Volume XVI Issue 1

The prediction of peak outflow and the associated flood hydrographs is an important component in any dam safety assessment. In particular, the establishment of the Incremental Consequence Category (ICC) [or Incremental Hazard Potential (IHP)] and the development of an Emergency Preparedness Plan (EPP) for a dam site that has been classified as a HIGH ICC or IHP site often relies on this analysis. The estimation is normally accomplished by the requirement to undertake a full scale detailed dam break modelling using the NWS DAMBRK model (replaced by the NWS FLDWAV model), the Mike 11 model, the newly developed HEC-RAS dam break module or other similar models. The application of these hydrodynamic simulation models can take some considerable time and budget.

However, in some cases, for the purpose of establishing the classification of a dam, only a quick estimation with reasonable accuracy may be needed. For this reason, a spreadsheet solution, that follows the logic detailed in similar tools that are used by the Washington State Dam Safety Office (Walther, 2000), was developed using simplified predicting equations.

This paper describes the general concepts of the method and the modifications made to the existing Washington State model to extend its capabilities. Using the simplified model, comparisons are made for a typical site with full scale FLDWAV model results in order to assess relative accuracy of the approach.

Want to read the full paper?

To purchase a copy of this Dam Engineering paper, please email the Editor, Carrieann Davies, on: cdavies@wilmington.co.uk or fax: +44 (0) 20 8269 7804.
Please include your name, postal address, credit card number and issue number.
The cost is £20 sterling for each paper, postage & handling free.
Your order will be confirmed by email. We aim to dispatch your order within 48 hours of receipt.