Following an exceptionally dry and hot summer across Britain, the autumn and winter rains for most of England and Wales so far have been about one-third below the long-term average. Many reservoirs are at unprecedentedly low levels for the time of year.
In some areas of southern and eastern England which rely on borehole supplies the water table in the underground aquifers is falling - by this time of year it should be rising.
In a drought report to John Gummer, Secretary of State for the Environment, the authority identifies the Yorkshire, North West and South West Water companies as those whose supplies are most vulnerable.
The report says: ''It is essential to avoid any complacency or undue risk-taking on the part of the [water] companies.''
Late last summer almost half Britain's population was covered by hosepipe bans, many of which are still in place. It was the worst drought since the prolonged and severe shortages of 1976.
Several water companies are now applying for drought orders which would allow them to take extra water from rivers for their underfilled reservoirs during the winter, when river flows are highest.
Yorkshire Water, the worst affected, has several hundred road tankers ferrying in supplies to the worst-affected areas and has begun large-scale emergency engineering works to improve its water grid and reduce its mains leakage rate, one of the highest in Britain.The authority's report avoids explicit criticism of any companies.
The Water Services Association, which represents the big 10 water companies, called on the authority to be flexible in allowing it to take more water from rivers and boreholes.Reuse content