Urban Runoff Management Research Articles

An integrated stormwater management/GIS software system

Computing pollutant loadings are increasingly important for master planning flood control and environmental systems. In this paper, a stormwater pollutant estimation analog is coupled to a flood control master planning procedure linked to a GIS capability. The GIS functions develop land use versus area tabulations that readily input into pollutant loading equations. Because the linkage between the master plan of drainage databases and the pollutant loading equations is direct, an important advancement can be made in stormwater quantity and quality evaluation by a modest integration effort between software applications. For application in urban storm runoff management, a simple rainfall-runoff volumetric model can be linked to the stormwater pollutant model to estimate pollutant loadings on a storm event basis. Calibration of the model is achieved by matching mean annual loadings to NURP estimates.

Challenges for the development of advanced constructed wetlands technology

Widespread demands for improved receiving water quality, water reclamation and reuse require the implementation of advanced catchment management techniques. Increasingly, management options for reducing the impact of effluent and run-off on receiving waters involve the application of constructed wetlands (CWS) technology. Current applications of CWS technology include the treatment of primary settled and secondary treated sewage, tertiary effluent polishing, disinfection, urban and rural run-off management, toxicant management, land-fill and mining leachate treatment, sludge management, industrial effluent treatment, enhancement of instream nutrient assimilation, nutrient removal via biomass production and export, and groundwater recharge. Major CWS research and development work needs to be directed at refining our understanding of nutrient immobilisation and other pollutant processing mechanisms and the application of this knowledge to the development of advanced wetland designs. Concomitantly, the ‘user-friendliness’ of wetland design criteria and the wetland planning process needs to be enhanced. In the first instance this is being addressed by the development and refinement of information databases and decision support systems so as to foster the employment of the most environmentally and economically advantageous systems for a given application and locality.

Challenges for the development of advanced constructed wetlands technology

Widespread demands for improved receiving water quality, water reclamation and reuse require the implementation of advanced catchment management techniques. Increasingly, management options for reducing the impact of effluent and run-off on receiving waters involve the application of constructed wetlands (CWS) technology. Current applications of CWS technology include the treatment of primary settled and secondary treated sewage, tertiary effluent polishing, disinfection, urban and rural run-off management, toxicant management, land-fill and mining leachate treatment, sludge management, industrial effluent treatment, enhancement of instream nutrient assimilation, nutrient removal via biomass production and export, and groundwater recharge. Major CWS research and development work needs to be directed at refining our understanding of nutrient immobilisation and other pollutant processing mechanisms and the application of this knowledge to the development of advanced wetland designs. Concomitantly, the ‘user-friendliness’ of wetland design criteria and the wetland planning process needs to be enhanced. In the first instance this is being addressed by the development and refinement of information databases and decision support systems so as to foster the employment of the most environmentally and economically advantageous systems for a given application and locality.

Analysis of rainfall series in the design of urban drainage control systems

Intensity-duration-frequency curves are traditionally used in the design of urban runoff treatment and management systems. The uniform intensity for a specified duration and return period is selected for a design storm without consideration of the inter-event dry periods between two successive rainfall events. For many purposes, especially those related to urban storm pollution control and receiving water impacts, the cumulative effects of successive storm events must be taken into account. This fact requires the selection of design storms where the minimum inter-event dry periods are adjusted to the effect in question. This paper will discuss the concept of inter-event dry periods for evaluation of design storms derived from a rainfall record. As an example the rainfall record for the city of Odense, Denmark, has been analyzed. The basic statistics as well as the importance of the concept will be illustrated.

Stormwater-Combined Sewage Pollution Abatement

The mission of the USEPA’s Storm and Combined Sewer Pollution Control Research and Development Program is to quantify the urban storm and combined sewer overflow pollution problems and develop countermeasure controls. As a result of the Program’s efforts an advanced technology or state-of-the-art has been developed, demonstrated, and disseminated. This paper addresses the problem and characterization of stormwater and combined sewage impacts upon our Nation’s receiving waters while presenting various levels of pollution control technology. Efforts of urban runoff management examined deal with source control, collection system control, storage and treatment, and integrated (complex) systems.

Urban Runoff Management Strategies

A dramatic shift has occurred in the control of urban runoff over the past 10 yr to 15 yr. The conventional practice of rapid removal and delivery of urban runoff to downstream areas is being replaced by the newer concept of reduction and detention of urban runoff in upstream source areas. A successful strategy for managing urban runoff must be based on: (1)Application of proper hydrologic tools for the analysis of urban runoff under alternative land-use conditions in the watershed; (2)hydrologic and economic evaluation of the performance of alternative runoff abatement measures; and (3)projection of downstream impacts of selected abatement schemes. The purpose of this paper is to review these basic elements in urban runoff management and to comment on future directions in this evolving field.

Urban Runoff Management: Future Modeling

Several recent studies have demonstrated that computer based mathematical models are becoming a standard part of the engineer's arsenal of tools for analyzing and designing urban drainage systems, and for evaluating the impacts of runoff-generated pollution and the remedial measures therefore. It is equally clear that while the catalogue of available models is quite large, only a few are in common use. Future model use will emphasize applications. New model development will proceed at a slower pace until an adequate data base is available. Receiving water quality models will receive increased use. The use of mini/micro computers will increase rapidly, and models will be adapted for use with low-cost hardware.