I'm looking for some help in finding information on forecasted or planned water release at Whitney Dam, Morris Sheppard, and Denison.

I was below Whitney when the BRA? opened up for generation, it was more water than I expecting and would like to avoid that situation in the future.

Start here and look for the forecast of reservoir releases: https://www.swd.usace.army.mil

It should look something like this, which is what I use in Kansas:
http://www.nwd-mr.usace.army.mil/rcc/nwk/lakepool.txt

Whitney is tied to the power grid and is triggered by demand. There is no schedule. Best you can do is look at previous days and make a educated guess by trying to pattern the releases. Safe bet is to plan to shuttle from dam to Dicks or go upstream from Dicks and ride it down if they release.