Flood Alert Info - Upper River Colne and Radlett Brook

Area Description

The Upper River Colne and Radlett Brook at Colney Heath, London Colney, Borehamwood and Radlett.

This is a Flood Alert Area. For this area the highest level of flood notification that you will receive is a Flood Alert. No Flood Warnings or Severe Flood Warnings are issued for this area.
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Flood Alert Currently in Force

There are no Flood Alerts currently in force for this area. See below for historical flood warnings.

Area Covered by this Flood Alert

The orange highlighted area on the map below outlines the area covered by this Flood Alert.
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Flood Alert History

Number of historic Flood Alerts that have previously been recorded for this area:
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Historical Flood Alert Messages for this Area


Flood Alert issued on 29 May 2018 20:35
River Colne
Heavy rain has fallen in the Upper Colne catchment today causing river levels to rise, especially on the Borehamwood Brook and Radlett Brook. Levels have begun to fall, however further rain is possible through the evening on Tuesday 29 May and overnight into Wednesday morning. The time, location and amount of further rain is very uncertain. If further heavy rain falls in this area river levels could again rise rapidly. Flooding to low lying land and roads close to the river is possible, and surface water flooding is possible. Flooding to properties is not currently expected. Take care near the areas of concern. We recommend you monitor local water levels and weather conditions. Consider putting your flood plan into action. You should avoid walking, cycling or driving through flood water We are constantly monitoring river levels and have staff checking for and clearing blockages in this location. This message will be updated by 10am on Wednesday 30 May.


Flood Alert issued on 29 May 2018 15:02
River Colne
Heavy rain has been falling in the Upper Colne area and rivers are rising rapidly in response. Flooding to low lying land and roads close to the river is possible from 3pm on Tuesday 29 May. Flooding from surface water could also occur. Take care near the areas of concern. We recommend you monitor local water levels and weather conditions. Consider putting your flood plan into action. You should avoid walking, cycling or driving through flood water We are constantly monitoring river levels and have staff in the field checking for and clearing blockages in this location. This message will be updated by 9pm on Tuesday 29 May or earlier if the situation changes.


Flood Alert issued on 2 Apr 2018 07:15
River Colne
Over the last few days and overnight on Sunday we have seen some heavy rainfall in the area. This means that the River Colne is now rising. Levels suggest that there will be flooding to low lying land and roads close to the river from 7:00 today (Monday 02 April). Flooding from surface water could also occur. We expect the river to remain high for the rest of today, although no flooding to properties is forecast and warnings are not expected to be issued. Take care near the areas of concern and monitor your local weather conditions. We are constantly monitoring river levels. This message will be updated on Monday evening or earlier if the situation changes


Flood Alert issued on 30 Mar 2018 19:39
River Colne
Over the last 24 hours we have seen heavy rainfall in the London Colney and Colney Heath area. This means that the River Colne is now rising. Levels suggest that there will be flooding to low lying land and roads close to the river from 8pm today (Friday 30th March). Flooding from surface water could also occur. We expect the river to remain high for the rest of today and overnight, although no flooding to properties is forecast and warnings are not expected to be issued. Take care near the areas of concern and monitor your local weather conditions. We are constantly monitoring river levels and have staff in the field checking for and clearing blockages in this location. This message will be updated on Saturday morning or earlier if the situation changes.


Flood Alert issued on 9 Mar 2018 19:21
River Colne
Throughout this afternoon (Friday 09 March) and into this evening we have seen heavy rainfall across the area. This rain is likely to continue through the night and will cause rivers and streams to rise. The main area of concern is currently Colney Heath where river levels are likely to rise the most. There is likely to be flooding to low lying land and roads close to the river in the early hours of Saturday 10 March. Flooding from surface water, where water gathers and flows off road surfaces, could also occur. No flooding to properties is currently expected. We expect the river to remain high throughout Saturday but water levels should start to recede later in the weekend. We are constantly monitoring river levels and have staff on standby to attend to any blockages in the river. Please avoid walking, cycling or driving through flood water. This message will be updated in the morning or earlier if the situation changes.


Flood Alert issued on 26 Dec 2017 19:23
River Colne
Over the course of the day we have seen moderately heavy rainfall in the area. The River Colne and its tributaries have started to rise in response to this rainfall. We expect rivers to continue to rise overnight Tuesday 26th December and remain high throughout Wednesday 27th December. No flooding to properties is forecast and warnings are not expected to be issued. We are continuing to monitor river levels and have staff in the field checking for and clearing blockages. This message will be updated at 10am on Wednesday 27th December or earlier if the situation changes.


Flood Alert issued on 26 Dec 2017 12:41
River Colne
Persistent heavy rain is expected during the evening of Tuesday 26th December 2017 and overnight in to the morning of Wednesday 27th December 2017. River levels are currently normal for the time of year and are expected to rise following the forecast rainfall. Flooding to low lying roads, land, gardens backing on to rivers and surface water flooding is expected between Tuesday evening and Wednesday morning, 26th to 27th December. We expect the river to remain high in to the afternoon and evening of 27th December 2017. We will be closely monitoring the situation throughout the day and this message will be updated as the situation changes. We will be assessing the need for the operation of local defences. We also have staff on standby to attend to any blockages in the river. This message will be updated this evening or earlier if the situation changes.


Flood Alert issued on 13 Dec 2017 17:11
River Colne
We have issued a Flood Alert. Rain that has fallen today, Wednesday 13 December, and melting snow has caused the River Colne to rise, particularly in the Colney Heath area. Flooding to low-lying land, roads and riverside gardens is possible today. Surface water flooding may also affect these areas. We recommend you monitor local water levels and weather conditions. Consider putting your flood plan into action. You should avoid walking, cycling or driving through flood water. We expect the river to remain high overnight as a result of further showers this evening. Tomorrow should be mostly dry. We are constantly monitoring river levels and the weather forecast. This message will be updated tomorrow morning or earlier if the situation changes.


Flood Alert issued on 9 Aug 2017 20:33
River Colne
Throughout Wednesday there has been heavy rainfall across the area which has caused the river Colne to rise. The river remains high in Colney Heath and will rise slowly at London Colney for the early part of Wednesday night. It is not expected to cause any further flooding but this Alert will remain in force whilst the river remains high. Take care near the areas of concern and monitor your local weather conditions. We are constantly monitoring river levels and have staff on standby ready to attend any blockages in the river, where we become aware of them. This message will be updated by 10am Thursday morning.


Flood Alert issued on 9 Aug 2017 15:18
River Colne
Throughout the day on Wednesday, we have seen heavy rainfall across the area. This has caused rivers and streams to rise. The main area of concern is currently Borehamwood where river levels have risen the most. There is likely to be flooding to low lying land and roads close to the river this afternoon on Wednesday. Flooding from surface water, where water gathers and flows off road surfaces, could also occur. We expect the river to remain high this afternoon but should start to recede this evening. No flooding to properties is currently expected. We are constantly monitoring river levels and have staff on standby to attend to any blockages in the river. This message will be updated this evening or earlier if the situation changes.


Flood Alert issued on 11 Jul 2017 21:20
River Colne
We have seen widespread rain across much of Hertfordshire this afternoon, Tuesday 11 July. As we move through this evening and into the early hours of tomorrow morning (Wednesday 12 July) there is a risk of further heavy bursts of rain. We expect the river Colne to rise in response to this rainfall during the early hours of Wednesday morning. There is the potential for flooding to affect low lying land and roads. No flooding to properties is anticipated. The river should return to normal levels by lunchtime tomorrow. Take care near the areas of concern and monitor your local weather conditions. We are constantly monitoring river levels and will update this message on Wednesday morning or earlier if the situation changes.