VOODOO HYDROLOGY WEBINAR #1 IN THE ANNUAL SERIES (February 2013): “In the absence of flow data, we make the Big Assumption,” says Andy Reese, prominent and popular American water resources engineer, writer, speaker, and textbook author
Note to Reader:
Andy Reese is a leading American water resources engineer and popular writer, speaker, and co-author of the best-selling textbook Municipal Stormwater Management. He is known for his mantra: Stormwater – Back to the Future.
In February 2013, Andy Reese delivered a webinar for Forester University titled “Voodoo Hydrology – Pitfalls of Urban Hydrology Methods & What You Need to Know’”. To download a report-style PDF copy of the 2013 waterbucket.ca story complete with the 2006 article by Andy Reese, click here.
Voodoo: Magical practice considered to be a form of black magic, but also considered a religion to some
In the July/August 2006 issue of Stormwater Magazine, Andy Reese offered his perspective on urban hydrologic practice. His article explains why it is necessary to understand some of the basics of methods drainage designers have taken for granted for years. In this regard, the article serves as an especially relevant Primer on contemporary practices.
“The article is standing the test of time. It is as relevant in 2013 as when it was published in 2006,” states Ted van der Gulik, Chair of the British Columbia Water Balance Model Partnership.
In the absence of flow data…the “Big Assumption”
“Urban hydrology, as commonly practiced, is an inexact science at best. If we were omniscient, we could do an exact job of urban hydrology,” explains Andy Reese.
“Instead, we rely on engineering judgment and guesswork, ultimately striking a compromise between accuracy and data availability, and resulting in an answer that is close to correct. All uses of rainfall instead of flow data make the ‘Big Assumption’. We know that there is only one 10-year peak flow for our site.”
“Perhaps, if we make enough estimates of enough factors, the errors in estimation, high and low, will average out to the right answer. This is where voodoo really comes in handy.”
“The good news is that, as Dr. Debo says, ‘Who can prove you are wrong?’ Well, the Omniscient Being can, but is probably busy elsewhere,” concludes Andy Reese.
To Learn More:
To download a report-style copy of the 2013 waterbucket.ca story complete with the 2006 article by Andy Reese, click on Voodoo Hydrology: Andy Reese on “Pitfalls of Urban Hydrology Methods and What You Need to Know”.
Provocative Articles by Andy Reese!
Do you know where you really are in the shifting paradigms of stormwater management? –
Surface Water Management in the United States: “We have one chance to develop things right,” says Andy Reese –
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Green Infrastructure and Storm Depth Retention Criteria explained by Andy Reese –
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