Location: Greater Manchester , United Kingdom
City population: 2,679,318
Project duration: 2015 - 2017
Project cost: Unknown
Financing source(s): Public national budget, Public local authority's budget, Corporate investment

Howard Street project Streetscape

Three London Plane trees were planted in a specially designed trench in Howard Street, Salford, Greater Manchester in 2015 with the aim of capturing the impact that trees had on both cleaning polluted water from road run off and managing levels of surface water, which can lead to flooding. (ref 1) This project in the City of Salford to studies how trees can aid the management of urban stormwater as a novel retrofit street tree demonstration. (ref 5). It is led by Manchester's City of Trees movement.

Urban setting

  • Grey infrastructure with green features
    • Alley and street trees/hedges/greens

Key challenges

  • Climate action for adaptation, resilience and mitigation (SDG 13)
  • Environmental quality, including air quality and waste management
  • Green space, habitats and biodiversity (SDG 15)
  • Water management (SDG 6)

Main beneficiaries

  • Local government/Municipality
  • Non-government organisation/Civil Society
  • Researchers/University
  • Citizens or community groups
Project objectives
The aim of the Howard Street project is to demonstrate and quantify how, in an urban context, Green Infrastructure such as street trees can provide a natural solution to managing surface water runoff and addressing diffuse pollution. To explore real life natural solutions for tackling localized flooding and diffuse pollution. (ref 3)
Implementation activities
Three fifteen year old London Plane trees were planted in the specially designed roadside tree trench in Howard Street, Salford. (ref 5) The project, which will run till 2017, has already produced promising initial monitoring results in June 2016 which reveal that the average water volume retention by the tree pit system was approximately 40% and the average storm peak reduction was 50%. Storm waters were also slowed by the system by up to 2 hours. (ref 2)

Type of initiating organisation

  • Private Foundation

Management set-up

Co-governance or hybrid governance (mix of responsibilities between government and non-government actors)

Participatory approaches/ community involvement

  • Unknown
Details on the roles of the organisations involved in the project
Funded By - 1. City Of Trees (Red Rose Forest) 2. Salford City Council 3. The Environment Agency 4. United Utilities Monitored By Manchester University (ref 7) Project Designer: City of Trees Manchester (ref3)
Project implemented in response to ...
... an EU policy or strategy? Yes
fulfills a key requirement of the European Water Framework Directive (ref 3)
... a national policy or strategy? Unknown
... a local policy or strategy? Yes
The Salford City Council Development Plan Document (Publication Core Strategy, February 2012) - a section on “Green infrastructure spatial strategy” is mentioned (ref 4)
Expected impacts
  • Climate action for adaptation, resilience and mitigation (SDG 13)
  • Environmental quality, including air quality and waste management
  • Water management (SDG 6)
Details on impacts and indicators used As per the evaluation reports: (ref 6, page 55) Reduction in peak flow rates are measured 1. Average flow rate reduction: • 70% summer of 2016 2. Largest summer storm ‐ June 25th 2016: • 98% reduction (3.6 litres/sec on the inlet – negligible flow on the outlet) 3. Average Runoff volume reduction • 60% 4. Average Peak Flow Reduction: • 1.5 hours

Presence of formal monitoring system


Presence of indicators used in reporting


Presence of monitoring/ evaluation reports

Availability of a web-based monitoring tool

  • Howard Street Project
    Steve Chatwin-Grindey (Deeproot), retrieved 08/24/2018
  • Howard Street Project (2016)
    Steve Chatwin-Grindey (Deeproot), retrieved 08/24/2018


Disclaimer: The data collection was carried out between June and August 2017, the information presented has not been updated afterwards.