The recent news that Leeds is to benefit from flood defences has met with mixed feelings for those who live along the River Aire, not least with those who live in the Kirkstall Valley. Are these defences necessary and are they likely to impact on the green space that Kirkstall currently enjoys? This report looks into these questions from the information currently available online.

Leeds’ Vulnerability

Currently there are no flood defences along the River Aire in Leeds and it has a rather narrow flood plain, which means that flooding in the city centre is likely. With a steep profile, over 25 tributaries upstream and surface flooding from urban drainage this makes Leeds city centre particularly vulnerable from large bodies of water.

In recent history the river valley and city centre has been hit by small floods, mainly disrupting infrastructure (roads and railways), namely in the years 2002, 2004, 2005, 2007 and 2008. It is thought that a major flood could cause damage to over 4,500 properties and that this kind of flooding is inevitable in the future.

But you may ask: “how far in the future and how regularly?” With changes to climate change and our weather systems becoming increasingly erratic it is probable that we will be seeing an increase in rainfall and in turn flooding. Indeed, the Environment Agency predicts that climate change could produce a 25% increase in flood volumes, which means the Kirkstall Valley could see a 50cm rise in peak flood levels. The last major flood occurred in Leeds in the year 2000 when the water levels came within 10cm of flooding the city centre, but previous to that the most recent and worst flooding events occurred in 1946 and 1866.

Kirkstall Vulnerability

The usual smaller floods have kept development back from the river which means that very few Kirkstall homes are at risk from the localised, frequent flooding we currently see on an annual basis. A catastrophic weather events that could lead to a once every 200 year flood, however, would lead to extensive flooding, even away from the immediate river bank.

Our local councilors are of the view that the flood plain should be protected so that the river can function as it was meant: “Our policy is to do the bare minimum in Kirkstall, sufficient only to protect life, but not property. We would keep development back from the river so that the flood plain can perform its natural functions, and use the riverside for recreational open space. Instead of enormous flood defences in the city centre, we urge more work on the river catchment, creating wetlands and flood storage areas upstream to delay run-off and attenuate the storm peak. This would increase biodiversity and reduce the scale of engineering work required in Leeds city centre, producing a more attractive city and a more pleasant place to live.” (John Illingworth).

By implementing flood defences rather than utilising the natural flood plan, the Kirkstall Concillors believe the expensively protected land would cause economic pressure and allow developers to build property up to the river edges. Although this would spell bad news for our river ecosystem and natural environment, the argument that more development would bring more businesses and a better economy to the area should also be considered.

Flood Alleviation Scheme

The Flood Alleviation Scheme proposals have been put together by the City Council working together with the Environment Agency and Yorkshire Water.

Various proposals have been looked at over the years. Initially the scheme looked into protecting the area from a flood that was likely to happen once every 200 years. To put this in perspective, an event of this size would see 347 tonnes of water per second running through Kirkstall, with the water being chest deep on Kirkstall Road! The scheme included walls over 2m high along the side of the river in the city centre, but at a cost of £190m this was deemed too costly, particularly to protect against such a rare event. This scheme would have seen a mixture of large flood walls and raised earth embankments along the river in the Kirkstall Valley.

Since then, the council has developed a proposal that will protect the area from a flood, likely to occur once every 75 years. They are approaching it in phases as follows:

Phase 1 – City Centre protection.

Phase 2 – Upstream protection to Newlay Bridge and downstream to Woodlesford.

Phase 3 – Working to increase to protection of a once every 200 year flood. Starting in City Centre initially.

As yet, we have only managed to find information regarding the specifics of the plans for phase 1. These being:

• Remove the existing weirs at Knostrop and Crown Point and replace them with moveable weirs
• Provide defences (embankments, terracing, setting back of defences, walls etc – presumably these are smaller than the 2m high one’s initially proposed?)
• Remove Knostrop Cut to merge the Canal and River Aire.

Works for phase 2 and 3 have not apparently yet been confirmed at this stage and are not available for public view. It is to be expected that walls and embankments are to be constructed in Kirkstall, although the height and size of them is to be lower than originally proposed and many of them are to be constructed in the form of terracing to blend in better with the local environment.

The cost of this scheme is reported to be £50.5m with Leeds City Council contributing £10m and the remainder from the government, an ERDF bid and the private sector.

By the end of the project, it is thought the scheme will protect 495 businesses and create 18,000 jobs.

What does this mean for Kirkstall?

So it looks like Kirkstall is set to receive flood defences in the form of walls and embankments. Even if they are to be designed to ‘blend’ into the local environment the disruption they will make to our local ecosystems and access to the riverbank is likely to be significant.

It would also appear that much of our flood plain will become protected against flood water and that this will increase the commercial value of this land, increasing development and perhaps the local and regional economy.

Whether this will be beneficial to Kirkstall and the local residents remains to be seen. If you have any further information, or would like to comment, please leave your opinion below.