Rainfall Data - Edwards Aquifer Authority

Rainfall Data & Rain Gauge Network

The EAA rain gauge network collects rainfall totals every five minutes from over 70 gauges throughout the region. These rainfall data are made available to the TexMesonet for inclusion in the statewide earth observation network.

Individual rain gauges are not always reliable indicators of true rainfall over a large area because precipitation can vary significantly, even over short distances. Additionally, rain gauges can be susceptible to occasional clogging or other malfunctions and fail to record some rain events.

Next-Generation Radar (NEXRAD) rainfall data from the National Weather Service provides rainfall estimates that are continuous over the entire region. However, the NEXRAD data need to be calibrated based on ground observations from the rain gauges. Thus, the main utility to the EAA of the rain gauge network is as a source of “ground truth” for calibrating NEXRAD radar rainfall data.

The EAA compiles the rain gauge data into hourly totals for archiving and uses these data to calibrate the NEXRAD radar rainfall data over the Edwards Aquifer region. The calibrated hourly NEXRAD data provides the most accurate available historical rainfall data for the Edwards Aquifer region. EAA uses this data set for input to numerical watershed models that are used to estimate the amount of rainfall that becomes recharge to the aquifer. The numerical watershed models can also be used to simulate streamflow responses to storm events.

Monthly Calibrated Rain Maps

Precipitation data is gathered from the EAA’s network of rain gauge stations and National Oceanic and Atmospheric Administration (NOAA) weather stations located throughout the region. Once collected, data is shared with other official entities, such as the National Weather Service (NWS). Rain gauge data are used by the EAA and the NWS to calibrate hourly NEXRAD radar rainfall data to obtain accurate rainfall estimates for anywhere in the Edwards Aquifer region. The calibrated NWS radar rain maps are available online to the public. The EAA uses this information to help calculate recharge to the Edwards Aquifer, monitor any precipitation trends that may affect recharge to the Aquifer and help evaluate the effectiveness of the EAA’s Precipitation Enhancement Program.

The Calibrated Rain Maps are generated using EAA and NOAA rain gauge networks. They are produced and published here monthly.

Select the map you would like to display from the list below. The list is ordered by year. Selecting a map from the menu will open a new window to display the requested rain map.

Calibrated Rain Maps

The EAA Board Meeting will take place on July 9, 2024 at 1pm.
Please click here for more information.