As part of a European funded FLOWS project the County Council arranged for the installation of a Sustainable Drainage System (SuDS) in part of a housing development in Cambourne, Cambridgeshire. The work was completed in 2006 and is owned and maintained by the Cambridge Housing Society.
Following on from the completion of the construction, A two-year monitoring project of the site was commissioned by the County Council in 2008, using funding secured from Defra, the Environment Agency and Cambridgeshire Horizons. The monitoring project was due to finish at the end of 2010, but has been extended for another 12 months after the Council secured funding from Defra. The Council commissioned Royal Haskoning to undertake the monitoring project - with the bespoke flow monitoring equipment supplied by RS Hydro.
The project aimed to assess the performance of SuDS at the Lamb Drove site and compare it to a nearby site that uses only conventional drainage systems. The following table demonstrates the objectives and outputs of this project:
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Monitoring Objectives
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Required Benefits
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Evidence, Outputs and Deliverables
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Effectiveness of water flow management and volume attenuation
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Reduce the impact of urbanisation on flooding
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Flows monitored daily by remote web access through sensors on site; Summary of results in interim and final reports
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Effectiveness of water quality control
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Protect and enhance water quality
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Quarterly testing of water quality by Anglian Water to be summarised in interim and final reports
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Environmental benefits
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Create habitats in urban watercourses and open spaces with greater wildlife diversity
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Base habitat survey and final habitat survey; Results and analysis to be incorporated in interim and final reports
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Robustness and Operation of Systems
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Ease of operation with minimum maintenance and repair
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Assessment of robustness and operation of SuDs measures (to include permeable paving) within final report
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Costs of maintenance
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Annual costs close to or less than conventional drainage
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Table of costs and analysis within final report
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Assessment of whole life costs
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Overall costs close to or less than conventional drainage
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Interim report with larger section in final report (to incorporate assessment of permeable paving)
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Resident’s feedback on appearance, health, safety and practicality
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Create a better quality of life within the local community with attractive green spaces and enhanced local amenity
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Residents surveys at commencement and at the end of the study; Results incorporated in interim and final reports
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The key findings of this project have been included in the Final Monitoring Report published in March 2012 - see report at the bottom of this page. The executive summary note is also provided below.
The results were being used to help guide the national approach to SuDS being led by Defra.
These key findings confirm the significant advantages for SuDS over conventional drainage systems, including substantial retaining and attenuation of surface water flows reducing flood risks and measurable improvements to water quality.
Results of the monitoring project are being communicated as widely as possible to help enable better direction and implementation of SuDS schemes throughout the UK and in particular for residential developments.