The London/Harrow/Hertfordshire boundary cuts across the southern edge of the reservoir south of Elstree Road, and then continues along Elstree Road, north east.
Tykes Water flows northwards from the reservoir.
This site stands on the London border to the west of Elstree and north east of the A41. Nearby is the site of the never-built northern tube extension. The area is dominated by the late 18th century reservoir
Post to the east Elstree
Post to the south Stanmore Common
Post to the north Aldenham House
Sites on the Hertfordshire side of the boundary
Reservoir. Built following an Act of Parliament in 1793 when the Grand Junction Canal Company was given rights to an area of Aldenham Common to construct a reservoir. Sixty eight acres were originally and a further ten acres were added in 1801. It was a feeder to the Grand Junction Canal because mill owners thought the Grand Union would take all their water and this would maintain water levels on the Gade and Colne. It was dug by French prisoners of war who built a dam, which has leaked ever since. 700 acres belonging to the Regent's Canal Company. It affords excellent boating and fishing and is much frequented on that account. There is a tunnel leading under the dam. It was originally built of clay, but the reservoir wall was reinforced during the 20th with a concrete dam wall. In the early 20th century the reservoir was used for pleasure boating with teas being served from the Pump Masters House. Hertfordshire County Council took it over and turned it into a public country park in the 1970s.
Linear dam wall; reinforced concrete wall to the northeast of the park with a series of landing areas out into the lake and a path on the north side.
Railway line; northeast of the dam wall are the remains of a brick base that carried the old railway line which transported fuel up to the pump house from the former Pump Masters House. Demolished.
Pump house; remains of the demolished pump house close to the tunnel entrance on the banks of the stream.
Tunnel: Mid way along the east side of the dam is a tunnel with buttresses and an entrance dated 1914 constructed / faced with patterned / rusticated brick. It leads under the dam wall and a short distance under the reservoir.
Lismarrane Industrial Park
The Waterfront. Office complex
Watford Way junction. There was a proposed station at Aldenham on the pre-Second World War, abandoned, tube extension. The first plan was for a site in the 'V of Elstree Road and Watford By-Pass and would have had four platforms plus an extensive development, with a cinema, pub and many shops. However this changed to ‘Bushey Heath Station’ , and to a site east of the Watford By-Pass which would have meant the railway passing under Elstree Road
Bushey Heath - proposed station on the pre-Second World War, abandoned, tube extension. This would have been a much larger station than the one planned for Watford Way junction. It was designed as a through station with four platforms. There would have been a cafe and mess facilities for staff upstairs. There would have been an Underground style tower plus a as well as a car park and bus shelters and a subway under Elstree Road to link the bus stop with the station.
Beard. By Tube Beyond Edgware
Blake. Northern Wastes
British History Online. Harrow
London Borough of Harrow. Web site
London Railway Record
Thames Basin archaeology group report
The Waterfront. Web site
Walford. Village London