Flood ahead

Flood Ahead

After the drought that affected much of the country over the summer, the autumn, so far, has been incredibly wet.

This brings two significant risks for us:

  1. Road Conditions
  2. Diffuse Pollution

Road Conditions

Driving in wet weather requires us to slow down, be more cautious, and use a different way of controlling the vehicle with a much gentler use of the accelerator, brake and steering systems.

Delay your journey if you expect very bad weather but if you must drive, remember the following:

  • Wet shoes can slip off pedals. Dry them on your floor mats before you set off.
  • Don’t follow large vehicles closely as their spray will reduce your visibility.
  • Keep your windscreen demisted as you drive.
  • Avoid using cruise control; it slows your ability to control the vehicle.
  • If you go into a skid, take your foot off the accelerator and steer in the direction you want to go in.
  • Turn your headlights on but don’t use your rear fog lights as these can dazzle the driver behind you. Avoid using your main beam as this can reflect back at you off the rain.
  • The glare from lights at night can be amplified by rain on the windscreen, making pedestrians harder to spot. Be aware of the limits to your visibility and adjust your driving style accordingly.


When water on the road accumulates under the tyres quicker than the weight of the vehicle can push it away, the vehicle can start to aquaplane. The water pressure causes the vehicle to sit on a thin layer of water and within seconds you can lose control of your vehicle.
There are three factors that cause aquaplaning:

  1. Vehicle Speed – aquaplaning is more likely to happen at speeds over 40 mph.
  2. Tyre tread depth – the more worn the tyre, the more likely you are to aquaplane.
  3. Water depth – the deeper the water, the more likely you are to lose traction.

At 60mph in moderate rain the tyre needs to displace between 4-5 litres of water every second and the tyre is only contacting the road for 1/150th of a second so it has a lot of work to do. Other factors that affect the propensity of a vehicle to aquaplane include:

  • Vehicle weight – the lighter the vehicle, the more likely it is to aquaplane.
  • Drivetrain – an all-wheel drive vehicle is more likely to aquaplane than a two wheel drive vehicle in certain conditions.
  • Tyre size, pattern and incorrect pressure also affect the likelihood of aquaplaning.

Watch the road ahead for standing water  and, if your steering starts to feel loose, you  may be starting to aquaplane. Once you  find your vehicle aquaplaning don’t apply  your brakes or turn your steering wheel.  Instead, take your foot off the accelerator  and let your vehicle slow down. If you do have to brake, use a gentle pump action.


Do not attempt to drive through water if  you are unsure of the depth. According  to the AA, a third of flood-related deaths  involving  a  vehicle  occur  because  the  driver has taken unnecessary risks. Last  year, it rescued almost 9,000 vehicles that  had driven through or were stuck in flood  water, with an estimated insurance bill of  more than £34 million.

Vehicles  can  quickly  become  unstable  in moving water – about 30cm of water  moving at only 6mph is enough to float  the average-sized family car.

Where the risk of flooding comes from rivers or the sea, you’re likely to get some advanced warning from the Environment Agency, but surface water flooding resulting from heavy rain combined with  drains that cannot cope is much more difficult to predict.

Plan your journey to avoid areas that could be prone to flooding. Factor in extra time for travelling so congestion does not put you under time pressure. Research suggests that time-pressurised drivers are nearly eight times more likely to be impatient, which may then lead on to speeding and greater risk-taking.

Safety & Assurance Bulletin December 2022

Vehicle Checklist

1. Bulbs

Check your lights regularly to make sure they’re in a good condition and replace any failed bulbs as soon as you spot them.

2. Wiper blades

Signs that your blades might need replacing include if they leave smears or make a noise while moving, or if they’re not clearing the whole of your windscreen. Check for any splits in the blade or missing pieces of rubber as that’s another indication that it’s time for a change.

3. Battery

Lower temperatures slow batteries down and reduce their ability to hold a charge. Batteries naturally lose charge over time. You need to be making journeys of at least 30 minutes for your car to effectively charge your battery.

4. Tyres

Keep an eye out for any glass, nails or screws that might cause a puncture. The tread depth should also be within legal limits (1.6mm) and the pressure should match whatever numbers are listed in your car’s handbook.

5. Oil level

Remember to regularly check your oil levels. Your oil cleans, cools and protects your engine – helping to keep it running smoothly and to maintain the life of your vehicle.

Tackling flooded roads:

  • Do your best to estimate the depth of the water. Parking up and watching other cars and trucks negotiate the flood can be a good way of checking to see how deep it is.
  • Drive slowly and steadily through the water and try to avoid creating a large bow wave.
  • If a puddle gets deeper than the bottom of your car doors, do not proceed, as the water levels may cause serious damage to the vehicle.
  • Do not drive in water that downed electrical or power lines have fallen in – electric currents pass through water easily.
  • If you have driven through water up to the wheel rims or higher, test your brakes on a clear patch of road at low speed at the earliest opportunity. If they are wet and not stopping the vehicle as they should, dry them by pressing gently on the brake pedal with your left foot while maintaining speed with your right foot.
  • Keep your revs high and your speed low and don’t stall the engine. The exhaust gases will stop the flood water getting into the exhaust pipe.
  • If your vehicle does stall in deep water you may need to restart the engine to make it to safety. However, restarting the engine may cause irreparable damage, particularly if water has egressed into the combustion chamber, so if it’s safe to do so, wait for professional help to arrive.
  • Stay in the centre of the road if possible where the tarmac is at its highest point.
  • Be wary of flood water washing away the tarmac road surface.

Diffuse Pollution

Diffuse Pollution is one of the keys risks that can occur on our sites over the winter months. The current pattern of extreme rain events can saturate a site in just a day or less.

We risk assess our sites for the potential for diffuse pollution, put mitigation in place and have an industry leading training programme for managers and operators.

But the most effective tool in our armoury is to STOP WORK. If a site is getting saturated, or the ground is getting churned up then the best thing to do is stop before it becomes a problem and talk to your Forest Works Manager. It is far easier to plan while the situation is under control, than whilst siltation is running off site into a watercourse or private water supply.

All machinery operators working on Tilhill managed sites should have completed our Diffuse Pollution training, including standing sales on our managed properties.

Requesting Access to the Training: Scan this QR Code to register for access to the training. You can also request access by emailing: ios@tilhill.com

Safety & Assurance bulletin December 2022