Technical Abstract: The west side of the San Joaquin Valley of California has had drainage disposal problems since irrigation was introduced in the early 1900's. Selenium toxicity problems associated with the Kesterson Reservoir caused closure of the existing agricultural drainage system in 16, 194 Ha (40,000 acres) in 1986. The continuing need for drainage of irrigated agricultural llands has prompted several water management studies by the Water Managemen Research Laboratory of the USDA. One of the essential data requirements in these studies is the quantification of drain flows. A measurement station was constructed for this purpose employing a manhole with a 90 degree V- notch weir and datalogging electronics to provide hourly water flow data. Power was supplied by solar and conventional sources. Construction details, costs (for a solar-powered station), and resulting data are shown. As configured, the measurement station has provided seasonal data streams for analysis during 3 years of operation. Keywords: Drainage Discharge, Datalogging, 90 degree V-Notch Weir, Construction Costs, Manhole.