Leeds Flood Alleviation Scheme
After Storm Eva hit Leeds in 2015 the City Council have proposed the Leeds Flood Alleviation Scheme to reduce the risk of flooding. This has resulted in one of the largest river flood schemes in the UK. Phase 1 was completed in October 2017 providing a innovative approach to water management, involving moveable weirs. As a major civil engineering project the river and canal have been merged. Flood walls and reinforced embankments now stretch for more than 4.5Km in the city centre to provide protection from rising water levels. Phase 2 is underway, with ground works planned to start in late Summer 2019
Phase 1 – Leeds City Centre
With the completion of Phase 1 of the Leeds Flood Alleviation Scheme, this has brought confidence back to 3000 homes and 500 businesses in the city centre that were affected by Storm Eva in 2015 providing a one-in-75 year level of protection against flooding. The £50 million project was undertaken as a joint venture between BAM Nuttall & Mott MacDonald based on a design by ARUP for Leeds City Council. ARUP’s engineering teams devised a scheme that removed 2 main navigation weirs at Knostrop & Crown Point and replaced them with innovative mechanical moving weirs which can be lowered which river levels raise to reduce flooding levels.
At Knostrop Cut, a whole island was removed and the canal and river merged resulting in a navigable channel with a greater water holding capacity.
Low level locations long the city centre including embankments, terracing and walls were improved to provide greater protection against flooding.
Phase 2 – Kirkstall A65 Corridor
Planning Permission was granted in June 2019 for Phase 2 of the Leeds Flood Alleviation Scheme with a joint funding package of £75 million pounds, £65 million from central goverment, £6 million from Leeds City Council and £4 million from West Yorkshire Combined Authority. The aim of Phase 2 is to reduce the risk of flooding using a catchment-wide approach offering a one-in-100 year level of protection. The project will again be undertaken as a joint venture between BAM Nuttall and Mott MacDonald
- 8 km of Flood walls will be installed along the River Aire from Leeds railway station upto Kirkstall Bridge
- The removal of obstructions along the river to reduce water levels
- the creation of new woodlands areas
- Flood storage areas that will only release water when it is safe to do so
Phase 2 will be broken down into 3 key areas:-
- At Armley Mills & Kirkstall Trading Estate new protective walls, a new higher bridge and two new control structures on the goit (small water channel) which can close when the river levels raise
- Kirkstall Abbey will have a new structure in front of Kirkabbey sluice gates which will limit the volume of water when the river level rise going down the goit channel
- The transformation of 2.4 hectares into wetland habitat at Kirkstall Meadows and the installation of new flood embankment to reduce the flood risk.
Construction of Phase 2 will take approximately 3 years to complete and works will be starting downstream nearer to the city centre in December 2019. Around Kirkstall construction is expected to start in the Autumn of 2020 and will take approximately 6 months to complete. Detailed design of all the works will be available in January 2020 with the plans for Kirkstall unchanged from the proposed concrete clad wall 1.8 metres high.
Natural Flood Management
All along the River Aire a new Natural Flood Management plan has been implemented including the creation of new woodlands, woody debris dams & wetlands which has been proven to slow the flow of water and reduce the risk of flooding. The project starts at the source of the River Aire in Malham, North Yorkshire and continues through the Yorkshire Dales National Park, Pendle, Craven, Bradford and finally Leeds city centre.
Background information: Flooding in Leeds is nothing new , with the worst ever recorded in 1866 when flood water was 1 metre deep on the Kirkstall Road running into the city. There have been 7 floods since 2000, but Storm Eva on the 26th December 2015 caused the most damage in Kirsktall along the A65 corridor, at the railway station and in the commercial areas of Stourton. The city has been prone to rapidly rising waters from the River Aire and Hol Beck. Before the completion of Phase 1, Leeds lacked any formal flood defenses and therefore was vulnerable to heavy downpours upstream.
On going discussions on upgrading the scheme to a one-in-a-200 year level of protection between all the stakeholders are continuing.