ELEVATION aux can be defined for RIV but not LAK?

[Claudio Vergara Sáez]

Hi!

I'm trying to understand the logic of allowing users to define the "ELEVATION" AUX value to be used in the density calculation of head-dependent boundaries such as GHB or RIV but not LAK. Why is RIV different than LAK in this case? Are not both dependent of the river/lake stage?

Thanks!

Claudio