King's Lynn Sewer Improvements

King's Lynn is a typical English port and market town, located at the edge of the very flat fenland area in East Anglia. The town doubled in size to its present population of 40000 from the end of the Second World War. Although the sewerage system expanded with the growth of the town, the prevailing flat gradients gave rise to much sedimentation and loss of capacity, while tide-locked outfalls restricted freedom of flow from the storm-overflow facilities. The result was widespread flooding in many areas of the town during relatively minor storms. This paper describes the studies which were carried out using computer simulation methods to identify the weaknesses and deficiencies of the complex sewerage system, and the innovative tunnelling solution which was adopted to overcome the problems. An indication is also given of the benefits of good public relations when working across the urban environment.     

National Rivers Authority National Strategy and Planning for the Future

The protracted drought from 1988 to 1992 has focused attention upon the availability of water sources in England and Wales. The drought was most severe in the east and south-east parts of England, which also coincides with the areas having (a) the least available water resources, (b) the greatest forecast increase in demand, and (c) the majority of low-flow problems due to excessive authorized abstraction. Even with increasing attention being paid to demand management, there is a need to develop further water-resource schemes. Once local options have been developed it is likely that inter-basin transfers will be required.     

Main Drainage Design for the New Kuala Lumpur International Airport

The new Kuala Lumpur International Airport in Malaysia requires substantial works for the management and attenuation of surface-water runoff from a large platform constructed on both high ground and low-lying swamp. This paper describes the key features of the main drainage system and reviews (a) the hydrological context of the scheme, (b) the design principles, and (c) the methodologies which were adopted. The platform drainage works comprise concrete-lined open channels discharging through large balancing ponds into the local rivers. Other components of the scheme include numerous culverts, a river diversion, and an interim system to drain the earthworks'platform prior to completion of the permanent airport drainage. Measures to mitigate the impact of the development, and the application of hydrodynamic modelling in optimizing the system design, are discussed.     

Hydraulic Performance of Environmental Features in Rivers

From 1986 to 1992 a drainage improvement scheme was undertaken on the River Blackwater, Northern Ireland, following which the Department of Agriculture (for Northern Ireland) carried out a programme of fishhabitat reconstruction in an attempt to restore the river's depleted stock. Over three hundred sites were refurbished by introducing pools, spawning and nursery areas.
This paper investigates the hydraulic performance of the refurbished habitats, with particular interest in the roughtness characteristics of the incorporated features.     

KNOWLEDGE-BASED SYSTEM ON WATER-RESOURCE MANAGEMENT IN COASTAL WATERS

Computers which are used conventionally in numerical models for problem-solving and fast number-crunching are not user-friendly and lack knowledge transfer in model interpretation. Recent advances in artificial intelligence make it possible to systemise the experience and decision-making procedures of human experts. This paper describes the development of a prototype knowledge-based system (an advanced technique of artificial intelligence) as a knowledge-transfer tool for water-resource planning and management in coastal waters. The system can (a) run on a desktop computer and (b) act as a design aid, to assist in numerical modelling to simulate flow and/or water quality. Using the application in Hong Kong coastal waters, it was verified that the prototype system had the capability to undertake the reasoning process to select the model and associated parameters, equivalent to a human expert.     

A REVIEW OF THE DANGEROUS SUBSTANCES AND EXPLOSIVE ATMOSPHERE REGULATIONS IN RELATION TO THE WATER INDUSTRY

This Technical Note presents the impact on the UK water industry of the Dangerous Substances and Explosive Atmosphere Regulations which became law in December 2002. These regulations introduce (into UK legislation) the requirements of a number of European Union Directives, including the Chemical Agents Directive and ATEX Directives dealing with potentially explosive and hazardous situations. The impact of the Dangerous Substances and Explosive Atmosphere Regulations on thermal-drying installations is relatively clear. However, there are potentially greater and far-reaching implications for the UK water industry.     

PRACTICAL METHODOLOGY FOR DETERMINING THE SIGNIFICANCE OF IMPACTS ON THE WATER ENVIRONMENT

There is currently limited guidance available in the UK for predicting the significance of the impacts of developments on the water environment. This may be partly due to the disparate nature of the components of the water environment, which are covered by a range of scientific and engineering disciplines. This paper reviews the current status of Environmental Impact Assessment for the water environment in the UK and identifies key methodologies and guidance. Proposals are made for a more detailed approach to determining the significance of impacts on rivers, stillwaters (lakes and ponds), groundwater and floodplains, building on methodologies previously developed for highways schemes. Account is taken of the Environment Agency's ongoing work to classify water features to meet the requirements of the Water Framework Directive.     

Health Impacts in Developing Countries: New Evidence and New Prospects

This review of recent studies of the health impact of water supply and sanitation programmes in developing countries shows that they share many findings, and some methodological problems, with older studies of the subject. Considerable health impacts can occur under appropriate conditions, and it is suggested that the greatest impact can be produced by targeting water and sanitation facilities to those whose existing water sources are furthest away, or whose environment is most faecally polluted.
Another finding is that health benefits stem from the changes in hygiene behaviour which water and sanitation make possible. The measurement of such behavioural changes is a subject in need of development. Nevertheless, it is likely to be easier, more reliable, and more useful to water and sanitation programme managers as an operational evaluation tool than any attempt to measure the health benefits directly.     

A Standardized Low-Cost Low-Flow Gauging Station

This paper describes the origins and development of a simple, low-cost, low-flow stream gauging station to meet the operational requirements of a major water resource management system. The utilitarian design uses standardized, prefabricated components in order to achieve maximum economy and ease of construction without sacrificing durability or hydrometric accuracy.     

Performance of Fabric-Protected Slow Sand Filters Treating a Lowland Surface Water

The performance of slow sand nitration can be; substantially improved by the application of a non-woven synthetic fabric layer to the surface of the sand. By means of pilot-scale experiments, using the i River Thames as the source water and pretreatment by sludge blanket clarifiers, the comparative performance of fabric-protected slow sand filters has been evaluated over an eight-month period. Under conditions designed to simulate poorly-controlled pretreatment, a correctly-specified fabric type, configuration and thickness can extend filter run times by a factor of 3–5 compared to a conventional slow sand filter. Furthermore, this can be achieved, together with the avoidance of any significant change in the hydraulic behaviour of the underlying sand, thereby avoiding the need to remove and clean sand. Fabric washing is relatively simple and efficient.