Flow through lake, water level befor dam failure

[Karin&Bethi]

Dear Chris,

Thank you for your help. Unfortunately we have two more questions:

1. How can we define the flow depth in the channel before dam failure or before the wave due to dam failure is approaching.
2. We have to simulate the run of the wave through a 7 km long channel. In the middle of its way, there is a lake. We are using Option 7 and an estimated wave due to a dam failure.

Now we don't know how to tell the program that there is water in the lake. Is the program able to solve this problem? Or can you tell us, how we can handle this problem otherwise?

Thank you very much in advance and sorry for our english.

Karin and Bethi

[Chris Maeder]

Dear Karin and Bethi:

Note that Problem Specification Option 7 is really meant for a run of river. You can have a reservoir (or lake) in the run of river if you want. However, if you are needing to model a dam failure, you do not want to use Problem Specification Option 7. I would recommend using Options 1, 11, or 13.

Note that Options 1 and 13 assume level pool modeling of the reservoir, so cross sections are not necessary in the reservoir. But, if your reservoir is quite long and you are wanting to also model the run of river, then I would recommend Option 11.

Problem Specification Option 11 requires cross sections to define the geometry of the reservoir and run of river upstream of the reservoir.

Also, options 1, 11, and 13 allow you to define the initial water surface elevation in the reservoir. Option 7 computes the run of river elevation at each cross section (and therefore the reservoir) using St. Venants equation.

If you have any additional questions or need any further information, please contact me again.

Sincerely,

Chris E. Maeder, M.S., P.E.
Senior Technical Engineer
chris.maeder@bossintl.com