nwis.get_measurements() only pulls USGS measurements, even if nwis.get_siteinfo() found measurements from other agencies #15
Description
When I use nwis.get_siteinfo() for the area I am working in, several of the results are from non-USGS measurements (in this case, MN). When I use nwis.get_measurements(), 'agency=USGS' is hard-coded into the url that is pulled. I suggest including an option for the user to specify the agency to be included in the url, in this case it would be 'agency = 'MN040'. I only found this by going through the nwis mapper GUI.