SuDS in London - a guide

Recommendations

Info

1.1 Planning for SuDs Controlling stormwater quantity and water quality to mitigate flooding and the risk of pollution respectively are the main drivers for SuDS. Potential flooding is not limited to large one in 100 year storms; flooding in urban areas often results from the more frequent and intense rainfall we are experiencing in the Capital as a result of climate change. When localised flooding happens, it is usually linked to surface water flows exceeding the capacity of the drainage system. It is therefore important to slow down the flow rate or hold the rainfall back, whether that be within developments or the public realm. The London Sustainable Drainable Action Plan (LSDAP) also seeks to reduce surface water flows into the sewer network through a series of wide-ranging actions. SuDS are crucial to help achieve this; they also reduce risk and address policies dealing with current and future flood issues in a sustainable and cost effective way (London Plan Policy 5.12). Ideally, SuDS need to be delivered in a coordinated and integrated manner, subject to the constraints and considerations set out in this document. The additional benefits that can arise from SuDS in the public realm and streetscape are discussed throughout this chapter. They can contribute positively to the character of the streets, open spaces and parks in the Capital, as well as address flood risk and pollution concerns. The aim for the reduction in flow rate – or ‘betterment’ – is to achieve levels that emulate a greenfield site which is supported by the London Plan (Policy 5.13). Although greenfield rates are not always achievable, the London Sustainable Design and Construction SPD reports that ‘most developments referred to the Mayor have been able to achieve at least 50% attenuation of the site’s surface water runoff at peak times’. Surface water flooding is the greatest short-term flood risk to London 8 1 Principles of SuDS
1.2 Wider benefits The ambition for SuDS in London is not based solely on reducing water runoff rates; it is also about the multiple benefits that ensue. SuDS can play a significant role in enhancing health and quality of life via better air quality, improved surroundings and other attributes embedded in TfL’s Health Action Plan. SuDS are made up of a sequence of components that: • Control surface water flow rates • Control flow volumes • Regulate frequency of runoff • Reduce contaminants to acceptable levels CIRIA calls this sequence the SuDS management train and this terminology is widely used in the water management industry. An important principle which influences the planning and design process is the preference that SuDS components are at or near the surface. This provides new opportunities to integrate SuDS into the urban realm, which can include: • Creating and enhancing a sense of place • Water management using the natural hydrological cycle as a baseline • Enhancing catchment permeability and reducing surface water runoff • Improving resilience to the effects of climate change • Adaptability in managing rainfall events • Improving air quality • Mitigating urban heat island effects • Long-term and effective upstream source control measures These contributions are encompassed within the four main principles, or ‘pillars’ of SuDS. SuDS can provide multiple benefits 9 1 Principles of SuDS
Page 1 and 2: SuDS in London - a guide November 2
Page 3 and 4: Introduction
Page 5 and 6: II Who is the guidance for? Primari
Page 7: 1 Principles of SuDS
Page 11 and 12: 1.3.1 Water quantity SuDS mitigate
Page 13 and 14: 1.3.2 Water quality Surface water i
Page 15 and 16: 1.3.4 Biodiversity London’s natur
Page 17 and 18: 2.1 What is unique about London? Th
Page 19 and 20: Hampstead Ridge Valley Lea Valley L
Page 21 and 22: • Amenity/biodiversity: the natur
Page 23 and 24: 2.7 Townscape Townscape is the mix
Page 25 and 26: 2.9 London’s green infrastructure
Page 27 and 28: 2.13 Archaeology London’s history
Page 29 and 30: 3 SuDS components
Page 31 and 32: A number of case studies illustrati
Page 33 and 34: 3.2 Structures Roofs and walls can
Page 35 and 36: Case study 1 - Structures Location
Page 37 and 38: 3.3 Infiltration systems London’s
Page 39 and 40: Case study 3 - Infiltration systems
Page 41 and 42: 3.4 Filter strips Filter strips are
Page 43 and 44: 3.6 Wet swales and dry swales Swale
Page 45 and 46: Case study 5 - Swale Location Mill
Page 47 and 48: Maintenance Channel systems require
Page 49 and 50: Case study 6 - Bioretention Locatio
Page 51 and 52: 3.9 Trees Trees in the hard landsca
Page 53 and 54: Street trees: biodiversity Where tr
Page 55 and 56: 3.10 Permeable paving Permeable pav
Page 57 and 58: Case study 9 - Permeable paving Loc
Page 59 and 60:
3.11 Detention basins Detention bas
Page 61 and 62:
3.12 Attenuation and storage tanks
Page 63 and 64:
Design considerations Sedimentation
Page 65 and 66:
4 SuDS in London’s streets
Page 67 and 68:
4.2 Street scenarios Street scenari
Page 69 and 70:
Street scenario 3 An important foca
Page 71 and 72:
Street scenario 5 A well-connected
Page 73 and 74:
Street scenario 7 A local shopping
Page 75 and 76:
5 Case studies
Page 77 and 78:
5.1 Priory Common rain meadow Locat
Page 79 and 80:
5.2 Upminster Bridge swale Location
Page 81 and 82:
5.3 Kenmont Gardens Location Kensal
Page 83 and 84:
5.4 Derbyshire Street Pocket Park L
Page 85 and 86:
5.5 Renfrew Close Location London B
Page 87 and 88:
5.6 Islington Town Hall Location Up
Page 89 and 90:
5.7 Rectory Gardens Location Hornse
Page 91 and 92:
5.8 Talgarth Road Location Talgarth
Page 93 and 94:
5.9 Mile End Green Bridge Location
Page 95 and 96:
5.10 Queen Caroline Estate Location
Page 97 and 98:
5.11 Bridget Joyce Square, Australi
Page 99 and 100:
5.12 Crown Woods Way Location Eltha
Page 101 and 102:
5.13 Hackbridge Location Hackbridge
Page 103 and 104:
5.14 Goldhawk Road Location Shepher
Page 105 and 106:
5.15 Firs Farm Wetlands Location Wi
Page 107 and 108:
5.16 Salmons Brook Glenbrook Stream
Page 109 and 110:
5.17 LuL depot roof, Middlesex Loca
Page 111 and 112:
5.18 A23 Coulsdon Bypass, Farthing
Page 113 and 114:
5.19 London Sustainable Industries
Page 115 and 116:
5.20 Great Kneighton / Clay Farm, C
Page 117 and 118:
5.21 Alnarpsgården Swedish Univers
Page 119 and 120:
5.22 Benthemplein (Water Square) Lo
Page 121 and 122:
5.23 Rue Garibaldi Location Lyon Fr
Page 123 and 124:
5.24 Bo01 Võstra Hamnen Location M
Page 125 and 126:
6 Implementation
Page 127 and 128:
Kings Cross LWT: Camley Street A so
Page 129 and 130:
6.3 Drainage hierarchy SuDS designs
Page 131 and 132:
7 Cost benefit
Page 133 and 134:
7.2 Methodology Cost benefit estima
Page 135 and 136:
4.4 LANDSCAPE WATER MANAGEMENT STRA
Page 137 and 138:
Appendices
Page 139 and 140:
i-Tree Eco Project (2015) Valuing L
Page 141 and 142:
Movement of water from one location
Page 143 and 144:
Heat island Describes urban built u
Page 145 and 146:
Prevention Site design and manageme
Page 147 and 148:
Team The guidance has been produced
Page 149 and 150:
Photo credits 80 Swale sections TfL
show all

SuDS in London - a guide

Create successful ePaper yourself

Delete template?

Save as template?