FWR/WaPUG Workshops

From time to time, the FWR Wastewater Research & Industry Support Forum, together with WaPUG (Wastewater Planning Users Group), conducts Workshops on subjects relevant to Urban Pollution. Copies of the Reports from these workshops are available from FWR, price 10.00, or they may be accessed from this page as a pdf document.

The Urban Flood Route Prediction - Can We Do It? (900k pdf)

26th September 2002. Land management of unpaved areas can modulate run-off but inevitably there will be times when the intensity and volume of storm water exceeds the capacity of the underground infrastructure to carry it away. Modelling issues are discussed, especially when considering unconfined flows. 1-D modelling is well developed but 3-D stretched current computing power. Getting flooded with water is bad enough but sewage (even diluted) is far worse. Is there an argument for keeping some of the storm water out of the sanitary sewers? The Workshop recommends giving consideration to engineering selected roads as flood-routes for extreme events, which would require co-ordination between agencies.

The report contains 29 pages, 5 references, illustrations and the contact details of the participants

Design Criteria & Performance Standards for Urban Drainage Systems - Is Historic Practice Still Good Enough? (1.5mb pdf)

24th September 2003 Basically the answer was "no". However that's not to say that things are bad at present but that in a changing climate (meteorologically and otherwise) it is time to question and move forward; we could and should do better. There can be tough strategic and financial choices; engaging the public in choosing between the options and getting their buy-in to the solutions can prove valuable. Ultimately it is they who pay the bills.

The report contains 50 pages, 11 references, illustrations and the contact names of the participants.

Urban Rainfall & Run-Off (1.4mb pdf)

30th April 2004 Much has been delivered already regarding sanitary sewerage and reducing the risk of urban flooding. Properties classed as being at risk of flooding have been reduced, but internal flooding has remained constant at about 25/100,000 properties. Are the unaffected willing to pay the massive bill for further reduction which a linear extension of historic practice would entail? High resolution precipitation-radar reveals spatial variation in rainfall is much greater than rain-gauges suggested. Existing models for predicting run-off are good but based on relatively few calibration data. More long term data and flow-monitoring are needed to refine models. Almost inevitably further reducing the risk of flooding in a time of inherently increasing difficulty (because of climate change) will require a step-change in approach.

The report contains 43 pages, 11 references, illustrations and the contact details of the participants

CSO Screens - A Design and Installation Review (1.8mb pdf)

6th July 2005 Combined Sewer Overflows (CSOs) are essential safety valves for the sewerage network. When storm events are intense enough  there is bound to be more stormwater than sewers can carry. In its 2000-2005 Asset Management Plan the water industry built and upgraded 2,500-3,000 CSOs at a total cost of about 1 billion. In 2000 screening CSOs was unproven technology and it has improved considerably by research and experience. In the rush to complete schemes some of the work was poor. In such intensive programmes application of "partnering", with its sharing of information, would have considerable benefits. There should be attention to the eventual operation and maintenance of installations. Good construction/contracting practice and adequate training are vital. There is much to learn from post project appraisal.

The report contains 56 pages, 6 references, illustrations and the contact details of the participants.

Urban Run-Off Modelling - Why Not Do It Properly? (3.6 mb pdf) 

8th March 2006 The most popular runoff process in use is more than 30 years old. It was based on field data but they have not been documented formally and few understand them. Further field work is overdue, especially for evaporation and depression storage on impervious surfaces. The data on surfaces are too general. There is need for standardisation to extend the life and transferability of models. The report describes ways in which surface characterisation, data capture and processes could all be improved.

The report contains 56 pages, 6 references, illustrations and the contact details of the participants.

Action Workshop on Urban Run-off Modelling Why Not Do it Properly? (541k pdf)

18th April 2007 The ability to model urban run-off is essential in order to protect people and assets cost effectively and with confidence. We need to improve understanding of the fundamentals and to supplement the original field work that underpins the process models. Digital mapping, computing power and remote sensing combine to make surface characterisation better. Particular attention is needed for our understanding of drainage from roofs and surface water entry via gullies. Urban creep (paving, extensions etc)confounds run-off models; a standardised means of accounting for it in the next generation of models is essential. There is a need for communication between river, sewer and STW models.

The report contains 33 pages, 3 references, illustrations and the contact details of the participants.

Retrofitting Green Infrastructure for Rainwater - What's Stopping Us? A Workshop to Explore the Issues (933k pdf)

19th April 2010 The objective of using green infrastructure (GI) for rainwater is to reduce the rate at which rainwater falling on urban areas runs off and also the total amount of that runoff. It might be complemented by grey infrastructure where GI does not have sufficient capacity to treat all of the runoff but in that case the grey infrastructure can be much smaller, less expensive and less disruptive to build.

The report contains 32 pages, 11 references, illustrations and the contact details of the participants.