Should the sediment pool elevation and storage be used?

[BillsSis]

I'm fairly new to the Dam / Reservoir hydraulic modeling, so I'm sure there a million questions zooming around in my head, but, for now, I have just a couple.

I'm working on a Dam that was built in 1967. Before the previous drainage engineer retired, he told me to use the sediment pool information in the dam documents. In other words, the bottom of the reservoir elevation would be the elevation of the 50-yr sediment pool. And the bottom of the dam would be the top of the sediment pool.

However, when I put in the inlet elevation for the horizontal pipe and try a simulation run, an error in HEC-HMS says "Elevation for outlet 1 in reservoir "Reservoir-1" is below minimum elevation." How can I get around this? Or should I not use the sediment pool information at all? When is it correct to use this?

Thanks for any and all advice!!

BillsSis

 

[SMIAH]

The storage-dischare or elevation-storage (or area) has to cover the same elevation in HMS.
If you use the outlets option, it has to cover the elevation of the elevation-storage (or area)

 

[SMIAH]

So probably that the elevation of the "outlet 1" is below the minimum value of the elevation-storage (area) : you have to change that e.g. saying that this minimu elevation has 0 storage.