OpenStreetMap has it as Waterway.
Data Source (shapefile)
Extract and load into a GIS (QGIS used here).
Extract using the attributes flcass='riverbank' or name='River Thames'
Then dissolve the polygons into one (if required).
Those are the HU-2 (2-digit Hydrologic Units) boundaries from the national Watershed Boundary Dataset (WBD). Sometimes you'll see them referred to as HUC-2 instead of HU-2 (HUC = Hydrologic Unit Code).
It should be possible to download this data for the entire continental US as a single dataset. However...
It's very easy to get the metadata for this ...
Natural Earth Data has Rivers and Lake Centerlines and Lakes and Reservoirs.
The USGS Earth Explorer will let you download data from anywhere in the world. Type "Kazakhstan" into the place search criteria box, click over to data sets and type "hydro" into the data set search box. The dataset called GTOPO30 HYDRO1K is a hydrology raster. There's a download ...
We are currently developing Veleda, an open source, open data platform for hydroponics. We have a live data view of the state in our greenhouses. We develop the software and hardware (ESP8266) behind it and are in the process of extending it with additional parameters.
Parameters for which we are building low-cost sensors range from air and water ...