Webinar: Watering the Garden - landscape led approaches to managing water in Garden Communities

This half day online conference, hosted by the Urban Flood Resilience Research Consortium, looked at the latest landscape-led approaches to managing water in large scale developments and new communities. This is a great way to incorporate water landscapes into projects from the initial stages.

Simon Harrison, Head of Design at Ebbsfleet Development Corporation started the conference by mentioning how Ebbsfleet was used as a case study research project for developing a Garden City. This was an opportunity to develop ideas such as sustainable drainage in the master plan.

The first presentation was from Emily O’Donnell from the University of Nottingham, who presented her Urban Flood Resilience research outputs. She started by outlining that water challenges in the UK are not just flood related. Issues also include water shortages; watercourse health such as quality standards, biodiversity and aesthetics; connection of people with water, supporting growth and development; and supporting liveable urban places in blue and green space.

Emily mentioned that flood risk is everywhere, and flooding from rainfall can happen in lots of places spatially. We aim to manage this, and blue-green cities is an approach which can help. These patches of vegetation and water landscapes can help connect communities to outdoor spaces and improve wellbeing, whilst adopting a whole systems approach to the urban water cycle (e.g. incorporating storm water).

It is quite complex to develop a resilient city, made harder by uncertainty as to how climate and the economy will change. Research at universities all across the UK has been taking place, looking at a few aims in particular. These include considering the engineering design; the interface between planners and engineers; and the development of urban flood risk management that functions with other urban systems such as transport links, land use and natural systems.

Emily suggested the need to change the narrative and show that storm water is not just a nuisance, but presents opportunities to make cities resilient, attractive, competitive and liveable. This can be achieved through rainwater harvesting, restoration of rivers, creation of diverse wetlands, topping up groundwater aquifer resources, energy generation and recovery, and enhancing ecosystem services.

Community engagement is also a massive factor for blue-green infrastructure. Getting people involved in design will help local communities feel empowered and engaged in their local decisions. More collaborative, democratic, sustainable decisions will help communities understand how we can manage floodwater problems.

Next Justin Abbot, Director at Arup, presented on integrating water management in new communities and designing with water. He stressed the significance of water in the environment, and how it helps shape and develop our communities. Particularly, we need to consider integrated, catchment scale and systems view. We need to manage water in a more sustainable way, reconnect people with water and enhance the vision of what water can do for our communities.

Justin outlined 6 key principles for designing with water:

  1. Supporting human-wellbeing and natural systems through community engagement and co-creation. Recognise the role water plays in our communities, especially now in this pandemic where we are more frequently washing hands and looking towards open spaces. Working towards tackling existing problems with new, innovative solutions. Preventing water entering the sewer network has both local benefits and impacts on carbon storage, when compared to traditional grey infrastructure solutions. Explore a health-led approach to place, in practice. Look at water problems through a health and wellbeing lens.
  2. Using a guided systems thinking. Innovative approaches and tools that help cities build water resilience at the urban scale. Help cities grow their capacity and provide high quality water resources for all residents, protect from water hazards and connect through water-based transportation networks. (provide – protect – connect). Think about what works in one city and how it might be transferrable to another.
  3. Digital technology on accessible platforms, enabling asset sharing and new insights. (Inputs – analysis – outputs). Categorise different land use and areas and look for improvements and developments to incorporate green infrastructure. This is similar to NFM mapping to locate appropriate areas for interventions.
  4. Holistic urban planning and design for resilience. Importance of the use of technology incorporated into techniques. Approaches don’t need to be static – innovative ideas to help techniques move/amend in line with channel conditions.
  5. Work in partnership, encourage early engagement, look for shared opportunities. Need to be creative, expansive and understand governance of the water cycle. Consider how many people are involved in the cycle across its path.
  6. Understand the full value of water, and recognise and value the wider benefits. This can be the hardest principle as it is tricky to identify, quantify and value water as a valuable asset and resource.

Following this, Tom Smith, Director of Spacehub, talked about Masterplanning with water. Tom is a Landscape Architect who works on master plans. He provided an interesting overview of a few projects where green-blue infrastructure is being incorporated. He stressed the importance of integrated systems, and considering water management alongside ecology, rooftops for vegetation, land use, streets, and open park space. All deliver many benefits including attractive, green areas and streets, also helping to reduce climate footprint.

The Ebbsfleet Garden City project site was defined by water, marshes, estuary and wetlands. These projects often start with big broad ideas, which are turned into meaningful water management ideas. It is important to develop an inspiring approach to motivate the community, which is also flexible to change in circumstances and climate. This project aimed to de-pave impermeable surfaces and increase the amount of soft landscape. Topography and geology are also important considerations for the most effective systems.

A second project example was Eddington, Cambridge. This is a picturesque water management approach, where techniques expanded into university farm land, including rain water harvesting, and other sustainable ideas. Tom talked about breaking down key open spaces and setting green infrastructure networks into a masterplan and planning system that all partners then work around, involving engineers, designers and architects.

Stephen Birkinshaw, a Research Fellow from Newcastle University then briefly demonstrated CityCAT, a modelling software to which analyses and visualises surface water flooding. It looks at the effects of different interventions, for example the impact of a Swale installation on flow paths of storm water.

Sheena Bell from Gillespies then presented on integrating water into street design and public spaces. Sheena works in leading landscape architecture and urban design practice. She pointed out how the pandemic has amplified what we already knew about climate change and the importance of green open local spaces. Streets are key areas which we interact with daily, and Sheena demonstrated examples of where green-infrastructure has been implemented.

Sheena pointed out the importance of integrative, inclusive design for all stakeholders and local community, and remembering that water is a powerful place-making tool. She worked on the Ebbsfleet Garden City project, and showed some good examples of tree lined streets which are attractive to look at. She also found some areas with a lack of street trees and poor urban design framing. This provided an opportunity to connect with the local community to develop these areas and progress towards achieving the Garden City ambitions. Guidance was designed to review and quantify the development of the Garden City. This included an evaluation framework encouraging an integrated approach to deliver good quality spaces that can work on multiple levels. Water design guidance included checklists to maximise water management, biodiversity and amenity opportunities.

Another example Sheena provided was Elephant Park rain gardens. All the streets around the park drain into gardens in the park, providing an opportunity for the storm water to be filtered through soils and a gravel bed to top up groundwater. The gardens also have capacity to fill up, attenuating flood risk. Vegetation included plant species which can stand both dry and wet conditions. This showed a very integrated, joined up approach to implementing green infrastructure.

Sheena finally mentioned that this is an exciting time to be a planner, with all the current economic and climatic changes, and new innovative approaches to consider and implement.

Richard Fenner, Professor of Engineering Sustainability at the University of Cambridge then presented key questions to address in Blue Green Cities and Urban Flood Resilience projects:

  1. What is the right mix of grey and blue-green infrastructure in a given location and specific local context? This considers an adaptation pathways approach, involving identifying alternative options for storm water protection i.e. ponds, permeable pavements. Then, establishing triggers for when the thresholds of these techniques are exceeded. Incorporate a jump to another pathway in order to provide additional capacity. Evaluate all possible pathways through a multiple benefit analysis.
  2. How do the multiple benefits associated with SuDS and green-infrastructure propagate over an urban landscape? This depends on the use of a score or index to compare to a reference condition. This allows you to spatially identify relevant dominant benefits to create or enhance in a particular area.
  3. Can the use of SuDS for flood management improve habitat connectivity in an urban environment? SuDS can act as corridors for species dispersal across urban areas. Green roofs have potential to increase connectivity, and SuDS/ponds play a valuable role.

After a quick break, Adrienne Soudain, an Associate Landscape Architect with Chris Blandford Associates talked about water in parks and open spaces. She stressed the point of considering the end user first. Consider what activities the open space will be used for. Careful integration of water adds visual variety, helps create distinct character areas, makes a landscape more memorable, encourages people to spend more time outdoors, and engage with nature, improving wellbeing.

Adrienne made a really interesting link to heritage, and the importance of tapping into history and heritage of an area. This can encourage local communities to support a project, if it is backed up by local meaning, knowledge or experience. She mentioned how water has many unique qualities such as reflections, sound, smell and the wildlife it attracts, that brings a water landscape to life. Water can be a great asset for integration in parks and open spaces.

Adrienne went on to talk about a few projects she has worked on. She provided more information about the strategies behind Northfleet Riverside City Park, including enhanced access to the River Thames through stepped seating, beach areas, and planting vegetation that would sway in the wind, mimicking the movement of water. Flood resilience was also considered, with potential flood risk parts of the park adapted to sustain the flood water.

Another project, London City Island, East of Canary Wharf, is a peninsula surrounded on 3 sides by the tidal River Lea, nestled within an urban park. This site has a rich history in dock trading, and the open space strategy distinguishes between the central heart/spine of the site and peripheral spaces. A Red Ribbon Strategy was applied on the river walls, which provided playful pocket spaces all the way around the island. These spaces poke through the perimeter landscape and offer engagement tools to engage with the river, with red platforms inspired by local lighthouse architecture.

Adrienne summarised by highlighting the importance of interventions to inspire communities and interlinked approaches across all disciplines.

Emily O’Donnell from the University of Nottingham then presented on restoration of urban streams to create blue-green infrastructure. She showed an example of a successful river restoration project and the importance of engaging local community with blue-green space. Alger Park in Hillcrest, Washington DC, USA is an example highlighting a holistic approach to restoring streams. The channel had been severely incised, with eroding, unstable banks. Floodplain habitats were disconnected from the stream and little instream habitat was present. Permeable pavements, rain gardens and swales were introduced upstream to reduced runoff and slow flows moving downstream. This demonstrates a whole catchment approach, and not just looking at the river in isolation to the rest of the catchment. As well as this, regenerative stream conveyance was opted for, to return the river to a pre-disturbance state. The elevation of the channel was altered, and weirs and cascades were installed to prevent the channel re-incising. Lots of trees were planted to blend the project with the existing environment.

This shows how urban modification must start with managing water input into streams, then focusing on the stream improvement itself. 250 local residents were involved, and the project continually progressed with residents in mind, at the forefront of the project. Emily pointed out how the biggest challenge had been reaching out to and engaging with the community, as well as partnerships with different city stakeholders. Delays were caused by permitting and contract issues.

Founder and Director of The Environmental Design Studio, Ed Barsley, then gave a thorough presentation on the types of things we can do to manage water at the building level and how we can turn concrete jungles into more sustainable, permeable environments. Where possible, we need to ensure any new developments are progressed in line with the environment, and should be built into the way we are designing and developing.

There are so many different types of flood risk with different characteristics such as sea level rise, storm surge, tidal, river, breaches, sewers. We need to understand the pathway of flood to our buildings and how and where we can intervene. At a building level different types of houses will be impacted differently, and we need to consider the property type and what materials and approaches would be appropriate.

Interventions include green roofs, installing vegetation planters, disconnecting down pipes so they filter into rain gardens or water butts, rain water harvesting tanks, permeable paving, fitting devices to use less water, and retention ponds installed in landscapes.

As well as developing outside the house, some houses are developed to be flood recoverable. This involves interventions such as moveable tables and furniture, water compatible floor, wall mounted televisions, fridge cooker and cabinets at higher level, non-return valves, back up data off site/on the Cloud, and minimal hard standings.

In summary, Ed mentioned that site designs are tailored to be site specific. We should encourage flood resilient mixed-mode landscapes, and design for the future climate conditions. We should explore creative/sculptural ways to slow, store and convey water at the building level. We need to ensure we design in a clear process for maintenance/operations, recognise and utilise the multiple benefits of integrated water management.

Sangaralingam Ahilan, Research Fellow at the University of Exeter then also presented on managing water at the building level. He talked about Rainwater Management Systems (RMS), and how they offer multiple benefits compared to single function methods such as rainwater harvesting. RMS can reduce water demand, reduce energy, reduce storm water discharge, increase resilience and sustainability. Sangaralingam mentioned the performance of these systems and how to make these water management strategies more sustainable, by incorporating rainwater harvesting, grey water recycling, water efficient appliances and leakage reduction.

Simon Harrison finally summarised the conference by emphasising the point of thinking about water in all its functions in our landscape, and more than just flood resilience.

Thanks to Ebbsfleet Development Corporation and Urban Flood Resilience for hosting this online conference. Great to see so many examples where green-infrastructure has been implemented or planned, different techniques demonstrated, and various benefits illustrated. Great to see so many organisations and partners involved in helping progress this approach.

 

There are lots of references available including:

Blue-Green Cities: Integrating urban flood risk management with green infrastructure

Delivering better water management through the planning system

 

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