In March 2000, a document entitled Draft Regional Planning Guidance for the South East was published with the primary aim of providing a regional framework for the preparation of development plans to the year 2016. This paper discusses the potential effects for the water industry of SERPLAN’s predicted levels of housing growth on water resources, sewage treatment and the environment. The need for sustainable development with the competing pressures of water‐resource limitation, changing regulation, increasing demand and the environment, are discussed. Thames Water’s scale of operations is described together with the range of measures aimed at managing the reasonable demands of customers, consistent with achieving sustainable growth. Basingstoke is described as a wastewater case study, highlighting the problem in fulfilling the sewerage undertaker’s statutory duties in (a) meeting already stringent effluent‐treatment standards which are necessary to maintain and improve river quality, and (b) providing the necessary infrastructure for an area which is earmarked for continuing development.

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In recent years the requirement for carp in the U.K. has escalated, mainly due to the restocking market. This demand cannot be met from mainland Europe because of import restrictions and home production has increased. Freshwater coarse fish farming has been historically unimportant in Britain and few scientific data exist for pond culture under British conditions. In general, continental guidelines are followed but the growing-on ponds are smaller. The climate and the nature of the sites have often resulted in unreliable spawning. First year survival and growth tends to be poorer but growth rates in the second year are comparable. Carp for restocking (c. 300 g) can be reared in 2 years and carp for the table (c. 1000 g) can sometimes be produced in 3 years. Levels of production, however, compare favourably with more traditional carp culture, up to 480 kg ha-' per year using extensive cultivation and up to 2200 kg ha-per year with intensive rearing and pelleted foods. The sites in Britain for which data exist have, however, been eutrophic in contrast to the more mesotrophic sites on the mainland. This apparent difference in base line productivity may explain the relatively good production performance so far in Britain.

Carp feeding trials were conducted to assess dietary effectiveness in relation to growth rate, cost, conversion ratio, logistics and the contribution of natural pond foods. Overall, trout pellets containing 40% protein were found to be the most effective. In laboratory trials this diet fed at 5% bwd~' produced a food conversion ratio (FCR) of 1-99. Another trout food containing 477o protein, fed at the same ration, had a superior FCR and specific growth rate (SGR) but proved more costly because of a poorer protein efficiency ratio (PER). Optimum ration size declined with increasing body size. The mammalian herbivore diets, with higher carbohydrate but low lipid levels, were cheaper to purchase but had poorer SGRs and FCRs. Some evidence of protein sparing occurred with low levels of activated sludge substitution but condition and growth rate declined above the 20% substitution level probably due to increasing heavy metal concentrations. In the pond trials extensive production levels of 300-350 kg ha" 'year^' arose from zooplankton consumption. The associated SGR was around 1-70 and the FCR was calculated at 1-64 (dw) assuming 47% utilization of the zooplankton. Higher levels of production (1400-2200 kg ha~'year~') occurred with supplementary feeding with SGRs at 1-78-2-35. The contribution of natural food was slight in intensive rearing. An FCR of 2-01 was found with trout pellets and an estimated 6-3 with barley.

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