NOAA provided Atlas 14, Volume 11 rainfall data in a GIS compatible ASCii format. The resulting processed rainfall isopluvials align in a general east-west direction. Using the east-west isopluvial orientation as a general guide, the datasets listed below were used to inform and refine the delineation of the Precipitation Area boundaries. The five (5) Precipitation Areas are generally orientated lengthwise in an east-west direction to follow the isopluvial orientation. Precipitation Area numbering followed a north-south direction, with PA-1 being the most northerly area and PA-5 being the most southerly area.

Datasets used to inform the PA boundary delineations and source (acquired in 2018):

• San Antonio River watershed subbasins - San Antonio River Authority

• HUC 12 layers – Texas Natural Resources Information System

• Rivers & Creeks – United States Geological Survey

• Bexar County boundary – City of San Antonio

• Cibolo Creek subbasins – San Antonio River Authority

This dataset will be evaluated for general accuracy on an annual basis, or more frequently as necessary.