Major changes are planned for the way a wetland nature reserve of national importance - which will contain Britain’s biggest reed bed - is being developed near Needingworth.
A number of conditions covering the construction of the reserve at Needingworth Quarry have been changed after sand and gravel firm Hanson and the Royal Society for the Protection of Birds sought amendments, recognising that the working of the quarry and its restoration could be improved following their experience on the site over nearly two decades.
Changes will include the creation of larger "cells" of reeds during the operation to restore the 2,400-acre quarry site as a huge wildlife haven for rare birds like the bittern.
Hanson has been working the quarry since it opened in 1997 and has been involved in the adjacent Barleycroft Quarry for decades longer.
Needingworth quarry covers ground between Needingworth, Over, Willingham and Earith and the creation of a wetland habitat is a joint project between Hanson, which is responsible for the quarrying and site restoration, and the RSPB which is has taken on the management and the development of the nature reserve.
They sought approval from Cambridgeshire County Council for a significant number of changes to the original development conditions. This will allow a smaller number of quarrying phases and to reduce the area of extraction to protect archaeological remains at the former Willingham Mere. They also wanted to create larger reed bed cells which were more beneficial to wildlife.
Quarrying and the restoration of the land as a wetland was given the go-ahead in 2001 and involved the extraction of around 28 million tonnes of sand and gravel over a period of 30 years.
Extraction is just over half way through with restoration following closely behind. The reed bed will cover more than 1,100 acres and will be Britain's biggest.
The reserve will include meres and wet scrub and is expected to cover around 1,700 acres.
A report to the county council said: "Ultimately, the changes do not result in any new effects beyond the excavation boundary and are little more than an internal rearrangement of working restoration boundaries in areas remote from sensitive receptors."