If you rely on a private water supply and suffer a flooding event, you should assume the supply has been contaminated and is not fit to use without boiling. Alternatively you could use a bottled water supply, but please refer to the advice of the Health Protection Agency on giving bottled water to infants. Even if you have a treatment system, it may be the contamination is so great (this may not be visible) and the treatment method may have been unable to cope with it. Therefore still treat the water as contaminated and boil accordingly. Testing may be required to assess quality.
On occasion, we experience periods of drought. This may cause groundwater levels to become exceptionally low which can affect private water supplies, for example springs sources and wells drying up or pumps running dry.
The Drinking Water Inspectorate (DWI) have summarised the Private Water Supply Legislation with regards to drought conditions detailing the responsibilities of the Local Authority, the local water company and the person(s) responsible for the Private water Supply. Should a domestic supply become insufficient you can contact the Local Authority or local water company for advice. Only when it is considered that there is a danger to life or human health is there an obligation to provide an alternative supply, in these circumstances the Local Authority has the power to require the local water company to supply water by means other than in pipes. Charges will be made for this service. In practice, owners of domestic supplies should approach their water company directly.
Owners or large and/or commercial supplies need to have their own arrangements in place for an alternate supply of water.