Is your street or business in danger of flooding?

Marking Flood Action Week this week, John Miles of the Haringey Water Squad has shared some information about local flood risk in Haringey.

John writes, "The Environment Agency has said that 'the odds of repeated storms, prolonged rain and saturated catchments are higher than average this winter'. The last major rainfall-related floods in Haringey were on July 12th 2021 and July 25th 2021. You can find the three Section 19 reports analysing the nature and impact of the flooding on the council website. There were significant local variations but the rain on July 12th was assessed as between a one in five and one in twenty year incident while the gauges at Wanstead on July 25th recorded a 1 in 70 year incident! " 

A Cabinet report sets out the council's subsequent responses and plans here. [pdf]

John continues, "The three Section 19 reports for July 2021 list 28 locations affected in Hornsey and Crouch End, 33 in South Tottenham and 10 in Wood Green. These range from flooded streets to swamped basements, shop-floors and school premises. The Council has published an updated Local Flood Risk Management Strategy. Like so much information in this field the mapping is often hard to read and the technical distinctions difficult to follow. "

Find this document here: [pdf]

John suggests using the Flood Water Management Asset Register. If you go to the box on the left of the window that opens and put your post code into Find Address and click on Surface Water Flood Zones you'll see three illuminated boxes. Click to turn off the '1 in 100 year extent' and '1 in 1000 year extent' boxes and you'll be left with the 1 in 30 year box. Flood-risk areas are highlighted in dark blue. John says this may offer a reasonable approximation of what might happen if there was a repeat of the 2021 events. Though obviously it depends on how long it rains for and then on whether it rains heavily again over a period. 

The register is here:

John comments, "Some localities in Haringey would be vulnerable if there was a repeat of the events in 2021 - which seems at least a possibility. Unfortunately, this approach to the register doesn't work once you get east of Tottenham High Road. Here a lighter blue blankets the streets and open spaces indicating that the Lea would have flooded and started to back up through the sewers and across the low-lying ground to the west. This didn't happen in 2021 and would indicate a much wider catastrophe in London as a whole. "