WSR-88D radar reflectivity derived rainfall products are often used for hydrological studies. In this study, the High-resolution Digital Precipitation (HDP) product derived by the WSR-88D with a temporal resolution of 1 hour and a spatial resolution of 2x2 miles was the main source of rainfall information for an area extending over South Florida. This product is derived by the lowest elevation radar reflectivities that are converted to rainfall rates (R) using a Z-R relationship. The default relationship is Z=300R1.4, although the relationship has been modified lately (2-3 years) especially for radar sites near the tropics. The 1-hour HDP product is quality controlled for spurious radar effects, ground clutter and anomalous propagation. The NWS creates HDP products each individual WSR-88D. Given the area of interest, four WSR-88D radars were selected: Miami (AMX), BYX (Key West), MLB (Melbourne) and TBW (Tampa). In addition to the HDP product, rainfall records from 260 rain gauges distributed within the domain were available for radar calibration. Monthly, seasonal and annual statistics and comparisons between the radars and rain gauges are presented. A radar merging methodology is presented along with problems identified relating to SR-88D calibration and artifacts. The multi-year refined hydrological product provides the necessary rainfall information to South Florida Water Management District for various applications related to water resource management within South Florida.