Spring rainfall is easing drought conditions, but many lakes remain low.
Numerous rain events this spring have added considerable water to many area reservoirs. Just 3 months ago, the water supply lakes for the city of Dallas were less than two thirds full but are now at nearly 95 percent of capacity. Although many lakes continue to struggle in western portions of North Texas, Lake Mineral Wells doubled its storage during April and is full for the first time since early 2012.
The extent of at least severe drought (D2) within the state of Texas has fallen below 16% for the first time since November 2010. During March and April, the Dallas/Fort Worth Metroplex experienced improvement of 2 to 3 drought categories. Much of Central and East Texas is now free of drought. However, exceptional drought (D4) continues to plague the Possum Kingdom area where it has been in place since June 2014.
The U.S. Seasonal Drought Outlook suggests additonal improvement could occur in portions of North and Central Texas with above normal rainfall expected to continue during the month of May. Although the wet start to the year is helping the region's agriculture, the extensive hydrologic drought across western portions of North Texas is unlikely to end before the summer arrives.
Current Drought Conditions
The growing season is in full swing. Perennials, including warm season grasses, can effectively hold moisture long after rain events. When green, this vegetation limits fire initiation and spread. However, the spring months can still have days with low humidity and strong winds. If these days occur after a prolonged dry spell, there can be a risk of wildfires, especially where extreme and exceptional drought conditions persist.
Even though there are no formal burn bans in effect within North or Central Texas, it is still important to be vigilant about fire usage. Avoid open flames near dry vegetation, and assure all coals and embers are fully extinguished.
The Keetch-Byram Drought Index is a drought statistic specifically designed to assess fire danger.
April rainfall totals were well above normal across nearly all of North and Central Texas. Although year-to-date totals through the first 4 months of 2016 are generally above normal, long term deficits persist. While the short term rainfall has turned the region green, these multi-year deficits continue to manifest themselves in low lake levels and in the deep soil moisture needed to recharge the region's aquifers.
Numerous rain events have maintained adequate and even surplus topsoil moisture, enhancing the runoff into the creeks and streams that feed the major river/reservoir systems. Lake Ray Hubbard fell to an all-time record low level in December, but after gaining more than 38 billion gallons of water in the last 3 months, it is nearly full, its highest level in 3 years.
Although most lakes east of the I-35 corridor are now full, most of the reservoirs west of the Dallas/Fort Worth Metroplex remain very low. Much more rainfall is needed within these lakes' watersheds to reverse several years of drought.
Lake Storage at the End of April (and Total Change in Storage During the Month)
As the summer approaches, evaporation and water usage will steadily rise. Even if warm season crops thrive from adequate rainfall, the multi-year hydrologic drought across western portions of North Texas is likely to persist this summer.
For current lake level information (including pool height, departure from conservation pool height, and percent of conservation volume), visit Water Data for Texas.
After nearly 5 years of significant water restrictions, the North Texas Municipal Water District (NTMWD) began allowing twice-per-week watering on May 1. Sprinklers and other irrigation systems are still be prohibited between 10 am and 6 pm (April 1 to October 31). The NTMWD serves 1.6 million customers east and northeast of the city of Dallas.
In April 2014, the Fort Worth City Council made permanent its twice-per-week limit on landscape watering. Only hand watering is allowed between 10 am and 6 pm. Arlington, also within the Tarrant Regional Water District (TRWD) service area, has similar restrictions but is not ready to make them permanent. Dallas has made permanent its twice-per-week limit, but the restriction on daytime watering is limited to the warm season (April 1 to October 31). Since water restrictions vary considerably throughout the Metroplex, residents should keep informed with the current guidelines from their municipality or water utility provider.
The Brazos River Authority (BRA) projects the Stage 2 drought warning within much of the Upper Brazos Basin (Possum Kingdom, Granbury, and Whitney) will come to an end by June 30. However, Proctor Lake, which is currently only one third full and in Stage 4 pro-rata curtailment, will likely be much slower to improve.
Throughout the Lone Star State, above normal rainfall is more likely than below normal rainfall during the month of May, which is climatologically the wettest month of the year in this region. Across western portions of North Texas, where exceptional drought (D4) persists, well above normal rainfall this month is twice as likely as well below normal rainfall.
Precipitation Outlook for May
Precipitation Outlooks for Summer and Early Fall
The outlooks for the summer months are less conclusive at this time, but with El Niño conditions expected to strengthen this year, projections for above normal rainfall return this fall and continue into 2016. Hydrologic issues will continue this summer, but the tide may be finally turning on our multi-year drought.
These outlooks present the likelihood of receiving a precipitation total that differs significantly from normal. Green areas denote parts of the country with an increased chance of being in the wettest tercile, or the wettest third of historical data. Similarly, brown areas denote parts of the country that are projected to have an elevated chance of being in the driest tercile. Where neither color is shaded, there is no strong signal to determine an accentuated chance of being in either the driest or wettest tercile. This does not mean that near normal precipitation is expected, but simply that the period is just as likely to be in the wettest tercile as it is to be in the driest tercile.
The U.S. Seasonal Drought Outlook suggests additional improvement could occur in portions of North and Central Texas with above normal rainfall expected to continue during the month of May. However, the extensive hydrologic drought across western portions of North Texas is expected to persist into the upcoming summer.