DWR_2726118 - Laserfiche WebLink

 Page 1 Upper and Lower Emerald Valley Dam Failure Report January 23, 2015 FINAL Dam Failure Forensic Investigation Report To: File: Upper Emerald Valley Dam, DAMID: 100469 Lower Emerald Valley Dam, DAMID: 100470 From: John Hunyadi, Dam Safety Engineer CC: Bill McCormick, Chief of Dam Safety Date: 23 JANUARY 2015 Re: Upper & Lower Emerald Valley Dams Failure – 12 SEP 2013 Table of Contents Section 1.0: References Section 2.0: Scope & Purpose Section 3.0: General Background Section 4.0: Description of Dam Geometries Section 5.0: Post Failure Field Investigations Section 6.0: Eyewitness Accounts Section 7.0: Analysis Section 8.0: Model Results Section 9.0: Conclusions Appendix A: Field Investigation Photos Appendix B: Field Investigation Notes Appendix C: Sept 8 – 17, 2013, 5 minute precipitation Data for Little Fountain Creek, Provided by Applied Weather Associates, Inc. Appendix D: NOAA Atlas 14 Precipitation Frequency Estimates for Little Fountain Creek Basin Appendix E: Breach, Hydraulic Modeling Supporting Documentation ________________________________________________________________________ 1.0 References 1. Dam Failure Investigation Guideline, ASDSO, Dec. 8, 2011. 2. Hazard Classification Report, Emerald Valley Ranch Dams, RJH Consultants, January 2014. 2.0 Scope & Purpose The purpose of this report is to document the 12 SEP 2013 failures of the Upper Emerald Valley (UEV) and Lower Emerald Valley (LEV) dams, with respect to the following:  Possible causes of the failure,  Possible incremental damages from the breach floodwave, and  Lessons that can be learned to help avoid future dam failures.