by Ruth Slavid
Collaboration between different disciplines is helping Leicester develop a depth of knowledge about dealing with water
At Spinney Hill Park, the council worked with Chris Blandford Associates to create a less formal edge to a stream with enhanced flood capacity. - Photo ©Leicester City Council
Chryse Tinsley, landscape planner with Leicester City Council, titled a recent presentation on SuDS ‘the story of good and bad water’. Avoiding bad water is what she is helping Leicester to do, in a role where she sees the key task as working across the disciplines.
While some kinds of ‘bad water’ are reasonably easy to define, such as flooding, she is also keen to avoid what one could see as the tragedy of good intentions. Her presentation showed, for example, a carefully designed swale ruined by a ‘protective fence’ that has been put up around it.
By pulling together teams in Leicester, and treating every project as a learning experience, the hope is that these problems can be avoided there, and the city can benefit from some improved spaces and a reduced flooding risk.
Currently this risk is high. Leicester is one of the most
likely places in the country to suffer from surface water floods – not from large rivers bursting their banks but from run-off with nowhere to go. Leicester’s susceptibility may be surprising because we have not seen pictures on the news of residents being forced out of their homes.
Fortunately, Tinsley says, ‘Flooding in Leicester doesn’t wash through houses.’ But there may well be water in the streets and in basements and, in particular, it affects infrastructure, leading to lights going out and power failing. And, because of distribution patterns, these problems may affect people who are not particularly close to where the flooding actually occurs.
‘This has provided funding to us as a lead local flood authority to find out the causes and to look at solutions,’ Tinsley explained. ‘The Surface Water Management Plan level 3 identifies and maps critical drainage areas and suggests mitigation measures.’
Spinney Hill Park before improvement. - Photo ©Leicester City Council
The projects carried out so far are relatively small in scale – in fact what the city needs is a large number of smallish interventions – so that their overall impact is not great. But they are being studied and monitored so that they can inform best practice in the future.
One might imagine that most of what needs to be known about SuDS is known already, and on a purely technical level that may be true for all but the most ambitious projects. But the value in the Leicester projects, beyond the straightforward amelioration provided in a fairly localised area, lies in the lessons learnt about consultation, about public fears and also about the behaviour of and learning needed by those who have not engaged in this type of work before.
So, for example, a report on the Abbey Meadows Wetland project, completed in 2011, lists the main lesson learnt as ‘That projects of this nature can be over designed – nearly lost the start date by over insistence on numbers of sections.’
What this meant, Tinsley said, was that engineers working on widening an existing ditch were eager to design the section of a floodable area with the degree of accuracy that they would have given to a highways section. The slightly more relaxed approach to engineering in this type of natural environment is something that has to be learnt by people who have been trained in other disciplines.
Work in progress at Spinney Hill Park. - Photo ©Leicester City Council
The project itself is simple, but no less admirable for that. It is set on an area of open land, near to the Grand Union Canal and the River Soar, and also near to an area prone to flooding. A ditch that runs through the area frequently flooded in winter, making sport pitches unusable, and also flooding on to the nearby road, washing pollution off it and into watercourses. By widening the ditch, the council has created about 1,000m3 of flood storage capacity. It was not possible to create more because of the proximity to a badger sett.
As well as making the open space usable all year round, new planting has enhanced biodiversity. The consultation process was a way that the council could learn about concerns. Through its displays and meetings it won over some who were initially opposed to the plans.
Another project, at Castle Hill Country Park on the edge of the city, was driven mainly by a desire to increase biodiversity. The intention was to create a number of wetland scrapes in varying environments: three within stormwater areas that would be mostly dry; three nearer to a brook which would usually contain some water; and three near on/offline ponds that would help to store floodwaters.
At Abbey Meadows the council has created a floodable area that protects playing fields. - Photo ©Leicester City Council
It was this last category that represented some new thinking. On / offline ponds are what they sound like – at times of low water they are independent ponds, but when water is high the brook can overflow into them, bringing them ‘online’. This was another project in which skills were built, and that worked because of good cooperation. In this case, the lessons learnt were about getting the scale right – the larger ponds worked better – and the importance of dealing well with spoil.
At Spinney Hill Park, the council worked with Chris Blandford Associates, again deformalising the edges of a stream, enhancing its appearance and biodiversity and at the same time increasing its flood capacity.
Tinsley works very closely on these projects with a highly qualified nature conservation officer and the flood risk manager who ‘was a drainage engineer for many years but has seen the light and is a born again SuDS enthusiast’ and a range of people from other departments. She adds, ‘At a landscape architect level, I see my role as to spread knowledge about SuDS and to look for practical opportunities to implement schemes. I got some RIEP funding a few years back to provide training; through that I have run workshops both for local authorities in Leicestershire, for urban designers in the region, given talks to developers; in fact anyone who will listen, taken groups out to see schemes, built up case studies and set up the County SuDS group for us to share knowledge through quarterly meetings.’
What Leicester is doing today, much of the rest of the country will, we hope, be doing in the future.