With the ongoing exceptional drought, it would
probably surprise no one that water levels are falling
steadily at the 11 reservoirs in the Brazos River basin.
For those who live next to or like to visit one of these
lakes and have seen water being released from the
dam, you might wonder, “Why in the world are you
letting out water from the lake when the level is already
so low?”
This is a question posed often to the staff at the Brazos
River Authority. After all, the lakes are popular
destinations for many recreationists, from boater to anglers to families enjoying a weekend camping and
swimming trip.
To answer the question, one must first understand
that the reservoirs in the Brazos River Authority
system were built for water supply and flood control.
While we enjoy many recreational benefits from the
reservoirs, recreation is not their primary purpose.
The lakes are not designed to remain at a constant
level but are rather part of a dynamic system.
The concept behind a water supply reservoir is to
capture and store water during wet times for use
during periods of droughts when rainfall and river
flows are down. It might help to think of the lakes
as massive storage tanks with an added
recreational benefit. When the weather is kind to us
and the lakes are full, they are great spots to go and
have fun. But when Texans get thirsty, these tanks
are ready to swing into action and send water their
way. That makes them all the more vital in times of severe shortage, when other local water sources begin to
dry up.
The current drought provides a good example. All of Texas, including the Brazos River basin, has seen
unprecedented rainfall shortages over the last ten months, with some areas more than 20 inches below normal
amounts. Add to this the large-scale evaporation
caused by the string of record high temperatures
and the drought quickly takes a toll on Texas
water supplies.
Currently, there is little, if any water flowing into
the reservoirs. In fact, the Brazos River upstream
of Possum Kingdom Lake is entirely dry. So
imagine that the reservoirs did not exist today.
Those that rely on the rivers’ flow for drinking
water would literally be left “high and dry.”
Following the drought of the 1950 the US Army Corps of Engineers and state
organizations such as the Brazos River Authority, built numerous reservoirs
for both flood control and water supply. The stored water in the reservoirs
provides access to water supply even in these exceptional drought conditions.
During drought and when water supply is needed, the reservoirs
are able to release water to flow downstream to those in need.
Releases from these reservoirs also provide environmental benefits.
The current flow of water on the majority of tributaries.