The Alders Brook is a tributary of the River Roding, with its source difficult to determine but appearing to be within the City of London Cemetery. Presumably the stream's origin is run-off water from the slightly higher ground to the south-west (i.e., Wanstead Flats). It can be seen that at the main gate of the City of London Cemetery, a shallow valley stretches generally towards the east, passing past what is now the Crematorium buildings and culminating apparently at the catacombs and columbarium - the area which was in the times of the Aldersbrook Manor was an ornamental lake, the Great Pond. One can conjecture that overflow water from Alexandra Lake may well find its way through underground drains down this valley. No sign of this can now be seen, although there is an ornamental pond near the new crematorium which may have some bearing on the present source of water. Beyond the catacombs was another ornamental lake known as the Great Canal, which now lies within an area of woodland. At the east end of this woodland a pond has been created as part of a wildlife refuge known as the Birches. The source of the pond's water is a concrete culvert which contains a stream that - prior to culverting - could be seen to flow from the direction of the catacombs.

This constantly flowing stream, together with the pond, now constitutes the visible source of the Alders Brook. Via a culvert, the outflow from the pond passes beneath the cemetery railings and the Bridle Path which follows the cemetery boundary fence, and can be see as the stream that is called the Alders Brook. Its course takes it east and then southwards to flow to the east of the Bridle Path Allotment Site, maintained by the London Borough of Newham. Its course between the allotments and Ilford Golf Course means that it is not accessible to pedestrians. South of the allotments, between the cemetery railings and the brook, there is some open land known locally by some as "The Butts". Access is through a foot-tunnel under the railway line from Romford Road at Little Ilford or via the bridle path which follows the perimeter of the cemetery either from Rabbits Road or from Empress Avenue. There is also access from the Aldersbrook Exchange Land - the old Sewage Works site - in Epping Forest. On the east side of the Alders Brook is Ilford Golf Course, beyond which is the A406 North Circular Road.

The area had an incredibly rural feel for part of Newham, although in 2007 this was spoilt by the laying of a 2 meter wide cycle path - part of the Roding Valley Way, a combined footpath and
cycleway through the London Boroughs of Redbridge, Barking & Dagenham and Newham. Instead of using the existing path (known as the Bridle Path - although apparently not designated officially as a bridle path) along the edge of the cemetery, the new route was insensitively laid across what was effectively a wildflower meadow!

This new path also led to the severe trimming of some small but nice oak and other trees beyond the allotments, and potentially will lead to stress on the root system of these tree. However, it has considerably improved access to the area by pedestrians as well as cyclists, and is a much easier walk in many parts which were almost invariably muddy and overgrown. However, the surfaced route at its present northern end veers again from the existing route to end unceremoniously at the very gates of the Exchange Land site of Epping Forest (the Old Sewage Works Site). This means that the Exchange Land, with its wealth of flora and fauna, will also suffer a disturbance which it has not until now had, and - for pedestrian visitors - a change in the ambience of the place. It is shameful that some lovely and unique wildlife areas have suffered - and all unnecessarily for the route of the existing path was perfectly adequate, and particularly at its northern end could have benefited from surfacing. It is interesting to note that the L B Newham Adopted UDP 2001 ( Unitary Development Plan ) includes the following statement : • Sites of nature conservation importance will be protected and enhanced. The encouragement of cyclists and - particularly if it were come to pass the provision of a hard-surface track - cannot protect and enhance the site!

At the southern end of the Butts, the brook encounters a concrete barrage, where the water is controlled as it passes under the main Liverpool Street railway lines. Adjacent to this is a foot-tunnel below the railway lines which which allows foot and cycle traffic to access the Romford Road in Little Ilford. The brook of course continues beyond the barrage, but once again is inaccessible to pedestrians. Eventually it emerges to join with the River Roding at Ilford Bridge, from where it can just about be viewed.