From Ickham & Well Parish Council Flood update Wednesday 12 February 2014
Summary – At 12.15pm from the EA.
The EA are currently being positive.
The relief channel was designed for a 3 to 1 split with the Little Stour but is working so well it’s currently a 50/50 split. In order to keep the Little Stour at its maximum the main channel could work better if a board went back into the relief channel. This would give more flow and, apparently, not more volume. A panel has also been taken off at Ickham Mill to give a better flow.
This means that with the rain that we are expecting there is capacity in the relief channel that can kick in.
The ramps in the road have also been removed at Wickham Lane and this is flowing much better over the road. With all these changes things are still being monitored with teams measuring flow etc along the river. The EA say that if they can keep it traveling we should be fine, and that they are trying to avoid any pinch points and blockages being created.
From the EA and their website
Expecting further rain, starting at 1pm for 4 hours. Fairly heavy 10-15mm, some heavier bursts in that front so it may be higher. This will have an impact on surface water and levels are staying high and not receding. They are expected to increase over next few days.
Isolated showers tomorrow, but 5-10mm only, then more on Friday/Sat. This will be significant (10-25 mm) and groundwater will increase.
Groundwater levels at the head of the Nailbourne valley are at an historical high. Spring systems will begin to emerge within the next 24 to 48 hours in Wickhambreaux and Littlebourne as spring activity moves down the Nailbourne valley flooding the low lying areas. The Environment Agency along with KCC, CCC , KFRS and Kent Police have constructed sandbag walls to reduce flood risk at Bridge, Barham, Littlebourne and Wickhambreaux. These temporary defences are at full capacity. We anticipate that approx 20 properties could flood over the next few days in these locations. This will be a gradual process as levels rise slowly. Be aware that any heavy rainfall will exacerbate and prolong the situation. We continue to work with our partners to coordinate the deployment of temporary defences, pumps and staff.
Keep groundwater out
If your property could flood through the ground, a pump will be the best way to keep water out. Other methods such as sandbags will be ineffective because water comes up through the ground. You are likely to have to pump water for days, weeks or months. Pumps work best when the inlet is installed in a low point where water can drain (a sump).
Pumps can be electric or petrol/diesel. Electric pumps may be the most convenient, but you will need to take care using an electric pump near floodwater. You may need a back up generator in case of power cuts during a flood. Contact a qualified electrician for further advice. Petrol or diesel pumps can be noisier and will require refueling. Position the generator outside as generators produce carbon monoxide fumes which can kill.
Only pump out water when flood levels outside your property are lower than inside to reduce the risk of structural damage. Contact a structural engineer before pumping very deep water from basements.
A good quality pump should last around 10 years. However, this depends on how often it is used and the acidity and dirtiness of the water. Regularly check and test your pump. Remove and thoroughly clean the pump at least once a year. Disconnect the pump from the power source before you handle or clean it.
Pumping from one place to another may cause flooding elsewhere. You must not pump water into the public foul sewer. When deciding where to pump water, you should contact:
- your local Environment Agency office if you are thinking about pumping water into main rivers or boreholes
- your local authority if you are thinking about pumping water into ditches, watercourses or piped watercourses
- the water company if you are thinking about pumping water into public surface water sewers or foul sewers
- the Highways Authority if you are thinking about pumping water into a highway drain
Reduce flood water damage
Prepare your property in advance to reduce the damage floodwater might cause inside, making drying out and cleaning up quicker and easier.
- Shelving: keep irreplaceable or valuable items on high mounted shelves.
- Home entertainment: fix your audio-visual equipment such as your TV and hi-fi to the wall, about 1.5 metres above floor level.
- Skirting: fit water-resistant skirting boards or varnish wooden ones.
- Walls: use horizontal plasterboard or lime-based plaster to dry-line, instead of gypsum. Get a special draining system for cavity walls.
- Floors: lay tiles with rugs rather than fitted carpets.
- Internal doors: fit synthetic or waxed doors, or make sure wooden doors are easy to remove before a flood.
- External doors and windows: install synthetic or waxed windows and doors, or varnish wooden ones.
- Kitchen and bathroom: use water-resistant materials such as stainless steel, plastic or solid wood rather than chipboard. Where possible raise fridges and other appliances on plinths.
- Electricals: raise electrical sockets, fuse boxes, controls and wiring to at least 1.5 metres above floor level. If re-wiring, bring cables down the wall to the raised sockets so cabling isn’t affected by flood water.
- Large items: buy extra large, sealable bags that you can use to protect items that are difficult to move such as electrical goods and sofas.
Reduce groundwater damage
If your property could flood from groundwater, there are things you can do in advance to reduce damage.
Fit a pump in a basement or under-floor void so you have a way to extract flood water. This will also help to dry out the property .
A reinforced concrete floor with a continuous damp proof membrane can be effective where groundwater pressures are low. Take particular care where the floor and the walls join as water can penetrate through this point.
If there’s enough headroom, you could raise the floor level either by laying a reinforced concrete floor directly onto the existing floor or by creating a suspended floor. Remember that water exerts considerable pressure: a 300mm depth (1 foot) of water pressure will lift a 125mm thick (5 inch) concrete slab. It’s this pressure that makes groundwater flooding difficult to prevent.
Suspended floors create a void beneath the floor which will flood before water rises to enter the house. They may be built from timber or concrete, but flooding beneath wooden floors will often cause the timber to rot so get specialist advice before carrying out this work.
Basements are prone to flooding and it’s difficult to prevent. ‘Tanking’ materials are available, but these are best applied on the outside walls. This is often impractical and you may have to construct an inner wall. Specialist advice is strongly recommended. Sealing the walls can lead to an increase in water pressure which may cause structural damage.
Foul sewage is the waste from sinks, baths and toilets, which often backs up and causes problems during groundwater flooding. What you can do to prevent sewage flooding depends on your system.
Main drainage systems: Report any flooding problems with main drainage systems to the water company or housing association that operates them. For further advice you can also contact Ofwat, the economic regulator of the water and sewerage industry. If you have a continuing problem with sewage flooding which the authorities are unable to solve, you can try fitting non-return valves. Get guidance on these from the Construction Industry Research Information Association (CIRIA).
Septic tanks: These frequently have problems when groundwater levels rise. You may need to hire portable facilities. Adding a pump to the outlet side of the tank may help keep your system working and pump the sewage to high ground above the groundwater table. You must contact the Environment Agency if you want to do this as you will need a consent to discharge. The design of pumped sewerage systems is complex and you should always seek specialist advice.
Cesspits: If these are well built, they should not be a problem. Rising groundwater will test the integrity of the structure and small leaks may occur which will quickly fill the tank. Be aware that if you call a tanker to empty a septic tank or cesspit when the toilet will not flush, but the tank has not been installed with a sufficient concrete surround, there is a risk it could float the tank or it will quickly fill with groundwater.