The Crane Valley Partnership

Reduced Rick of Flooding in Built-up Areas

We need increased innovative solutions to improve the catchment’s capacity to store and slowly release stormwater

The Crane is surrounded by an urban landscape surfaced with impermeable materials and as a result the river receives large quantities of surface water runoff. We think we can promote change in this landscape to soften the effects of excessive storm water entering our river. Green roofs, Sustainable Urban Drainage Systems, attenuation ponds, and other green infrastructure should be promoted through the borough planning process and local developers should incorporate these sustainable methods of flood prevention in their plans.

We want to improve the ability of the River Crane to adapt to stormwater events

Many of the Crane’s backwaters now lie unconnected to the main river and urban development has encroached on the Crane’s floodplain. We want to ensure that connectivity is improved between the river and the floodplain to ensure the floodplain functions as naturally as possible.

Work has already begun to reconnect disconnected meanders to the main river, increasing the catchment’s capability to store stormwater. Habitat suitability mapping is being used to assess areas where wet woodland can be created or enhanced.

In order to secure this objective, we want local authorities and developers to adhere to the following policies of the London Plan 2011

Policy 5.11: Green Roofs and Development Site Environs

Major development proposals should be designed to include roof, wall and site planting, especially green roofs and walls where feasible, to deliver as many of the following objectives as possible:
1. Adaptation to climate change. 2. Sustainable urban drainage. 3. Mitigation of climate change. 4. Enhancement of biodiversity. 5. Accessible roof space. 6. Improvements to appearance and resilience of buildings. 7. Growing food.
Local Development Framework Preparation

Within LDFs, boroughs may wish to develop more detailed policies and proposals to support the development of green roofs and the greening of development sites. Boroughs should also promote the use of green roofs in smaller developments, renovations and extensions where feasible.
Policy 5.13: Sustainable Drainage

Developments should utilise Sustainable Urban Drainage Systems unless there are practical reasons for not doing so, and should aim to achieve greenfield runoff rates and ensure that surface water runoff is managed as close to its source as possible in line with the following drainage hierarchy: 1. Store rainwater for later use. 2. Use infiltration techniques, such as porous surfaces in non clay areas. 3. Attenuate rainwater in ponds or open water features for gradual release. 4. Attenuate rainwater by storing in tanks or sealed water features for gradual release. 5. Discharge rainwater direct to a watercourse. 6. Discharge rainwater to a surface water sewer/drain. 7. Discharge rainwater to the combined sewer.
Local Development Framework Preparation

Within LDFs, boroughs should, in line with the Flood and Water Management Act 2010, utilise Surface Water Management Plans to identify areas where there are particular surface water management issues and develop actions and policy approaches aimed at reducing these risks.
Policy 7.28: Restoration of the Blue Ribbon Network

Development proposals should restore and enhance the Blue Ribbon Network by: 1. Taking opportunities to open culverts and naturalise river channels. 2. Increasing habitat value; development which reduces biodiversity should be refused. 3. Preventing development and structures into the water space, unless it serves a water related purpose. 4. Protecting the value of the foreshore of the Thames and tidal rivers. 5. Protecting the open character of the Blue Ribbon Network.
Local Development Framework Preparation

Within LDFs, boroughs should identify any parts of the Blue Ribbon Network where particular biodiversity improvements will be sought, having reference to the London Rivers Action Plan.
Policy 5.14: Water Quality and Wastewater Infrastructure

Development proposals must ensure that adequate wastewater infrastructure capacity is available in tandem with development. Proposals that would benefit water quality, the delivery of the policies on this page and of the Thames River Basin Management Plan should be supported while those with adverse impacts should be refused.
Development proposals to upgrade London’s sewage treatment capacity should be supported provided they utilise best available techniques and energy capture.
The development of the Thames Tideway Sewer Tunnels to address London’s combined sewer overflows should be supported in principle.
Local Development Framework Preparation

Within LDFs, boroughs should identify wastewater infrastructure requirements and relevant boroughs should in principle support the Thames Tideway Sewer Tunnels.


  • Increased innovative solutions to improve the catchment’s capacity to store and slowly release storm water.
  • To Improve the ability of the River Crane to adapt to storm water events.