Development of Louth flood alleviation scheme outline design

Abstract

The market town of Louth (in Lincolnshire), on the River Lud, has suffered from flooding on many occasions, most recently in 2007. Atkins was commissioned to conduct a feasibility study into the potential for a flood defence scheme. This paper begins once the preferred option of two online flood storage areas had been identified; the brief from this point was to develop their outline design. Atkins worked closely with a contractor to develop a cost estimate for the works and to ensure buildability was considered. The two dams are designed as homogenous earth fill embankments, with heights of circa 6 m, and retaining a combined volume of 213 000 m3 (during a flood event); both storage areas fall under the requirements of the Reservoirs Act 1975. As in many cases, these reservoirs present particular challenges; designed to be empty for the majority of their life, they are required to meet the needs of a variety of stakeholders. The design was further complicated by the risk of unexploded ordnance and burrowing animals. This paper presents the outline design under three sections: the location, embankments and control structures. For each section the paper discusses the alternatives considered, the selection process and the adopted design.