Publications Home || Browse by topic || Browse by program || Ecology website

Publication Summary

Our Ecology website has changed, which can cause broken links.
To report these, please contact us with the publication and broken link.


Bonasa Breaks Ranch Dam: Dam Failure and Hydrologic Report

Publication number Date Published
17-11-008August 2017
VIEW NOW Bonasa Breaks Ranch Dam: Dam Failure and Hydrologic Report (Number of pages: 53) (Publication Size: 5802KB)

Trouble viewing? Try these free options.
Author(s) Guy Hoyle-Dodson P.E., and Gus Ordonez, P.E.
Description This report summarizes the Dam Safety Office’s observations and findings of our May 3, 2017, inspection of the breached Bonasa Breaks Ranch Dam, and our subsequent engineering analyses. Our primary objective was to determine the causes of the April 13, 2017, dam breach failure of the Bonasa Breaks Ranch Dam by evaluating the hydrologic response of the reservoir and spillway to potential and design hydrologic and hydraulic operating conditions.
The mission of the Department of Ecology is to protect, preserve, and enhance Washington’s environment. To help us meet that goal, please consider the environment before you print or request a copy.

ADA Accessibility
The Department of Ecology is committed to providing people with disabilities access to information and services by meeting or exceeding the requirements of the Americans with Disabilities Act (ADA), Section 504 and 508 of the Rehabilitation Act, and Washington State Policy #188.
Visit Ecology’s website for more information.
Contact Water Resources Program at 360-407-6872 or
Keywords dams, dam construction, dam inspection, dam safety
WATERSHED Water Resource Inventory Area 35 Middle Snake