Fish distribution in a small domestic water supply reservoir: a case study of Kangimi Reservoir, Kaduna, Nigeria

A study of the composition and distribution of fish populations in the inshore, surface and bottom water habitats of Kangimi Reservoir showed that the most abundant family was the Cichlidae followed in order of abundance by the familiesCyprinidae, Schilbeidae, Mormyridae, Mochokidae, Characidae, centropomidae and Bagridae. Though the overall composition of families caught inn the three habitats did not vary significantly (P>0.05) only family Cichlidae showed habitat preference: there was a preponderance of Cichlidae in the inshore water habitat (P<0.05). The families Bagridae and Centropomidae were caught only in the inshore and bottom water habitats while the other families were caught from all habitats and showed no habitat preference. The dominance of primary and secondary consumers indicates high fish production potential under adequate management

Devil's Gate Reservoir and its effect upon Pasadena's water supply

[Intro.] The Devil’s Gate Dam has been of great benefit to Pasadena’s water supply, in that it prevents a large amount of the flood waters of the Arroyo Seco being wasted into the ocean.

Freshwater biology and water supply in Britain

This paper is designed to give a general account of freshwater biology as it bears on waterworks practice. Most water that is used for consumption will commonly go through a storage reservoir. Here special reference is given to the biological relations in standing waters, the biological control of water supplies, methods of plankton estimation, the biology of slow sand filtration and the use of algicides.

Current water supply conditions in California

This paper contains a brief report on the status of the California water supply situation on March 1, 1989, including a review of the antecedent conditions of the past two dry water years.

Water supply to a geotechnical centrifuge

The supply of water to a centrifuge experiment has always been important. This paper details a new system which has been successfully commissioned for use on the geotechnical centrifuge at University of Cambridge. High water pressures and large flow rates were delivered to an experimental package, for the modelling of water injection-aided pile jacking. The practicalities of such a system are discussed in relation to existing alternatives, in addition to the precautions taken to ensure safe centrifuge operation. A method for calculating water pressures in the system away from instrumented locations is also proposed, using a linear relationship between energy per unit volume and the flow rate squared. Experimental data are presented to support these relationships.

Water supply to a geotechnical centrifuge for pile jetting in sand

The supply of water is often required during a centrifuge experiment. For the case of pile jetting, significant flow volumes and pressures are required from the water supply. This paper aims to detail the successful provision of water at high pressures and large flow rates to a centrifuge, using a novel water supply system. An impeller pump was used to pressurise the water in advance of the slip rings, with further pressure provided by the fluid accelerating along the centrifuge beam arm. A maximum pressure of 2 MPa and continuous flow rate of 6 litres per minute were achieved. The calculation of water pressure away from the measurement location is presented, offering a repeatable solution for the pressure at any point in the pipe work. © 2010 Taylor & Francis Group, London.

Variation of microcystins in a lake for water supply

A site investigation was conducted to correlate the relationships between microcystins (MC) concentration and algal growth in Dianchi Lake in China. Laboratory experiments were undertaken to test the effects of sediment adsorption, photoirradiation and biodegradation on microcystins removal. Bioaccumulation of microcystins was also determined using silver carp fish. It was observed that MC concentrations varied in accordance with algae growth in Dianchi Lake. The results obtained in the laboratory demonstrated that the removal of MC with fresh sediments was less than 10%, photoirradiation removed more than 75% MC within two hours, and the biodegradation needed much longer time to produce substantial degradation of MC. The results suggest that bioaccumulation of microcystins in fish was not significant in Dianchi Lake.

The comparative advantage of the public sector in the development of urban water supply

This paper addresses the potential of public water operations in achieving developmental goals such as the Millennium Development Goals, and argues that the public sector has a comparative advantage in developing water services. The global importance of the public sector in urban water supply is examined through a review of current practice in the world's largest cities, including operational presence and distribution and ongoing trends. Empirical evidence shows that, in transition and developing countries, public operators are capable of undergoing successful reform. One explanatory factor is proposed to be the creation through the public sphere of highly interconnected networks among stakeholders. Such accountability networks act as vehicles for the generation and distribution of public knowledge among stakeholders, which in turn inform rational decision making on the reform and management of operations.