Rivers, Canals, Ponds, Lakes, Reservoirs and Water Mains

Abstract

Urban water provides some elegant examples of how man, by carrying out his normal day-to-day activities and making himself comfortable in his environment, can comprehensively alter an ecosystem. As usual, certain species are eliminated by urban influences, others are strongly favoured by them while a few groups appear unaffected. Hydrologists are able to provide a broad picture of the physical and chemical aspects of water flow in urban areas (Douglas, 1983; Hall, 1984; Lazro, 1979), but there are only patchy biological data to complement this. Reviews of urban aquatic ecosystems are provided by Hynes (1960) and Whitton (1984), while at a natural history level Teagle (1978) and Kelcey (1985) have collected a certain amount of information. Given the ‘state of the art’, a fully integrated treatment of this habitat is not possible, so the general principles of urban hydrology will be outlined followed by a range of examples which illustrate the special ecological relationships that characterize urban rivers, canals, lakes, ponds, reservoirs and water mains.