Towards a Minerals Local Plan for Derbyshire and Derby

Towards a Restoration Strategy for Carboniferous Limestone Quarries

Introduction

1            Introduction

1.1                    A variety of minerals are excavated from ‘hard rock’ quarries within the Plan area; predominantly limestone but also some sandstone. The majority of the limestone quarries lie on the Carboniferous Limestone deposit, a nationally important source of both aggregate and industrial mineral, which is quarried extensively within the Plan area. The Carboniferous Limestone also gives rise to landscapes and habitats which are designated for their quality and which lie close to the Peak District National Park. It is considered that the restoration of these quarries, taken together with their sensitive location, raises particular issues which merit the preparation of a separate restoration strategy.

1.2       Many of these quarries are large scale and were established before the advent of modern planning conditions; they have vast permitted reserves of mineral that will last well beyond the end of the Plan period in 2030. The original planning permissions that established these limestone quarries had few controls by current standards e.g. there were little in the way of environmental controls (no restrictions on hours of operation, no noise or blasting conditions, no dust controls), or landscaping and restoration conditions etc. Whilst planning conditions have now been updated for all existing operational sites under the Review of Old Mineral Permissions (ROMP)[1] process, they remain subject to future periodic reviews.

1.3       The scale of hard rock quarries and the often relatively small quantities of waste material involved compared to the rock which is removed means that it is not generally possible to restore land to its original levels following completion of working. This means that the configuration of the land is changed permanently, although where the operation can be designed so as to be visually contained by the existing topography in advance of working, visual impact can be limited. Progressive restoration is difficult to achieve, although an early start can often be made in the treatment of the quarry faces, benches and tips. Innovative restoration blasting techniques can be used to create more varied and more natural looking slope sequences consisting of rock screes, buttresses and headwalls, which can be vegetated selectively to replicate natural limestone valley sides.

1.4       Final restoration depends to a large extent on the depth of the quarry and level of the water table. Restoration incorporating water is often an unavoidable consequence of working at depth; deeper remote quarries are often left to regenerate naturally and, in such cases, they can become important areas for wildlife and natural history. In shallower quarries, the quarry floor can be restored for agriculture or informal leisure uses, or in a few cases built development, where appropriate.

1.5       The preparation of the Minerals Local Plan presents an opportunity for the mineral planning authority to ensure that a co-ordinated approach is taken towards mineral restoration at Carboniferous Limestone quarries by establishing a framework of strategic principles aimed at delivering a co-ordinated approach to the restoration of the quarries. This strategic framework would guide operators in preparing their ROMP submissions to review their current planning permissions, and would enable any new or revised working and restoration schemes to be guided by the overall strategic principles. It could also act as a guide for applicants submitting planning applications for any new limestone working.

 

[1] Review of Mineral Planning Conditions (NPPG Reference ID: 27-189-20140306)