Sur 1 - Management of Surface Water Run-off from Developments

Aim:
To design housing developments which avoid, reduce and delay the discharge of rainfall to public sewers and watercourses. This will protect watercourses and reduce the risk of localised flooding, pollution and other environmental damage.

Credits: Mandatory Elements + Max. 2 additional credits

Assessment Criteria:
Mandatory Elements must be achieved i.e. showing that the peak rate of run-off does not increase following development. 

Sur 1 Default Cases:
The CSH includes 'default cases' where by the mandatory criteria of Sur1 can be met by default - see our Sur1 default cases page to check if this applies to your site.

Surface water run-off calculations.
Where Sur1 can not be met by default, surface water run-off calculations to calculated the increase in run-off rates and volumes will be required to meet the mandatory elements of Sur1.

Surface Water Run-off Calculations

SUDS Design (Possible Additional 2 Credits)
The only way to get the Sur1 credits is by achieving the following:

We can assist you in the process of achieving credits by doing the following:

Flood Risk Assessment (FRA)(Mandatory)

Although not clear in the CSH, a FRA is part of the 'Design Stage Mandatory Elements' listed under Sur1 (see page 141 of May 2009 CSH or page 127 of Nov 2010 CSH).  Therefore, it is mandatory for all sites to have a FRA.  See our Sur2 - Flood Risk page.

If you are unsur how you are going to deal with drainage from your site a Preliminanary Drainage Assessments (PDA) may be what you need - see the  Preliminary Drainage Assessment page.

View Printable SUR1 PDF