.

Each lake is joined to its neighbour by underground drains, open ditches, or open spillways, and the system finally finishes with a weir at the southeast corner, feeding a spillway/overflow into the river Roding.

From the top lake to the bottom lake, there is a drop of over fifty feet, into the valley of the Roding. Lying entirely within the Wanstead Park designated Conservation Area, the system comprises, in descending order:

The Basin
Shoulder of Mutton Pond
Heronry Pond
Perch Pond
The Ornamental Water

Two lakes of the originally developed system, i.e. The Reservoir and The Great Lake, have already been lost and of the remaining five, one - Heronry Pond - is under serious threat. Its loss would completely break the chain of which it forms the central link.

Brief details of each of the present lakes are given below, and pages 22 and 23 show working plan and elevation.

The Basin

Area about 10.12 acres. Octagonal in shape, exactly aligned on a north-south axis, and originally part of the formal frontispiece to Wanstead House (demolished about 1822). No islands. Now situated within Wanstead Golf Course, and not accessible to the general public. Overflows via a sluice located in its southwest side, now heavily rusted through disuse. From the Basin an underground pipeline runs southwest about 150 feet, almost to the boundary of Silcocks & Collins Sports Ground, which it than follows, south and then west, for about 600 feet. It then turns south, emerging about 120 feet south of the sports ground boundary into open ditch alternating with covered pipeline in sections as it crosses the golf course.

The pipeline thus has three right-angle corners, none with inspection/clearage manholes, and has occasionally been the cause of blockage. Where submerged, the flow is carried in one foot inside diameter heavy glazed earthen-ware pipe, and it finally emerges into open ditch when it passes beneath the boundary fence between golf course and Reservoir Wood. A part of Epping Forest and open to the public.

The open ditch continues south a further 230 feet before joining the original main stream, running in an easterly direction a further 800 feet before flowing into the southwest corner of Shoulder of Mutton Pond. This section of open drain through Reservoir Wood is subject to frequent blockage by falling leaves, other debris, and by general vandalism. (See photographs)

Shoulder of Mutton Pond

Area about 3.5 acres. Takes its modern name from its distinctive shape. Formerly called House Pond or House Field Pond. No islands. Swimming is permitted daily before 8.30 a.m.

The southwest corner is now a marshy delta, caused by the carriage of silt into the pond from the feeder stream at this point.

North of the pond, inside the golf course, a line of bunkers running north-south tends to feed a surface stream which delivers small amounts or water into the pond during periods of heavy rain. This inflow is not significant.

Shoulder of Mutton Pond overflows into an underground drain on its east side, which runs east about 340 feet in twin pipes, to spill into Heronry Pond. Halfway along this twin pipeline it crosses a gas main, laid at a lower level, in about 1974. Precautions were taken at the time of these works to ensure that the drain was kept water-tight. (See photographs)

Technically, Shoulder of Mutton Pond is not in Wanstead Park, but is within Epping Forest.

Heronry Pond

Area about 8.38 acres*. Contains two islands each about half an acre in site. The only lake in the system with concrete base and sides, which slope inwards at about forty degrees. The concrete base is not generally apparent, due to an accumulation of silt several inches thick in most places.

*Areas recorded in this descriptive section are as given in the 1954 Ordnance Survey. However, our measurements of Heronry Pond and of the survey maps indicate a water surface area for Heronry Pond of 332,788 sq.ft., or 8.7876 acres, and this slightly larger figure is used in our calculations. The difference is very small (less than 5%), and may be accounted for by the slope of the sides of the pond. Our larger figure is taken from the top edge of the concrete rim of the lake.

Heronry Pond is also fed by several other sources. The principal one is a storm sewer running into the south west corner of the lake, from the Junction of Park Road and Northumberland Avenue, about 310 feet away. The catchment area for this storm sewer is approximately the area bounded by Park Road, Aldersbrook Road, Blake Hall Road, and Woodlands Avenue, i.e. about 31 acres, plus a connecting pipe at the end of Park Road across to a drainage system beneath Wanstead Flats (see page 39 below). The storm sewer pipe leading into Heronry Pond has been designed to flow full once every two years, at a discharge rate of 280 litres per second for the duration of a storm, i.e. about 3,695 gallons per minute. It was re-built during the winter or 1977-8, as part of the re-laying of the foul and storm sewer systems beneath Woodlands Avenue and Northumberland Avenue. Originally however, this feedpipe was laid out in 1906 as part of a scheme to increase inflow into Heronry Pond, by feeding water drained from Wanstead Flats. The arm of Heronry Pond into which the storm sewer flows is now heavily silted to a depth of 21 inches, i.e. almost half the original depth.

Heronry Pond is also fed by a small underground drain from the golf course, entering the pond a few yards east of the main inflow pipes from Shoulder of Mutton Pond.

During periods of heavy rainfall, a surface stream is often formed which also flows into Heronry Pond at about its northern midpoint. It brings the surface run-off from the golf course, and the southern part of Warren Road (unadopted). At this point, immediately north of the East Island in Heronry Pond, there is also a small underground drain in the bankside. However, this appears to be blocked, and no flow occurs.

Technically, the west half of Heronry Pond is within Epping Forest, and only the eastern half or slightly less, is actually in Wanstead Park. Since both are under the control of the Conservators of Epping Forest however, this distinction is not of great consequence. Boundary fences between forest and park run into the pond on its north and southeast banks.

The most significant feature of Heronry Pond is its inability to maintain a stable water level. In most winters it fills to a varying extent, peaking at about the end of March. It then dries to practically nothing by about end August each Summer.

Only very exceptionally, and last in the winter of 1974/5, does it overflow via an underground spillway in its eastern bank, into neighbouring Perch Pond. (see photographs)

Perch Pond

Area about 5.5 acres. Seven small islands at its western end. Used intensively for fishing, together with some boating in summer. A dilapidated boathouse is situated on the north bank, and a few yards to the west of the boathouse, Roman ruins and a mosaic flooring were found both when the park was laid out in the l730's, and again in the early l960s*.

*see 'The Re-discovery of the Roman Site in Wanstead Park' (1963) by J. Elsden Tuffs, available in Ilford Reference Library.

Boat maintenance is carried out in a second building, just north of the embankment running between Heronry and Perch Ponds, and this building also serves as a snack and coffee kiosk at weekends and Bank Holidays throughout the year.

Perch Pond is also fed by a storm sewer of similar dimension to the one feeding into Heronry Pond (see preceding description). It leads into the southern side, just south of the peninsular at the southwestern corner of the lake. This corner of the lake is heavily silted, and a ditch has been cut from the mouth of the storm sewer pipe, through the silted area, to the open lake beyond the islands. A substantial amount of silt remains to be removed.

Reconstructed in 1977, the catchment area of the storm sewer is Northumberland Avenue, and the roads running south between Ingatestone Road and Clavering Road, plus some drainage from Alexandra Pond on Wanstead Flats (but see page 40).

From the north east side of Perch Pond, an open spillway, crossed by a small wooden footbridge, leads down into the Dell, a small wood (see photograph). Open ditch then leads beneath a brick bridge which carries the forest track, ending in the Ornamental Water.

The Ornamental Water.

Area about 15.0 acres. Various islands totalling a further ten acres approximately. Considerable wildfowl with many nests on the islands. No fishing permitted.

The level of water is maintained at a higher level than the adjacent river Roding by pumping water from the river, and a pumphouse is situated at the northern-most point of the lake. (photo)

Between the 1930's and 1976, this contained a 6 inch Gwynne's Invincible pump, type KL, No. 52669, Originally rated for a duty of approximately 800 gallons per minute at 10 feet total head when operating at 730 r.p.m., fitted with a 10.75 inch diameter impeller. It had a 9 inch diameter intake, and was driven via a belt, by a 7.5 HP 400V Brook electric motor, No. R3-94760.

The Conservators of Epping Forest hold a licence from the Thames Water Authority, permitting extraction of water at this point, from the Roding, as follows:

27,000,000 gallons per year
Maximum 50,000 gallons per hour
Maximum 350,000 gallons per 24 hours

In 1972, the Conservators embarked upon a programme of dredging, to remove silt deposits from the lake, and a crude silt trap was constructed near the point where water is pumped in. During the period 1972-76 the pump was hardly used, for reasons associated with adjacent engineering works conducted first by the Gas Council, then the Greater London Council (main sewer), and subsequently by the drought conditions which led to the virtual drying up of the Roding in the summer of 1976.

In November 1976, the Conservator, instructed the London Electricity Board to install a new meter and a new power outlet in the pumphouse, prior to the installation of a new pump. The Conservators then went ahead in February 1977 with the installation of a Flygt medium pressure pump, which is located in a pit outside and behind the pumphouse. This is a submersible dewatering pump, intended for the prevention of flooding of construction sites. The model installed is type B 2102, fitted with a threephase a.c. motor, 5.2Kw (7 HP), working at 2,850 r.p.m. It has a 4 inch discharge connection, and the complete unit is described by the manufacturer as being "…. easy to handle by one man between sites." Its speed and capability, compared with its predecessor, are as follows.

Operating Speed Delivery Rate (rpm) @ 10 ft gauge head:
Old Gynne pump 730 800 gal/min
New Flygt pump 2,850 410 gal/min

We do not consider the unit is suited to its current use. Low capacity has meant high-speed operation over long hours to deliver any given volume of water. This, coupled with the very long period (1972-76) when the Ornamental Water had been allowed to drop considerably in level, has led to heavy utilisation of the pump. In addition, there is the possibility that disturbance of the adjacent sub-soil may have accelerated the rate of natural seepage from the lake (see Permeability Tests below), leading to a requirement for more pumping than in the past, simply to maintain a stable and satisfactory level. In any event, between 30 November 1976, when the new meter was installed, and 22 February 1978, a total of 21,080 units of electricity were consumed - mostly from February 1977 when the new Flygt pump came into operation.

By a false economy with installation of an inadequate pump, the Conservators are now consuming electricity at the Installed Load Rate of 2.545p per unit on a continuing basis. Had a more powerful pump been installed at a higher one-time initial cost, the same total volume of water could have been pumped in much shorter periods, e.g. nightly between 2300 hrs and 0700 hrs, enabling advantage to be taken of the Day/Night Rate of only l.14p per unit - less than half the current cost.

Dutch Elm disease has recently destroyed many of the larger trees surrounding the Ornamental Water and on its islands so that heavy leaf falls are unlikely to cause pollution as they have done in the past. Dead trees on the islands still provide valuable refuge for the prolific wild life however, and it is hoped they will not be disturbed.

At the south east corner of the lake is a weir, feeding a spillway/overflow into the river Roding, to complete the system.

Ornamental Water has many attractive and unusual features which date back to previous centuries. They include a purpose-built Grotto (now in ruins following a fire in 1884, and years of vandalism), "fortifications" which are now partially flooded due to raising of the lake level - but which once were the centre-piece of a wildfowling lair for the residents and guests at the great Wanstead House, and a "canal" to provide a fine view through an avenue of trees, from the great house on the brow of the hill above.

*See also "The Lake Sanctuary at Wanstead Park" by CS Cornish, Country Life, vol VII, pp 645-8, 26 May 1900, for a description of the profusion of bird life in the park. This is still the case, and the Wren Conservation Group bird survey of 1977 identified 100 different species in the park during the year.

Amenity Value of the Lake System

In the system of lakes today, each one - with a single exception - has a high amenity value.

The Basin is not directly accessible to the public, but it is skirted by Overton Drive to the north, and so contributes an open and pleasing perspective to the casual passer-by. For the golfer it provides a most interesting obstacle, and a focus of the course. It is also available to members and friends for fishing.

Shoulder of Mutton Pond is available to the public for swimming in certain hours, and is a peaceful haven for waterfowl.

Perch Pond is used intensively for public fishing, and this is in conflict with boating which is also available to the public on the lake.

The Ornamental Water provides a beautiful lake-side walk over 1½ miles in circuit, and is an area of great tranquillity for man and the profusion of birdlife which uses it as a staging post along the Roding valley.

The complete system offers a unique centre so close to central London, for ornithologists and many others seeking outdoor recreation.

Only Heronry Pond makes a nil contribution, and its sad state is both an eyesore and a continuing threat to the integrity of the chain, of which it is the central - and weakest - link.

This research project was started in 1974, under the auspices of the Wren Conservation Group, in an effort to discover what lies behind the problem of Heronry Pond, and if possible, to offer a solution.

(See also Part 2 - Heronry Pond by James Berry & Alan Cornish)

(See also Wanstead Watercourses: the "River Holt" by Barry Hughes)