asked Her Majesty's Government:Whether they agree with the estimate of a figure between £875 million and £3,286 million as being required for remedial work on sewers in Britain within the next two years and, if not, what is their own estimate of the requirement; what is their estimate of the sums that need spending on underground gas pipes within the next two years; what is their estimate of the sums that need spending on water mains; whether they intend that these repairs should be carried out and, if so, to what extent; whether traffic heavier than that for which the sewers and pipes were designed is reponsible for accelerating the decay of the pipes and, if so, what steps they are proposing to take to reduce the sum of public money spent on avoidable damage.
Responsibility for the assessment of the condition of underground services and the preparation of programmes of renewal lies with the water authorities in England and Wales for water mains and sewers and with British Gas Corporation for gas pipelines. The latest five-year plans of the water authorities, published earlier this year, give no indication of the need to spend sums of the order of £875 million to £3,286 million in the short term on sewer renewals. The National Water Council's appraisal of the aggregate capital programme for all water services suggests that 38 per cent, of annual expenditure—that is, about £230 million—is spent on renewal works. There is no separate breakdown of renewal expenditure on water mains and sewers within this total. The council concludes that, in many areas, current investment on renewal and renovation of sewers appears to be of the right order to maintain present levels of service and to deal with any serious cases of deterioration.However, in some areas, there may be a need to increase this type of investment, for example, substantially, in the case of the north west where the problem is most serious. The required level of renewal investment over the next few years will be reviewed and revised as the water authorities gain more information on the condition of their assets. Expenditure by the Gas Corporation on renewal of pipelines is partly from revenue and partly on capital account, and the gross annual rate of spending is considered to be adequate in relation to needs. Again, there is no apparent need for any sudden increase in the rate of renewals in the near future.Increase in traffic intensity is only one of the factors which affect the rate of decay of underground services. The responsible authorities have a substantial programme of research and survey work under way to determine the present condition and rate of deterioration of such services, but it is too early to say what the results might show will be necessary in the way of future annual maintenance and renewal costs.