Correspondence between our group and Scott Morgan from the Dam Safety Branch

From: Jeff Solomon
Sent: Monday, March 25, 2013 7:30 AM
To: Scott Morgan, Dam Safety Branch
Subject: Information

Scott, can you clarify something for me.  I would like to know when a flood inundation report is required and whether or not there is a time frame attached.  Your prompt response is appreciated.   

 - Jeff Solomon

From: Scott Morgan, Dam Safety Branch
Sent: Monday, March 25, 2013 7:30 AM
To: Jeff Solomon, CDPS
Subject: re: Information

The analyses leading to consequence assessment and classification of the dam should include characterization of a hypothetical dam breach, flood wave routing, inundation mapping, and evaluation of the impacts. The level of effort and the resulting level of accuracy should be commensurate with the importance of the dam safety decisions that need to be made.

In general, a preliminary assessment using simple and conservative procedures should be done to obtain a first approximation of the level of consequences. Complexity and accuracy should be increased if there is a need for greater detail to confirm the dam classification, support a detailed emergency response plan, or inform management decisions. This approach allows for consequence classification to be used for small or obvious low-consequence structures where the cost and complexity of larger, more detailed studies may not be required.

- Scott Morgan

From: Glen Davidson, Dam Safety Branch
Sent: Monday, March 27, 2013 9:30 AM
To: Jeff Solomon, CDPS
Subject: re: Information

In other words

There is no requirement under the Dam Safety Regulation for a dam owner to undertake a dam break inundation study.

However, dam break inundation studies are undertaken by dam owners to assist them in determining their dam’s consequence classification and/or in support of an emergency response plan. Dam Safety Reviews, performed every ten years for high, very high and extreme consequence dams, often include a detailed dam break inundation study to confirm the dam’s consequence classification.

- Glen Davidson