What a difference a rain can make. Not long ago the
drought was causing a continuous drain on Brazos
basin water supplies, leading to steadily falling lake
levels. Then came the heavy rains in early October that
dumped more than 8 inches of water in parts of the
basin followed by numerous days of misty, intermittant
rain events. As a result, the Brazos River Authority
closed reservoir gates that had been expected to remain
open through the fall and winter.
However, Texas State Climatologist John Nielsen-
Gammon continues to predict the drought could last into
next year and beyond. In the midst of such severe dry
conditions even infrequent rains can have a big impact on water planning.
Before the beginning of October, a gate at Lake Granbury was opened indefinitely to meet continuing needs
downstream. At the time, plans were also set for a long term release from Possum Kingdom Lake. Authority
hydrologists had predicted that due to those water demands, if the drought conditions continued, the entire
reservoir system would be down to 57 percent capacity by Oct. 31. By then
Stillhouse Hollow Lake was expected to join lakes Limestone, Georgetown
and Procter at Stage 2 – Drought Warning Status.
But then it rained. It wasn’t enough to break the drought but it caused a drop
in water demand downstream and led Authority hydrologists to reevaluate
their water management plans. Lake levels rose in some places, and the
Authority ended the indefinite release at Granbury instituting instead periodic
releases lasting 4-5 days. The PK release was pushed further into the future,
currently scheduled for mid-December.
So how did the rain affect the system overall? Instead of reaching the
projected 57 percent capacity around Oct. 31, water levels now are not
expected to drop to that level until mid-February. In other words, the system
gained more than 3 months of water supply through just a few rain events.
Water planning is based on conditions at the time it is undertaken. Hydrologists constantly reevaluate the plan
as each change occurs, such as rain in the midst of this record drought. With the state receiving rain in past
few weeks, you can rest assured the plan will change again.
To learn more about the Authority’s drought status, including current and projected reservoir levels, click here.
Current gate operations at Lakes PK, Granbury and Limestone are listed at the bottom of the Authority home
page, here. Gate releases and other Authority news can be found on our Facebook page, here.