Instrumentation of urban hydrology monitoring sites in southeast Florida

An instrumentation system developed and built in laboratories of the U.S. Geological Survey, Reston, Va., has been used since 1974 to collect synchronized rainfall, runoff, and water-quality data from urban basins. A number of field modifications were made to adapt the system to local hydrologic conditions and for collection of data on about 350 rainstorms at four sites in south Florida. The instrumentation system measures rainfall at three sites, records two pressure or water-level readings for flow computations, and collects and refrigerates up to 24 water samples and rainfall-quality samples. Rainfall and runoff data are recorded every 36 seconds on a six-channel analog recorder so that all variables are time-synchronous. Flow in the storm sewer is computed from pressure measurements in a U-shaped venturi-type constriction or, when the constriction is not used, from water levels. (Kosco-USGS)