Revisiting Croome’s restoration ten years on

Croome Park is one of the most significant landscapes in England. Its design was commissioned by the sixth Earl of Coventry, who pursued a vast programme of landscape improvement from 1747 until his death in 1809. It is for the pioneering work by Lancelot ‘Capability’ Brown (1715–83) that Croome is most renowned. At Croome, Brown established the English Landscape Style that was to be admired and copied throughout the western world, and in turn Croome made Brown’s reputation.

From an unpromising boggy mire, The Earl of Coventry wanted to create an artificial river resembling the nearby River Severn running within a seemless pastoral landscape. This required pioneering drainage methods in addition to the creative genius of Brown which enabled the finished result to look effortless and natural.

Playing a key role in the National Trust’s restoration of Croome Park, in Worcestershire, Haycock recreated the important mirrored lake and river, revisiting the methods and techniques of Capability Brown whilst exploring new approaches to achieve his aims.

The challenge for Haycock was re-creating Brown’s ambitious vision and methods, whilst managing the impact of the M5 motorway and local land-use changes on water quantity and quality. These resulted in a dissection of the original catchment and a reduced water input to the lakes plus dramatic siltation and eutrophication from the use of the landscape park over many years as arable land. Land-use change along with the creation of three new wetlands improved water quality in the lakes with the added benefit of introducing thriving new habitats.

Haycock invested considerable effort understanding Brown’s methods and discovered an extensive network of drainage channels feeding the ornamental lake from a wide area. One drain was found to be a mile and a half long, with a drop of only 6 inches; a feat of incredible engineering. Nevertheless, Brown struggled to source enough water and sustain the flow throughout winter and summer. The introduction of new wetlands into the landscape helps resolve this problem by acting as winter storage and buffering flow to the lake through the year; as well as creating a reference to the landscape’s original wetland form.

Another problem Brown faced was in making the lake water-tight. With 20 acres of water, Brown had to keep returning to resolve leaks as the varying geology meant that although some areas of the lakes lay on permeable clay others had to be sealed with puddling techniques. Again in the lake’s restoration these challenges had to be revisited. Huge quantities of silt were removed and the lake re-profiled and sealed. Soils from this and the new wetlands were spread over surrounding farmland and also used to create a bank that buffers noise from the nearby motorway.

Although it is some years since the restoration was undertaken, we are still learning lessons from the ongoing maturation and management of the landscape park. It has taken years for the disturbed soils to settle out of the lake and for water clarity to improve. Meanwhile the wetlands have become incredibly valuable biodiversity hotspots: valuable in themselves for the local environment. Ten years on, the wetlands have become heavily silted up, demonstrating the importance of their role in protecting the lakes. The National Trust has carried out dredging on these to maintain their function. Long-term monitoring is enabling Haycock to assess whether the drainage and wetlands are working at their optimum.

Haycock’s experience of such historically sensitive hydrological restoration is unique. They:

1. -Modelled the site’s hydrology overlaying up-to-date digital terrain maps with the original 18th century plans
   

2. -Planned and managed the dredging and re-profiling of the lake and “river”, during which 50,000 cubic metres of silt was removed and then spread on nearby farmland
   

3. -Designed three constructed wetlands, covering 5 hectares, to improve water quality before it enters the lake. These were fitted sensitively into the landscape and now support a thriving habitat.
   

The project featured in detail in a BBC2 'Hidden Garden' program screened on 30th January 2004 and was also reviewed in the associated book on the programme (Cassell Illustrated).