Arcadis: Making natural capital count in the infrastructure industry

Transport for London (TfL) engaged Arcadis for the permitting process of their proposed Silvertown Tunnel under the Thames River.

For the permit, we were required to demonstrate that there would not be any residual effects on biodiversity. We wanted to demonstrate an overall net gain applying the Biodiversity Action Plan and Mitigation Strategy (BAP MS).

The site was an urban brownfield habitat, undervalued for biodiversity and other natural capital values.

The goal of the BAP MS was to minimize, quantify, qualify and monetize biodiversity impacts and ultimately deliver a net gain for biodiversity.

Targets and parameters were set for onsite and offsite mitigation. We monetized different ecosystem services and allocated a maximum deficit value for natural capital to support the offsite delivery. This helped to communicate the investment requirements to the client, provided targets and auditable values for such mitigation. In addition, this study served as a pilot example for future assessments and stakeholder engagement. 

Natural Capital Protocol used
  • Yes
Impact drivers assessed
  • GHG emissions e.g. volume of CO2, CH4, N2O, SF6, HFCs and PFCs etc.
  • Impact on biodiversity e.g. impact on species, ecosystems, habitats or genetic diversity
  • Non-GHG air pollutants e.g. PM2.5, PM10, VOCs, NO, NO2, SO2, CO, etc.
  • Water pollutants e.g. volume discharged to receiving water body
  • Water use e.g. volume of ground- or surface water consumed
Organizational Focus
  • Project
Valuation Type
  • Qualitative
  • Quantitative
  • Monetary
  • Value to business
  • Value to society
Geographical Scope
  • United Kingdom
Dependencies assessed
  • Biodiversity
  • Energy e.g. solar, wind, hydro, geothermal, biofuel, fossil fuel
  • Experience e.g. nature-based recreation, tourism
  • Regulation of biological environment e.g. pollination, crop pest control
  • Regulation of physical environment e.g. flood attenuation, water quality regulation
  • Regulation of waste and emissions e.g. waste assimilation, noise and dust regulation
  • Well-being and spiritual/ethical values e.g. employee satisfaction and stress release, sacred sites and indigenous traditions
Value Chain Boundary
  • Downstream
  • Engineering

Key findings

This approach has the potential to release valuable land for development and to establish a robust process for on and off-site mitigation to ensure that we retain valuable and functional habitats for the local and wider community.

In the case of Transport for London’s (TfL) proposed Silvertown Tunnel under the River Thames, Arcadis was able to demonstrate a net gain in biodiversity while maintaining or enhancing ecosystem functions.

No Net Less (NNL) has been achieved through a combination of onsite mitigation and off-site compensation using natural capital valuation. This reduces project costs by avoiding the need to acquire expensive, adjoining land with complex ownership issues. Stakeholder expectations have been managed and regulatory obligations met, both critical requirements to secure the necessary planning approval.