All London Green Grid - London Downlands Planning Guidance

Working closely with Design for London (UK) and the London Boroughs of Bromley, Sutton and Croydon, Kinnear Landscape Architects (KLA) acted as design advisors to Area 7: London's Downlands section of the All London Green Grid (ALGG), defining a strategic vision for the London region, where one of the key issues for the city is the health of three large rivers that run through the area.

A strategic challenge for London is management of water flow and quality into the Thames and the blue ribbon network*. The London Rivers Action plan has key aspirations which can be addressed by proposals for the rivers and its route from the Chalk Aquifer of London and Kent's Downlands to the Thames.

The initial task was to gain a thorough understanding of the strategic area and understand underlying issues and opportunities; and to negotiate with the partners to achieve a joined up approach and understanding of the potential for change for incorporation into the Mayor of London Supplementary Planning Guidance: ALGG SPG.

The project was organised through steering group meetings with group members and others invited to debate specific issues. Members of the steering group were: London Boroughs of Bromley, Sutton, Croydon; Sustrans; Design for London; City of London Corporation; National Trust and the Environment Agency.

London's Downlands has a unique range of landscapes, from the internationally important habitats of Darwin's landscape sitting within the Chalk Downs, to the valleys and woodland areas. The Downlands and the wider All London Green Grid has huge potential to contribute to the health of the London region both socially and environmentally.

Improving the health of the River Wandle, the River Ravensbourne and the River Cray was a key opportunity. The Downlands area provides a wonderful opportunity for strategic environmental sustainability issues such as flood retention, reducing drain hot spots (see below), safeguarding the drinking water aquifer for London and reducing the heat island effect through the increase in woodland and green space.

The Downlands area also provides large swathes of countryside and open space for the population of London as a whole and provides stunning leisure routes throughout, linking to Areas of Outstanding Natural Beauty in Kent and Surrey.

The London Downlands project explored green initiatives for increased water catchment water within the chalk rivers upstream from the Thames to reduce the chance of flooding in London. The river catchment in Downlands is wide and affects a large area of the London. Within this area sit many hotspots of the Drain London project, caused by increasing surface water run-off and low drain capacity.

Each area and river provided their own individual considerations. The River Cray, for example, is canalised or culverted in some areas and also runs through the Crayford industrial estate which effectively dominates the flood plain of the river and constrains flood capacity. A number of interesting opportunities were outlined for the river:

- Ecology transects in the urban grain between woodlands and wetland, transition between floodplain and development;

- Water catchment in the marsh using a series of ditches and hollows to hold water;

- Support river-centric communities by making the water ways central to their lives again both visually and economically;

- Creating space for flood water on the Crayford Industrial Estate to make an industrial water meadow;

- Exploring the feasibility of hydro energy generation on the River Cray which historically was populated with mills;

- River restoration and deculverting to improve the water holding properties of the river; and

- Recreate the picturesque vision of the river valley that Capability Brown realised at Foots Cray Meadow.

Many of the highlighted opportunities and constraints were identified as priority phase one individual projects for Sutton, Bromley and Croydon and are now being funded through the Mayor's funding initiatives.

Meetings with many stakeholders sometimes produced polarised views and the landscape architects' role has been to mediate in these situations and gradually win round hearts and minds to a joint way forward. This approach has been very successful and partnership bids are now being progressed (February 2015) which have been strengthened by client involvement on the All London Green Grid. KLA have gone on to develop an approach for the Cray Valley that demonstrates the principles embedded in the approach to ALGG Area 7.

The catchment-scale landscape planning input provided by landscape professionals was important in maximising the multiple benefits that could be achieved through defining a strategic vision, focussing on the river water as a resource. An over-arching understanding of ecology, river restoration techniques and benefits, building-in of amenity value, economic benefits and historical links, communicated in a positive way helped bring together an agreement between stakeholders on the direction of the strategy.

*The Blue Ribbon Network is a policy element of the <a title="London Plan" href="http://en.wikipedia.org/wiki/London_Plan">London Plan</a> relating to the <a title="Waterway" href="http://en.wikipedia.org/wiki/Waterway">waterways</a> of <a title="London" href="http://en.wikipedia.org/wiki/London">London</a>.