Water Resources of the United States
Date: Mon, 24 Sep 2012 11:58:28 EDT
Summary: Although Texas has experienced some widespread rains recently, drought effects are still ongoing throughout much of the state.
On September 18, 2012, the U.S. Drought Monitor indicates that drought conditions still persist throughout much of the state-–southeast TX is not in drought status (11.3%), whereas 88.7% of TX is experiencing conditions ranging from abnormally dry (12.6%), moderate (24.3%), severe (28.9%), extreme (18.0%), to exceptional (4.9%, in parts of north and south TX).
For 10 defined climatic regions in Texas, the Texas Water Development Board (TWDB) has determined indicators (indices) of reservoir storage (Reservoir Storage Index, RSI) and streamflow (Streamflow Index, SFI). Daily reservoir storage data for 109 major water supply reservoirs or lakes are collected from USGS and US Army Corps of Engineers gages. The TWDB RSI represents the combined storage for these reservoirs in a climatic region or river basin as a percentage of the combined conservation storage capacity. The TWDB SFI for a climatic region is an average value for all stations in that region. Twenty-nine USGS stream stations with daily gauging data are used to measure drought conditions. As of September 23, the TWDB RSIs indicate water supply conditions to be near normal for 3 regions, moderately low for 1, severely low for 3, and exceptionally low for 2, and there are no data for 1. The TWDB SFIs indicate that conditions are near normal for 2 regions, abnormally dry for 1, moderately low for 2, severely low for 3, extremely low for 1, and there are no data for 1.
As of September 19, 1023 of 4692 active Community Water Systems are experiencing water restrictions to water shortages as a result of the drought; 275 groundwater and 157 surface water systems have implemented voluntary water use restriction programs; and 426 groundwater and 312 surface water systems have implemented mandatory water use restrictions (Texas Commission on Environmental Quality).
According to USGS WaterWatch on September 23, of 435 real-time stations where flow is measured, 96 have zero flow and another 71 have flows of less than 1 cfs. Many stations in Texas have very low to no flows during summer months or in west TX; however, a number of these stations are affected by the current drought. According to the drought table, there are 3 stations with more than 30 years of record (45 to 75 years) that have new record low flows for 7-day average flow conditions. An additional 4 sites with 4 to 20 years of record have record low flows for 7-day average flow conditions. These sites are located throughout the state.
Stream and Reservoir Gages:
The City of San Angelo is pumping water from the south pool to the north pool of Twin Buttes Reservoir near San Angelo, TX (08131200); therefore, the south pool has dropped several feet. Reconnaissance occurred for a new location for a new staff plate for the south pool; installation is planned this week.
Groundwater Levels: Routine measurements are being made.
Water Quality: Routine measurements are being made.
Special Project: Report review ongoing, nothing new to report.
Communication and Outreach: nothing new to report.
Sub-Region: Central South; Region: Central United States