Streams, Groundwater, and Lakes
The USGS maintains a database with current and historical surface-water, groundwater, and water-quality data called the National Water Information System, or NWIS. See below for various ways to access the database.
NWISWeb - Search and download surface-water, groundwater, water-quality, and water-use data.
NWISWeb Oklahoma - Access data specific to Oklahoma.
NWIS Mapper - Visualize surface-water, groundwater, and atmospheric data from NWIS.
WaterWatch - View current stream-flow, drought, and flood information.
GroundwaterWatch - Access the national groundwater level network.
WaterQualityWatch - View real-time water-quality parameters.
Oklahoma StreamStats - Estimate flow and flooding frequency in ungauged basins.