Flood Protection Plans

Bad news for the Kirkstall Valley?

The Environment Agency, responding to political pressures, has resurrected the Leeds Flood Alleviation Scheme [Leeds FAS]. At first glance this looks like good news, but a moment's reflection shows this could easily turn into an environmental disaster.

Flood protection schemes could allow property developers to build right up to the water's edge. Instead of leaving a broad green swathe for public access to the river banks, there are powerful economic pressures to fully utilise all the land which has been so expensively protected. We have little need for flood protection works in Kirkstall, since there are only two dwelling houses in the entire Kirkstall flood plain. Periodic flooding has kept much of the valley bottom free from built development, and long may it remain so. This land is better used for sport and public recreation and for water storage in times of flood. The Kirkstall councillors are opposed to needless flood protection works, and will press for the removal of those that have already been constructed.

Full marks to the Environment Agency

Although we oppose many aspects of the current Leeds FAS, the Environment Agency deserve maximum credit for their public consultation efforts. They are making a proper job of this, releasing information as soon as this is available, and fully implementing the European Environmental Impact Directives. Best of all, they are prepared to take their time, so that people have an opportunity to think and form a balanced view. This is a refreshing change from Leeds City Council, which frequently springs proposals on the public, often has a hidden agenda, and cannot be trusted to supply accurate information. For the council, sadly, "public consultation" is often an elaborate and expensive sham.

WS Atkins (civil engineering consultants) prepared a flood alleviation scheme for Leeds in 2005. This was initially shelved because of its enormous cost, and the relatively small number of domestic properties at risk. This scheme only covered the River Aire in central Leeds. Most houses in Leeds are flooded from peripheral becks and streams, which are usually the responsibility of Leeds City Council rather than the Environment Agency.

The Atkins scheme has been resurected, but the emphasis is now on protecting commercial (rather than domestic) properties in Leeds city centre. In 2008 the Agency drilled boreholes in Kirkstall to estimate ground permeability, and has published an initial "scoping study" and some draft designs. The main public consultation started in May 2009.

Download an Environment Agency Press Release (June 2008).

There is an Environment Agency website for the Leeds FAS. At first this contained little information beyond their public consultation timetable, but they recently added more detailed drawings and we hope for more to come. The agency are much more forthcoming in response to specific questions, and should be congratulated for their Access to Information policies.

The biggest recorded flood in Leeds was in 1866, when 20 people were drowned and the water was knee deep on Kirkstall Road. The railway line at Bridge Road was waist deep in water, when the track was higher than it is today. The Agency has revised its estimates in response to climate change, and their current "extreme event" envisages the River Aire thundering past at 400 tonnes per second, and the water chest deep on Kirkstall Road.

Massive, multi-metre flood defence works are needed to handle such extremely rare events. People are questioning both their cost-effectiveness and their potentially ugly appearance. There could be alternative solutions, one of which is to improve the drainage from the city centre. Another solution might be to create distributed flood storage higher up the river catchment in the Yorkshire Dales. This could store water upstream, broadening, delaying and reducing the flooding peaks, so that much smaller defences would be sufficient to protect the city centre. This solution could also be expensive, and there are political issues about land ownership, but it is much more friendly towards the environment, creating new wetland habitats and increasing biodiversity.

The Environment Agency argue that upstream storage is not a realistic option for Leeds, because the most obvious storage areas are above the major tributaries, and also because prolonged periods of heavy rain could largely fill the store before the extreme peak arrives. Plainly there is some truth in these theories, but the agency's published data suggests the position is not as hopeless as might first appear.

Here are two graphs from figure 9.5 on page 68 of the 2008 Flood Modeling Report (which shows the effect of flood storage at Holden Park, near Keighley) replotted on the same axes. We are using the 1% extreme event because it is difficult to find data for the 0.5% event. The green line shows a recording of the November 2000 flood peak at Armley, and the purple line shows what would have happened with additional flood storage in place at Holden Park. The red line shows the Environment Agency test model for a 1 in 100 year flood, and the blue line shows the prediction with additional flood storage.

We know that Leeds successfully accepted 250 cumecs in November 2000 without major flooding (although it was a close run thing!) and these graphs show that a single upstream storage site could significantly reduce excursions into the yellow danger zone. The Environment Agency has not yet published figures for more extensive upstream storage distributed over several sites. In view of the importance for Leeds, this work should now be attempted as a matter of urgency.

Initial proposals from the Environment Agency.

These drawings date from 2008. The scheme is still being modified as the consultation proceeds. Scroll down for more recent drawings.

The principal elements initially proposed in Kirkstall Ward are listed below:

1. New flow control equipment at the head of Abbey Mill goit.

2. Enlarged or additional flood walls along the western boundary of the BHS site.

3. New earth embankment to the north of the Archie Gordon sports ground.

4. New flood walls along the railway track near Kirkstall Bridge.

5. Raised earth embankment alongside Morrisons car park.

6. New earth embankment to the west of St Ann's Mills.

7. New flow control equipment in the goit above St Ann's Mills.

8. New flood walls to the south of St Ann's Mills.

9. New flood walls from Burley Mills to Armley Mills.

10. New earth embankment around the Kirkstall sub-station off Redcote Lane.

11. New flood walls to the west of the Cardigan Fields leisure complex.

12. Increased flood wall to the west of the Cardigan Trading Estate

Download initial sketch proposals for Morrisons Supermarket, St Ann's Mills, Burley Mills (option one), Burley Mills (option four) and Duffield Printers. We did not support these draft measures and urged the Agency to think again about this problem.

Here is the latest scheme

This image of the Kirkstall area has been cropped from a larger Environment Agency document created 12 May 2009. The map shows only a small part of the total works, which continue through the city centre into South Leeds at a total cost exceeding £75,000,000. People can download a fuller set of plans from the Environment Agency website.

The Environment Agency is only responsible for the main river. Many houses in Leeds have been repeatedly flooded by becks and streams, which are a Leeds City Council responsibility. Considering its enormous budget, relatively few domestic properties will be protected by the current Leeds Flood Alleviation Scheme.

To get more information, people should contact the Environment Agency directly:

Telephone: 08708 506 506 (Mon-Fri, 8am - 6pm) - they will usually put you through to their Leeds office, but this way your call is properly logged.

email: enquiries@environment-agency.gov.uk (24 hour typical response: do not use for reporting urgent incidents)

Postal addresses:

Last updated 7 June 2009 at 20:27. Back to the top