To ask the Secretary of State for the Environment what is the estimated total length of riverways and total surface area of freshwater lakes administered by each of the English regional water authorities.

The lengths of rivers administered or controlled by water authorities vary for different functions and responsibilities. For example, the lengths of designated main rivers under the English water authorities' management for the purposes of the Land Drainage Act 1976 are:

Authority	km
Anglian	6,518
Northumbrian	1,459
North West	5,807
Severn Trent	3,548
Southern	2,757
South West	1,465
Thames	5,072
Wessex	2,242
Yorkshire	1,806
Total	30,674

The lengths of rivers surveyed for the purposes of the river quality survey 1985 were:

Authority	km
Anglian	4,328
Northumbrian	2,784
North West	5,323
Severn Trent	5,150
Southern	1,992
South West	2,941
Thames	3,546
Wessex	2,467
Yorkshire	5,767
Total	34,298

Information about the surface areas of freshwater lakes within a particular water authority's area would only be obtainable from the water authority in question.