The National Oceanic and Atmospheric Administration (NOAA) has released the Atlas 14, Vol 11 Precipitation-Frequency Atlast of the United States for Texas. This report released on September, 27 updates Texas rainfall frequency values. The analysis find significantly higher rainfall frequency values in parts of Texas, redefining the amount of rainfall it taeks to qualify as a 100-year or 1000-year event.
The Atlas 14 study uses historical rainfall data to predict future events. This data can help planners analyze waterways and help design stormwater infrastructures. This statistical data can help assign probabilities to rainfall volumes to estimate the likelihood of a rainfall event.
Two areas recently hit with significant rainfall, Austin and Houston show increased rain values used to define a 100-year event. From the map, NOAA published that it will increase by 2 inches the amount of rainfall used to determine a 100-year rainfall event in the Austin region. A 100-year event is an event that on average will occur once in 100 years or have a 1% chance of happening in any given year.
Thomas Graziano, Ph.D., director, NOAA Office of Water Prediction said, “NOAA’s new rainfall frequency values for Texas will help state and local authorities better understand their flood risk and more accurately plan and design infrastructure to minimize the threat of flooding,”
These values are important for design engineers who use this data to predict how much rain will fall, how much will infiltrate into the soil, how much will runoff and what is the possibility of flooding.
- Mark Hubbard, Lead Compliance Manager - Texas