Case Study: Surface Water Drainage Strategy for Planning
Unda was appointed by an Eco-property entrepreneur who required an effective Surface Water and Foul Water Drainage Strategy to support his planning application for the proposed development of a new 35 bed Eco-hotel with access road, large parking area and the benefit of trees and shrubs around the periphery of the proposed development site in Cheshire.
The client had previously submitted the planning application for the development, the Local Planning Authority had raised an objection as they did not believe the application in its current form had provided a satisfactory drainage strategy. In addition the LPA was concerned of the risk of flooding both on the site itself and the surrounding area. They had requested that a Flood Risk Assessment including Surface Water Drainage Strategy be submitted for review.
Benefit to client:
By working closely with the client, Unda was able to provide a comprehensive and robust Surface Water and Foul Water Drainage Strategy to support the planning application to ensure there was no further time delays in a project that was already behind schedule.
Unda was also available to provide telephone support the client as time was of the essence. Unda’s consultants provided prompt responses to various questions which arose from the planners post submission of the planning application.
Through Unda’s Drainage Strategy approach it was concluded that all surface water run off generated by the proposed hotel would be dealt with on site using infiltration through permeable pavement surfaces, attenuation and discharge at Greenfield rates, or would be re-used through rainwater harvesting. The additional run-off from the paved areas would either soak into the ground through permeable paving surfaces, or be attenuated within the sub-surface storage and released at green field rates.
All attenuation or storage features required a 5.0m clearance from any building as specified by the Building Regulations, and were specified to be 2m away from any boundary.
All on site SuDs features proposed for the development were to be privately maintained, and the sub-surface attenuation for the road and garage roof drainage required agreements in place for long term maintenance – particularly the oil/petrol interception and silt trap, which may require cleaning every 10 years or more. Unda provided guidance to the development for all aspects of the required maintenance program.
Additionally, it was concluded that the risk of flooding posed to the site from fluvial, tidal, groundwater and sewer surcharge was negligible.
If you have been asked to provide a Surface Water Drainage Strategy to support a planning application, please contact Unda. Our expert Flood Risk consultants will be able to assist. Tel: 01293 214 444
The proposed location.
The drainage strategy plans