Backwater Valve Installation near you

An anti-flooding valve is passive. It costs nothing to run, needs no power, and protects against backflow from the sewer only. It does not protect against river, surface water or groundwater flooding, and while it is closed nothing can leave the property either — a point worth understanding before relying on one in a house whose only WC drains through it.

A pumping installation is active. Approved Document H calls for one where gravity drainage is impracticable or where protection against flooding due to surcharge in downstream sewers is required, and it is what the guidance points to for basements with sanitary appliances where the undertaker considers surcharge risk high. Packaged units for installation within buildings should conform to BS EN 12050 and be designed in accordance with BS EN 12056-4, and where foul water is pumped the effluent receiving chamber should be sized to contain 24-hour inflow to allow for disruption in service, with the minimum daily discharge for domestic use taken as 150 litres per head per day. It works when the sewer is full, and it fails when the power does.

Property flood resilience is the third category and a different problem: flood doors, airbrick covers, barriers, non-return valves on other openings, raised sockets and finishes chosen so water does not destroy them. Flood Re's Build Back Better initiative exists precisely for this, enabling householders to install property flood resilience measures up to the value of £10,000 when repairing their properties after a flood, through participating insurers. Ask your insurer whether your policy includes it before you buy, because each provider's offering differs.

Start with the undertaker. Approved Document H makes the sewerage undertaker's assessment of the extent and possible frequency of the likely surcharge the input that determines whether a valve or a pumped system is appropriate, and water companies hold the flooding history for the sewer in your street that you cannot see from the garden. Some also run their own property-level protection programmes in areas with a record of sewer flooding, so ask what they will do before you commission anything.

Then establish what you own. The Consumer Council for Water sets out that homeowners are responsible for repairs to drains that serve their property and lie beneath the property, garden or driveway, while wastewater companies are responsible for the large sewers normally found under the road or pavement and for shared pipework connecting to a public sewer. A valve goes on your drain; anything beyond the point where responsibility transfers is not yours to alter.

The installation itself is drainage work: an inspection chamber or a new chamber on the run, the valve set so it is accessible for inspection and so the manual closure can actually be reached, the notice fixed inside the building as the guidance requires, and the unaffected parts of the system left to discharge by gravity past the valve. A CCTV survey of the drain before the work is worth paying for, because a valve installed on a drain that is itself broken or root-filled treats the wrong problem. LokalMatch handles the introduction and nothing beyond it: set out the property, what has backed up and your postcode once, and drainage firms covering your area respond directly, having paid for the request. LokalMatch installs nothing, influences no prices, and does not vet, rank or endorse the businesses that reply, so the survey, the undertaker's assessment and the building control question remain yours to pin down.

There is a statutory scheme behind sewer flooding in England and Wales, set out in the Water Supply and Sewerage Services (Customer Service Standards) Regulations 2008 as amended. It starts from a flat rule: effluent from a sewer vested in a sewerage undertaker must not enter a customer's building.

In England, for incidents from 2 July 2025, the amended regulation 17H requires the service provider to pay, for each incident of entry, the lesser of the sewerage charge amount and a maximum payment amount. The sewerage charge amount is the greater of the customer's sewerage charges for the following twelve months and a minimum payment amount of £300, and the maximum payment amount is £2,000. Both figures escalate for repeat incidents within the relevant period — the minimum rising by £100 and the maximum by £500 for each previous incident already paid for in the preceding twelve months.

In Wales, regulation 11 still applies to Welsh undertakers in its earlier form: for internal flooding the undertaker must pay the lesser of a sum equal to the customer's sewerage charges for the financial year and £1,000, with a floor of £150. Regulation 12 covers external flooding of land or property, at the lesser of 50% of the annual sewerage charges and £500, with a floor of £75, claimed within three months. In both nations there are exclusions — notably where the entry was caused by a defect, inadequacy or blockage in the customer's own drain or sewer. These payments are a customer service standard, not compensation for the damage; that is what your buildings insurance is for.

Stop using water in the property, because every flush and every basin of washing-up adds to what is trying to leave through a drain that is already surcharged. Keep people and pets away from the contaminated area, and if water has reached electrics, switch off at the consumer unit and do not touch anything wet.

Report it to your sewerage undertaker the same day, by phone, and note the time and the reference. Under the customer service standards regulations the entitlement to a payment can depend on claiming within three months of the effluent entering the building or the land, so the record matters. Photograph the extent of the water before anything is cleaned up, for both the undertaker and your insurer.

Then let the cause be established before the repair is designed. Approved Document C notes that flooding can create blockages in drains and sewers that lead to backflow of sewage into properties through low level drain gullies and toilets, and a house that has backed up once will usually back up again in comparable rainfall. A valve is often the right answer, but only once someone has confirmed the water came back from the sewer rather than out of a collapsed drain of your own.

Flood Re is the reinsurance scheme that sits behind household flood cover in the UK. It is funded by a levy on every insurer offering home insurance here, raising £160m every year, and it applies a standard excess of £250 for each policy ceded to it, with the premium charged to the insurer fixed by council tax band. Eligibility is set by criteria rather than by postcode: among other conditions, the property must be in a domestic council tax band A to H or equivalent, used for private residential purposes, insured on an individual basis, and built before 1 January 2009.

That date is the one that catches people out. A home built on or after 1 January 2009 is outside the scheme, which is deliberate — the intention is not to underwrite building in flood-prone places. Prices, excesses and terms are still set by insurers, not by Flood Re.

Sewer backflow is not the same peril as river or surface water flooding, and policies treat them differently, so read the wording rather than assuming. Where you have installed protection, tell your insurer: it is evidence of the risk being managed, and where Build Back Better applies, resilience measures can be funded up to £10,000 as part of repairing flood damage rather than being an out-of-pocket improvement afterwards.