November Rain
A look at the Environment Agency’s flood warning systems and services during the major flood event in north east England between 7th and 21st November 2019
The storm before the storm
England and Wales experienced prolonged periods of unsettled weather and heavy rain throughout September and October 2019, with central and north east England receiving 171% and 194% (respectively) of the rainfall normally expected for these months.
Many river catchments were very wet — the Don and the Trent catchments were already ‘exceptionally high’ (i.e. high river flows that are only seen 5% of the time) — before a slow moving weather front brought heavy and persistent rain to Lincolnshire, Nottinghamshire, Derbyshire and South Yorkshire on 6 November 2019.
In places, up to 150% of the expected monthly rainfall fell across the 6th and 7th of November alone and Sheffield saw the 7th highest daily rainfall total since records began. A detailed analysis of the weather conditions which led to the flood event can be found on the Met Office website.
As a result, flooding occurred in several places across central and north east England. Large numbers of Flood Alerts, Warnings and Severe Warnings were issued in response to the rainfall. Although Environment Agency assets protected some 22,775 properties, 1102 properties are known to have flooded and tragically 1 person lost their life.
In the weeks after the flooding, the Digital Services teams undertook a detailed analysis of the performance of the flood warning and informing services. This helped us understand system performance whilst under pressure as well as highlighting successes and challenges for the future.
Getting the message out
The Flood Warning System (FWS) has been the Environment Agency’s primary method for sending flood warning information to the public and our partner organisations since April 2017. The November 2019 flood event was the largest test yet of FWS since its launch and the first major event since several significant changes and improvements to our services and structures.
The system sends warning information via telephone voice messages (to landlines and mobiles), as well as by SMS text message and email. FWS also automatically updates the Flood Information Service (FIS) on GOV.UK and the Floodline Interactive Voice Recording service (IVR) whenever a warning is issued, changed or removed.
There was a total of 673,713 calls sent between 7th November 2019 and 21st November 2019. For clarity, a call is an attempt by FWS to contact a customer using a method (or methods) chosen by that customer — so ‘calls’ can be SMS text messages or emails as well as telephone calls. Each customer may receive calls via several different methods. XML channels that update other systems are also included in these figures.
Call delivery results show a different picture. Although the Telephone channel is by far the most utilised channel, it is the least successful with only 26% of calls getting through to someone. 35% were unsuccessful and 39% were ‘partially successful’ i.e. a call was made but we aren’t sure if they message was listened to by a person — for example, it went straight to voicemail.
When a message is sent from FWS there are several factors that influence the time it takes to complete it:
- FWS has access to a suite of telephone lines for outbound calls - only when there are unused lines available can a new call be made
- If a contact is initially unavailable, FWS will wait for a set amount of time and then retry the number
- Messages are processed in priority order for the initial attempt, so if a severe flood warning is sent after a remove message, the severe flood warning is sent first.
Of the 5987 messages sent, 81% were completed within 10 minutes, 94% within 20 minutes and 99% within 30 minutes. Those taking longer were usually the result of the system repeatedly trying to contact an invalid number.
Inbound calls
Floodline is a service provided by Teleperformance on behalf of the Environment Agency, Natural Resources Wales (NRW) and the Scottish Environment Protection Agency (SEPA) and is available to customers 24 hours a day, 7 days a week, 365 days a year. Floodline provides call centre services for all customer enquiries and a direct link to the IVR which provides up to date flood warning information to the public. There is a dedicated team of staff who focus on flooding full time with the ability to draw on additional support during incidents.
In total 7332 calls were made to Floodline between the 7th and 21st November, with approximately ¾ of callers going to the IVR for information and ¼ wanting to speak to a live agent. November the 8th was the single busiest day with 1,660 calls going to the IVR and 718 talking to a live agent. Over the event, 96% of calls offered to the live agent were answered, and 93% were answered within 30 seconds — both well above their SLA of 85%.
On the morning of 7th November 2019, new functionality was introduced whereby a member of the public could access information in the IVR that was relevant to them via a clickable link in the SMS message sent to them from FWS. Through the 14 days of the flood event, a total of 1090 customers accessed the IVR via this SMS link. This represents 13% of all traffic to the IVR. Considering this functionality was introduced just as the flood event was starting to gain momentum, this is a very promising start to this new element of the service. In line with other services, the 14th of November proved to be the day this was most utilised, with 259 customers accessing the IVR using the SMS link.
Let’s get digital
The Flood Information Service (FIS) is the online part of the flood warning offering and allows members of the public in England to get a better understanding of the current flooding situation. It is composed of 4 main parts:
- Live flood warnings — showing which flood alerts and warnings are currently in force
- 5-day forecast — flood risk outlook for the next 5 days
- River and sea levels — access to the Environment Agency’s river and tide gauges
- Long term flood risk — look at flood risk maps for an area
There is also a link to allow people to register to receive direct warnings from FWS.
FIS was launched in October 2015 and has seen a steady increase in users over the years. In November 2019 it received over 14,013,573 page views during the 14 days spanning the flood incident. This is by far the highest usage of the site since it was launched and meant that the Flood Information Service nearly surpassed 100 million page-views in total during the November flooding (this threshold was finally crossed on December 8th, 2019).
Most visitors to FIS in the November flood event were new users, with only 28.8% of website traffic being accounted for by return visitors. 23,350 visitors to the site in November got there via a clickable bit.ly link in the SMS alerting message sent to them by FWS. This represents the highest monthly utilisation of this functionality since it was introduced in January 2018.
Conclusions
The prolonged flood event of 7th — 21st November 2019 provided the largest test yet of FWS since its launch in April 2017. It is clear from the data that all the warning and informing systems and services were successful in processing messages quickly and delivering a good service to the public and our partner organisations across a range of platforms
- The systems processed large numbers of warnings very quickly and without any service disruption — customers there received their warning messages quickly
- All warning and informing platforms were robust with no major incidents or faults reported
- Many properties were warned through a variety of contact methods
This hasn’t happened by accident though and there have been a number of improvements delivered over the last 24 months which helped us during this flood event:
- Improvements to service components of FIS to make sure it can update quicker when flood alerts and warnings are issued and to cope better with greater volumes of traffic and activity
- We have made forecast river levels available at certain site on the ‘river and sea levels’ part of FIS, so communities can take action further in advance of potential flooding
- Upgrading our text to speech engine in the Flood Warning System to provide clearer messages via the telephone calls and IVR
- Integration of the GOV.UK Notify platform into the Flood Warning System for sending text messages meaning we can now get detailed information on the delivery status of our texts
- Introduction of Google Public Alerts as a new channel for sharing our flood warning information. We saw a marked increase in users coming to FIS from Google as a result of this work
- The addition of an IVR calling link in our text messages — allowing non digital users who receive a text from the Flood Warning System to instantly go to their relevant area in the IVR with a single click
We cannot rest on our laurels though and one item in particular we need to address is whether we still want to enforce the use of a telephone as a main way of receiving flood warnings. This has proven to be the least successful of the warning channels and poor data quality (i.e. invalid telephone numbers) can cause long delays in message completion. If we do continue to send messages to telephone numbers then we need to look at the data quality in FWS to maximise the success rate of this channel.
