Lichfield Groundwater Model - Recalibration and timeseries update

Description

The procurement documents are available for unrestricted and full direct access, free of charge, at https://defra-family.force.com/s/Welcome Any questions, requests to participate or tender submissions must be submitted electronically via this portal. The Lichfield Permo-Triassic Sandstone aquifer is a regionally significant groundwater resource providing public water supply to areas of south and central Staffordshire. The aquifer is also an important source of baseflow to several tributaries of the River Trent. The Lichfield groundwater model was developed for the Environment Agency during the period 2005-2008. The main purpose of this model was to increase the ability of the Agency to make abstraction licensing decisions on a sound scientific basis and, in doing so, protect and/or enhance sensitive surface water features on the outcrop of the Lichfield Permo-Triassic Sandstone aquifer. In 2012 the simulation period was extended up to March 2011. Subsequently, the model was recalibrated and the ability to simulate distributed runoff and total stream flows were added with the help of 4R code in 2013. The main tasks of the current project will be to further extent simulation period up to the end of March 2023, complete various model refinements and improve model calibration and credibility. Moreover, the model will be migrated to Modflow 6. Finally, a set of standard and predictive scenarios will be completed using the refined and updated historical baseline. The updated model will be also used to delineate Source Protection Zones (SPZs) for a number of public water supply sources.