Wednesday, December 9, 2020

2020 Aquifer Status In Review

Stage II Alram Drought

Lovelady Well Height: 469 ft-msl

Barton Springs: approximately 30 cfs 10-day average


Year 2020 began with a status of No Drought due to a very wet 2018, but below-average rainfall in 2019 caused water levels and spring flow to enter a downward trend beginning in late July. The declining trend continued with below-average rainfall up to 2020. The new year started out very wet with a combined 11 inches of rain from January to April (3 inches above historical average) reversing the downward trend and avoiding crossing drought thresholds in mid-March. A total of 35 inches of rain as of mid-December 2020 has provided much needed recharge to the Edwards and Trinity Aquifers, but not enough to reverse the downward trend. On October 8, 2020, the Board declared Stage II Alarm Drought.

 To look back in more detail, a combined 14 inches of spring rain fell in May and June 2020 providing even more recharge to that provided in January through April. Barton Springs flow quickly responded to these rains, propelling spring flow further away from drought triggers. The below-average rainfall in the fall of 2019 and additional spring 2020 rains maintained an average daily spring flow of 58 cfs throughout 2020.

The wet spring only temporarily held off drought as summer came with a drying trend that brought water levels and spring flow back into decline beginning in early July. September provided 7 more inches of rain but did little to reverse the downward trend. This decrease has continued through a dry fall season and on October 8, 2020, the Board declared Stage II Alarm Drought. The last groundwater drought declaration commenced on July 12, 2018 and ended on October 11, 2018. This dry period is projected through the winter and into spring 2021, as we enter a La Nina year bringing drier and warmer conditions to the southern United States.

To summarize, the Austin/Hill Country area has received an average 36 inches of rainfall so far in 2020, producing recharge for local aquifers. However, below-average rainfall in 2019 and a relatively dry summer and fall 2020 hasn’t provided enough recharge to stay above Stage II Alarm Drought. Official forecasts point toward the La Nina effect bringing drier and milder-than-normal conditions across Central Texas, which will likely result in further declines as 2021 gets underway. Hopefully, spring of 2021 will bring its usual upward swing of recharge to keep the aquifers well-supplied.