La Niña is gone, now what?
Good news is on the horizon. According to the National Oceanic and Atmosphere Administration’s (NOAA) Climate Prediction Center (CPC), the La Niña advisory has been removed, and we’ve moved it to a neutral classification. But what does this mean for the Brazos River basin?
La Niña is the cool phase of the El Niño-Southern Oscillation (ENSO) climate pattern that usually brings drought conditions to the southern United States. El Niño, on the other hand, is the warming phase of the ENSO climate pattern, often bringing wet weather and even flooding to some areas. Neutral is neither La Niña nor El Niño. ENSO patterns create significant differences in the average ocean temperatures and play a key role in how global weather patterns unfold.
The Brazos River basin has been experiencing 50% or more drought conditions since November 4, 2021. The last time the basin had zero drought was July 9, 2021
Following several extremely dry months, on August 17, 2022, a Stage 1 Drought Watch was declared for the entire BRA Water Supply System. We currently remain in Stage 1, which calls for a 5% reduction in water use, with Lake Proctor in a Stage 3 Drought Emergency which calls for a 20% reduction in water use.
What does this mean for us?
A timeframe for the beginning of a drought is hard to determine since it’s something that occurs gradually. The first evidence of drought is usually seen with the lack of significant rainfall over a long period of time.
Soaking rain is the best way to improve a drought. As Texas history has shown us, droughts are often-times followed by floods.
According to Aaron Abel, water services manager for the BRA, to understand why droughts usually end with some sort of flooding event, it helps to look at what causes drought from the water supply perspective.
“After several years of below-normal rainfall, the soils are typically very dry, and the rivers, creeks, and tributaries have very little water. The ponds and stock tanks, as well as reservoirs within the BRA water supply system, also typically show lower levels because of the lack of water to replenish storage,” explains Abel.
Abel continues, “to increase moisture levels in the soils and overcome the water deficits and initiate runoff and higher streamflow and inflows into the reservoirs, above normal rainfall is needed for an extended period…several weeks to several months.”
“When we have above normal rainfall to swing the system from drought conditions to full reservoirs, it typically coincides with flood events,” said Abel. “We can have flood events in any month in the Brazos River basin, but typically they coincide with our wetter months of the year (April through June) and then again in the fall (October to November).”
On March 9, 2023, the National Weather Service (NWS) Climate Prediction Center gave a final La Niña advisory stating that neutral conditions are expected to continue through spring and early summer of this year. Its prediction also informed that El Niño could form during the summer of 2023 and persist through the fall.
Since El Niño events tend to bring cooler and wetter conditions, this could lead to heavy rainfall in the Brazos River basin. The springs of 2015 and 2017 were very wet. Flooding conditions hit Lake Granbury during the Memorial Day weekends in 2015 and 2016.
How do we prepare?
Flooding is nothing new to Texas. Historically, Texas has had major flooding in 1833, 1842, 1913, and 1921. In 1923, the Texas State Legislature surveyed all the rivers in the state to analyze flood and water problems. That study established the need for state agencies to be created to harness and control the rivers during times of flood. Ultimately, building reservoirs to hold the excess water to be used in periods of drought is what the BRA and other river authorities have been doing since their creation.
The three reservoirs managed by the BRA, Possum Kingdom Lake, Lake Granbury, and Lake Limestone, are each experiencing deficits and are prepared to take on extra storage from significant rain events.
However, since the weather is unpredictable, it’s always a good idea to be prepared for anything. Here are some things you can do to prepare for a possible flood event:
- Stay informed: Stay current on flood warnings and alerts from local authorities, the National Weather Service, or other trusted sources. Be aware of the risk of flash floods, which can occur quickly and without warning. If the Brazos River basin begins to experience flooding conditions with significant releases from BRA’s water supply reservoirs, notifications will go out through our downstream notification system. Go here to sign up for downstream notifications.
- Create an emergency plan: Develop a family emergency plan, including an evacuation plan. Identify safe evacuation routes and determine where you will go if you must leave your home.
- Prepare an emergency kit: Assemble an emergency kit that includes essential supplies such as non-perishable food, water, medications, flashlights, batteries, and a first-aid kit.
- Protect your property: If you live in a flood-prone area, consider investing in flood insurance and take steps to protect your property by elevating utilities, installing flood vents or barriers, and securing any outdoor items.
- Evacuate when instructed: If local authorities issue an evacuation order, follow it immediately. Do not wait until the last minute to leave.
- Practice safety during and after the flood: During a flood, avoid driving or walking through flooded areas. After the flood, be cautious when returning home, as floodwaters can cause hazards like downed power lines and contaminated water.
Taking these steps can help you prepare for a flood and minimize the risk of damage to yourself and your property.
La Niña has been a part of life since 2021, and the move to neutral is a welcome change. We may have to wait a few months to see any signs of El Niño arriving. In the meantime, take this opportunity to be proactive and prepare for flooding events if or when they occur.