Highways·Bradford Metropolitan Council Trees as stormwater attenuation and treatment pits·—·Bradford Metropolitan Council Trees as stormwater attenuation and treatment pits

Bradford Council ArborFlow SuDS Tree Pits

6 Field Maples · 30.81m³ storage · handles 1-in-30-year storm surge · Yorkshire Water sewer relief

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Key insight

ArborFlow tree pits are estimated to handle a 1-in-30-year storm with no significant maintenance — effectively delivering flood protection as a side-effect of routine street tree planting, at a fraction of the cost of drainage infrastructure upgrades.

Transferability to UK: HighDirectly applicable across UK urban road networks experiencing surface water flooding.

Six Field Maple trees with large-volume ArborFlow tree pits were installed on North Street, Keighley to relieve pressure on Yorkshire Water's combined sewer during storm events. The joint system stores 30.81m³ and accommodates peak rainfall for 3.5 hours during a 1-in-30-year storm. Post-installation monitoring confirmed strong tree vigour, effective pollutant filtration, and no major maintenance requirement.

Climate drivers

Heavy rainfallFlooding – surface water

Impacts

→Sewer surcharge→Surface water flooding→Road flooding

Adaptation measures

  • ArborFlow SuDS tree pits
  • Stormwater attenuation and filtration
  • Urban tree planting
  • Combined sewer relief

Assets affected

Road pavementDrainage infrastructure

Investment

Not publicly reported; low-cost urban tree-pit system

Band: Under £1m

Delivery period

—

  • The Bradford District has experienced significant flooding, with approximately 7,250 properties in the Bradford District at risk from surface water flooding for a rainfall event with a 1 in 200 chance of occurring .
  • One particular town in the Bradford District, Keighley, experiences drainage-related issues, caused by strain on the combined sewer capacity. Between November and December 2015, river and surface water flooding primarily affected Keighley when a significant portion of the catchment's rainfall occurred in this area .

Ref: ID_30 · Bradford Metropolitan Council Trees as stormwater attenuation and treatment pits · Curated & verified by HIVE

Transferability to UK: High

Directly applicable across UK urban road networks experiencing surface water flooding. Particularly relevant for local highway authorities seeking low-cost, low-maintenance SuDS solutions that can be integrated with road alterations. Field Maples confirmed as effective species for this application.

UK contexts

UK urban roads with surface water floodingLocal authority highway flood managementNorthern England road networksUrban drainage relief alongside Yorkshire Water infrastructure

Yorkshire & Humber

Transfer to other sectors (AI)