NewsDrop July 2023

EDWARDS AQUIFER AUTHORITY

Whether you’re a water utility, a farmer, or a homeowner, you probably spend a lot of time watching the local weather channel hoping for good news about rainfall during a drought. Well, the Edwards Aquifer Authority (EAA) has been taking a proactive approach to giving our rain clouds a nudge to be more productive. For over 20 years, the EAA has been involved with a Precipitation Enhancement Program (PEP), also known as cloud seeding, by partnering with the Evergreen Underground Water Conservation District (UWCD) to perform cloud seeding operations. The actual cloud seeding is performed by the South Texas Weather Modification Association (STWMA) over Bandera, Medina, Uvalde counties and the outskirts of Bexar County. STWMA is a non-profit organization committed to enhancing rainfall across the South Texas region and is one of five permitted weather modification projects for rain enhancement in the state of Texas. STWMA is headquartered in Pleasanton Texas and its staff meteorologist, Bria Hieatt, surveils the skies for convective storm cells over the EAA’s target area. STWMA airplane pilots stationed in Pleasanton and Uvalde County are directed by Ms. Hieatt on which storm cells need to be seeded during the months of April to September. PEPs are not designed to create rain, but rather, they enhance developing storm cells. A standard cloud seeding operation involves pilots flying Piper Comanche type planes into storm clouds. Using flares, the pilots deposit Silver Iodide or Calcium Chloride materials into the supercooled region of the storm cells.

By : Javier Hernandez, EAA Special Programs Liaison and Marc Friberg, EAA Deputy General Manager

EAA’s PRECIPITATION ENHANCEMENT P R O G R A M

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