Author Topic: SURPRISE! SURPRISE! USA Dams & Levees get a D Rating, Lessons Learned  (Read 163 times)

Michael Caswell

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This article explains why woody vegetation is very undesirable on a dam.

One very valid point made here is that even though this vegetation may not be the MAJOR cause of failure, it certainly contributes to it for a number of reasons.

Relative to the number of trees known to exist on dams and a review of past dam failure case studies, it is generally uncommon for woody vegetation alone to cause dam failure; however, numerous dam failure case histories identify woody vegetation as a contributing factor in the dam failure process.  For this reason, it is important to eliminate woody vegetation on and around dams and levees to minimize the potential for internal erosion and structural damage while maintaining beneficial grassy vegetation to reduce the potential for surface erosion.

The article states - While it is reasonable to anticipate some benefit will be realized by allowing woody vegetation to remain, it only takes one weak link to initiate failure , BUT, it is important to note that in this instance, they are discussing LEVEES.

This is something that those in opposition to the vegetation removal simply do not understand. They are stuck and continue to say, no trees have ever caused a problem.

The permanent reservoir loading at active storage dams creates a much higher likelihood that adverse consequences might occur. (Hydrostatic Pressure)

In conclusion, state and federal dam safety officials and industry experts generally agree that trees and woody vegetation should be eliminated from all water impounding structures.

It doesn't get any clearer than that folks!

« Last Edit: July 29, 2021, 07:00:33 am by Michael Caswell »