Water is piped infrom the bottom of the lake. The pressure liftsthe bear-trap gates using...

[narrator] Water is piped in
from the bottom of the lake. The pressure lifts
the bear-trap gates using giant hinges
on the riverbed, creating a raised barrier
that maintains
the required water level. Shutting off the pipes
allows water to escape,
lowering the trap. The gates are essentially
like giant trap doors with a series
of huge metal hinges
on the lakebed that allow them
to raise and lower with
the pressure of the water, helping to regulate
the lake level. [suspenseful music playing] [narrator] May 14, 2019. It was the start
of another beautiful day
on Lake Dunlap. I was actually getting ready
to go into town, San Antonio,
for a meeting