OR/14/041 Introduction

Lafare, A E A, Hughes, A G, and Peach, D W. 2014. Eden Valley observation boreholes: hydrogeological framework and groundwater level time series analysis. British Geological Survey Internal Report, OR/14/041.

This report has been prepared as part of the Hydrological Extremes and Feedbacks (HyDEF) project, which is funded by the Natural Environment Research Council (NERC) Changing Water Cycle programme. This project (see http://www.bgs.ac.uk/changingwatercycle/hydef.html) is led by Imperial College (ICL) and is a collaboration between ICL, University College (UCL), Reading University and the British Geological Survey (BGS). The project is investigating how extreme weather events (floods and droughts) will impact on the hydrology and in particular groundwater flow in the Thames Basin and the River Eden catchment in Cumbria under climate change. BGS’ role is to ensure that the sub-surface processes are characterized, understood and simulated appropriately.

This report summarises the work undertaken in the Permo-Triassic sandstones in the Eden Valley and is based on the analysis of decade long daily time series of groundwater head data and an examination of the hydrogeology of the Vale of Eden. These head data, supplied by the Environment Agency, have allowed the development of an improved understanding of the groundwater behavior within the Permo-Triassic sandstone. The report consists of a short introductory section on the geology and hydrogeology of the Eden Valley, a description of the methodology employed to analyse the data, including how the time series decomposition was undertaken, and presents the main conclusions of the work. A detailed description of the boreholes, their geological and hydrogeological setting and the groundwater hydrographs are provided in an appendix.