The Foss Barrier Information Page

Overview

The purpose of this page is to provide information on how upgrades to the Foss Barrier in York are progressing.

On Boxing Day 2015 the city of York experienced exceptional flooding, affecting over 600 homes and businesses across the city. The volume of water in the Foss catchment was so great that it overwhelmed the pumps at the Foss Barrier, resulting in extensive flooding for many residents living upstream of the barrier.  Following this, the Government immediately announced an investment of £17 million to improve the Foss Barrier.  Emergency work started as the floods were receding and within days the pumping station was operational again. Since then the Environment Agency has worked continuously to upgrade the Foss Barrier and increase its pumping capacity.

The old Foss Barrier

Upgrading the Old Foss Barrier

The Foss Barrier is the strategic flood defence designed to protect properties upstream in the Foss River catchment. Situated at the confluence of both rivers, it works by preventing water from the River Ouse backing up into the Foss.  When water levels in the Ouse are higher than the Foss, the barrier is closed and pumps operate to lift water from the Foss into the Ouse so that water levels in the Foss are controlled.  On Boxing Day 2015, when the barrier was closed, the volume of water travelling down the Foss was so great that the pumps could not deal with it. After this event, a decision was made to upgrade the barrier and the existing pumps so that they could more effectively control water levels in the Foss catchment, even in the event of another storm of such magnitude.

The first phase of work involved building a new floor above the existing pumping station, to house new equipment above the level of the 2015 floods.  To ensure the pumps and the barrier could still operate whilst building works took place, we built a temporary platform at the side of the existing structure and relocated the existing equipment here.  Once this was done, we began to construct the floor above the old pumping station.

Eight new pumps were then installed into the existing pump chambers. This has increased the pumping capacity overall from 30 to 50 cubic metres per second (during the floods in 2015 the flow rate of water in the Foss was 40 cubic metres per second). The pumps have two independent electrical supplies so that if one fails, a backup supply is still on hand and they will continue to operate.

Artists impression of the completed Foss Barrier

The second stage of the project has focused on the installation of new equipment.  Whilst we worked on structural changes to the building, the electrical equipment needed to support the barrier and the new pumps was being designed and manufactured.  In summer 2018 this was installed in the newly constructed rooms above the 2015 flood level. Work to finish installing four new emergency back-up generators will be completed by Christmas 2018. 

We also need to make significant improvements to the lifting gate of the barrier. This will include replacing the gate mechanism, the gate itself (which will offer a higher level of flood protection) and replacing the ladder to the top of the tower with an external staircase. All of the electrical cabling will be re-routed to keep it above the flood level. This means no electrical equipment will be kept in the ground level of the building. This part of the project is due to be completed by the middle of 2019.

Works progressing September 2018.

Works progressing September 2018