Our lake - Travis - in centex is very similar to yours in construction and geology, although we have no ‘extra’ spillways and it’s 720ft tall. In our 4yr drought, it dropped almost 50ft. Our river authority is quite happy to drown us behind the dam to avoid splashing the boats docked in Lake Austin below, done it many times to us. Even the governor has a hard time forcing them to open #2 of the 8 floodgates.
Intentionally dropping our lake 50ft would take Months.. but we recovered 50’ of depth in one month two years ago, torrential rains.
According to this site
http://cdec.water.ca.gov/cgi-progs/queryF?ORO
The lake is down about 4 feet from yesterday evening. Good sign.