Flood Risk In Hertfordshire

0.9% of homes in Hertfordshire are in a Medium or High flood risk band, across 522,200 dwellings. It ranks 20 of 21 English counties.

Rivers and the sea Low a 0.1% to 1% chance in any year

Surface water 73,932 addresses at risk that rivers and sea does not explain — a minimum, not a total

Groundwater Not mapped 38 postcodes here are in a groundwater alert area; no likelihood band is published

Reservoirs Not mapped No national band is published for this source

The county band is the aggregate of its 10 districts: 2,625 homes at High, 2,035 at Medium, 8,738 at Low and 2,475 at Very Low — summing to the 15,873 homes at risk this page opens with.

Towns In Hertfordshire, Ranked By Flood Risk

1 Ware Low 5% of homes at Medium or High
2 Hertford Low 4.9% of homes at Medium or High
3 London Colney High 4.9% of homes at Medium or High
4 Rickmansworth High 4.5% of homes at Medium or High
5 Bushey Medium 2.7% of homes at Medium or High
6 Radlett Medium 2.4% of homes at Medium or High
7 Cheshunt Low 2% of homes at Medium or High
8 Hoddesdon Low 2% of homes at Medium or High
9 Waltham Cross Low 1.4% of homes at Medium or High
10 Sawbridgeworth Low 1.2% of homes at Medium or High
11 Hitchin Low 1.2% of homes at Medium or High
12 Bishop's Stortford Low 1.1% of homes at Medium or High
13 Potters Bar High 0.8% of homes at Medium or High
14 Tring Low 0.6% of homes at Medium or High
15 Watford (Watford) Low 0.6% of homes at Medium or High
16 Berkhamsted Low 0.6% of homes at Medium or High
17 Redbourn Low 0.2% of homes at Medium or High
18 Buntingford Low 0.2% of homes at Medium or High
19 Letchworth High 0.1% of homes at Medium or High
20 Abbots Langley and Kings Langley Low 0.1% of homes at Medium or High
21 Stevenage Low 0.1% of homes at Medium or High
22 Hemel Hempstead Very low 0.1% of homes at Medium or High
23 Hatfield Low 0% of homes at Medium or High
24 St Albans Low 0% of homes at Medium or High
25 Welwyn Garden City Low 0% of homes at Medium or High
26 Baldock Not mapped 0% of homes at Medium or High
27 Borehamwood Low 0% of homes at Medium or High
28 Chiswell Green Not mapped 0% of homes at Medium or High
29 Chorleywood Not mapped 0% of homes at Medium or High
30 Harpenden Low 0% of homes at Medium or High
31 Moor Park Low 0% of homes at Medium or High
32 Royston (North Hertfordshire) Not mapped 0% of homes at Medium or High
33 Woolmer Green Not mapped 0% of homes at Medium or High

Ranked within England only. Each town's figure counts its own homes, so the shares are comparable with each other but not with towns in Scotland, Wales or Northern Ireland.

Which Rivers Run Through Hertfordshire?

Rivers with a gauged station in one of the towns ranked above. Each river page carries every gauge on it and the live level at each.

River Colne levels 11 gauging stations on this river
River Pinn levels 10 gauging stations on this river
River Lee levels 8 gauging stations on this river
River Stort levels 5 gauging stations on this river
River Beane levels 4 gauging stations on this river
River Gade levels 3 gauging stations on this river
River Ver levels 3 gauging stations on this river
River Bulbourne levels 2 gauging stations on this river
River Chess levels 2 gauging stations on this river
River Rib levels 2 gauging stations on this river
Small River Lee levels 2 gauging stations on this river
Radlett Brook levels 1 gauging station on this river

How Does Hertfordshire Compare With Other English Counties?

Hertfordshire ranks 20 of 21 English counties for the share of homes in a Medium or High flood risk band. That is below the median county, at 1.8%. The comparison covers the 21 shire counties only — the 132 unitary authorities, including Bristol, York and Sheffield, have no county above them and so take no rank here.

A county figure is an aggregate of its districts, and districts differ sharply: a fenland district and an upland one in the same county can sit at opposite ends of the national ranking. Compare the towns above rather than the county total where it matters.

Share of homes in a Medium or High band, from the Environment Agency's national assessment. The method · The national picture