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Presents a study designed to create a water quality monitoring network for the Keelung River in order to evaluate the effects of artificial cutoff across two bend channels. Use of a steady-state water quality model to simulate the BOD and DO curves; Application of the Kriging theory was applied to select the optimal locations for a water quality monitoring network.

Focuses on high rate algal ponds (HRAP) with a filamentous algae matrix (FAM) as the predominant species, which were operated to evaluate the characteristics of FAM and the basic design parameters for treating polluted rural stream water. How the porous and gelatinous FAM was formed like a sponge, which functions to prevent excessive loss of the algae in the effluent and can easily be retrieved from the ponds.

Discusses the state of the art of quantification of sources, pathways and sinks of nutrients in the Danube Basin and their transport from the catchment to the Black Sea. Results of emission estimates to surface waters and the Danube Water Quality Model approach to link these emissions estimates to measured water monitoring data; Quantitative synthesis of available knowledge regarding the fate of nutrients in the Danube Basin.

Evaluates non-point sources pollution impacts using a fast methodology for catchment land-use identification and waste load estimation in the watershed area of the Kao-Ping River in Taiwan. Components of the methodology; Classification of land-use patterns; Improvement of pollution prevention and control.

Presents a web-based decision support system (DSS) for the sustainable management of an urban river system in southern Taiwan. Capability of the DSS to perform normal queries and statistical analysis in a web-enabled database; Achievement of the rehabilitation of the estuarine ecosystem; Satisfaction of the goals for sustainable management in a regional sense.

Examines the significance of Project CARE, a program developed to improve the separated wastewater and stormwater systems in order to protect the streams and beaches in North Shore, New Zealand. Public outcry on frequent beach pollution caused by wet weather sewer overflows; Utilization of a cost optimization model; Exploration of options for improvement.

Studies the legal and administrative arrangements for river health in the Kangaroo River in New South Wales. Water quantity and quality; Water management plans; Catchment strategies.

Describes the ecological condition of arid-zone rivers in central Australia. Water chemistry; Periods of hydrological isolation; Maintenance of ecological integrity.

Describes a water planning approach to the determination of environmental needs in regulated river systems in Australia. Sustainable sharing of surface and groundwater resources between the environment and consumptive water use; Water allocation; Water management.

Examines the opportunities for sustainable riverine management in the Queensland Murray-Darling Basin. Riverine management projects; Improvement of the condition of river systems; Implications for policies on water management.

Describes the application of sensitivity analysis and auto-calibration of an integral dynamic model for river water quality. Extended Soil and Water Assessment Tool; Application to the river Dender in Belgium.

Evaluates the pollutants loading characteristics in the Lake Biwa watershed in Japan through comprehensive surveys on river mouths and forest sites, and discovers unit loading factors for main pollutants in dry weather conditions. Quantitative comparison of forests and other areas; Nutrients loading; River mouths.

Describes the application of an automatic sampling and measurement system to a mountainous stream investigation during rain events. Efficient gathering of water samples; Testing of the system in a stream in a forested watershed; Water quality.

Describes real-time water quality monitoring and regression analysis to estimate nutrient and bacteria concentrations in Kansas streams. Fecal coliform bacteria; Nitrogen; Phosphorus.

Studies runoff characteristics of pesticides from paddy fields in Japan and reduction of risk to the aquatic environment. Biodegradation; Biofilm; Passing downstream; River water.

Studies runoff characteristics of particulate pesticides from paddy fields in the Koise River in Japan. Particulate pesticide concentrations in river water.

Describes the prediction of pesticide concentrations in river water with a hydrologically calibrated GIS-based basin-scale runoff model. Hydrograph; Pollutograph; Hydrological diffuse pollution.

Determines if the concentrations of pesticides measured in U.S. midwestern streams during the spring and early-summer runoff events in 1998 were at levels that maybe toxic to non-target aquatic organisms. Potential toxicity of pesticides.

Presents the results of an experimental work undertaken in a stream in Portugal, with the main objective of characterizing stormwater quality in drainage systems. Prediction of the effects of the performance of partially separate sewer systems on receiving waters; Integrated management; Urban stormwater.

Focuses on stormwater detention facilities which led to a significant drop of the pollution originating from stormwater runoff in the river basin of the Ruhr in Germany. Costs; Hydraulic load; Pollution load.

Discusses sustainable rainwater management in the Emscher river catchment area in Germany. Costs; Disconnection; Reconstitution of bodies of water and watercourses; Retention; Run-off events; Seepage; Start-up financing.

Describes real time control of the integrated urban wastewater system using simultaneously simulating surrogate models. Integrated model of the urban wastewater system; Optimization of the resulting river water quality; Wastewater treatment.

Models the impact of the combined urban drainage and WWTP system of the village of Dessel, Belgium on the Witte Nete receiving water in terms of emission and immissions. Hydrodynamic and water quality modeling; Uncertainty analysis.

Studies the runoff characteristics of nutrients in the forest streams of Hyogo Prefecture in Japan. Concentrations of suspended solids; Chemical oxygen demand; Total organic carbon; Daily fluctuation of water quality.

Investigates the sources, distribution and fate of fecal coliform populations in the North Fork of the New River flowing through the city of Fort Lauderdale, Florida. Computer modeling of the hydrodynamic and advection/diffusion behavior of the river.; Prediction of fecal coliform concentrations.

Clarifies the characteristics of non-point pollution of Ishikari River, Hokkaido, Japan by comparing flux characteristics of chemical components in three periods of a year. Snow melting period; Typhoon flooding period; Stable period; Specific flow and specific runoff loads of chemical components.

Presents a water quality management model for a lignite mining affected river catchment area. Development of a coupled stochastic water management; Algorithms to describe water quality; Verification of the model's applicability.

Evaluates the total nitrogen pollution reduction strategies in river basins in Europe and Slovenia. Sources of nitrogen and pathways into the surface waters; Impact of the wastewater and agricultural management practices on nitrogen input into the surface water.

Studies the impact of treated wastewater to the Krka river in Slovenia. Chemical characteristics of effluents; Toxicological analysis of effluents; Temperature of the river water; Measurements of oxygen concentrations.

Stringent environmental laws in Europe and Northern America lead to the development towards closure of the process water streams in pulp and paper mills. Application of a "zero-discharge" process is already a feasible option for the board and packaging paper industry, provided in-line treatment is applied. Concomitant energy conservation inside the mill results in process water temperatures of 50-60°C. Thermophilic anaerobic treatment complemented with appropriate post-treatment is considered as the most cost-effective solution to meet re-use criteria of the process water and to keep its temperature. In the proposed closed-cycle, the anaerobic treatment step removes the largest fraction of the biodegradable COD and eliminates "S" as H[sub2]S from the process stream, without the use of additional chemicals. The anaerobic step is regarded as the only possible location to bleed "S" from the process water cycle. In laboratory experiments, the effect of upward liquid velocity (V[subupw]) and the specific gas loading rate (V[subgas]) on the S removal capacity of thermophilic anaerobic bio-reactors was investigated. Acidifying, sulphate reducing sludge bed reactors were fed with partly acidified synthetic paper mill wastewater and were operated at 55°C and pH 6. The reactors were operated at organic loading rates up to 50 g COD.l[sup-1].day[sup-1] at COD/SO[sub4][sup2-] ratios of 10. The effect of Vupw was researched by comparing the performance of a UASB reactor operated at 1.0 m.h[sub-1] and an EGSB reactor, operated at 6.8 m.h[sub-1]. The Vupw had a strong effect on the fermentation patterns. In the UASB reactor, acidification yielded H2, acetate and propionate, leading to an accumulation of reducing equivalents. These were partly disposed of by the production of n-butyrate and n-valerate from propionate. In the EGSB reactor net acetate consumption was observed as well as high volumetric gas (CO[sub2] and CH[sub4]) production rates. The higher gas production... [ABSTRACT FROM AUTHOR]

The absence of large rivers with rather high niveau of self purifying effect in parts of east Germany leads to a discharging of the effluent of wastewater treatment plants into the groundwater in many cases. One useful consequence is the idea of realisation of decentralised measures and concepts in urban water resources management concerning municipal wastewater as well as rainfall, precipitation. At the same time, only the upper soil zone--a few decimetres--is water--saturated and thus discharge effective, even when extreme rainfall takes place. Underneath, however, there generally exists an unsaturated soil zone, which is up to now a rather unexplored retardation element of the hydrologic- and substrate-cycle. Nutrient removal in small wastewater treatment plants that are emptying into ground waters is often beneficial. The presented studies optimised an inexpensive method of subsequent enhanced wastewater treatment. The developed reactor is similar to a concentrated subsoil passage. The fixed bed reactor is divided in two sections to achieve aerobic and anoxic conditions for nitrification/denitrification processes. To enhance phosphorus removal, ferrous particles are put into the aerobic zone. Two series of column tests were carried out and a technical pilot plant was built to verify the efficiency of the process. The results show that this method can be implemented successfully. [ABSTRACT FROM AUTHOR]

Classification systems have been developed over the last century as a tool to aid managers in the preservation, conservation, enhancement and management of rivers. The classification systems developed to date have been designed to differentiate between relatively unimpacted, mainly rural rivers. Urban rivers typically show poor water quality and biological diversity, and so most current classification systems tend to group urban rivers into a single ?poor? category. In this paper we describe a hierarchical framework for recording information about urban rivers that allows a more sensitive description of these rivers enabling subdivision into several classes according to the purpose of the classification. The different levels in the hierarchy, the types of attributes that are to be recorded at each level, and the relational database structure for storing the data are described. The 100-500 m river stretch level in the hierarchy relates to the engineered modification of urban rivers and is the key to their classification. An example classification at this scale illustrates a link between engineering modification, bank and bed materials and the number and diversity of physical habitats present. This classification underlines the importance of adopting a hierarchy of nested spatial scales for data collection, classification and interpretation since it illustrates a clear link between characteristics at the stretch scale and at the finer habitat scale. The classification also illustrates the varied nature of urban rivers and the fact that even quite heavily engineered stretches can contain a diversity of habitat types. [ABSTRACT FROM AUTHOR]

In February 2000 the Swan-Canning estuary in Western Australia experienced a record bloom of the toxic cyanobacteria Microcystis aeruginosa. At its height, concentrations of M. aeruginosa reached integrated water column cell counts of 15,000/ml and formed bright green scums in sheltered bays, where counts of 130 million cells/ml were recorded. Due to public health concerns parts of the river were closed from 10 to 22 February 2000. Two unseasonably large summer rain events in early and late January 2000 created conditions for the bloom. Freshwater runoff, estimated at 270 GL, was enough to fill the Swan-Canning estuary five times over and brought with it high levels of nutrients, mainly nitrogen (>2.0mg/L TN) and phosphorus (>0.15mg/L TP). A number of methods to reduce bloom accumulations were tried, including an attempt to increase the salinity of the surface water above the critical 10 ppt level for Microcystis; using a bentonite clay and poly-aluminium chloride mixture to flocculate and sink the algae; and sucking up scums using oil spill equipment. Over 900 tonnes of M. aeruginosa were removed and safely disposed using sewage treatment facilities. The bloom collapsed when the freshwater flush subsided and seawater intrusion from the Indian Ocean re-established itself, raising the salinities above the tolerance of Microcystis. [ABSTRACT FROM AUTHOR]

Enhanced run-off of nutrients from agricultural development in catchments bordering the Great Barrier Reef (GBR) is regarded as a potential threat to inshore reefs. In an attempt to better understand the impact of river run-off, the Australian Institute of Marine Science (AIMS) initiated a sampling program to measure nutrient concentrations in rivers draining to the GBR shelf. Our longest data set is from the Tully River in the wet tropics, sampled in collaboration with the Bureau of Sugar Experiment Stations (BSES). After thirteen years, we ask whether there has been any change in river nutrient levels. Water samples were collected at monthly intervals, with additional, wet-season samples. In recent years, a trend of increase in nitrate (at low flow) and particulate nitrogen concentrations has been observed. In this period, a significant increase in agricultural activity has occurred within the Tully basin. The area under sugarcane and bananas has doubled and fertiliser nitrogen use has increased by 130%. Increased concentrations of nitrogen in the river system may be a consequence of this increase in agricultural activity. [ABSTRACT FROM AUTHOR]

Winning the 2000 International Riverprize resulted from a significant investment by the community of Ontario over a long period of time in the Grand River Conservation Authority, GRCA. Innovative partnerships with the business community, government, universities, First Nations tribes, environment groups and the general community have been the hallmark of a broad-based river management program that has returned the Grand River to a healthy environment and usable resource. Recognising this, the Grand River received special recognition from the Canadian Heritage Rivers Board--as a designated Heritage River. Not content with the achievements of the past, the GRCA has turned its attention to the future needs of this river system and to increasing the depth and breadth of community partnerships. [ABSTRACT FROM AUTHOR]

River basin management is receiving considerable attention at present. Part of the debate, now occurring worldwide, concerns the nature of the organisations that are required to manage river basins successfully, and whether special-purpose river basin organisations (RBOs) are always necessary and in what circumstance they are likely to (i) add to the management of the water resources and (ii) be successful. The development of river basin management requires a number of important elements to be developed to a point where the river basin can be managed successfully. These include the relevant laws, the public and non-government institutions, the technical capabilities of the people, the understanding and motivation of people, and the technical capacity and systems, including information. A river basin organisation (or RBO) is taken to mean a special-purpose organisation charged with some part of the management of the water resources of a particular river basin. Generally speaking, such organisations are responsible for various functions related to the supply, distribution, protection and allocation of water, and their boundaries follow the watershed of the river in question. However, the same functions can be carried out by various organisations, which are not configured on the geographical boundaries of a river basin. This paper outlines recent work on river basin organisation in Vietnam, and makes some comparisons with the situation in Australia. [ABSTRACT FROM AUTHOR]

The presence of indigenous property rights and interests arising from the survival of native title in Australia presents unique issues in the management of rivers and riverine lands. Existing common law and statutory tidal and non-tidal rights are a complex overlay of public and private property rights which are themselves undergoing significant change through the commodification of many natural resources by Commonwealth and State governments, such as marine species stock and non-tidal water. The melding of indigenous values and management practices with existing management regimes for rivers and riverine lands offers considerable potential for both sustainability of resource utilisation, and respect and recognition of native title with resultant predicted benefits in the vexed area of compensation. [ABSTRACT FROM AUTHOR]

While specifying ?responsibilities? for river planning and management implies that outcomes are desired, defining ?accountabilities? demands that results are achieved. This paper examines innovative ways of converting aspirations to results, with particular reference to the changes initiated in New South Wales in response to the establishment of the Healthy Rivers Commission of New South Wales and its first round of Inquiries. [ABSTRACT FROM AUTHOR]

Artificial oxygenation has been used for two summer periods to improve the water quality of the Canning River in Perth, Western Australia. The project is part of the Swan Canning Cleanup Program, which aims to reduce the frequency and severity of nuisance and toxic algal blooms in the Swan-Canning estuary. The trials have proved that oxygenation has increased the dissolved oxygen concentrations in the water column, particularly in the bottom waters where dissolved oxygen concentrations are frequently below a critical level of three milligrams per litre. Oxygenation has had a positive impact on nutrient concentrations in the water column and nitrogen cycling processes. Reductions in nutrient concentrations were highlighted by drops in ammonium and total phosphorus concentrations of 97% and 64% following the recommencement of oxygenation after a plant shutdown. Results of a microbiological study combined with the data analysis indicate that the number of nitrifying microbes have increased due to oxygenation. However, comparisons between oxygenated and control areas were inconclusive about the ability of the oxygenation plant to reduce total nitrogen and phosphorus levels. This could be explained by factors such as spatial variability, water flow during the trials and measurement limitations in the monitoring program. Future work will concentrate on assessing the impact of the oxygenation plant on nutrient concentrations. [ABSTRACT FROM AUTHOR]

Conventional wisdom has it that we already have enough science to address the problems causing degradation of our environment, including rivers. This is not true. However it is the case that we could be using existing knowledge better, and that we could be doing more to learn the lessons from the huge sums being spent on river restoration and management. Informing good policy and practical on-ground management with R&D outputs has proven to be is difficult, but essential. This paper reviews some of the history of water and river management in Australia and how perceptions of rivers have evolved. It discusses the challenge of enhancing the linkages between science, policy and practice in river management. It outlines the knowledge exchange, R&D and capacity building strategies of the National Rivers Consortium--a new initiative whose founding partners are LWRRDC, the MDBC, CSIRO Land and Water and the Western Australian Waters and Rivers Commission. This strategic collaboration between policy makers, river managers and scientists brings together organisations with responsibility and expertise to improve the health and management of Australian rivers. The National Rivers Consortium is making a major investment in knowledge exchange and capacity building, based on direct personal contact and learning by doing. The Consortium is establishing a program of training activities targeting river managers and policy makers, based on the best available science and high quality information products. It will support river managers as they plan and implement river restoration and protection projects. The paper concludes with a discussion of the key knowledge gaps that remain impediments to the better management of Australia's unique and diverse river landscapes. [ABSTRACT FROM AUTHOR]

Australians do face special opportunities and challenges in attempting to restore or rehabilitate their streams, when compared with Western Europe and North America. Some of these differences arise from the physical and ecological character of our streams, particularly in terms of flow variability, stream power, sediment, vegetation interactions, and nutrient levels. We also have modest resources available per-unit-length of stream, and no massive freshwater fishing industry. These, and many other differences, combine to produce an environment in which it can be slower and more difficult to rehabilitate streams, and we have less confidence in the results. International case studies are tremendously useful but in some cases we need to be circumspect in applying the results directly to Australian streams. [ABSTRACT FROM AUTHOR]

The Australian Institute of Marine Science (AIMS) has developed an in situ digital turbidity logger (AIMS River Logger) to record time series of fine suspended sediment concentrations in North Queensland rivers. The loggers use dual LED transmissometers (15 and 85 mm pathlength) to measure in situ turbidity associated with the range of suspended sediment concentrations (0-5 g L[sup-1]) encountered in regional rivers. A system of wiper brushes clean the optical surfaces prior to instrument readings. Overlying water depth and temperature are concurrently recorded. Internal batteries provide sufficient power for unattended deployments of 6+ months with readings taken at 30 minute intervals. Records of suspended sediment concentrations in the lower Tully River over three wet seasons (1996, 1997, 2000) are shown in relation to concurrent river discharge. Peaks in suspended sediment concentration coincide with discharge events. During each event, peak sediment concentrations typically occur during the rising stage of the hydrograph, then decline rapidly prior to significant falls in water level. Derived suspended loads during discharge events are generally proportional to the size of the event, though higher responses are recorded during the initial flood event of each wet season. [ABSTRACT FROM AUTHOR]

The Great Barrier Reef (GBR) system encompasses the largest system of corals and related life forms anywhere in the world. The health of this extensive system, particularly the inshore area, is dependent on the relationship between the GBR and adjacent coastal catchments. The major impact of agricultural practices on the GBR is the degradation of water quality in receiving (rivers) waters, caused by increased inputs of nutrients, suspended sediments and other pollutants. For the past three years, the Great Barrier Reef Marine Park Authority (GBRMPA) has been involved with the co-ordination of a river-monitoring program, specifically targeting the sampling of rivers during flood events. Representative sites were set up along two North Queensland rivers, the Russell-Mulgrave and Barron Rivers. This monitoring program is run in conjunction with the Queensland Department of Natural Resources' Waterwatch program. The program involves intensive sampling of first flush, extreme flow and post flood conditions over the two rivers. Extreme flow conditions are sampled over a limited time span (48 hours) with trained volunteers at 4-hour intervals. Concentrations measured in the flood events are dependent on landuse characteristic, and extent of flow. Concentrations of dissolved and particulate nutrients are higher if the extreme flow event is part of the first flush cycle. Concentrations of DIN and DIP measured before, during and after a major flood event suggest that there is a large storage of inorganic material within the Barron and Russell-Mulgrave agricultural subcatchments that move over a period of days, and perhaps weeks. This program created a forum in which GBRMPA liased with the Barron and Russell-Mulgrave community about the connectivity existing between the river and the Great Barrier Reef lagoon. [ABSTRACT FROM AUTHOR]

Many of Australia's river systems have been seriously degraded by inappropriate management of regulated flows. Other systems are facing threats from future water resources developments. There is a lack of information available to aid in allocation of environmental flows to rivers in order that they are managed in an ecologically sustainable manner. The Environmental Flows Initiative (EFI) is a major Australia-wide R&D program into environmental flows, funded through the Natural Heritage Trust (NHT), and administered by Environment Australia (EA). The program aims to identify environmental values, undertake targeted research to identify risks to river systems and flow requirements to sustain environmental values, to trial flow management options, and to evaluate these trials. The NHT relies on matching funding provided by the State and Territory authorities, and supports integrative approaches with emphasis on works on-the-ground where possible. While the EFI will close significant knowledge gaps, other gaps remain. Some of these relate to development and validation of rapid assessment techniques, understanding the importance of flow variability and how to define it, manipulation of flows to control alien species, developing a system of prioritising rivers for environmental flows, and enhancing flows with other catchment, channel and floodplain rehabilitation measures. [ABSTRACT FROM AUTHOR]

The Australian climate is highly variable and many Australian estuaries lack a seasonal pattern of freshwater flow. During periods of low freshwater inflow, saline waters enter from the ocean through the estuary mouth. These saline waters enter as density currents or as a result of tidal mixing. During periods of high freshwater inflow from the estuary catchment, salt water is flushed towards the estuary mouth. As a consequence, the saline structure of Australian estuaries can be highly variable, depending on the antecedent rainfall. The Richmond River in northern New South Wales is such an estuary. The biota inhabiting estuaries have varying levels of freshwater and saltwater tolerance and reducing the freshwater flow into and along an estuary will favour saltwater species. However, if extractions of freshwater from an estuary are sufficiently high, freshwater habitat could be eliminated entirely for short periods (~one month) but with consequent, and perhaps long-standing, damage to the environment. This contribution describes a new approach to quantify the impact of changes to freshwater flows to the Richmond River estuary. This approach includes a review of hydrological data gathered over the past century and includes a detailed assessment of: changes to the highly variable freshwater inflows and freshwater extraction below the tidal limit; consequent changes to the highly variable saline structure; and the risk to aquatic biota. The crucial factors of magnitude, frequency and duration of short-term intrusions of saline water into freshwater habitat and their impact are quantified by the methods developed. [ABSTRACT FROM AUTHOR]

Growing concern about the declining state of the catchment and river led to the formation of the Blackwood Basin Group in 1992. Funded primarily by the Natural Heritage Trust and using the river as the focus, the group aims to provide leadership and support to achieve sustainable management of natural resources in the catchment. Through an Integrated Catchment Management approach, the Blackwood Basin Group has managed a range of projects to improve the community's understanding and management of the Blackwood River and its catchment. A number of research, education, demonstration and on-ground action activities relating to river management have been undertaken in partnership with community and local, state and federal government organisations. Activities include demonstrations and evaluations of riparian restoration, funding riparian restoration activities, protection of high conservation value remnant vegetation, a flood risk study, zone action planning and monitoring the condition of the river and its tributaries. [ABSTRACT FROM AUTHOR]

The Brisbane River and Moreton Bay Study, an interdisciplinary study of Moreton Bay and its major tributaries, was initiated to address water quality issues which link sewage and diffuse loading with environmental degradation. Runoff and deposition of fine-grained sediments into Moreton Bay, followed by resuspension, have been linked with increased turbidity and significant loss of seagrass habitat. Sewage-derived nutrient enrichment, particularly nitrogen (N), has been linked to algal blooms by sewage plume maps. Blooms of a marine cyanobacterium, Lyngbya majuscula, in Moreton Bay have resulted in significant impacts on human health (e.g., contact dermatitis) and ecological health (e.g., seagrass loss), and the availability of dissolved iron from acid sulfate soil runoff has been hypothesised. The impacts of catchment activities resulting in runoff of sediments, nutrients and dissolved iron on the health of the Moreton Bay waterways are addressed. The Study, established by 6 local councils in association with two state departments in 1994, forms a regional component of a national and state program to achieve ecologically sustainable use of the waterways by protecting and enhancing their health, while maintaining economic and social development. The Study framework illustrates a unique integrated approach to water quality management whereby scientific research, community participation and the strategy development were done in parallel with each other. This collaborative effort resulted in a water quality management strategy which focuses on the integration of socioeconomic and ecological values of the waterways. This work has led to significant cost savings in infrastructure by providing a clear focus on initiatives towards achieving healthy waterways. The Study's Stage 2 initiatives form the basis for this paper. [ABSTRACT FROM AUTHOR]

Alongside science we need a parallel capability of exploring meaning so that intangible, uncountable aspects of our relationships with rivers, especially those understood by local communities, can be expressed. Common Ground has offered the concept of Local Distinctiveness and gives examples from England, including recent projects which they have initiated. [ABSTRACT FROM AUTHOR]

Analyzes how the Extended Soil and Water Assessment Tool (ESWAT) was developed to allow for an integral modelling of the water quantity and quality processes in river basins. How the diffuse pollution sources are assessed by considering crop and soil processes; Use of an autocalibration procedure which allows for the optimization of the process parameters; Consideration of a global optimization criterion which was applied to the river Dender in Belgium.

Discusses how the urban wastewater system components such as sewer, treatment plant, and river are often modelled using complex mechanistic models. How surrogate models are faster, but are less but still sufficiently accurate; Examinations of the possibilities of replacing actual field data by virtual data generated with a complex mechanistic model for calibration of the surrogate model; Status of a series of tanks with variable volume is shown to approximate sufficiently well the flow propagation in the river Zwalm in Belgium.