Subsidence watch 2018

With locations around the world tracking record-setting temperatures and hazardous drought conditions persisting in places such as the Pacific Northwest, Scandinavia and parts of Australia, where the drought has been considered to be among the worst the continent has endured, it should not be surprising to hear we are experiencing what may be the fourth hottest summer to ever be recorded. Unfortunately, this continuous heat and abnormally dry weather has resulted in dangerously dry soil conditions.

Across Europe, and particularly in the UK, the market is looking toward a possible subsidence surge event thanks to the dry, warm weather of 2018. Above-average temperatures have made this provisionally the third warmest June and July for the UK in a series from 1910. Rainfall was 48% of average, and most notably well below average over most of England and Wales with less than 10% of average in some southern counties: looking at June statistics for England, it was provisionally the third-driest in a series from 1910.

Subsidence becomes an issue, especially for properties in clay soils near trees, when loss of moisture in the soil causes it to dry and shrink. Instability in the soil and the resulting ground movement can lead to movement of building foundations. With shifting foundations comes the potential for property damage. The current weather trend and the possibility of subsidence is a great concern in places like London, with many of the city’s homes constructed on clay.

Whether or not 2018 becomes a subsidence surge year, however, is dependent on if weather trends continue throughout August. Data from the UK’s Meteorological Office Rainfall and Evaporation Calculation System (MORECS) shows the biggest changes we have seen for several years, as the effect of the prolonged dry, sunny weather has started to show in monitoring readings. MORECS readings increased sharply from June through mid-August, rising from under 100, hitting a peak last week of 302.5, and dropping slightly to the current 298.5. Looking at previous surge years of 2003 and 2006, the current position shows the soil drier than it was in 2003, but not quite as high as the surge of 2006, where we saw the maximum reading of 305. A surge event will be dependent on how long the MORECS remains at this maximum level: in 2003 we saw the maximum readings for seven consecutive weeks and 2006 for four weeks. For this to be repeated in 2018, the weather will need to remain dry and warm throughout August and into September. If we see cooler and wetter weather this month, then readings are likely to fall and surge volumes will not materialize.

With this weather pattern forecast to continue, especially in southern areas of the UK, we estimate that claim volumes will also continue to rise for the next few weeks; however, we remain watchful. With live remote crack monitoring in place, feeding back data every eight hours, we are able to anticipate claim volumes before they occur, along with tracking soil conditions, level monitoring readings and long-term weather forecasts. We’ve pulled together the soils and weather information to help predict volumes for this year; click here for our full report.

Our subsidence team in the UK is available to provide guidance, support and solutions. If you have questions, please contact me at kevin.williams@cl-uk.com.


References:

> CNN: 2018 is on pace to be the 4th-hottest year on record

> Quartz: The global heat wave as seen by satellites, airplanes, and weather stations

> European Drought Observatory (EDO): Drought in Central-Northern Europe – August 2018

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