Waterworks Nature Reserve #1: Great Meadow
The cache, a small black screw-capped pot, is hidden just off the trail at the eastern corner of the Reserve and of a large fenced meadow area, which at the time of hiding was occupied by two fine cows. This covers 4 of the old rectilinear Leyton filter beds which were filled in and grassed over. The other 3 (to the south west) are now managed willow woodland, accessed by a wooden boardwalk off the main path.
To Reach the Cache Location: park freely in the free parking area outside the Waterworks Centre @ N 51 33.900 W 0 2.175 accessed by Lammas Road on the south side of Lea Bridge Road. Enter the reserve through the gate at the south (right) end of the Centre. Cross the bridge into the Reserve then head left (south east) to the cache location.
Opening hours for access to the Reserve (which, with its well-surfaced paths, is wheelchair & buggy friendly) are 08:00-dusk daily.
By Public Transport: The 55, 56 and 48 buses stop on Lea Bridge Road close to the access road.
The Waterworks Nature Reserve, formerly known as the Essex Filter Beds (EFB), has one of the largest bird hides in London offering close-up views across a series of filter beds.
History: the site at Lea Bridge was first used for the extraction of water from the River Lea to supply Hackney and Clapton in 1707. Throughout the 18th century various owners developed the site both for water supply and as a corn mill until it was acquired in 1829 by the East London Waterworks Company which had been founded in 1807.
By the 1850s, due to the deteriorating quality of water in the lower River Lea, the role of the Lee Bridge Water Works had changed from being a point of extraction to that of storage, treatment and supply of water extracted higher up the river. To this end the site was developed with a number of filter beds. The six No1 Essex filter beds (radiating from a central well) on the east bank of the river) and the 6 similar Middlesex beds (on the west bank) were built under Acts of Parliament in 1852 and 1853 followed by the further six similar No2 Essex filter beds and the 7 rectilinear Leyton filter beds (LFB) after an Act of 1867, making a total of 19 beds.
These supplied the surrounding boroughs with a daily average of 42.5 million gallons of much-needed clean water following multiple serious cholera outbreaks in the capital. The disease had appeared in the 1830s and spread rapidly through the crowded and filthy streets. By 1855 over 30,000 people had died as a result.
By the time of construction, there was a better understanding of the spread of the disease (see GC7TCDY Middlesex Filter Beds #1: Wildlife Haven for details of the emerging science behind this and its huge impact) and increased demand for better sanitation.
The waterworks operated for over 100 years and were eventually closed in 1971-2 having been replaced by the new Coppermills Water Treatment Works in Walthamstow.
The No1 EFB were in-filled as part of the surviving depot on the site while the No2 EFB and the LFB have been developed as the WaterWorks Nature Reserve, fulfilling an important new role as a wildlife haven.
See here for more info on the history of Essex & Leyton Filter Beds and here for a series of historical maps of the beds.
See here for an interesting summary of an application for designation of the site by English Heritage - which was rejected. This has details of the history and of various architectural features of the site.