What’s on : Lectures

The Foss Barrier: the road to recovery

26 Mar 2019
Start time
7:30 PM
Tempest Anderson Hall
Ian Saxelby, The Environment Agency

Event Information

The Foss Barrier: the road to recovery
Ian Saxelby, Project Manager, The Environment Agency

The Foss Barrier was built in the late 1980’s to provide flood protection to properties in the Foss catchment from rising levels in the River Ouse. During high Ouse levels the gate is lowered to prevent the Ouse from backing up the Foss whilst the River Foss flows are pumped around the gate into the River Ouse. On Boxing Day 2015 the city of York experienced exceptional flooding. Intense rainfall over the River Foss catchment resulted in flows exceeding the pumping capacity of the Foss Barrier. This talk will explain what happened on Boxing Day and why the decision was taken to open the gate during the event. It will look at the actions taken to recover in the immediate aftermath, the establishment of temporary protection arrangements and the design and construction of the upgraded pumping station.

In partnership with IET North Yorkshire

Mini lecture series: “Celebrating Yorkshire”

Member’s report

Boxing Day 2015 saw a 1-in-200-year flooding event in York, when both the Ouse and Foss broke their banks. The Foss peaked at more a third higher than the pumps were designed for in the 1980s and even flooded the pumping station. There was no choice but to raise the barrier gate that prevents the Foss backing up, and to switch off the power to prevent worse flooding and damage to the Northern Power Grid. Six hundred properties were flooded.

Designs for the new pumping station have improved capacity, accessibility and operability in flood. Raised to sit partly on top of the existing building, its three power sources are a substation owned by the Northern Power Grid, its own substation and large generators. The self-contained generators and electric panels are all accessible on the roof. Pumping capacity has increased to 50 cubic m/sec. By the end of 2019, the station’s computer software will be in operation and a new barrier gate installed. The entire gate structure is being built offsite and will be brought in one piece to minimise time-out. At a cost of £29m, the new Foss Barrier is not future-proofed, so the flow from river catchments now needs attention.

Carole Smith