Flood management for developers

You should consider appropriate drainage systems early in the design phase for any new developments you are planning. 

Read our developers' guide for surface water management that covers:

• our flood risk and drainage requirements
• guidelines for hydraulic calculations
• guidelines for selecting sustainable drainage systems
• common issues encountered with planning submissions

Also read more about how we manage the risk of flooding in Southwark. 

When making a planning application you must consider sustainable drainage like:

• ponds
• green roofs
• soakaways
• swales

Sustainable drainage puts as much water back into the ground as possible, to:

• maintain healthy aquifers
• reduce the risk of flooding and drought
• improve water quality

Major new developments should include a completed sustainable drainage proforma. You can download a template for this from the London Mayor's website.

Download the sustainable drainage proforma template (XLSX, 322 KB)

We recommend that you have discussions with us before you submit a planning application.