By Chris Higgins, Senior Hydrologist
Drought is a common occurrence throughout Texas. It occurs anytime a region experiences below-average rainfall that causes a shortage of surface or groundwater supplies. Drought can be as short-lived as just a few weeks or last as long as several years, and its’ impacts can vary dramatically throughout the state considering factors such as climatic region, type of water use and weather patterns.
As a wholesale water provider, the Brazos River Authority (BRA) relies on its system of 11 reservoirs to ensure its customers have water even during the most severe drought conditions. Therefore, it is critical that the BRA monitor reservoir conditions and be aware of potential shortages during these drier periods.
As a result of the drought experienced in 2011, the BRA began regularly assessing projected reservoir conditions in an attempt to stay ahead of the drought. These projections were provided to the public via this website and the BRA Facebook page. The basin recovered from the multi-year drought as a result of heavy rainfall and basin-wide flooding in the spring of 2015. In May 2015 the BRA temporally discontinued the reservoir projections.
Despite some recent widespread rainfall, it appears that the wetter conditions we have been experiencing over the last couple of years have subsided. The trend toward drought intensification and expansion has resumed, and for now, the amount of water stored in the BRA reservoir system is on the decline.
As shown in the US Drought Monitor, most of the central and upper portions of the Brazos basin are either abnormally dry or in a moderate drought. According to the US Seasonal Drought Outlook, drought conditions will likely persist and continue to develop over the next couple of months. Additionally, the BRA issued a Stage 1 Drought Watch condition for Lake Georgetown in November. With these factors in mind, the BRA has resumed posting projected reservoir conditions.
There are two separate graphics posted for reservoir projections that will be updated at the beginning of each month. One will show the projected drop in lake levels, or drawdown, under extremely dry conditions and the other will show projected drawdown under normal conditions. These projections should be viewed as “what if” analyses to provide an envelope of possibilities contingent on the weather patterns that occur. The graphics also indicate if any of the drought stages identified in the BRA’s Drought Contingency Plan (DCP) will be triggered for a reservoir or reservoir system.
The BRA’s reservoir projections, DCP and current drought information specific to the BRA system, including the current drought status and other related drought information for the Brazos basin can be found on the BRA web site by clicking here.