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Lamb Drove SuDS

United Kingdom Lamb Drove, Cambridge

The sustainable drainage system (SuDS) in Lamb Drove, Cambridge is an award-winning project which has successfully reduced flooding risk. 

Nature-based intervention:

Lamb Drove, owned by the Cambridge Housing Society, is a residential development comprising 35 affordable houses. In January 2004, it was chosen to become a showcase for innovative water management techniques known as SuDS (sustainable drainage systems) as part of a broader European-funded initiative encompassing 40 projects across Germany, Norway, Sweden, and the UK. Over the course of 2 years, designers and engineers collaborated to plan and retrofit an integrated drainage system, with the primary goal of reducing flooding risk. This system comprises a management train of components arranged in series, which incrementally reduces pollution, flow rates, and the volume of the water passing through. A combination of measures were implemented including the use of water butts, permeable paving, green roofs, and grass swales, among others. To complete the system, detention basins and retention ponds were incorporated to store surplus water, ensuring the ability to handle a 1 in 100-year flood with an extra 20% allowance for potential climate change. These strategies work together to closely emulate natural drainage systems, whilst also enhancing the site’s value by creating biodiversity-rich and recreational areas. Cambridge County Council obtained funding to closely monitor the system for three years after its implementation (2008-2011). This monitoring aimed to showcase the long-term impact of SuDS on water quality and quantity leaving the site, as well as its environmental and socioeconomic outcomes.

Overview of context:

The driving force behind the initiative is the growing pressure for more housing in the UK. Alongside this, there is a call for the implementation of more sustainable drainage systems which can cope with the increased rainfall and flooding predicted under climate change. Cambridge holds particular significance for several reasons. Firstly, it has been identified as a key area for growth under the government’s housing strategy and promises were made to build 50,000 new houses in the area by 2016. Furthermore, being a low-lying county, Cambridge faces significant threats from flooding by rivers and urban watercourses. Given these factors, it is not surprising that Lamb Drove was chosen as a model for SuDS. The project received a commendation award at the Royal Town Planning Institute awards in 2006, and has been cited in the government’s planning policy statement. This project has also been useful from an educational perspective, featuring as a common case study in schools around the UK.

Case effectiveness on

Climate change

Mitigation: Not reported

Climate mitigation outcomes were not mentioned in reports. Nevertheless, the introduction of green roofs, grass swales and the maintenance of green recreational areas as part of this project may increase above-ground carbon storage by a small amount.

Adaptation: Positive

Monitoring has shown that the Lamb Drove site has attenuated surface water flows and significantly reduced peak flows compared to the Control Site. A permeable pavement infiltration study undertaken by Cranfield University has demonstrated the robustness of the SuDS to flooding. They reported that the infiltration capacity of the permeable pavements are able to adequately cope with the highest rainfall intensity thus far recorded in the study site. They also claim that on-site water storage will be large enough to cope with the increased storm frequency predicted under climate change.

Ecosystem health

Ecological effect: Positive

During the monitoring period, the number of species present in Lamb Drove was reported to have increased from 30 to 34. In contrast, the control site actually suffered a decrease from 34 to 21 species. As well as this,  overall biodiversity reportedly increased due to the SuDS implementation. In terms of water quality, pollutant concentrations were shown to progressively reduce throughout the treatment train. Specifically, significantly lower concentrations of hydrocarbons, heavy metals, organic carbon, and total suspended soils were observed in the study site relative to the control.

Socioeconomic outcomes

Both the capital and maintenance costs associated with the Lamb Drove SuDS project are lower than the majority of conventional pipe drainage systems. Estimated savings totalled to approximately £11,000. Furthermore, households benefit financially, saving an average of £30 annually, as they no longer need to be charged for stormwater disposal.


Local participation in Governance: Passive

Local authorities, especially county, unitary, or metropolitan authorities, are responsible for the approval and adoption of SuDS according to the Flood and Water Management Act 2010 regulatory framework. The projects require high quality stakeholder engagement at early stages, involving pre-planning stage discussions with local authorities, regulators (e.g. Environment Agency) and adoption authorities.

Lamb Drove is developed and owned by Cambridge Housing Society, with Royal Haskoning employed as drainage consultants to design SuDS schemes. The maintenance of the site is conducted by Cambridge Housing Society and the off-site care to pick litter, cut grass, and inspection of inlets and outlets is conducted by Cambridge Wildlife Trust.


The Lamb Drive SuDS scheme was funded as part of 40 projects funded by a European programme called FLOWS. In addition, Cambridgeshire County Council secured funding to monitor the project from 2008 – 2011. The SuDS scheme was found to provide savings on construction and maintenance costs of typical drainage schemes. Notably, 10% savings were facilitated from SuDS at Lamb Drove compared to design and capital costs from traditional drainage systems.

Monitoring and evaluation

A three-year monitoring programme took place between September 2008 and November 2011. The primary objective was to compare outcomes between the Lamb Drove area and a similar-sized control site located nearby, which maintained a traditional drainage system. One of the main research focuses was on water quality, for which quarterly surveying took place. Samples would be taken and subsequently sent to Anglian Water laboratories in Huntington, where testing for hydrocarbons, heavy metals, organic carbon, and total suspended solids occurred. Royal Haskoning were also commissioned to undertake additional investigations of the SuDS impact, examining factors such as flow, volume attenuation, wildlife impacts, maintenance costs, aesthetic appeal and health and safety issues. Resident surveys also took place to gauge public opinion of the scheme. These efforts were funded by Defra (Department for Environment, Food and Rural Affairs), Cambridgeshire Horizons, and the Environment Agency.

Trade-offs and limitations

Given that SuDS requires close engagement and cooperation of parties, there may be challenges faced in stakeholders agreeing to initiatives. For example, safety concerns were raised about potential standing water within the system. To address these concerns, information was provided to educate parties that only a small amount of water would pool in the case of heavy rainfall events, and a safety audit was successfully conducted by the Royal Society for the Prevention of Accidents. Ultimately, stakeholders were reassured about the level of risk from the project. In addition, parties were concerned with the maintenance procedure of SuDS. To address this, a document (The Operation and Maintenance of Sustainable Drainage Systems (and Associated Costs)) was drafted in simple language to provide a checklist of tasks to be implemented.


  1. Susdrove. N.d. Lamb Drove, Residential SuDS scheme, Cambourne.
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Street View of Lamb Grove
Photo © Google Maps

Intervention type

  • Created habitats

Ecosystem type

  • Created other

Climate change impacts addressed

  • Freshwater flooding


  • National government/agency

Societal challenges

  • Biodiversity conservation
  • Climate change adaptation
  • Disaster risk reduction
  • Water security


  • Food security: Not reported
  • Water security: Positive
  • Health: Not reported
  • Local economics: Positive
  • Livelihoods/goods/basic needs: Not reported
  • Energy security: Not reported
  • Disaster risk reduction: Positive
  • Rights/empowerment/equality: Not reported
  • Recreation: Positive
  • Education: Positive
  • Conflict and security: Not reported
  • No. developmental outcomes reported: 6


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Literature info

  • Grey literature
Case methodology reported